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S Chassis Technical discussion related to the S Chassis such as the S12, S13, S14, and S15.


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Old 12-17-2012, 07:14 AM   #1
Jays Performance
 
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Help car wont start, checked everything

2.5 months back car was running fine, its a fully built SR top and bottom. Reason it has not started in 2.5 months is because one night I threw a rocker arm and bend some valve. Now I have had the machine shop put new BC valves in, new seals, put my BC springs and retainers back in, valve job and the did a little port polishing on the intake side.

Motor is all back together with new a cosworth head gasket switched out my 270s solids and solid lifter and put greddy 256s and hyrdo lifters in along with the proper shims. Everything is all back in order.

Problem: car wont start

Steps I have check:
-compression 80 across the board
-filled cyl with air valves don't leak through either intake or exhaust
-hear some air coming out the crank case t
-compression before we took the head off was 140 135 20 140
- 3 the valves we def bent, the others were very minimal
- put oil in the cylinders did the compression test they shot to 220
-cleared cyl check comp again everything was 140-150
-tried to start it ran for 30 sec I touched the gas it cut off
-tried again and nothing
-another compression test 100 psi all 4
- timing is set correct 2nd mark in dots on cams lined up with the chain at 9 and 12
-CAS is set properly.
-check spark and firing order (strong spark)
-fuel pressure is 45psi


Up until now the car has ran 100% perfect its never smoked, pulled hard, just hard to start in the cold.

What would cause the compression to be low now when it was 140-150 before the hard came off. Going from 140-150 to 80 , 220 was because the oil in the cyl but then 140-150 after oil is cleared and back to 100?


Me and my friends brains are fried on what the hell is going on. Any ideas would be greatly appreciated.
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Old 12-17-2012, 07:00 PM   #2
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Your engine sat for a long time, my guess is you didn't lube the cylinders and periodically rotate the crank. The reason you hear air at the T, is the rings aren't sealing. The reason it won't start is timing.

Set the mechanical timing with cam lobes facing out, dowel pins at 10 and 12.
You can't really set the cas correctly until the engine is started (in the center is an estimate) when mechanical timing is correct. I suggest you reset mech timing, loosely set the CAS just until it starts, then when warm, set Ign timing to 15deg, lock cas down. Check codes boostleak test and leakdown etc.

Since you have some compression, it'll start. and after a few cycles the rings should be good.

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Old 12-17-2012, 07:01 PM   #3
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Bought a leak down tester and a compression tester to double check the snap on tester I was using to further more eliminate any valve leaks and ring leaks. This should point me into the direction of my timing be off one link on the crank gear which would make the cam gear be off 1 link each. Crank was set to TDC and cams were at 9 and 12 on the proper links to gears but one tooth off on the crank gear would not be noticeable up top on the cam gears.

After a good comp test before the head was removed there is no way the rings are fuck up, especially is the cylinders are holding air when I put are to it.
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Old 12-17-2012, 07:08 PM   #4
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Quote:
Originally Posted by cotbu View Post
Your engine sat for a long time, my guess is you didn't lube the cylinders and periodically rotate the crank. The reason you hear air at the T, is the rings aren't sealing. The reason it won't start is timing.

Set the mechanical timing with cam lobes facing out, dowel pins at 10 and 12.
You can't really set the cas correctly until the engine is started (in the center is an estimate) when mechanical timing is correct. I suggest you reset mech timing, loosely set the CAS just until it starts, then when warm, set Ign timing to 15deg, lock cas down. Check codes boostleak test and leakdown etc.

Since you have some compression, it'll start. and after a few cycles the rings should be good.

Your friends suck ass!
You are correct on I didn't rotate it, which thinking about it now I should have, but I did lube the walls every 2 weeks or so. I had talked to 3 shops today and all pointed me in the "timing is off direction" the timing chain did hang but knowing my oil pump is new and the dowl pin that keeps the chain from coming off the crank I thought it would be fine.

Thanks for the info. Ill be getting to this as soon as i get some daylight to go over it.
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