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Old 09-09-2007, 04:27 PM   #51
Homemade WRX
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I thought I was Irish
I'll also slap steve for you, who by the way we have rubbed off on. he now explains things to people and he's right.
yeah, figures you buy an AEM from a guy on NASIOC and he ships a broken one...still doing all the updates and just got the 6.6k resistor from AEM so I can make sure that those are the issues and that the box isn't completely fried. It did have a fried capacitor when I first opened it up!!!
So, I may be going Hydra and may be taking someone to court...

Let me know when you want to do your head work...I should have run a few sets run through the Serdi, developed a few different sized ports and possibly have them digitized too (yea for 5-axis cnc's). "My" machine shop might also be getting a Newen Contour for valve seats!!
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Old 09-09-2007, 04:50 PM   #52
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Looks to me like you have done a little port work in your time...

There is tons of room for improvement on the short side radius in these heads... Either sonic check them or measure the thickness with a micrometer thru the coolant ports... The heads I am still working on have different thicknesses (from the word go out of the box)...

Continue the short side radius of the outer port in the dogleg runner around the corner to what you see in the next picture... And enlarge it around the guide area...

Here is a picture of my exhaust side from about the same angle as the first picture... Notice that most of the material under the seat has been rounded into the port, following the angle of the port...

My inside dogleg port is all but an oval now... And the porting I did to mine forces the exhaust to sort of rotate or spiral out the port...

I cut my intake seat out(enlarged the inside diameter) almost to the valve seat area of the seat.. 90 cut about 3/8" into valve pocket, the blended it into the port area... Here is a picture of the intakes when first cut...


My intake ports are also dog legged to the outside of each port, but it isn't easy to see in the pictures... Lay a quarter into your ports and look at the difference from where you are now, to what I came up with... You can see that I have removed a ton of material from the bowls to get them to flow evenly around the valve heads...


I dont remember how many clay models I went thru to come up with all of this, but it was more than I ever did to any other heads...

These heads have been the most challenging heads to port that I have ever done... Getting the exhaust side to flow evenly from port to port, and from valve to valve is a real challenge...

Take your time and get your heads to flow early (low valve lift)...
Most people think that the highest number that a head flows, shows the heads potential, but it doesn't... It is the amount that it flows thruout the opening and closing of the valve... Think of it as an area under a curve...

If your aiming for high wheel hp, your looking in the right place for it... In the ports...

Keep up the good work...
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Old 09-09-2007, 05:22 PM   #53
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shvrdavid, I have wood.

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Old 09-09-2007, 05:54 PM   #54
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david, I must say I have wood too...I spent about 6 months of my NASA intern running the IC engines lab at ODU at which point I got to play with a lot of heads...as our subie heads are quite interesting in comparison to any head that I've done before. I stopped where I did as I didn't have a flowbench on hand and didn't want to go too far or too uneven for just that reason. I do plan on improving the shortside radius of the dog leg as you have already done but never thought of your way of getting it to spiral out...quite interesting and I'd love to see a wet flow bench test on that (just for visualiztion).
I'm still debating on cutting out the seat or making a new seat for the valve for the same reasons you did...to utilize the larger valve diameter.
I am still waiting on my flowbench adapter so that I can start testing, comparing and evening out the flow numbers. My big goal is low and mid lift gains...not peak as the cam spends very little time there.
Now cams, are going to be the most interesting part of build. Makes me wish I still had a seat of virtual 4-stroke

I'll take a "quarter" picture just to show everyone how much more room you have in your head. I'm really going to have to have 2 sets of heads for my car...the 35r/road course heads for port velocity and then the 42r drag strip heads for large WOT flow numbers...
hell, I will just have two complete engines and drivetrains...time for another shell
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Old 09-09-2007, 07:34 PM   #55
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wow you guys know your stuff...

On my first(current) real build I simply did not trust myself with such an expensive engine, and a tool(die grinder) that could so easily, completely destroy it.

I believe my machine shop did a "decent" job at porting and polishing my heads...but in the future I would LOVE to experiment on my own !

what do you guys recomend for someone to start on ?? is there a way to tell just how far I can grind away at the ports ? And the big question of mine... Why is it on every other motor I have heard, you basicly WANT to gasket match with the ports, but on ours you DON'T ???
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Old 09-09-2007, 07:45 PM   #56
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What adapters are you waiting for to flow the heads?? I made all of the ones for mine out of PVC and acrylic plastic... The intakes were flowed thru the tumbler delete with a 9 in stack on top of it that opens up into a box about the size of a Kleenex box, and a 4" inside diameter tube on the combustion side, about 5" long... The chamber tube has a fine mesh screen that can be moved up and down inside the tube to check for swirl and to break up the flow after it reaches the chamber area.. The exhausts were flowed thru 28" tubes on the exhaust ports, same setup on the chamber side... The reason I used these lengths was to simulate the approximate lengths that will be used when it is actually running on the car...

I am glad to hear that you are looking for lower lift gains on your port work... There are more than a few people that look at the peak numbers, and thats all they look at... Be prepared to spend many nights at the flow bench...

I have a virtual 4 stroke program and all the data from my heads/engine...

The cam specs I came up to use with a 4094r turbo .95ar, 8.5 to 1 compression... (I think it ran thru about 3million combinations to come up with these specs, and a 6000 to 9000 rpm power band... Thats why the lift is only 10.5)

Intake Dur 291 centerline 109.5
Exhaust Dur 283 centerline 111.5
IVO (BTDC) 36
IVC (ABDC) 75
EVO (BBDC) 73
EVC (ATDC) 30
10.5 mm lift on both valves

Keep in mind that these specs are for my setup... (I need to finish my new engine, I blew up my modded 30r and sent parts of it thru the engine, wastegate stuck closed, you do the math..... )

I have run just about everyones cam numbers thru it, and I may get these ground for my engine...

I know of a few people that set there scubbies up to road race them, and they used 260 Cosworth on the intake and 272 on the exhaust...

That combination makes a torque monster power curve from 4000 to 8000 rpm....

On another note, do any of the flow benches you have access to have smoke setups on them??? They are a big help in "seeing" how things are flowing...
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Old 09-09-2007, 09:00 PM   #57
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Originally Posted by IllNastyImpreza View Post
Is there a way to tell just how far I can grind away at the ports ? And the big question of mine... Why is it on every other motor I have heard, you basicly WANT to gasket match with the ports, but on ours you DON'T ???
This is one of the many tools to tell how thick metal is...
http://www.ndtsystems.com/Automotive/automotive.html

The ports need to have a step in them to break up shock waves that are created when the valves close... Think how the wave moves up and down a slinky... There is a shockwave that is very similar created in a port when the valve closes...
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Old 09-09-2007, 09:34 PM   #58
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Originally Posted by shvrdavid View Post
This is one of the many tools to tell how thick metal is...
http://www.ndtsystems.com/Automotive/automotive.html

The ports need to have a step in them to break up shock waves that are created when the valves close... Think how the wave moves up and down a slinky... There is a shockwave that is very similar created in a port when the valve closes...
wow thats crazzy.... wonder what one of those things goes for...
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Old 09-09-2007, 09:38 PM   #59
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no smoke setup right now...it is an easy way to do flow visualiztion...although making my own won't be too hard...used them quite frequently in windtunnel and making one would be quite easy.

Well, I'm making an adapter with two different bores (99.5mm and 4")and am just waiting for the bores to be machined for me. Asking a friend to do it, so of course I'm waiting

My test setup sounds like it will be rather similar to yours...I'm looking forward to playing extensively on the flowbench once i get everything set up.

So, can I borrow your virtual 4-stroke seat...I promise I won't tell anyone
Out of curiosity, what shortblock/disp/rod ratio are you running? if you don't mind me asking.

Last edited by Homemade WRX; 09-09-2007 at 09:44 PM.
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Old 09-09-2007, 09:43 PM   #60
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as far as gasket matching:
for the intake, I've stepped mine a bit smaller than the gasket size to keep reversion limited...similar to why you step an exhaust primary.
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Old 09-09-2007, 10:19 PM   #61
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Lets just say it's a 2.5 thats a tad tweaked...

i as far as rod ratio ,i'll be pushing 4000' a min limit on the rods... Keep your fingers crossed....

USDM block and a USDM modified crankshaft... JE coated pistons... H beam rods...
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Old 09-09-2007, 10:38 PM   #62
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like 4" bore tweaked...I'm wondering if you went "long rod" or not...

wondering about rod journal grinding, weight removal and/or oiling changes...?....will you let us know eventually? like I will eventually do

on the heads: I had been working on making a new larger valve seat for my heads as I really didn't want to run an aluminum valve seat...do you have concerns about that on your head? like smashing your seat and ruining your angle job.
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Old 09-10-2007, 12:28 AM   #63
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I am not to concerned about seat depression on the intake side... I took that into consideration on the exhaust... It is hard to see on the pictures I posted, but the exhaust seats are cut to a radius from the margin into the port... The only part that will be exposed when they are done is the mating area.. (coated chambers/ports)... And I will have a slightly wider contact patch and margin than most people run on the exhaust valve to get more heat out of the valve... Bronze guides help with that as well...

FWIW when seats get "smashed" as you put it, it usually has more to do with the ramp speed, clearance, and valvetrain float on the cam than the seat itself... The cams profiles I came up with take that into consideration as well...

The crank has tons of modifications done to it... The counterweights are re-profiled, and the oiling is modified just to name the most common ones... The re profiling is to help eliminate high rpm flex and they are slightly knife edged... The crank required "heavy metal" to balance after the mods were done to it... It is a tad lighter than it was when I started.. And yes, the rod journals require special bearings now... I am not real keen on sharp edges on a crankshaft, and tapering the journals allows for more bearing surface area, and better oiling control...

I stayed with the OE rod length... I want the higher piston speed for a couple reasons... You could get a little more power out of it with longer rods, but all you really do with longer rods is shift the hp band further up the rpm range, and increase crankshaft deflection...
There are a million arguments for rod ratio, but it all comes down to what angles you want the rod and crankshaft to be at when the cylinder it at its peak pressure so you can get the most work out of it...
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Old 09-10-2007, 12:04 PM   #64
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I'd still concerned with flattening the aluminum on the intake valve despite the larger seat area and with having a more "gentle" cam...I can there is only one way to really find out.

As I'm playing with my first crank, non-billet crank, I'm doing what sounds to be similar mods in lightening the crank. I'm curious as to what you've done to eliminate flex (are you talking harmonics/speed or load based flex?). I'm leaving the rod journals on the my first crank at oem sizes but with tolerances a bit on the loose side. Doing this for test reasons.
Also doing some "knife edging" on the counterweights and am thinking of doing something a little less common as well that will help eleviate the heavy metal counter weights.

I've decided to do a long rod for the purpose of moving the torque curve up in the powerband as that is where I'll be racing. I've chosen to do so despite the added flex of the crank as I think the gained mid-> top end VE's and gains through constant volume combustion are worth the trade off. I've also found that at the rpm's I'm looking to spin, with my estimated intake and exhuast pressure and flame speed my peak pressure should be a very favorable angle on the crank.

I did notice your larger exhaust valve seat area and assumed you did it for heat reasons...its an old but effective trick.

So, are you not going deshroud you valves or have you just not gotten around to that yet?
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Old 09-10-2007, 05:10 PM   #65
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The mods I did to the counter weights are for load based deflection... The harmonic flex requires a different balancer...

Not sure what I will do for that yet... There are a few people making different balancers for these engines, but they won't release any relevant info on them other than they are better than the stock ones... That isn't selling me one of them... I guess I will have to figure out what mods need to be done to the stock one to make it work at higher rpms/stress loads...

The valves will get more deshrouded after I have the valves that I will be using in the heads for the final build... There is already some deshrouding done, but I haven't taken any pictures of that stage yet... The pictures I posted so far only show deshrouding at the peak of the roof, between the intake and exhaust valves...

Speaking of that... When you flow these heads, you need to have all 4 valves in them, and check the overlap flow as well... When you do it, you will see why I mentioned it
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Old 09-10-2007, 05:15 PM   #66
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Not sure what I will do for that yet... There are a few people making different balancers for these engines, but they won't release any relevant info on them other than they are better than the stock ones... That isn't selling me one of them... I guess I will have to figure out what mods need to be done to the stock one to make it work at higher rpms/stress loads...
check into ARFab's balancer. They talk a big game......it may be worth looking at........just an FYI if you didn't know they had one....
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Old 09-10-2007, 05:16 PM   #67
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I can only listen to Micah speak for 45 seconds before the base of my brain starts to hurt. I guess this is why his head is so large... got to be stored somewhere.

Good luck Micah.... and where the hell are my TGV's?

BTW... as soon as my car is together.... FOR SALE.
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Old 09-10-2007, 05:16 PM   #68
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well, I had planned on having all 4 and now you have me anxious to see the overlap flow



man, I'm such a nerd


I didn't know ARFab had a balancer...I will have to check it out

Fred, I don't know where they are as I never had them. Did you call MJ about them? I have my space manifold that I may start on for you if I can find the time.
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Old 09-10-2007, 05:23 PM   #69
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I didn't know ARFab had a balancer...I will have to check it out
http://www.iwsti.com/forums/showthread.php?t=76165

I think it's about $350 bones.....
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Old 09-10-2007, 06:19 PM   #70
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I inquired about that balancer and they wouldn't tell me any details about it other than what they posted on the thread in the link above...
The one thing they said that took me by surprise was that it is lighter than the factory one...

With that in mind, go read this...http://www.grapeaperacing.com/GrapeA...ch/dampers.pdf

Did you pay attention to the part about changes to resonate frequency???
Did you pay attention to the part about viscous dampers???

Now that you have read that, explain to me how a lighter elastomer balancer can do a better job than the stock one that is heavier....
How can it work with all the different rotating weights you can come up with in our little boxers???
It will be different on just about every engine...

I am not bashing their product, just wondering how they came up with a lighter one that can do all of this, on every boxer...

Just some food for thought on the subject of torsional vibration...
If you want to read more on it, search for the research they did on airplanes... That research takes the entire drive train into account...
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Old 09-12-2007, 09:02 PM   #71
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dont slap steve...thats not cool.

especially now that hes (barely) in the Scooby club...

anyway, yea so lots of analytical stuff going on in here. I just wanted to be the first bearer of bad news. All your cars are going to blow up now.

Y'all have a good day.

And id love to talk port work and flow #s, but all i do is sit and watch Micah do the port work while i wonder what the point is and finish my beer before going back in the house to drool over the TV or XBOX.
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Old 09-13-2007, 10:55 PM   #72
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well, rods showed up as well as the 8.5:1 pistons. The pistons weigh 412 grams and the rods are well heavier than factory but still lighter than Rigoli's shorter rods
Also took some head pics for comparing to David's removed seat and opened up intake ports. I'm not even close to done with my heads but you can see the obvious copius amounts of extra room in his.
**moved pics to first page**

Last edited by Homemade WRX; 09-13-2007 at 11:12 PM.
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Old 09-13-2007, 11:35 PM   #73
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Old 09-14-2007, 08:17 PM   #74
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i love those new piston pics.
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Old 09-15-2007, 06:12 PM   #75
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makes great reading !
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