Another P2V problem
Thread Starter
Launching!
Joined: Aug 2002
Posts: 281
Likes: 1
From: Sherwood, AR
Another P2V problem Ok, here's the problem with the cam we put in this weekend (2000 Camaro SS with stock heads):
The cam:
Lunati 55008LUN
237/242 .595/.595 112LSA
http://www.lunaticams.com/Camshafts/ChevyLS1.html (2nd from the bottom)
This was bought used. Installed with a Rollmaster double roller timing chain, set straight up (no advance or retard). Thunder Racing pushrods (stock 7.400 length), along with new springs, retainers, oil pump, etc.
When I put in the rockers, I torqued them down, then turned the motor over a couple of revolutions with a socket wrench on the crank bolt. Then retorqued to be safe (I had one back off on my car a year or so ago). Anyway, we started the car, and it fired right up. Shut it off after 5 seconds or so (the car was sitting in my car port with open headers and no exhaust- the other mod we did along with the cam stuff). We thought it would be better to run it in the driveway so it wouldn't echo so much. Went to start it back uop and got a large backfire through the intake. THe car will not start at all now.
So, onto today. Did a compression test on all of the cyls. Six of them were 0. Yes, 0. Two of them (#5 and #7) were at 130.
Took the rockers off of #3, and hooked up the air compressor to it. HUGE air leak through the intake (nothing noticable through the exhaust, but maybe we just can't hear it). So I'm now thinking this cam had P2V issue. But only on 6 or the 8 pistons. Hmmm. We're pulling the heads now.
Just like in the T-Rex thread, we did not degree the cam, it was just aligned dot to dot (and was perfect). In retrospect, maybe 2-4* or retard should have been put in. With only .595 lift, I didn't think it necessary.
So, can anyone shed some light on this for me and let me know how to know when to retard the timing on a cam? I'd rather learn from this and not do it again. Thanks!
The cam:
Lunati 55008LUN
237/242 .595/.595 112LSA
http://www.lunaticams.com/Camshafts/ChevyLS1.html (2nd from the bottom)
This was bought used. Installed with a Rollmaster double roller timing chain, set straight up (no advance or retard). Thunder Racing pushrods (stock 7.400 length), along with new springs, retainers, oil pump, etc.
When I put in the rockers, I torqued them down, then turned the motor over a couple of revolutions with a socket wrench on the crank bolt. Then retorqued to be safe (I had one back off on my car a year or so ago). Anyway, we started the car, and it fired right up. Shut it off after 5 seconds or so (the car was sitting in my car port with open headers and no exhaust- the other mod we did along with the cam stuff). We thought it would be better to run it in the driveway so it wouldn't echo so much. Went to start it back uop and got a large backfire through the intake. THe car will not start at all now.
So, onto today. Did a compression test on all of the cyls. Six of them were 0. Yes, 0. Two of them (#5 and #7) were at 130.
Took the rockers off of #3, and hooked up the air compressor to it. HUGE air leak through the intake (nothing noticable through the exhaust, but maybe we just can't hear it). So I'm now thinking this cam had P2V issue. But only on 6 or the 8 pistons. Hmmm. We're pulling the heads now. Just like in the T-Rex thread, we did not degree the cam, it was just aligned dot to dot (and was perfect). In retrospect, maybe 2-4* or retard should have been put in. With only .595 lift, I didn't think it necessary.
So, can anyone shed some light on this for me and let me know how to know when to retard the timing on a cam? I'd rather learn from this and not do it again. Thanks!
lift isnt the only factor consider that...its a combination of the valve events that contribute to issues like this...if its an unknown cam as such you should always check p to v clearance just to be safe.
lata
Bill
lata
Bill
That's crappy that happend to Brandon. He has been wanting a cam forever. I guess it's time we sit down and learn the correct way to install a cam Jay. I guess with the smaller one's we have been tossing in it's not as big of an issue. Well we learned the hard way. After yall get it figured out you should post it on our local board. No since in keeping it hush hush. Let others learn from our mistakes. I'd hate for someone to fallow in our footsteps without a fair warning on how close these big cams are.
Damn that blows. I wish I was in town to help yall out ripping that bad boy appart. I need to get some labor in so yall can return the favor on the ole LT1.
Damn that blows. I wish I was in town to help yall out ripping that bad boy appart. I need to get some labor in so yall can return the favor on the ole LT1.
Launching!
Joined: Jul 2003
Posts: 237
Likes: 0
From: Ft. Worth, TX
TTT on this one. This is on the same car as the post "motor won't start"(mine)
https://ls1tech.com/forums/generation-iii-internal-engine/167338-motor-won-t-start.html
Brandon
https://ls1tech.com/forums/generation-iii-internal-engine/167338-motor-won-t-start.html
Brandon
Last edited by silverbullet00; May 3, 2004 at 10:46 PM.
