Welcome to the North American Subaru Impreza Owners Club Sunday November 23, 2014
Home Forums WikiNASIOC Products Store Modifications Upgrade Garage
NASIOC
Here you can view your subscribed threads, work with private messages and edit your profile and preferences Home Registration is free! Visit the NASIOC Store NASIOC Rules Search Find other members Frequently Asked Questions Calendar Archive NASIOC Upgrade Garage Logout
Go Back   NASIOC > NASIOC Technical > Normally Aspirated Powertrain

Welcome to NASIOC - The world's largest online community for Subaru enthusiasts!
Welcome to the NASIOC.com Subaru forum.

You are currently viewing our forum as a guest, which gives you limited access to view most discussions and access our other features. By joining our community, free of charge, you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is free, fast and simple, so please join our community today!

If you have any problems with the registration process or your account login, please contact us.
* Registered users of the site do not see these ads.
Reply
 
Thread Tools Display Modes
Old 10-15-2000, 09:30 PM   #1
ColinL
Scooby Guru
 
Member#: 114
Join Date: Jul 1999
Chapter/Region: MWSOC
Location: Wichita, KS and Whoring, OT
Vehicle:
'03 Evo, Rice White
'01 Erion CBR 929

Thumbs up Cams finally in.

For the first time in 8 days, my car is driveable. For the background on the first weekend's work, read the other thread here.

Here are the changes I did versus the "standard" install as documented by Trey and provided with the cams:
  • *removed cylinder heads (3 stripped bolts in camshaft cap)
    *removed intake manifold
    *removed intake valves
    *removed carbon deposits on back of intake valves, piston tops and top of cylinder bores
    *port matched intake side of head to intake manifold gasket
    *ground away casting flash and general roughness behind intake valves

Total man hours: approximately 52. Yep, 52. Always two people on it and sometimes three. I put in about 18-20 hours myself.

The result? Definitely more power up top. Haven't bounced off the rev limiter, but have definitely been to it and the car pulls harder. Now I need programmable EFI and a 6800 RPM rev limit.

Instrumented testing? None yet. I can borrow a gtech pro, but for me real results will be in 1-2 weeks when I take it to the local dragstrip. It sure as hell feels faster.

Now, the big question some of you out there are wondering: should an enthusiast attempt this?

Maybe not. What I did is certainly more difficult than installing a turbo kit, unless you're doing heavy fabrication. If someone is charging $400-600 to install these, that's probably fair. MAKE SURE they have a Torx Plus 40 bit (40TP). The work done to my car is probably worth $1200 - 1500. I'm glad I did it and am even more glad it is DONE.

[This message has been edited by ColinL (edited October 16, 2000).]
* Registered users of the site do not see these ads.
ColinL is offline   Reply With Quote
Old 10-15-2000, 09:30 PM   #2
ColinL
Scooby Guru
 
Member#: 114
Join Date: Jul 1999
Chapter/Region: MWSOC
Location: Wichita, KS and Whoring, OT
Vehicle:
'03 Evo, Rice White
'01 Erion CBR 929

Post

Oh and the scariest part? All the smoke when we fired it up the first time. It scared me enough to shut it down... 30 minutes later and sure there's nothing "wrong", we decided it was antifreeze and oil inside the exhaust manifold shielding, and sprayed on the valve covers, etc. It smoked for ~10 minutes pretty good while all that burned off, but NO smoke out the tail pipe and smooth idle. After the smoke died down I brought it to 2500 RPM for another 10-15 minutes to break in the cams. Hasn't smoked one bit since and it runs like a champ, including a steady ~700rpm idle.

Also forgot to mention my vital stats / relevant mods:
  • *'99 2.5RS, 23k miles, 5spd
    *2.25" midpipe, 2.25" borla turbo muffler
    *eliminated fender silencer, AMSOil panel filter in stock airbox
    *Unorthodox underdrive pulley w/ wrong belts (UR recommended are too long)
    *Bosch Platinum plugs (stock heat range)

[This message has been edited by ColinL (edited October 15, 2000).]
ColinL is offline   Reply With Quote
Old 10-15-2000, 09:40 PM   #3
ColinL
Scooby Guru
 
Member#: 114
Join Date: Jul 1999
Chapter/Region: MWSOC
Location: Wichita, KS and Whoring, OT
Vehicle:
'03 Evo, Rice White
'01 Erion CBR 929

Post

Also forgot: fuel of choice for this vehicle is 92 octane. It runs better and in case this crazy install didn't reveal it-- I don't give a crap about paying $.14 a gallon more.
ColinL is offline   Reply With Quote
Old 10-15-2000, 09:45 PM   #4
Big Tee
Scooby Newbie
 
Member#: 1802
Join Date: Jul 2000
Location: camillus, ny usa
Vehicle:
1998 Impreza RS2.5
Black

Post

Colin, congrats! What an effort. I can't wait to hear the results of your trip to the dragstrip.
Big Tee is offline   Reply With Quote
Old 10-15-2000, 09:50 PM   #5
Big Tee
Scooby Newbie
 
Member#: 1802
Join Date: Jul 2000
Location: camillus, ny usa
Vehicle:
1998 Impreza RS2.5
Black

Post

Colin, In my Chevy V-8 days when installing a cam, the drill was to start the car and keep in at a high idle for 20-30 minutes, I'm guessing that's also the case with our Subies based on your procedure. My question, because of the initial smoke, you turned the car off, is that going to be a long term problem, or because you restarted and then went to the high revs will it accomplish the same thing?
Thanks.
Big Tee is offline   Reply With Quote
Old 10-15-2000, 09:55 PM   #6
ColinL
Scooby Guru
 
Member#: 114
Join Date: Jul 1999
Chapter/Region: MWSOC
Location: Wichita, KS and Whoring, OT
Vehicle:
'03 Evo, Rice White
'01 Erion CBR 929

Post

I don't think there's going to be a problem because rockers are roller tipped and the valvesprings are fairly light.

The smoke was pretty damned bad and getting worse so I elected to shut it down. Those of you going forward, you'll know to keep on running it!
ColinL is offline   Reply With Quote
Old 10-15-2000, 09:59 PM   #7
Aphex
Scooby Specialist
 
Member#: 146
Join Date: Aug 1999
Location: Wahcheeta, KS
Vehicle:
'05 Legacy GT
Silver

Post

I want a ride colin don't forget that you also promised me a ride in your dad's camero. I was glad to have helped you (the little amount of work that I did do) but I wanted to thank you for the learning experience from you and your dad. let me know when you go out to the track, I may have to run that day too.
Aphex is offline   Reply With Quote
Old 10-15-2000, 10:05 PM   #8
Overtime
Scooby Specialist
 
Member#: 1346
Join Date: Apr 2000
Post

Wow, that's something. Congratulations on the install. Kudos to Trey for the design and Colin for the installation debugging. It's also good to hear that the cams when combined with larger exhaust and a freer flowing intake do produce gains.

Would be interesting to see the combination of freer flowing heads, higher flowing TB, increased CR, and the mildly aggressive cams-AKA Cobb Tuning's full N/A upgrade. Seeing as how you have experience removing the stock heads and all, you can be the guinea pig with those too.
Overtime is offline   Reply With Quote
Old 10-16-2000, 04:52 AM   #9
Orbiter
Scooby Specialist
 
Member#: 66
Join Date: Jul 1999
Location: Vancouver, British Columbia, C
Vehicle:
2002 Impreza WRX
Britney Edition

Post

ColinL: Does your butt-dyno tell you 18HP increase??

Orbiter is offline   Reply With Quote
Old 10-16-2000, 07:30 AM   #10
ColinL
Scooby Guru
 
Member#: 114
Join Date: Jul 1999
Chapter/Region: MWSOC
Location: Wichita, KS and Whoring, OT
Vehicle:
'03 Evo, Rice White
'01 Erion CBR 929

Post

I try my best to be a pessimistic curmudgeon, but... yes, there probably is an honest 20HP gained.
ColinL is offline   Reply With Quote
Old 10-16-2000, 08:12 AM   #11
Revision
Scooby Guru
 
Member#: 242
Join Date: Sep 1999
Chapter/Region: MWSOC
Location: Carol Stream, IL USA
Vehicle:
MY05 PSM GGA !STOCK
MY99 RS-RIP / MY95 MX-5

Post

I see a road trip to Kansas in the near future for the MWSOC.
Revision is offline   Reply With Quote
Old 10-16-2000, 08:16 AM   #12
SCRAPPYDO
Scooby Guru
 
Member#: 873
Join Date: Feb 2000
Chapter/Region: TXIC
Location: Just outside of Houston TX
Vehicle:
2013 F150 King Ranch
Datsun 71 240Z & 68 2000

Post

Thanks for the update Colin!

A few more posts like yours and my wallet will simply fly out to purchase these. Nice job and congrats!

SCRAPPYDO
SCRAPPYDO is offline   Reply With Quote
Old 10-16-2000, 08:37 AM   #13
Corey
Scooby Specialist
 
Member#: 618
Join Date: Dec 1999
Location: PA, USA
Vehicle:
2000 2.5 RS #89 STS
MODERacing / Bridgestone

Post

HOLLY! If Colin says they give 20HP... they must give at least that. Just from reading his posts I can tell that he is just as skeptical about big gains as I am. I am going to look into these a little better.

Thanks Colin!
Corey is offline   Reply With Quote
Old 10-16-2000, 08:56 AM   #14
ColinL
Scooby Guru
 
Member#: 114
Join Date: Jul 1999
Chapter/Region: MWSOC
Location: Wichita, KS and Whoring, OT
Vehicle:
'03 Evo, Rice White
'01 Erion CBR 929

Post

I don't think Jon Bogert perceived as big of a gain but I think he has stock intake, exhaust and no port matching.

After reading Cobb Tuning's write up on their ported cylinder heads, I would agree with Trey that the exhaust side needs some help because one port flows straight out while the other bends pretty hard. However that was beyond the scope of what we were doing, and the exhaust ports match the gasket.

And again, at this point it's just perception. Trey did instrumented testing (RWD dyno) that said there was more power up top, and it does seem to be there IMO.
ColinL is offline   Reply With Quote
Old 10-16-2000, 09:07 AM   #15
imprezive
Scooby Specialist
 
Member#: 746
Join Date: Jan 2000
Chapter/Region: South East
Location: FL
Post

I agree with corey. colin is very realalistic
imprezive is offline   Reply With Quote
Old 10-16-2000, 09:10 AM   #16
donjuan
Scooby Specialist
 
Member#: 2248
Join Date: Aug 2000
Post

ColinL--thanks for posting, i think ALOT of people were interested in the details of the Cobb cams.
donjuan is offline   Reply With Quote
Old 10-16-2000, 09:34 AM   #17
8Complex

Moderator
 
Member#: 922
Join Date: Feb 2000
Chapter/Region: MWSOC
Location: Schaumburg, IL
Vehicle:
04 FXT
Red

Post

Cool deal, Colin. Glad to hear you've finally got it back together. I'd hate to have to deal with driving a 69 Camaro every day.

Revision - Donnie & I should be heading to Iowa early November, is that anywhere near Kansas? (yeah, I'm great with Geography...)
8Complex is offline   Reply With Quote
Old 10-16-2000, 10:11 AM   #18
Gambit
Scooby Specialist
 
Member#: 102
Join Date: Jul 1999
Location: The meeting place
Post

Clap Clap Clap Clap!!! Applause for a job well done. Now..... to say N/A or FI.... choices choices....
Gambit is offline   Reply With Quote
Old 10-16-2000, 02:50 PM   #19
stimpy
Homicidal Maniac
Moderator
 
Member#: 1612
Join Date: Jun 2000
Location: Austin, TX
Vehicle:
2008 STI

Post

Great job ColinL. With your success and horror stories, I am now a little apprehensive of the cam install. When you say, 'should an enthusiast attempt this, maybe not', why is that? Is it because of the possible troubles that can occur if everything doesn't go smoothly, or is this referring to all the extra steps that you did? I feel fairly confident that me and some domestic motorheads (yes, they have changed cams) can do this, but I don't want to get myself into something I can't fix.
stimpy is offline   Reply With Quote
Old 10-16-2000, 03:13 PM   #20
ColinL
Scooby Guru
 
Member#: 114
Join Date: Jul 1999
Chapter/Region: MWSOC
Location: Wichita, KS and Whoring, OT
Vehicle:
'03 Evo, Rice White
'01 Erion CBR 929

Post

That is exactly why. If you strip one of 12 bolts securing the camshaft cap (six 5mm hex, six 40TP) you make a choice whether to pull the heads or put it back together and bring it in for service. And clearly this would be something you want an independent to work on and NOT a Subaru dealer...

We did the extra steps because they made sense once the heads were off.

[This message has been edited by ColinL (edited October 16, 2000).]
ColinL is offline   Reply With Quote
Old 10-16-2000, 07:46 PM   #21
gumby647
Scooby Specialist
 
Member#: 2532
Join Date: Sep 2000
Chapter/Region: South East
Location: Orlando, Fl
Vehicle:
2001 2.5RS-T
BRP

Post

Did you degree the cams in or just throw them in? Is there anyway to time the cams with stock pullies? If you guys are just throwing in cams that could explain why one guy feels more power than another. I haven't done any Scooby heads yet, haven't even got my car but I'm a motorcycle mechanic so I've been in some high output motors and we can make some big changes with cam timing. One thing I've found is that stock cam timing is never where it should be and aftermarket cams are worse.
I'm also curious why you didn't mill the heads while you had them off or used thinner head gaskets to get compression up.
gumby647 is offline   Reply With Quote
Old 10-16-2000, 09:01 PM   #22
ColinL
Scooby Guru
 
Member#: 114
Join Date: Jul 1999
Chapter/Region: MWSOC
Location: Wichita, KS and Whoring, OT
Vehicle:
'03 Evo, Rice White
'01 Erion CBR 929

Post

I installed the cams with stock timing. I did not elect to install them with any advance because this is not a carbureted 16 valve pushrod v8.

I also did not mill the heads because that is a stupid way to get compression in general and there is only a 2mm quench area. If you go beyond that the piston crashes into the head as the combustion chamber is significantly smaller than the bore.

I do not know the compressed thickness is of the stock head gaskets but let's just say that it is the thinnest I have ever seen.

I thought the difference between my other mods and Jon's lack thereof was a perfectly logical explanation for our resulting differences.

[This message has been edited by ColinL (edited October 16, 2000).]
ColinL is offline   Reply With Quote
Old 10-16-2000, 09:09 PM   #23
Joel Gat, 1.8L
Scooby Specialist
 
Member#: 32
Join Date: Jun 1999
Post

Hello,

Amen to Colin on that last response Milling the heads or reducing the thickness of the gasket affects timing and on a V or H engine, it will advance the intake timing and retard the exhaust timing on one head and retard the intake timing and advance the exhaust timing on the other head. Why would you want to even try to deal with that?

Like Colin alluded to, American old engines with pushrods are a different matter. There, you have one cam and reducing the height of the head only necessitates either changing pushrod length or adjusting the valves (or rocker arms or whatever, depending on the head design / manufacturer).

The next issue is why you would change cam timing on a cam that is built up and then reground. The timing is already changed from stock to reflect what CobbTuning felt was the best timing, given the mildness or wildness of the cam. If you want to play with the timing, you should get a different cam.

Finally, if you do want to play with timing, rumor has it Trey will come out with cam-gears in the not too distant future...

Joel

edit: as for degreeing the cams, the cams fit to the cam gear in only one direction (there's a notch). You could change the timing by moving one or more belt notches, but doing that would cause the valves to open or close earlier (ie, you want them to open earlier but then you cause them to close earlier).

[This message has been edited by Joel Gat, 1.8L (edited October 16, 2000).]
Joel Gat, 1.8L is offline   Reply With Quote
Old 10-16-2000, 10:11 PM   #24
gumby647
Scooby Specialist
 
Member#: 2532
Join Date: Sep 2000
Chapter/Region: South East
Location: Orlando, Fl
Vehicle:
2001 2.5RS-T
BRP

Post

Sorry I brought it up. But cam timing works on flat fours the same as v-eights and F1 cars. My point is that you say you installed them with stock timimg but you don't know if stock is spec or 4-5 deg off. I'm not talking about using the stock marks. The only real way to do it is with a degree wheel and dial indicator.

I went and looked at the heads on Trey's page and I don't understand what you mean by 2mm quench? If you mean 2mm piston to head clearance then milling the head will not make the pistons hit the head. His heads look milled. I'm sure that's what his $150 extra compression is. If he's welding up and reshaping the chambers for $150 then he's one hell of a guy.

To joel,
The reson I would want to deal with that is that to do the job right you need to get out the degree wheel and dial indicator anyway so why not go for all the power you can?
On afermarket cams they change lift and duration (and overlap on SOHC). That does not take into acount production tolerances of your motor. If stock spec is 108(I'm making this up cause i don't know the stock #s) lobe centers and your car stock is 104 when you put in the new cams even if they are perfect(they're not) they will still be 4deg off.

Moving the cams a whole tooth on the belt would be way too much and should not be done.
gumby647 is offline   Reply With Quote
Old 10-16-2000, 11:36 PM   #25
Joel Gat, 1.8L
Scooby Specialist
 
Member#: 32
Join Date: Jun 1999
Post

Hello,

Gumby, so how do you propose to degree the cam with its one way fitment to the cam gear? The cam only goes on the gear at one angle. Any change to that would require remanufacturing the core or fabbing an entirely new cam gear.

I think that's where we went in serperate directions. You can account for the timing differences caused by milling the heads by slightly changing the angle of the cam relative to the sprocket, but since we can't do that, voila.

That's also what I meant by changing the rods or adjusting the rocker arms. Those can re-spec the timing on a pushrod engine. We're stuck, though.

Joel
Joel Gat, 1.8L is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Brian Crower Cams Finally Available!!! Touge Tuning Engine/Power/Exhaust 14 07-30-2008 01:14 AM
Helix Cams back in stock - $519 Shipped! STi Mounts! Cobb APs in stock! Helix DPs! Gruppe-S Engine/Power/Exhaust 3 07-31-2006 07:59 PM
My car's finally in the body shop! Selling all the extra stuff in my room - LOOK Cashis Private 'For Sale' Classifieds 17 01-19-2006 05:14 AM
finally in car videos of my cammed RS. feelthebreak Normally Aspirated Powertrain 14 08-22-2005 07:28 PM
Cam Install in NY Tri-State Area nizz Normally Aspirated Powertrain 6 10-18-2000 03:52 PM


All times are GMT -4. The time now is 04:50 AM.


Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Powered by Searchlight © 2014 Axivo Inc.
Copyright ©1999 - 2014, North American Subaru Impreza Owners Club, Inc.