Won't start after H/C install
Drifting
Joined: Oct 2003
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From: bloomfield nj
Originally Posted by vettenuts
I'm not following this. If you tighten the rockers, the preload is set by pushrod length. There is no rocker adjustment. What length pushrods do you have? What is the cam?
i asked him that,he claims the pushrods are ok.but i hear what you are saying,i'm thinking about it now,you're right,i'm thinking about the old style rocker stud/nut theory.he must have pushrods that are too long and he has the lifters buried.
Melting Slicks
Joined: Sep 2005
Posts: 2,625
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From: Rhode Island
Originally Posted by DRIVER456
I'm going to take the valve covers off and check what you said.I did line dot to dot,I'm pretty sure the cam is 180 out. 
I'll be back later and let you know.Thanks................Paul
I'll be back later and let you know.Thanks................Paul
Drifting
Joined: Oct 2003
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From: bloomfield nj
Originally Posted by cbx1047cc
With #1 cylinder at TDC, crank dot at 12, cam dot a 6. Simple as that.
are you sure[not trying to be wise]? everything that i've looked at shows dot to dot as #6 firing.just curious as i've never had one of the ls motors apart. i know the older motors were that way too.
Melting Slicks
Joined: Sep 2005
Posts: 2,625
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From: Rhode Island
Originally Posted by dpd
are you sure[not trying to be wise]? everything that i've looked at shows dot to dot as #6 firing.just curious as i've never had one of the ls motors apart. i know the older motors were that way too.
Melting Slicks
Joined: Sep 2005
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From: Rhode Island
Team Owner
Joined: Mar 1999
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From: At the beach in little Rhody
It doesn't matter. If the crank is at 12 o'clock, the cam can either be at 6 or 12 o'clock. On an LS1, it won't matter as long is he isn't off a tooth on the timing chain. On the older motors it did, because it would throw off the distributor.
Thread Starter
Melting Slicks
Joined: Jun 2005
Posts: 3,088
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From: NY- 2013 Corvette Challenge Champion-2013 Index Combo Champion 2015 CC/MM Champion
St. Jude Donor '07
Let me make sure of something first. #1 piston is drivers side,close to the radiator? If thats it ,I put #1 piston up TDC and #6 exhaust was opening,according To Dpd the intake should open,So Am I 180 out? I did a compression check and it held compression,I left the gauge there for a few minutes and it held.If the pushrods are to long wouldn't it lose air? I have stock length pushrods.
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Le Mans Master
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From: Atlanta metro Ga.
I'll add my 2.5 cents.
Cam can't be "180 degrees out"; remember the cam rotates at 1/2 of crank RPM.
Also, assuming a higher-lift cam than stock (or course), the stock PR's might be too short, but never too long (unless these heads you've installed are milled quite a bit), so no way the valves are hanging open.
This isn't something silly like installing a cam that lacks a positioning nub, right? Did you follow the LS1 tech instructions to the letter?
You probably have a bad connection on one of the connectors you removed. Here's another tip; no need to unplug anything to crank w/o the injectors depositing fuel. Just hold the pedal all the way down (100% TP), and the PCM goes into "anti-flood" mode, just for this purpose.
Cam can't be "180 degrees out"; remember the cam rotates at 1/2 of crank RPM.
Also, assuming a higher-lift cam than stock (or course), the stock PR's might be too short, but never too long (unless these heads you've installed are milled quite a bit), so no way the valves are hanging open.
This isn't something silly like installing a cam that lacks a positioning nub, right? Did you follow the LS1 tech instructions to the letter?
You probably have a bad connection on one of the connectors you removed. Here's another tip; no need to unplug anything to crank w/o the injectors depositing fuel. Just hold the pedal all the way down (100% TP), and the PCM goes into "anti-flood" mode, just for this purpose.
Last edited by Dan_the_C5_Man; Feb 11, 2006 at 05:28 PM.
Drifting
Joined: Oct 2003
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From: bloomfield nj
Originally Posted by DRIVER456
Is the #1 piston drivers side close to the rad?
#1 is on the left closest to the radiator.with #1 firing,#6 is on the exhaust stroke[exhaust valve is moving to close and the intake is moving to open].
Thread Starter
Melting Slicks
Joined: Jun 2005
Posts: 3,088
Likes: 61
From: NY- 2013 Corvette Challenge Champion-2013 Index Combo Champion 2015 CC/MM Champion
St. Jude Donor '07
Originally Posted by dpd
#1 is on the left closest to the radiator.with #1 firing,#6 is on the exhaust stroke[exhaust valve is moving to close and the intake is moving to open].
Drifting
Joined: Oct 2003
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From: bloomfield nj
Originally Posted by DRIVER456
OK then I think the cam is 180 out if thats possible,because the #6 exhaust was opening.#6 would be passenger side 2nd one in from rad?
no,that's 4.left bank is 1-3-5-7.right bank is 2-4-6-8.you can't be out on the cam,like i said it doesn't matter.let me ask you this.did you pull out the cam sensor when you did the swap? your rockers are on a shaft.i was thinking of the older chevy motors[shame on me] with the rocker studs.the only things i can think of are:the pushrods are too long[if your running alot of lift],something is off or loose[ground wire,harness,etc].
do you have any faults??
are the injectors plugged in right? they HAVE to go back to the right cylinders[sequential fuel injection]
Last edited by dpd; Feb 11, 2006 at 06:15 PM.
Thread Starter
Melting Slicks
Joined: Jun 2005
Posts: 3,088
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From: NY- 2013 Corvette Challenge Champion-2013 Index Combo Champion 2015 CC/MM Champion
St. Jude Donor '07
Originally Posted by dpd
no,that's 4.left bank is 1-3-5-7.right bank is 2-4-6-8.you can't be out on the cam,like i said it doesn't matter.let me ask you this.did you pull out the cam sensor when you did the swap? your rockers are on a shaft.i was thinking of the older chevy motors[shame on me] with the rocker studs.the only things i can think of are:the pushrods are too long[if your running alot of lift],something is off or loose[ground wire,harness,etc].
do you have any faults??
do you have any faults??
Everything is plug in,ground wires on.But I'll check again.
Drifting
Joined: Oct 2003
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From: bloomfield nj
Originally Posted by DRIVER456
No i didn't pull the cam sensor out,BUT I get jackass of the day award,When I said I did a compression check,I forgot the hose has a valve core so air can't escape DUH!!! So I might run up tp Sears or Auto zone and see if they have a leak down tester. Everything is plug in,ground wires on.But I'll check again.
Everything is plug in,ground wires on.But I'll check again.stop.you may have hit the cam sensor when you swapped the cams.see if you have a fault for it first.recheck the injector plugs to make sure they are plugged in right[1/1-2/2-etc]they are labeled
Thread Starter
Melting Slicks
Joined: Jun 2005
Posts: 3,088
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From: NY- 2013 Corvette Challenge Champion-2013 Index Combo Champion 2015 CC/MM Champion
St. Jude Donor '07
Originally Posted by dpd
stop.you may have hit the cam sensor when you swapped the cams.see if you have a fault for it first.recheck the injector plugs to make sure they are plugged in right[1/1-2/2-etc]they are labeled
Last edited by DRIVER456; Feb 11, 2006 at 06:30 PM.
Drifting
Joined: Oct 2003
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From: bloomfield nj
Originally Posted by DRIVER456
Should I pull it out and reinstall it?.There were no codes for that,If thats what you mean.When I did a compression check and if the valves were hung open alittle,I wouldn't get very much comp.Right.But I got over 180psi on every cylinder.
how did you do your compression test? you should have a fault if the cam sensor got hit,but to check it,you have to pull the intake.
there's something out there that you touched that's not right.it's just figuring out what it is.i will tell you this.if you are washing cylinders out with fuel,there's no way you can have that high of compression.if the cylinders get washed out with fuel,sometimes your lucky if you get 50-60 pounds.
Instructor
Joined: Dec 2003
Posts: 107
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From: Baltimore MD
Originally Posted by DRIVER456
ttt
1. Valves hung open(did you use morel lifters or milled heads?)
2. forgot to connect the ground on the back of heads
3. Do you have spark?
4. Timing chain set up wrong
Thread Starter
Melting Slicks
Joined: Jun 2005
Posts: 3,088
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From: NY- 2013 Corvette Challenge Champion-2013 Index Combo Champion 2015 CC/MM Champion
St. Jude Donor '07
Originally Posted by brent02
Sorry about your problems. I once did a head and cam swap and this car would also not start. The valves were hanging open. Here are some suggestion
1. Valves hung open(did you use morel lifters or milled heads?)
2. forgot to connect the ground on the back of heads
3. Do you have spark?
4. Timing chain set up wrong
1. Valves hung open(did you use morel lifters or milled heads?)
2. forgot to connect the ground on the back of heads
3. Do you have spark?
4. Timing chain set up wrong
Pro
Joined: Oct 2003
Posts: 668
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From: Knoxville TN
Just curious since I'm considering a change. What heads and cam did you use. Typically when doing a cam change you would change lifters and pushrods as well. I wish you luck. I know how frustrating it can be. Please keep us posted.