i was wondering if anybody had or heard anything about the brian crower 2.71 stroker block with darton sleeves and billet crank. any info would be great!

i was wondering if anybody had or heard anything about the brian crower 2.71 stroker block with darton sleeves and billet crank. any info would be great!

Haven't heard or seen anything about this. Could you perhaps post a link to it ???

I've talked with them and the first thing i asked about was the crank. It's a billet piece but the oil supply is still crossdrilled like the factory. Also the stroke is more that I would want in a subie block.

I to have had interest in this but find the Subaru block needs a longer bore to aid in making the big 83mm stroke work. Deck plates come to mind with MD darton sleeves but The motor is already tight in the engine bay. A wider motor just sounds like trouble changing the spark plugs. I had A crower setup even ordered till Reality hit today from lots of feedback from Chris at Crawford and then Howard at AR-fab both talked me down.....AR Fab gave me a strait answer to there 83 mm setup. I wish we had more room for this but we don't.
Someone tell me I'm wrong and fast.
Now I'm reviewing if Brian can build me an 81mm crank but if there is no improvement to the oiling then whats the point.....
Brian I am guessing your going to here of this so I have only to say I was just unaware and unready as I have yet to find a solution to use a better rod ratio and prevent all the problems of the long stroke issues of the big 83mm. your setup is amazing at high boost short run drag motors that run 10:1 Compression and still boost to 30lbs. heck it mad 700 hp + but from what I Heard is the Interference and short rod is destroying the motor creating all kinds of new harmonic issues(hint hint Howard). Something internal balancing doesnt see in 4 bangers but stroker v8 cars do. this was the solution to my speed-o motive and Crower cam 383 Chevy that mad huge numbers n/a. Thanks Crower again, the whole family is Stand up just the Subaru world is not ready yet. Dam Honda's get everything easy.............................................. ...................
WEST:D

having further discussion with Brian himself...the oiling supplies are different (straight shot, I have pics) and he will cut a custom crank so long as it is a order of at least 5...

run the numbers on an 81 mm stroke...rod angularity isn't going to be too much better...rod in his motor is what, 128.5 mm (1.54 RR)? easily can get it back to 129.6 (1.56 rr)...
a 81 mm stroke with normal rod numbers would yield a 129.5 length rod (1.598 rr)


factory sklyines are a 1.54 if I recall and see 9k from the factory...evo 2.3 strokers are 1.5 and frequent the 8500-9000 mark...

I would just be afraid of spinning the motor to the sky personally...that and VE's would tail off (because of RR and head flow for an engine at that rpm) so torque would fall off the face of the earth...

Personally I'm building an engine that goes against everyone's trends (hence the knowledge on the custom crank) and am anxious to see how it compares in the real world and not on paper (I know who wins on paper).

http://i130.photobucket.com/albums/p263/checque/IMG_1256.jpg

http://i130.photobucket.com/albums/p263/checque/IMG_1255.jpg

http://i130.photobucket.com/albums/p263/checque/IMG_1254.jpg

I to have had interest in this but find the Subaru block needs a longer bore to aid in making the big 83mm stroke work. Deck plates come to mind with MD darton sleeves but The motor is already tight in the engine bay. A wider motor just sounds like trouble changing the spark plugs. I had A crower setup even ordered till Reality hit today from lots of feedback from Chris at Crawford and then Howard at AR-fab both talked me down.....AR Fab gave me a strait answer to there 83 mm setup. I wish we had more room for this but we don't.
Someone tell me I'm wrong and fast.
Now I'm reviewing if Brian can build me an 81mm crank but if there is no improvement to the oiling then whats the point.....
Brian I am guessing your going to here of this so I have only to say I was just unaware and unready as I have yet to find a solution to use a better rod ratio and prevent all the problems of the long stroke issues of the big 83mm. your setup is amazing at high boost short run drag motors that run 10:1 Compression and still boost to 30lbs. heck it mad 700 hp + but from what I Heard is the Interference and short rod is destroying the motor creating all kinds of new harmonic issues(hint hint Howard). Something internal balancing doesnt see in 4 bangers but stroker v8 cars do. this was the solution to my speed-o motive and Crower cam 383 Chevy that mad huge numbers n/a. Thanks Crower again, the whole family is Stand up just the Subaru world is not ready yet. Dam Honda's get everything easy.............................................. ...................
WEST:D

There are also other considerations to understand why the larger then 79mm crank is a problem. The fact that the piston skirt runs below the bore further. The crank is a nice crank but it hits everything and causes all sorts of clearance issues no-one is ready to pay for. Oiling is no issue with these cars if everything is prepped correctly. The oil pump is very similiar to the Honda. And I am not having bearing issues with the BC crank in our car other then we will not recommend the setup in customers cars. The long stroke setup for the EJ's is not the way to go unless you do extend the deck surfaces and increase the pin height and the ring heights to get the piston to stay in the bore for more stability. But once again no-one is willing to pay for this. The harmonic problem is resolved now that I have a manufacturer making us a damper. Which I spoke of briefly on IWSTI. But no-one has broke an oil pump yet with a Subaru because no-one is spinning them high and no-one is making real power with them yet. Another discussion to be made should be the lack of piston dwell with the current stroker kits. High airflowing turbos can not take advangtage of the stroker kits. Large displacement stroker kits are great for NA not a Large Turbo.

BTW the oiling of the BC crank and the factory is identical less the chamfer of the oil holes.

Yes Brian called me on Firday and asked me about different strokes too ...lets be different...blah blah....I dont build short lived drag engines. Eggums Honda engine took me 4 yrs to perfect in my own car because we followed idiot engine builders suggestions now I do them myself and build them the way I feel is neccessary to make power without problems...the last one I put together for them was in March of 06 and went all season long without the valve cover or oil pan removed. and the car ran 7.9seconds at 185mph on a stock crankshaft and oil pump. And thats 1100whp, turn the boost down and it will last longer. But its still a race engine it will need to be freshened up seasonally.

And if I really told the truth about the oil issue in the Subaru, I would lose business because the rest of the US EJ engine builders will figure it out too.

Howard

Howard/Race sleeves....you and I think a lot alike ;)

I'm working on seeing 10k on the factory pump...oh, and I love dwell :banana:

......

Is the part a drop-in part? nope

Can this part be made drop in? nope

Is there a benefit to the kit for a large turbo? nope

Will the kit be reliable at high RPM? nope

Most of the customers that ask for the kit are road racers with a 35-50lb/min turbo and road race and are looking for more throttle response/tq. The rest want to be the king ding-a-ling of power at the drag strip or the street racing scene. If you fall into the first catagory then by all means go that route and spend more money then you really need to. But what you and several others are asking for, this setup causes way too many problems to be reliable. And I get flamed because I stated my facts about the parts. We continue to advertise it because it gives people opportunity to have such a product if their race program qualifies for it. But there are many other better alternatives that we tell our customers when they tell us what they are doing. Thats why we have sold 1 2JzGTE crank from BC and I still have not seen the crank since the Nov 7th order. But I keep telling him no problem. Im not flaming him for it...

If RD did not take any time at all to get the correct facts and not lies then things would fall into place like buying shelf parts. But RD takes time, time your not willing to pay for. I have teams willing to pay for this on other projects so my time goes to these guys first. I do have a family just like many others and need to pay for expenses just like any other family guy. We built an intake manifold I was unhappy with , that you were interested in and that made you mad because I didnt finish it? Would you rather me send you a piece of **** that did not work? I can have a real nice manifold design for $4500-$6500. One off just for you and everything is CNC machined including the intake runners to match the port flow of your heads and cams. But you are not willing to pay for it are you? We have built 4 such manifolds for several other teams. Do not flame me for bringing to light the fact that companies bring out products to soon without really researching every angle first. We look at everything before we would recommend it for a situation thats its not ready for.

The latest adventure is the sleeves. You email me saying DARTON has the MID sleeve coming soon. "Thats what they told you". I know where the designs for the sleeves come from I speak with this man atleast 5-10 times a week. I told you its not happening anytime soon and you didnt believe me. Yes I was interested in doing them myself for my own developmental purposes. But cost becomes a factor when you want to pay for just a product and the price has to be just right. I told you the sleeve blanks we need will require way too much machining to make them cost effective. You did not step up and say I dont care about the cost. So I am the one to make the judgement call to acquire a better solution for less $$. Money is what makes all these parts work correctly. Winston Cup / Top Fuel etc have alot of it and can get things done ASAP. So unless you are ready to spend some time and money quit flaming me.

There are too many others that are interested in our approach to solving performance issues they have come across in their racing programs to continue to pursue any more time with you.


Sorry that this had to hit the forums.

Howard

And if I really told the truth about the oil issue in the Subaru, I would lose business because the rest of the US EJ engine builders will figure it out too.

Howard

Howard, how do I find out about this? Pay you to build me an engine....then will you tell me the secret?

......

Trust me, Howard knows his stuff. I have talked to him on many occasions and he blows my mind every time. We throw ideas back and forth to each other as well.

I sent 2 customers motors to be sleeved and built and we recieved a couple of weeks ago. Both are in and running and run damn good. I have never heard another built motor sound so freakin good.

Also, if you want to rev the motor high you dont want more displacement.

-Matt

[QUOTE=checque;17317740] The AR Fab stroker kit and BC stroker kit look exactly the same on both websites. Hey Howard, what makes your kit different? Will your kit be reliable at high rpm? Can you explain these clearance issues and the steps you've taken to correct them?
QUOTE]


We only use the BC Crank in our kit. As far as answering whats wrong, that goes back to explaining to the rest of the engine builders how to make it work. Im sorry but I can not do that.

Also, I started out exactly where you are today. No money and did not know anyone in the industry. I have climbed the ladder to where I am today. Along the way I have been taken advantage of many times by customers and vendors and have made it my mission not to return the favor to others. I could have stuck you with the bill for a bad intake and some over priced sleeves but I did not. I was looking after yours and my best interests for both projects. As far as the WRX intake is concerned, its a personal project on a best friends car and so is the Supra...where time is no issue. Which I explained but probably not clearly enough for you without giving specifics.

Understand one main thing here, we do not have others make the parts work for us, we have the manufactures make the parts to our specs. We did not send a stock piston from the STi to a piston manufacturer years ago to have them build the piston around stock rings, wrist pins and clips so we can buy new STi short blocks and remove the factory cast pistons and replace them with a forged piston set costing $240 and call it a forged combo for $2500-$3200!....We redesigned the whole piston combination around what we considered a fix to the arising problems everyone was coming across in the community. Also, the aftermarket did and has the incorrect C-C rod lengths available to you so we corrected the pin hieght in the pistons to compensate so you get the true compression ratios we build the pistons to. Some rods manufacturers have stepped up to the plate now.

Im fighting for you guys not for my car to get faster...I proved alot of things with the Honda community and recieved the same reactions there too so this is no surprise to me. We went faster then anyone else did and had no engine failures doing it with the Honda once I developed the right parts. Now Im doing so with the Subies. And until a major investor or North America Subaru comes along and sees our potential its going to take time and money....time I have and money thats going to my family this time around.

The crank obvious works. The work I had to go through to make it work should have been told to me during the purchase of it. But it was unknown to the manufacturer so we kept their name out of it until recently. I tell everyone the issues we found with it. Thats not bad mouthing the product its informing the customer and I hope thats what everyone is looking for, not the specifics so you or others can spend their hard earned money with someone without this knowledge rather then putting the money in my pocket for the proper directions on how to use their product. This goes for any type of product we endorse. We have lots of customers that ask my opinion during their build, then have the products sent to us becasue they found it cheaper elsewhere and wonder why they pay more for the install and get no guarentee on the work performed and get no technical information about the setup. We build the correct setups but when Im put against the wall to make everything work with parts that are substandard or they dont fit correctly I can not be held accountable for there ability to perform and be reliable.

I know what you want. Send back your 83mm and get a 75mm stroke. Send me the crank/block/heads. Budget atleast 20-25K for the engine build. I will send you a screaming high output setup with a fuel system, EMS, dry sump and turbo setup included in the package. Everything will be matched to eachother. Rpm power band will be 4500-9500. I will explain the entire setup at that point. And be more then reliable at 800whp. Add on $5000 for some custom Ti rods and you get rid of the Steel rod shooting out the block problem above 850whp. I personally have all the parts to build one for myself except the Ti Rods and FREE TIME. I also have all the correct parts to build my own Honda HotRod class car that would be capable of lo 7's and trapping 200mph too...but no time.

But start to pick and chose the parts you send me, cross talk to the vendors/manufacturers and its your own baby not mine.

Now Im going to try to spend some more time with my Pregnant soon to be wife before she leaves me because I spend way too much time after hours worrying about how to make cars go faster. :banana:

OH! And thank You Matt for the positive post....and to the others I really do not know yet. Thank You guys

Howard

No problem Howard. I just tell it how it is.

Dave is in love with the sound of his motor. I cant wait to get it back on the dyno to make more power than we did before. As I said I have never heard a better sounding built motor before. On initial startup and the first stage of break in there was NO SMOKE from the exhaust, not even a little bit!!!! Incredible is the only way to describe it.

If you get some free time give me a call on Monday give me a call on my cell phone # I gave you. They are screening all my calls up front so that I dont have to answer the phone 100 times a day and I can actually get work done.

-Matt

freaking great post howard!

thanks for your support!

Ryan

once again...howard, I think you and I are doing the same build have read your comments...funny, I'll have the same powerband...

I too don't have the money for the ti rods so my initial build is going to be steel while the shop car get's ti...
custom rods,caps and pistons are required which doesn't help with the poor college student aspect. that is done in may and the build should be done in august (assuming the job goes through)...

-Micah

freaking great post howard!

thanks for your support!

Ryan

Check your Email....

Yea Ti rods are going to get me put in the doghouse! I already have the money aside for the Trans parts...that was not cheap either!

Howard

I dont want to fuel the fire but the clearence issues due to stroking are common issue with any engine program. In other words maintaining a clearence around the crank through its rotation. Easy but time consuming job, now the skirt running lower in the bore. I'm guessing that the issue may be from running past the bore? It shouldnt be from the releifs for wrist pin removal since the skirt is 90 degrees out of that and if the rings where close to that theres more problems. Maybe the rod angle in relation to the block clearence?

I guess why I am beating this up is for those wanting strong street torque without spinning to the moon. Yes, stroking will lower the safe prm limits of the engine (without a huge amount of work) but in a daily driver car that wants more low end torque it's been proven many times over on other engine types that stroke is a good way to get there. However if you want to be the "big power" king then stroking might not be wise without lots of $$ for Ti rods, drysump, ect, ect.

I have alot of experience with building and stroking domestic sb, bb, chevs fords.... I am only using the knowlage I have from these. I worked in a machine shop for some time so I have an idea where Howard is comming from, but I have never stroked a subie so till I do theyre may be some tricks (most engines have them) but I do not see any huge reason why this shouldnt work.

Check your Email....

Howard

Talk about lightening quick response!

Holy hell!

Ryan

Here's an applicable link http://e30m3performance.com/tech_articles/engine-tech/rod-ratio/index.htm

I have alot of experience with building and stroking domestic sb, bb, chevs fords.... I am only using the knowlage I have from these. I worked in a machine shop for some time so I have an idea where Howard is comming from, but I have never stroked a subie so till I do theyre may be some tricks (most engines have them) but I do not see any huge reason why this shouldnt work.


Bah!...I deleted what I had to say since it explained too much.....Im sorry


I guess if you guys want to see some real ***** Im going to have to pull some strings. Met an interesting man tonite that owns a Chevy Dealership , a CarQuest and a few other places in WV thats interested in having us do a complete car top to bottom and the paint included....he wanted a "SUNDAY" car for the Summit Point track..lol....something to "scare him" as he put it...lol Ill keep you guys updated.

Oh and he was not interested in a Cobalt either! ;)

Howard

I hope your not taking what I said wrong Howard. I didnt mean anything negative towards you its more that this subject has my intrest and I may be looking at this for one of my projects.

Please pm me if I misunderstood your response.

BTW whats wrong with the cobalts? I have built a few of the Saturn redlines (runs the same SC eco that the ss does and in fact was released a year before the cobalt). The ecotec is a great engine program, however the trans and the fact that its only fwd sucks. I ran 400whp and shattered the trans case in three spots.

what's wrong with a cobalt?...for starters it is powering the wrong wheels :p

Funny, why do you think I own two STi's now? Va beach huh, I will be there in a month. No biggie just noticed in your sig.

I have yet to own a fwd car and hope that I never have to, Keep it in the rear or at all 4...

81mm billet cranks in stock...
Superior oiling and they are also 4lbs lighter than the factory crankshaft.

- J.

I to have had interest in this but find the Subaru block needs a longer bore to aid in making the big 83mm stroke work. Deck plates come to mind with MD darton sleeves but The motor is already tight in the engine bay. A wider motor just sounds like trouble changing the spark plugs. I had A crower setup even ordered till Reality hit today from lots of feedback from Chris at Crawford and then Howard at AR-fab both talked me down.....AR Fab gave me a strait answer to there 83 mm setup. I wish we had more room for this but we don't.
Someone tell me I'm wrong and fast.
Now I'm reviewing if Brian can build me an 81mm crank but if there is no improvement to the oiling then whats the point.....
Brian I am guessing your going to here of this so I have only to say I was just unaware and unready as I have yet to find a solution to use a better rod ratio and prevent all the problems of the long stroke issues of the big 83mm. your setup is amazing at high boost short run drag motors that run 10:1 Compression and still boost to 30lbs. heck it mad 700 hp + but from what I Heard is the Interference and short rod is destroying the motor creating all kinds of new harmonic issues(hint hint Howard). Something internal balancing doesnt see in 4 bangers but stroker v8 cars do. this was the solution to my speed-o motive and Crower cam 383 Chevy that mad huge numbers n/a. Thanks Crower again, the whole family is Stand up just the Subaru world is not ready yet. Dam Honda's get everything easy.............................................. ...................
WEST:D

On a side note, does anyone know how the newer BC cams are holding up? I heard there were a lot of issues with their older cam design but have yet to hear of anyone using them lately.

what's wrong with a cobalt?...for starters it is powering the wrong wheels :p


Yea that sums it up!

And like I stated above...he wanted to "be scared" And a fwd with street tires and 800whp is not that impressive, unless you want to just smoke the tires...

Now an AWD STi with 800whp+ and the correct driveline would just be a flat out scarey ride...

Besides GM has the Ecotec program on lockdown...nobody has the $$ to mess with them at the track.

Howard

81mm billet cranks in stock...
Superior oiling and they are also 4lbs lighter than the factory crankshaft.

- J.

So whats different with the 81mm Billet and 83mm Billet oiling?

I know that the BC Billets are drilled .215" for the Mains and .200" on the Rods.

OEM is .212" for the Mains and .173" Rods. 13% smaller in Dia.

Another note...I know im not comparing apples to apples here..BUT

The stock crank weighs in at 20#'s

The 83mm BC crank weighs in at 20#'s

Why would 2mm's reduce weight by 4#'s? Unless its a LW version.

OR its one of those SCAT billet cranks that costs alot more then BC crank.

Howard

EDIT: I may have jumped the gun...but Jeremy I understand you did not state COBB had the BC crank so that may be the difference. Like I stated in the end it could be someone elses crank.

So whats different with the 81mm Billet and 83mm Billet oiling?

I know that the BC Billets are drilled .215" for the Mains and .200" on the Rods.

OEM is .212" for the Mains and .173" Rods. 13% smaller in Dia.

Another note...I know im not comparing apples to apples here..BUT

The stock crank weighs in at 20#'s

The 83mm BC crank weighs in at 20#'s

Why would 2mm's reduce weight by 4#'s? Unless its a LW version.

OR its one of those SCAT billet cranks that costs alot more then BC crank.

Howard

EDIT: I may have jumped the gun...but Jeremy I understand you did not state COBB had the BC crank so that may be the difference. Like I stated in the end it could be someone elses crank.



VERY insteresting specs... :)

Now if we could get TJL Performance to come join the discussion about their 81mm crank . . .

I will post information about our coming stroker kit and 81mm cranks tomorrow.
Trying to get our race car ready for gatornationals.......
Thanks, Tomi

Our 81mm Billet crank design is similar to our 75 & 79mm crank. It is a straight shot oiling design. It is a lot stronger than stock and it will solve rod bearing issues so common on our motors. We are coming up with 81mm stroker kit with all the matching parts very soon.
Good news is that our 81mm crank will only cost $1999, 00.
If anybody is interested here, shoot us a PM.
Thanks, Tomi

Thank you for all PM's. By the way, if we can get 5 people to order these 81mm cranks, we can sell them a lot cheaper. PM us for this special
pricing!
Thanks, Tomi

It appears Crawford has their stroker cranks working just fine and winning races with them http://www.crawfordperformance.com/news/article_23.shtml

If stroker cranks are so bad, why are so many people starting to offer them?

yea id definitely like to hear what some people have to say. I know plenty of guys running 2.35 strokers. and even some guys who are running stroker kits larger than that. how do strokers not work well with large turbos exactly?

...If stroker cranks are so bad, why are so many people starting to offer them?

It's all about the benjamins baby.

Different stroke cranks are not bad! I definitely think there is a lot more to learn from this discussion and it shouldn't be killed so easily.

Stroked cranks getting spun to high rpms is the issue. Like Howard already stated, the BC crank has harmonic issues. He did not disclose at what rpms he was seeing the harmonics get all out of whack, but is currently (or already finished) making a dampener. I don't know how high he is spinning that engine or what the intended use is, but it's probably a safe bet he's developing a dampener for short duration racing (which would be lighter/smaller) and one for endurance events (which may be a case by case for him since I don't think many guys do enduros). Howard may post here with further information, but it's probably best that serious inquiries contact him.

It looks like Cobb has some counterweights worked into their design which solves the internal harmonic issues, hopefully (nothing against Cobb products intended, incredible quality actually and well thought out). Cobb would have to post or be contacted for any other issues that might arise at high rpm.

It really doesn't need to be about money. Professional crank shops could probably make a custom crank for cheaper than what vendors are offering billet cranks for, but that's another animal. I'm not even getting into market trends here . . .
Connecting rods will have to be custom made, but that's not expensive. I can pretty much guarantee that 99% of the people here will never get close to having a setup that needs titanium rods, much less the team behind them to do the maintenance/funding of that setup. Although Ti rods would really make that lightweight Cobb setup shine (with lightweight flywheel and clutch, that would be one hell of a BEAST coming out of corners!) Steel/billet rods can be made fairly light as well and they just offer much more durability.
Pistons will need to be custom made, and that's done cheaply as well. And the ring package is pretty much standard across the boards, so no worries about them.

When you're stroking an engine, either smaller or larger, you can't just figure it stops with the crank. There are benefits to different setups, long rod/short rod, increased stroke/descreased stroke, larger piston/smaller piston, and it depends on the type of racing that decides that setup. For budget racers, interchangeability of engine internals is the biggest deciding factor. For guys just wanting street beasts, there isn't any more to be gained with stroking than what can already be achieved with the stock crank.

Alright, I have some info for this thread... I just ordered a Brian Crower 2.71L kit with the Darton sleeves. I will be doing most of the machine work myself, as I used to work in a machine shop and have after hours benifits to still use the machines. So hopefully I will be able to find out why there is such a fuss about a little block clearancing. As far as harmonics I am not sure where you are going, as long as the rotating mass is balanced then I'm not sure what the big deal is (and yes I know about balancing as I worked in a machine shop). I will be sending my rotating mass to a shop that speacializes in balancing.

I also contacted fluidamper about an aplication for us as well. I sent out a damper for them to R&D with. Hopefully they will have an awnser for us soon. Here again I still dont understand why so many people are making this into a big deal, I have stroked several other engine programs (types) before without any failure.

resonance/harmonics in a motor don't deal with balancing as balancing isn't a resonance issue...balancing is like a driveshaft that just gets worse with speed...harmonics are a different beast all together...ask cosworth why they were having issues spinning their F1 2.4L V8's in the 16k range ;)
get above it and they were fine...
related but different and no I'm not saying it can't be worked out..I'd just avoid the issue all together personally until someone else has figured it out.

There is mention of not needing custom pistons, the longer the stroke and if you use longer rods then you will HAVE to compensate the wristpin location further up in the piston or the piston will simply move to far up the bore and contact valves, head and such no to mention have a really high compression. Here lies the next problem, if you move the wristpin to far the wristpin will be into the oil rings. In a normal engine this isnt usually an issue due to the installation prior to inserting into the block, but in a subie due to the wristpin installation after the block is together then you simply cannot install the wristpin with the rings already on the piston in the bore.

resonance/harmonics in a motor don't deal with balancing as balancing isn't a resonance issue...balancing is like a driveshaft that just gets worse with speed...harmonics are a different beast all together...ask cosworth why they were having issues spinning their F1 2.4L V8's in the 16k range ;)
get above it and they were fine...
related but different and no I'm not saying it can't be worked out..I'd just avoid the issue all together personally until someone else has figured it out.


I understand where you are going but a good damper will help with the torsional harmonics. Look at all the honda's that people went to aftermarket (higher quality) dampers due to the factory ones causing oilpump failures due to torsional harmonics in the engines that where pushing it.

I studied alot of this when I was working on my BA in mech engineering. So I know the concept but there are ways to remove the torsional harmonics, i.e. the fluidamper. Fluidamper is commonly known as one of the best desighns to accomplish this.

There is mention of not needing custom pistons, the longer the stroke and if you use longer rods then you will HAVE to compensate the wristpin location further up in the piston or the piston will simply move to far up the bore and contact valves, head and such no to mention have a really high compression. Here lies the next problem, if you move the wristpin to far the wristpin will be into the oil rings. In a normal engine this isnt usually an issue due to the installation prior to inserting into the block, but in a subie due to the wristpin installation after the block is together then you simply cannot install the wristpin with the rings already on the piston in the bore.

That was my fault, you definitely DO need custom pistons made, I should've looked over my post a little harder before replying. It's fixed now though.

Homemade WRX, I understand your point of view from a financial position on just waiting until someone else figures it out, and I mean no disrespect towards you, but you seem like one of the few members here with the knowledge to be able to figure it out. Luckily there are other people who are in a better position financially (but also have the knowledge) and take the approach of seeing a problem and wanting to find a solution to share and keep things moving forward, and we are all very grateful. I'll shoot you a PM with an idea . . .

Crawford has been selling their stroker cranks for years now, is anyone having harmonic or ballance problems with their stroker cranks?

The Subaru engine balances itself out in design.
Crankshaft counterweights, piston weight, rod weight... etc.
Harmonics are also taken care of in design- this is why Subaru did not add any harmonic balancer from the factory.

For this reason we are able to delete some of the counterweights all together and still have a perfectly balanced engine.
Factory 79mm USDM STI Crankshaft weight in at 21lbs
COBB 81mm Lightweight Crankshaft 17lbs

If any engine was not weight, and spin balanced it could have issues at high RPM's depending on how off it was.
The ONLY stroker engine we offer uses the same lightweight billet crankshaft, the rotating assembly is balanced and thus far we have not had any issues revving to 8500rpms+ (soon to be higher).
So whats different with the 81mm Billet and 83mm Billet oiling?

I know that the BC Billets are drilled .215" for the Mains and .200" on the Rods.

OEM is .212" for the Mains and .173" Rods. 13% smaller in Dia.


I can't really compare both cranks, since Cobb does not offer a 83mm crankshaft (not for oiling reasons per say, but because of other factors that come to play when designing an engine).

There are many aspects to factor, when looking at a cranks oiling design.
1- Size of orifice that feeds the bearings, and placement.
2- Size of orifice that feeds the orfice mentioned above (main supply in crank)
3- How much oil the mains vs rods draw from the system
4- A journal that is cross drilled and a journal that is not
5- Etc. etc. there are many other things to look at.
(This whole design has to work together like a series of pipes)

Take a look at our sizing vs. others you have researched..
Mains
1- .195"
2- .215" - Cross drilled
3- .195"
4- .215" - Cross drilled
5- .195"

Rods
.150"

By all means this is not to say this is the only solution, but this configuration on our specific crankshaft works great for us.


- J.

Harmonics are also taken care of in design- this is why Subaru did not add any harmonic balancer from the factory.


Huh? The two STi's I have sitting in my driveway came with balancers from the factory.

However the opposed four engine desighn is as Jeremy put it dynamicly much different than the typical I or V desighn. BUT this does not remove torsional harmonics, Yes you can run a non damper on the engine but its not wise. The early 283 chev's didnt have balancers either but once the engines where making more power then things changed, not to mention longevity.

The main issue with the harmonics is time, yes many people have made it work and havent had any issues BUT the potential is there in a built engine that is pushed for a long period of time. Track cars only run for a few times a month. Built street cars are tested usually every day.

I would like to point out that Jeremy mentioned that thier setup works for them and hasnt really made any derogitive comments towards others. Way cool ethics :)

The Subaru pulley on the front of your STI is not a harmonic balancer.
The pulley is just a few added Lbs. to your engines rotating assembly, this is why we offer a lightweight pulley of the same OEM diameter.
I have talked with many Subaru engineers about this.
http://forums.nasioc.com/forums/showthread.php?t=444518&highlight=harmonic+balancer

- J.

Huh? The two STi's I have sitting in my driveway came with balancers from the factory.

However the opposed four engine desighn is as Jeremy put it dynamicly much different than the typical I or V desighn. BUT this does not remove torsional harmonics, Yes you can run a non damper on the engine but its not wise. The early 283 chev's didnt have balancers either but once the engines where making more power then things changed, not to mention longevity.

The main issue with the harmonics is time, yes many people have made it work and havent had any issues BUT the potential is there in a built engine that is pushed for a long period of time. Track cars only run for a few times a month. Built street cars are tested usually every day.

I would like to point out that Jeremy mentioned that thier setup works for them and hasnt really made any derogitive comments towards others. Way cool ethics :)

The Subaru engine balances itself out in design.
Crankshaft counterweights, piston weight, rod weight... etc.
Harmonics are also taken care of in design- this is why Subaru did not add any harmonic balancer from the factory.

For this reason we are able to delete some of the counterweights all together and still have a perfectly balanced engine.
Factory 79mm USDM STI Crankshaft weight in at 21lbs
COBB 81mm Lightweight Crankshaft 17lbs

If any engine was not weight, and spin balanced it could have issues at high RPM's depending on how off it was.
The ONLY stroker engine we offer uses the same lightweight billet crankshaft, the rotating assembly is balanced and thus far we have not had any issues revving to 8500rpms+ (soon to be higher).


I can't really compare both cranks, since Cobb does not offer a 83mm crankshaft (not for oiling reasons per say, but because of other factors that come to play when designing an engine).

There are many aspects to factor, when looking at a cranks oiling design.
1- Size of orifice that feeds the bearings, and placement.
2- Size of orifice that feeds the orfice mentioned above (main supply in crank)
3- How much oil the mains vs rods draw from the system
4- A journal that is cross drilled and a journal that is not
5- Etc. etc. there are many other things to look at.
(This whole design has to work together like a series of pipes)

Take a look at our sizing vs. others you have researched..
Mains
1- .195"
2- .215" - Cross drilled
3- .195"
4- .215" - Cross drilled
5- .195"

Rods
.150"

By all means this is not to say this is the only solution, but this configuration on our specific crankshaft works great for us.


- J.

hey jeremy when you said you were spinning at 8500rpm with the billet crank ,were you refering to the 2.65l stroker you guys have sell?

I really have to disagree with that. The reason is that the front pulley if you will has a elastomer ring and the fact that the outer ring is of some weight is how it transmit the harmonics to heat.

This is basic physics, If you like I will scan and post the info right out of my physics 270 workbook. Maybe whoever you spoke to didnt realize what they did by putting that desighn on but since there is a hub then a elastomer ring then a ring of weight this is a basic torsional harmonic damper in desighn.

I dont want to start a pissing contest but look at it closer, I do respect the work COBB does and I do run many of your parts including the AP. I also do respect the fact there is no real bashing but a conversation about parts.

The elastomer is where the pen is pointing to....

http://i100.photobucket.com/albums/m29/sinisterredlines/cover023.jpg

I would rather have a 4.200 bore or 106.68mm instead of a longer stroke.....

it would take some playing with, but nothing that a good sleeve company couldn't accomplish...
HINT HINT!!!

haha....

Everyone gets on the stroker bandwagon and thinks that is the best way...

the best way is to get more air in and out of the engine with larger valves, bigger heads, more boost, longer duration cams, etc.... with a better rod to stroke ratio to keep the mechanical advantage high and the frictional loss numbers low.

Take a version 7 EJ207 engine for an example...

what other subaru engine has been tuned to over 500whp on a completely STOCK BLOCK????

It was made to REV!!!!

RPMS allow more horsepower from a large bore to small stroke ratio engine than a large bore and large stroke engine!!!

having a wide powerband is what makes a car with NORMAL gearing very fast.....

if you don't have a wide powerband, say hello to MR. HIGH STALL TORQUE CONVERTER and custom gearing......

Take the many 1000whp Supras for instance.... many of them don't make peak WTQ until 7K-8K RPM and then make their peak power at 9K-10KRPM !!!!!

do you think these cars are fun to drive at any normal speeds with stock gearing, even in a six speed??

No, THEY ARE SLOW!!!!

I have personally witnessed a 750whp Supra with a well built automatic with a PI 3800rpm stall whip on the 1000whp idiots cars like they were grandma's park avenue......


Things that make a car go fast: street or strip

WIDE POWERBAND
Proper final drive gearing to accent the powerband
Proper transmission for driving style and use expected
Overbuilt Fuel system
More oil pressure than you think you need to keep it alive
Lightweight rotating assembly that is balanced with oil sling weight allowed into the process

SOMEONE DRIVING THAT UNDERSTANDS HOW EVERYTHING WORKS AND HOW EACH PART AFFECTS THE OTHERS....

NO LOOSE NUTS BEHIND THE WHEEL!!!!

;-)

Cheers and Great thread for discussion!!!!!

I like the way u think HOWARD!!!!

The elastomer is where the pen is pointing to....

http://i100.photobucket.com/albums/m29/sinisterredlines/cover023.jpg



That, in my eyes, would also be called a harmonic dampner..... I agree..... not necessarily a Balancer ring, but it is made to eliminate slight harmonics at certain engine RPM's and loads..... it definetely helps, but, like everything else.... it is actually only tuned to be effective in a certain RPM range because RPM's cause a FREQUENCY of HARMONICS.... another reason why an aftermarket supplier should be making one that will eliminate harmful harmonics from Higher RPM engines.....

ATI makes some great stuff!!! It would be nice for them to offer something to Subaru guys also..... where there is a need...

Depends on what you are trying to accomplish. I dont want a drag race beast that makes huge horsepower at a million rpm's. I want a torque monster that I dont need to spin to the moon, why because I DD my car and track on the weekends.

I have driven built cars that rev to the moon and make killer power but in my opinion the car that makes mad torque down low is alot more enjoyable to drive. JMHO

Yes I know you balance and tune the harmonics to a specific rpm. But a harmonic balancer is short for torsional harmonic balancer just FYI no hate.

I actually just sent a damper off my other STi to fluidamper (they are my preference when I worked in the machine shop while I was finishing my degree).

For shiz and grins I went to the fluidamper web site and found this

http://www.fluidampr.com/TORSIONAL.html

hey jeremy when you said you were spinning at 8500rpm with the billet crank ,were you refering to the 2.65l stroker you guys have sell?

Yes Sir, the COBB Pro Series Stage 2.

Sinister redlines- I wil be taking a closer look,ATI has made SFI approved balancers for the Subarus in the past, but now no longer do. After talking with a rep at SEMA one year I got an answer that alluded that after testing the Subaru EJ engines do not benefit from a balancer, but that they could provide one if we insisted. (in other words.. if we wanted another product to offer).
So this can go back and forth, but
1- Subaru confirms the factory pulley is not a balancer.. or is not intended to be.
2- ATI found that the Subaru EJ engines do not benefit from the balancer.
.... the link you provided states the following
Unchecked torsional vibrations can cause:
• Crankshaft Cracking or Failure
• Excessive Bearing Wear
• Excessive Gear Wear or Failure
• Broken Accessory Drives
• Throwing or Slapping of Belts
(we don't have problems with any of these)

The reason why is because of the following
1- The Subaru EJ crankshaft is so short and harmonics that are even close to being detramental would be at such a high frequency that we never even see (severe RPM's).
2- Compare the diameter of your flywheel vs the diameter of the pulley on the front of the engine .. the factory designed the whole rotating assembly to work together. If you are afraid of harmonics that can come about if you remove the front pulley.. you should be terrified of the harmonics that can come into play when removing the flywheel for an aftermarket.
Fact is that our engines do not see the RPM's where these bad harmonics come into play. (the design of the Subaru EJ with short crankshaft is great in this regard.)

Harmonic dampeners? check out this thread for EJ harmonics: (please read the whole thread, it's not long)

http://www.iwsti.com/forums/showthread.php?t=76165




Then, you might want to check out this thread: (this one is long) ;)

http://www.iwsti.com/forums/showthread.php?t=70714

another thing that many people do not realize or think about is the harmonic effect and crank-flexing that High horsepower tends to cause....

couple this with any slight detonation or pre-ignition, and the harmonic dampner might be all the keeps the crankshaft from cracking....


here is a fact check for ya'!!!!!

Ever seen a crank HUB for a small block for use with a blower??? the crankshaft must be of a special design and even then, it will not last long before developing cracks.....

Look at a top fuel crank that is used..... every one of them is cracked.... they make 6K-8K HP, but, the only run for an average of 3-6 runs.... sometimes more....

Here is my thought on it....

ATI may have said it wasn't really needed.... it really isn't , but, if subaru puts one on from the factory, there is a reason for it.... also, the subaru unit is factory quality and designed for a factory RPM range.... IT IS NOT SFI approved, which is another reason to get an ATI or FLUIDAMPER made unit....

HIGH RPMS!!!!

Have you ever seen the outer hub of a balancer come off on a running drag engine??? It is horrifying how much energy it has at 8K RPM when it comes off....

It will literally rip a chassis in half on the way to the side of the track or the bleachers......

SAFETY, NOT JUST HARMONICS, is another very important reason to run one of these quality units...

RYNO

well said.....

well, I'm quite excited...I now will be testing both ends of the spectrum in the coming months...my shortblock and then the brian crower set up (being loaned to the shop)...

1 - Subaru confirms the factory pulley is not a balancer.. or is not intended to be.

...

If you are afraid of harmonics that can come about if you remove the front pulley.. you should be terrified of the harmonics that can come into play when removing the flywheel for an aftermarket.

To address the first one: I totally agree. The stock pulley is not a balancer. It is a torsional dampener. Fact of the matter is that the stock pulley is a hub-elastomer-weighted ring. That, by design, will - let me repeat this - WILL dampen torsional vibration. ATI saying that it is not necessary is almost irrelevant. There are so many factors that go into this statement and we have no specifics as to what type of testing ATI did (or if they even did real testing). Again, fact of the matter is that the stock pulley has the ability to dampen vibration and I, for one, never will give up that ability. I only want to improve it (long live fluidampr!!!).

Second, I totally disagree with that statement. The stock flywheel - IN NO WAY SHAPE OR FORM - has any form of built-in harmonic dampening. The only thing to worry about is if it is balanced. Removing a part that CAN dampen harmonics is totally different (apples to oranges).

t

The post where you mentioned a 106mm bore, this would require a wet sleeve desighn. Problem with wet sleeves is it can have sealing issues where it uses o-rings between the block and the sleeve. After time the o-rings will fail. Where a traditional dry sleeve only seals at the head gasket from coolant(still a potential issue).

This being said I have thought of welding in larger aluminum case rounds that would accept larger sleeves. But this is a expensive time consuming mod and would require a huge amount of set up time. No doubt a good idea though.

^^that, and could a stock headgasket even work on a 106mm bore?

add in extra maching costs to o-ring the whole block + heads.

The post where you mentioned a 106mm bore, this would require a wet sleeve desighn. Problem with wet sleeves is it can have sealing issues where it uses o-rings between the block and the sleeve. After time the o-rings will fail. Where a traditional dry sleeve only seals at the head gasket from coolant(still a potential issue).

This being said I have thought of welding in larger aluminum case rounds that would accept larger sleeves. But this is a expensive time consuming mod and would require a huge amount of set up time. No doubt a good idea though.

not to mention how would you go about installing the case bolts ;)
the factory sleeves are already clearanced a good amount for them...

as for the factory headgasket...those stop at 100mm...people are already past that...call up cometic and tell them what you want. Just be ready to pay

The cobb Pro Seires crank appears to be made by Doug Kiddie engineering (now owned by Arrow) in the UK, it's looks like the same crank offered by cosworth.

Big bore = bad with boost (detonation due to flame propagation issues)
Big stroke = bad due to rod angles

since our motors are so over square as is it seems a stroker would be the better of the two ideas. How much money, where do i find and how strong would it be to raise the deck height and sleeve the motor accordingly?
then after thats done what do i use for rods?

SOMEONE MAKE US A MORE PISTONS KIT!

seriously though... an h6 would be the way to go if its parts were as beefy as an sti's bummer its nearly impossible to legally swap one in where i live unless its stock ecu is maintained... and then i don't know if anyone makes something to tune the stock ecu for boost.

4 month old bump?




if you're looking at raising the deck height, honestly the only company I have heard of (possibly) doing that is Crawford. I believe it's their "M" series engines. BTW, you won't find anything on those engines and I know there's 1 conversation about the "M" series on Crawford's forum. The next problem with increasing the deck height is the room to install it in the car! Can you imagine changing the spark plugs THEN! :lol: we are space limited already...then you go to this extreme....it's a whole 'nother level. Not to meantion $$$$$ when your talking the machining for a deckplate, custom sleeves, install, custom pistons and rods............$$$$$$$$ to each his own though!



Other than that, I think most of the builders do strokers in the factory block.

Crawford does a 2.6l, 2.7l, 2.8l, and 2.9l in the 2.5 casing (I believe). the problem with the larger cube engines, is they are bored AND stroked. Increasing the bore makes it easier to detonate as you said.

Big bore = bad with boost (detonation due to flame propagation issues)
Big stroke = bad due to rod angles

since our motors are so over square as is it seems a stroker would be the better of the two ideas. How much money, where do i find and how strong would it be to raise the deck height and sleeve the motor accordingly?
then after thats done what do i use for rods?

SOMEONE MAKE US A MORE PISTONS KIT!

seriously though... an h6 would be the way to go if its parts were as beefy as an sti's bummer its nearly impossible to legally swap one in where i live unless its stock ecu is maintained... and then i don't know if anyone makes something to tune the stock ecu for boost.

Our Cobb Pro Series sleeved engines use a 4" bore, we handle this by keeping our same piston crown design which is matched to the 2.5L STI combustion chamber.
This way you can have a larger bore, yet have similar burn properties as the smaller bore engine and keep a tight quench.

- J.

4 month old bump?



magic of [search]

Dear Mr. cobb guy,

you're heads.... how are they better than cosworth's?


2 years of development, refinement and testing we are proud to say our CNC ported cylinder heads are superior to all cylinder heads currently available surpassing even our own prior offerings.

I am not sure what cylinder heads being better have to do with big bore engines, if you would like to start another thread on this topic I would be happy to answer your questions.

- Jeremy.. Mr. Cobb Guy. ;)

Big bore = bad with boost (detonation due to flame propagation issues) no true at all...but with the given motor I could see being an issue...that and the pistons need some redesigning.

Big stroke = bad due to rod angles debatable and I would agree with you except there are some small benefits to a short rod...

The post where you mentioned a 106mm bore, this would require a wet sleeve desighn. Problem with wet sleeves is it can have sealing issues where it uses o-rings between the block and the sleeve. After time the o-rings will fail. Where a traditional dry sleeve only seals at the head gasket from coolant(still a potential issue).

This being said I have thought of welding in larger aluminum case rounds that would accept larger sleeves. But this is a expensive time consuming mod and would require a huge amount of set up time. No doubt a good idea though.

Running a 106mm bore would be quite difficult. The largest you would be able to go safely with a wet sleeve design is 103mm. There is not much room in the lower portion of the block to make the sleeve thick enough to make a 106mm bore. In order to go that large you would break through on a few spots on the block.

As for o-rings it will take a very long time for an o-ring to fail. The rest of the engine will go before an o-ring will. We use a Buna 70 o-ring which is used because of its resistance to petroleum oils and glycol based fluids. these same o-rings are used in many diesel application where a diesel truck will run easily a million miles before being rebuilt. Sealing issues are generally caused by improper installation of the o-rings or machining of the block. Ferrari and Dodge Vipers also use this same type of o-ring on their liners. We have been using these o-rings without a single failure.