timing issues
dirtdriver11
09-30-2008, 09:31 PM
I got a 350 sbc in a hobby stock race car. I replaced the timing chain and gears. The crank gear has the 3 slots for advance, oem, and retard. The first time I put it in the oem slot, and my timing mark on the harmonic balancer was pointing towards the driver's side fender. The motor sounded good, but I had no way of timing it. I tore it all apart again, but this time I put it in the advanced slot. The car won't start and makes a pop sound out of one exhaust and then the other. Tried turning the distributor, but that didn't work. Took the distributor completely out and turned it 180 degrees, but no change. Any suggestions, I'm lost!
Thanks
Chris
Thanks
Chris
MrPbody
10-01-2008, 08:05 AM
You must "degree" the cam. Install the cam with the crank gear on the "O" or "straight up". The marks should both be a 12 o'clock. This insures no.1 cylinder is up on compression, not overlap. "Dot to dot" will make you up on no.6 compression. Install a degree wheel and follow instructions on the Comp Cams website for degreeing. You'll need the cam "card" or the intake centerline information.
It sounds like you got it way off the second time. Don't feel bad, it happens. If "degreeing" is not a viable optoin, at least make sure the marks are at 12 and 12. Then you can drop you distributor in pointing at no.1 wire. Verify your firing order (1 8 4 3 6 5 7 2, clockwise rotation).
It's possible your balancer has "slipped" as well. While not as common as you might hear, it DOES happen. That would explain the timing mark in the wrong place. A "piston stop" and a degree wheel are used to verify true TDC.
Jim
It sounds like you got it way off the second time. Don't feel bad, it happens. If "degreeing" is not a viable optoin, at least make sure the marks are at 12 and 12. Then you can drop you distributor in pointing at no.1 wire. Verify your firing order (1 8 4 3 6 5 7 2, clockwise rotation).
It's possible your balancer has "slipped" as well. While not as common as you might hear, it DOES happen. That would explain the timing mark in the wrong place. A "piston stop" and a degree wheel are used to verify true TDC.
Jim
dirtdriver11
10-01-2008, 08:14 PM
Thanks,
Thought about the balancer slipping, but it seemed tight when I tried turning it by hand and it all looks to be in good shape. Could it have still possibly slipped? This is the first time I've tried changing a timing chain. I don't really know anything about the motor, it was in the car when I bought. All I was told was it had a mild race cam from Speedway Motors, I think it is also hydralic cam and lifters. I don't have the knowledge to tear it completely apart or the money to have it done. I have one more question, should the key way on the balancer and the timing mark be in line with each other or is there a way to tell if it has slipped? Thanks again.
Chris
Thought about the balancer slipping, but it seemed tight when I tried turning it by hand and it all looks to be in good shape. Could it have still possibly slipped? This is the first time I've tried changing a timing chain. I don't really know anything about the motor, it was in the car when I bought. All I was told was it had a mild race cam from Speedway Motors, I think it is also hydralic cam and lifters. I don't have the knowledge to tear it completely apart or the money to have it done. I have one more question, should the key way on the balancer and the timing mark be in line with each other or is there a way to tell if it has slipped? Thanks again.
Chris
MrPbody
10-02-2008, 08:30 AM
Chris,
Just "eye-balling", it appears the keyway in the balancer is directly lined up with the TDC mark. But... Balancers vary, as some have timing marks on one side, others on the opposite. The one I'm looking at has the timing mark at TDC when it's on the driver's side (right side, looking directly at it).
Jim
Just "eye-balling", it appears the keyway in the balancer is directly lined up with the TDC mark. But... Balancers vary, as some have timing marks on one side, others on the opposite. The one I'm looking at has the timing mark at TDC when it's on the driver's side (right side, looking directly at it).
Jim
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