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It's a 54 235 with Roch carb, it idles good but I have a nice popping sound inside the carb. I've checked the timing three times and brought the engine to TDC and the ball bearing was right on the money. I checked where the pointer was inside the dist and it was pointing where I have #1. I then checked my firing order, removed my plugs checked the gap. Everything was good to go. I also pulled the carb apart and built it/ cleaned it. Any help anyone can give would be greatly appreciated. Thanks

ryanb790,

A hung or burnt intake valve will allow the firing cylinder to pop back through the carburetor. If this is happening as the engine idles, I would pull the valve cover and look at the valve train. Adjusting them would be a top priority too! A compression check might turn up a bum cylinder.

Be sure your plug wires are arranged 153624 and that the cap is clean inside and out with no cracks. My guess would be a valve issue. Keep us posted.

Stuart

Start with a valve adjustment. It's possible you've got too little, or no clearance at all on an intake valve, and as the engine warms up, the valve stem grows in length enough to let compression and/or combustion pressure pop back into the intake. A sticky valve will do the same thing. If the clearance is OK and it still pops, pour about 4 ounces of Marvel Mystery Oil down the carb throat at a fast idle until you get a heavy smoke out of the exhaust. Shut the engine off and let it sit overnight. Next morning, start it and goose the throttle hard five or six times. That should dislodge any carbon buildup on the valve stems.

The last-resort fix would be to pull the head and do a valve job.
Jerry

Could be a stuck intake valve. Do you have stale gas. If so, get it out of there. Ty something like Marvel Mystery Oil.

Thanks for the quick response!
Lincoln- the head was just rebuilt. I will check the valve adjustments though. My shop manual says .006 and .016 is this correct. I'll do the mystery oil thing

Crenwelge- There could be some stale gas, it was almost empty so I poured a fresh 5 gallons in it yesterday.

Stuart- it's popping during idle and when i give it some throttle. I pulled the valve cover off and watched the valves and they seem to be rocking pretty good. As I mentioned I just had the head rebuilt with harden seats for unleaded gas.

Sometimes it takes a couple of valve adjustments for a new head job to stabilize. I've seen valve clearances go away pretty quickly and need a readjustment in the first couple of hundred miles. I guess it's caused by the valves and seats establishing their new running relationship. Hydraulic lifters pretty much eliminated that problem with their pretty liberal self-adjustment ability, but solids still need a followup adjustment some of the time.
Jerry

ryanb790,

The chances of a burnt or hung valve are pretty slim if you just had the head rebuilt. A blown head gasket will cause this same thing but is usually accompanied with other telltale signs.

Be 100% sure on your firing order, it's strange how they will magically get mixed up. The compression check could solve this mystery, don't forget it. Good luck.

Stuart

Good news! After running it up to temp, I readjusted my valves and it purrs like a kitten. Slight ticking. Everyone thanks for the help, I really appreciate.
Patrick

Patrick, take it from recent experience, if you've just done a valve job, check the head torque after you’ve run it for a little while it's gonna change and that's gonna change the valve adjustment. I never re-torqued a head after a valve job but I’m a believer from now on.
Denny G

Thanks Denny, I will check the torque.