LT1 Based Engine Tech 1993-1997 LT1/LT4 Engine Related

New Engine, missing 70-80 RWHP any thoughts

Thread Tools
 
Search this Thread
 
Old 05-28-2004, 01:41 PM
  #16  
Registered User
 
Mindgame's Avatar
 
Join Date: Nov 2001
Location: In a house by the bay
Posts: 2,985
Tough to say with a rebuild. Could be the rings never seated and/or other tolerances are just not "on". Ring seat in itself can cost you alot of power. But let's just take it one step at a time and be positive.

First off, those R lifters need a max of 1/4 turn. I've had good luck with them at 1/8 turn. Try a readjust and let us know. One step at a time.....

-Mindgame
Mindgame is offline  
Old 05-28-2004, 04:16 PM
  #17  
Registered User
 
disco192's Avatar
 
Join Date: Apr 2004
Location: Austin/Houston, TX
Posts: 1,347
There is nothing wrong with the heads. You should be easily over 400 rwhp. My bet is the valve lash was too tight. The R lifters only need 1/8-1/4 turn past zero lash. You also need to make sure that you adjust the rockers when the car is warmed up also. The oil in the lifters will react differently when it is hot.

My suggestion would be to heat the engine up and then re-adjust the rockers with 1/8 turn on the comp-R's.

Good Luck
-Stu
disco192 is offline  
Old 05-28-2004, 06:39 PM
  #18  
Registered User
 
med_reject's Avatar
 
Join Date: Sep 2003
Location: Edmonton, AB, Canada
Posts: 627
why not leave it at zero lash?
med_reject is offline  
Old 05-28-2004, 06:45 PM
  #19  
Registered User
 
Kevin97ss's Avatar
 
Join Date: Aug 2001
Location: Central NJ USA
Posts: 305
You said your running .625 in. lift and have valvetrain noise? Makes me wonder if the retainers are hitting the guide boss/seal @ max lift. Did you check this clearance before assembling the engine?
Kevin97ss is offline  
Old 05-28-2004, 08:26 PM
  #20  
Registered User
Thread Starter
 
526 SS 96's Avatar
 
Join Date: Dec 1998
Location: Cleveland, Ohio
Posts: 455
The retainers are not hitting the guides.
526 SS 96 is offline  
Old 05-28-2004, 08:57 PM
  #21  
Registered User
 
Mindgame's Avatar
 
Join Date: Nov 2001
Location: In a house by the bay
Posts: 2,985
Originally posted by disco192
There is nothing wrong with the heads. You should be easily over 400 rwhp. My bet is the valve lash was too tight. The R lifters only need 1/8-1/4 turn past zero lash. You also need to make sure that you adjust the rockers when the car is warmed up also. The oil in the lifters will react differently when it is hot.

My suggestion would be to heat the engine up and then re-adjust the rockers with 1/8 turn on the comp-R's.

Good Luck
-Stu
dejavu or is there an echo in here

Good advice for the first step.

-Mindgame
Mindgame is offline  
Old 05-28-2004, 09:13 PM
  #22  
Registered User
 
disco192's Avatar
 
Join Date: Apr 2004
Location: Austin/Houston, TX
Posts: 1,347
I thought i would add a little in there about warming up the engine too. MG you are my hero.
disco192 is offline  
Old 05-28-2004, 09:15 PM
  #23  
Registered User
 
Mindgame's Avatar
 
Join Date: Nov 2001
Location: In a house by the bay
Posts: 2,985
Talking

Hey its alright disco, I was just poking at you a little bit.

Warming things up is a good thing to do.

Later,
Mg
Mindgame is offline  
Old 05-28-2004, 09:32 PM
  #24  
Ai
Registered User
 
Ai's Avatar
 
Join Date: Oct 2000
Location: Charlotte, NC
Posts: 786
Well I don't really take offense, anyone's going to question everything, so that's fine. There's so much to these things that you almost never have something work completely perfectly the first time out (when youre sending parts across the country anyhow ).

I wont give out specs, however I will say that this is literally the same topend that was on Russ Ethridge's car which made 425rwhp SAE by 6300rpm with exhaust, pump fuel, and a moser 12 bolt. Actually Alex has another 7-11cfm across the board after some minor tweaking & freshening

We've been ridiculously busy lately fighting stupid issues (office things, computers etc.) but I've been in contact with Alex and we've laid out the exact differences between his setup & russ', and have that much figured out. It's not a long list & I'd rather not give away information, but fortunately (or unfortunately?) between restrictions, physical setup and tuning it more than adds up

I'm more than confident that when we swap to a configuration more oriented towards a 400-430rwhp SAE car he should easily be where one would anticipate


Oh, and for those waiting on email responses, I'm still working on it & I apologize for making people wait. I've little time these days to fix computers, but should have our email service functioning again sometime this weekend.

Thanks for the good tips from a few of you guys, that stuff is certainly on the list .

-Phil
Ai is offline  
Old 05-29-2004, 11:09 AM
  #25  
Registered User
 
SS MPSTR's Avatar
 
Join Date: Oct 2001
Location: SoCal
Posts: 2,525
You da Man, Phil.
SS MPSTR is offline  
Old 05-29-2004, 12:59 PM
  #26  
Registered User
Thread Starter
 
526 SS 96's Avatar
 
Join Date: Dec 1998
Location: Cleveland, Ohio
Posts: 455
I will have to wait till next week to get any more info for you guys. Thanks for the good ideas. I am sure this thing will be ironed out in a couple of weeks. My goal is to have about 650 RWHP w/a 200 shot.
526 SS 96 is offline  
Old 05-29-2004, 01:43 PM
  #27  
Registered User
 
bunker's Avatar
 
Join Date: Aug 2000
Location: North Vancouver, BC
Posts: 4,305
Originally posted by 526 SS 96
The car is a manual. I am running the comp R lifter, I set them at zero lash + 1/2 turn. I still have some valve train noise (in spots, I think 2-3 rockers are ticking very slightly, and I was going to check their adjustment. By saying "zero lash" you mean to take all the play (up & dn) out, and then tighten the set screw?

Yes leave them at zero lash or 1/16th of a turn past, I found that even with 1/8th of a turn you start having problems, set them to zero lash like you said, tighten the set screw real tight, then turn the whole nut just a bit more, it won't turn much, maybe 1/16th of a turn but it will make sure the set screw doesnt come loose, so:

-set zero lash
-tighten set screw
-now tighten the nut another 1/16th of a turn or less, this is to make sure they stay tight as the set screw will be pushed up against the rocker stud much harder & stay.

You will gain a ton of power trust me!
bunker is offline  
Old 05-29-2004, 02:46 PM
  #28  
Registered User
 
97 RedSS's Avatar
 
Join Date: Aug 2000
Location: Dallas,TX
Posts: 1,071
I dont understand how you can gain any power at all w/ that small of an adjustment having a hyrdraulic cam Maybe I need some more clarification?

Cody
97 RedSS is offline  
Old 07-03-2004, 11:16 AM
  #29  
Registered User
 
96speed's Avatar
 
Join Date: Dec 1999
Location: Houston, TX
Posts: 2,248
Originally posted by 97 RedSS
I dont understand how you can gain any power at all w/ that small of an adjustment having a hyrdraulic cam Maybe I need some more clarification?

Cody
I'd like to know too.

How about throwing some of us a bone here. You don't have to talk cam/heads/secrets to tell us what the problem is here, do you? Everyone starts off low on power and has to fight for the missing hp. Any light on initial troublehshooting would benefit many guys on this board .

Ryan
96speed is offline  
Old 07-03-2004, 12:29 PM
  #30  
Registered User
 
racer7088's Avatar
 
Join Date: Jan 2001
Location: houston, Tx
Posts: 293
Arrow

Not trying to step on anyone's toes but I have never seen that kind of power adjusting ANY kind of hydraulics or for that matter solid lifters! We've done 8500 rpm hydraulics too but that stuff is cheating anyway.
racer7088 is offline  


Quick Reply: New Engine, missing 70-80 RWHP any thoughts



All times are GMT -5. The time now is 02:49 AM.