Billy, the crank is timed right with the camshaft. My machinist came over sunday to look at it since I had the timing cover off. I have another 292 crank sitting here to look at. He had a hard time believing the crank keyway wouldn't be straight up for timing it.

  Dennis in Lititz PA

We're wired up right. A couple of years ago I had 7 and 8 reversed at the engine, boy does the exhaust really crack loud that way.

  Dennis in Lititz PA

Frank,I too thought the backfiring comes from a lean condition. Could the G heads be flowing that much better that I'm running lean? I'm thinking I need to increase jet sizes. I have .53 in the center and .51's on the outer ones.

I'm sure the intake isn't leaking at the heads, I've sprayed starting fluid around the base using the little straw that comes with a can of carb cleaner.

I'm running centrifugal advance only.

  Dennis in Lititz PA

The 239's don't have a damper, just a pulley with timing marks on it. I'm sure it's timed right.

  Dennis in Lititz PA

Are you determining that it is timed right with a degree wheel?

During my second build of the engine, the cam was almost 10 degrees retarded in the straight up position. That was with the same cam and timing set. Unfortunately, I never checked the previous build so I can't know if it is the crank or cam or timing set that is so far off.

If you're going based on where it was with the old crank, you're probably not timed the same because of manufacturing tolerances. And if you changed the cam or timing set, I can almost guarantee that you are not. I don't know if that could make it bad enough to cause problems, though.


Lawrenceville, GA

Try setting the timing by ear. I'm assuming you know how. Mark the current timing advance point. Then see how close the sweet spot and the timing mark are. Its a quick check. I mentioned earlier that with the increase in cubic inches and other changes you could be running lean. Does it act sort of like a fuel pump going bad? Misses and backfires under load? Chuck

Y's guys rule!
Looking for McCullouch VS57 brackets and parts. Also looking for 28 Chrysler series 72 parts. And early Hemi parts.

MoonShadow, 292 w/McCulloch, 28 Chrysler Roadster, 354 Hemi)
Manchester, New Hampshire

I think I can try that. The engine is running faster at idle now since the spring tension from the other 2 carbs isn't holding the butterfly shut tight.

  Dennis in Lititz PA

Charlie, I used a degree wheel. It took me a long time to understand what I was doing. Every time I did it I'd come up with a different number. I walked away from it for 2 weeks. Then I was getting consistent numbers. I talked with Ted and I ended up using the 2 degree retarded keyway which gives me 3 degrees advance.

  Dennis in Lititz PA

Chuck, the exhaust is too loud to hear pinging. I only ever heard some pinging when I was towing the camper last year. I don't have the blackness on the plugs like when I'd have to change them to race. I must have 8 sets of plugs for the old heads.

I've got through a tank of gas since the end of june, that should have showed up on the plugs.

  Dennis in Lititz PA

Try a Google search of backfire vs afterfire ( popping in the exhaust system) this is caused by a RICH fuel condition from unburned gas in the exhaust. Check the ignition and ignition timing. How do the plugs look? Pete