POLL: Cranking Compression psi check on stock TPI.
Thread Starter
Member
Joined: Jan 2001
Posts: 436
Likes: 0
From: Ft. Worth, TX
Car: 89 Turbo Trans Am and lots of non-3rd gens
Engine: 231 SFI Turbo's, LT4, LT1
Transmission: 2004r, 4L60E
POLL: Cranking Compression psi check on stock TPI.
In trying to track down my ping/detonation problem on my 5.7 TPI motor, I've discovered my cranking compression was 170-180psi on each cyclinder. Some feel this is way to high, while others think its no big deal.
*
What is your cranking compression on a stock TPI.
Please specify if STOCK or not, really interested in the stock heads setup.
------------------
Rob
High Performance & Party page
Pics of my rides past & present and recent party pics!
89 TTA #426 20th Anniversary turbo 3.8 bone stock
94 Silverado Tuned Port Injected
87 Grand National- lil' ole V6, highly modded
95 Trans Am Conv.- LT1
*
What is your cranking compression on a stock TPI.
Please specify if STOCK or not, really interested in the stock heads setup.
------------------
Rob
High Performance & Party page
Pics of my rides past & present and recent party pics!
89 TTA #426 20th Anniversary turbo 3.8 bone stock
94 Silverado Tuned Port Injected
87 Grand National- lil' ole V6, highly modded
95 Trans Am Conv.- LT1
Member
Joined: Jun 2000
Posts: 109
Likes: 0
From: Ft. Worth, TX
When I did a comp. check on my 305 before I put my cam in, it was around 170. I've haven't check it since, but from what I've heard that was normal. BTW do you ever run out at Kennedale ? If you do look for grey Iroc with a silver bowtie sticker on the back window.
------------------
86 TPI 305 Iroc-Z
700R4 (rebuilt)
3.42 Posi
Accel HEI SuperCoil
Flowmaster
K&N Filters
Comp Cams High Energy H268 218@.050 454/454
------------------
86 TPI 305 Iroc-Z
700R4 (rebuilt)
3.42 Posi
Accel HEI SuperCoil
Flowmaster
K&N Filters
Comp Cams High Energy H268 218@.050 454/454
Senior Member
Joined: Jan 2001
Posts: 527
Likes: 0
From: outerspace(maybe..pluto)?
thats about normal for a stock 5.7 just so you know. does it ever fluctulate?(to extremes?)
------------------
1989 firebird formula
Mods: converted from T.B.I. to a carburator 305 to a 350. Flowmater exhaust,hedman shortie hedders,202 heads,350 horse cam,bored.40 over, Edlebrock torker2 intake.
Future mods performer rpm air gap intake (polished) and 600 edlebrock carb, comp roller cam, and way better headsa 400 defintely in the works!
------------------
1989 firebird formula
Mods: converted from T.B.I. to a carburator 305 to a 350. Flowmater exhaust,hedman shortie hedders,202 heads,350 horse cam,bored.40 over, Edlebrock torker2 intake.
Future mods performer rpm air gap intake (polished) and 600 edlebrock carb, comp roller cam, and way better headsa 400 defintely in the works!
Thread Starter
Member
Joined: Jan 2001
Posts: 436
Likes: 0
From: Ft. Worth, TX
Car: 89 Turbo Trans Am and lots of non-3rd gens
Engine: 231 SFI Turbo's, LT4, LT1
Transmission: 2004r, 4L60E
Didn't seem to fluctuate any.
86IROC, I go out to Kennedale a couple a of times a year with the GN, hadn't been out there this year though, hope to go soon. Ever go out to the street races on Beach? Only been out there a few times, just been too busy to go. Ennis is usually better because there is less people out there, you can get in as many runs as you want out there. Kennedale, I'm lucky to get 3 or 4 runs the entire night.
86IROC, I go out to Kennedale a couple a of times a year with the GN, hadn't been out there this year though, hope to go soon. Ever go out to the street races on Beach? Only been out there a few times, just been too busy to go. Ennis is usually better because there is less people out there, you can get in as many runs as you want out there. Kennedale, I'm lucky to get 3 or 4 runs the entire night.
TGO Supporter
Joined: Jul 1999
Posts: 607
Likes: 0
At about 130k miles, my stock 86 305tpi varies from 179-183 on different cylinders....After 170k, it is pretty much the same.
------------------
Mike Metzler (Desert86Roc)
Mike@SpeedworldMotorplex.com
[*] Webmaster: SpeedWorldMotorplex.com[*] Click Here For My Racing Page[*]86 IROC 305 TPI (406 build in progress)
ET's @ 1250 ft[*] 14.28 @ 95.461 mph (uncorrected, NOS, no headers)[*] 15.365 @ 86.785 mph (uncorrected, Headers, no NOS)
------------------
Mike Metzler (Desert86Roc)
Mike@SpeedworldMotorplex.com
[*] Webmaster: SpeedWorldMotorplex.com[*] Click Here For My Racing Page[*]86 IROC 305 TPI (406 build in progress)
ET's @ 1250 ft[*] 14.28 @ 95.461 mph (uncorrected, NOS, no headers)[*] 15.365 @ 86.785 mph (uncorrected, Headers, no NOS)
Member
Joined: Jun 2000
Posts: 109
Likes: 0
From: Ft. Worth, TX
2QUIK6, I've never ran out at Beach St (can't afford the tickets 
) and Ennis is too far a drive. I usually go to Kennedale about 1 or 2 times a month on Friday's, but I'd love to see what I'd run in the 1/4 mile. I'll probably run it this Friday at Kennedale, Too bad there isn't a 1/4 mile track closer. Maybe I'll see you around sometime.
------------------
86 TPI 305 Iroc-Z
700R4 (rebuilt)
Accel HEI SuperCoil
Flowmaster
K&N Filters
Comp Cams H268 218@.050 454/454
) and Ennis is too far a drive. I usually go to Kennedale about 1 or 2 times a month on Friday's, but I'd love to see what I'd run in the 1/4 mile. I'll probably run it this Friday at Kennedale, Too bad there isn't a 1/4 mile track closer. Maybe I'll see you around sometime.------------------
86 TPI 305 Iroc-Z
700R4 (rebuilt)
Accel HEI SuperCoil
Flowmaster
K&N Filters
Comp Cams H268 218@.050 454/454
Thread
Thread Starter
Forum
Replies
Last Post
