Thread: C10 w/ 327 lack of power/wacky timing!!!

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To start, I have a 67 C10 short bed. The engine is a 67-327, dual plane intake, new 600cfm carb, HEI, mild cam. Tranny is a 350, rear end has 307 gears and is open. The engine runs great, starts great, idles, seems fine. But with the above set up, from a stop I can't even chirp the tires. Also to go with this is the odd engine timing, At 12-18 degrees the thing won't even run, so I advanced it until it runs good. Where everything is happy is at 45 DEGREES advance!!! I checked it with two different timing lights. So the question is, any ideas??? I didn't rebuild the engine, it was in it when I bought it. I was thinking maybe the timing chain sprockets are off a tooth or so??? HELP!!!!!!!

are you certain that you have the inductive lead on the #1 plug wire? It should be closest to the water pump on the left side. Its actually the closest cylinder to the water pump.

Did you disconnect and plug the vacuum advance line when you timed it?

If you didn't, the engine will be very retarded.

Assuming you have the vacuum advance connected to full time vacuum.

I know of a quick easy way to tell if its the timing chain or not. Timing chains don't usualy JUMP a tooth unless they are streched out a lot. Take your distributor cap off, While watching the rotor turn the crank by hand back and forward. If you can turn the crank any distance in either direction and the rotor not turn then the chain is bad. Just a little somthing I got from playing with these engines for so long. If your engine has the orignal 67 T-chain then it probably is bad. Its only a few hr job.

Definitely on the number one cylinder, double and triple checked. Vacuum is diconnected. Not any noticeable slack in timing chain(thanks for the idea), engine was rebuilt 30,000 ago. Like I said I didn't do the rebuild. I have used two different lights with the same result. Just curious, with this set up, should it have ample power to break the tires loose from a stop???? Everything runs great, just not a lot of power. I've also heard of balancer slippage, not sure what his is.

Harmonic dampeners - also called balancers - have an internal hub, a rubber ring and an outside hub.
The rubber ring is vulcanized to the inner and outer hubs.

When the rubber ring deteriorates the outer hub can slip and factory TDC is lost.

Try another dampener or find true TDC and go from there.

You don't need a degree wheel to find true TDC.
It can be done with a piston stop and a tape measure.

Just don't crank the starter with the piston stop in place or you'll be hearing many expensive noises.

Originally Posted by Rambam

To start, I have a 67 C10 short bed. The engine is a 67-327, dual plane intake, new 600cfm carb, HEI, mild cam. Tranny is a 350, rear end has 307 gears and is open. The engine runs great, starts great, idles, seems fine. But with the above set up, from a stop I can't even chirp the tires. Also to go with this is the odd engine timing, At 12-18 degrees the thing won't even run, so I advanced it until it runs good. Where everything is happy is at 45 DEGREES advance!!! I checked it with two different timing lights. So the question is, any ideas??? I didn't rebuild the engine, it was in it when I bought it. I was thinking maybe the timing chain sprockets are off a tooth or so??? HELP!!!!!!!

It probably won't chirp the tires unless in a turn. The timing issue sounds like a dampner problem. If the timing chain was worn bad enough to jump you would know it. I would look into the timing issue. You can pull the number one plug on the compression stroke and use a piston stop and timing tape to verify TDC. You don't want the dampner to fly apart on you. Mine took out the radiator and it was a $325.00 Fluiddampner.

It is also possible that the timing cover is the wrong one, the timing tab is in a different place for small journal blocks versus large journals. Also, they could have put the wrong balancer on when it was rebuilt. Spinning the balancer ring into the wrong position is not that uncommon. C9x nailed that one.