The Stovebolt Site Forums The Shop Area Engine Shop 1962 Chevy 235 car engine in my 1942 truck - out of "time" ?????????

I have a 1962 235 Chevy car engine in my 1942 Chevy truck that is out of time now.Last fall in the process of putting it away for the winter the truck was running veryy rough but I though because of the cold weather that was the cause also maybe I did noy let the engine warm up enough.I find this spring it is still running very rough and now back firing all the time my guess it some how it got out of time.The only thing I found was the coil on the motor has some oil dampness will relpace that and see if makes a difference. Also does the 1962 Chevy engine have a timinig gear or chain???? I would appreciate if someone would call me I may have more questions.Thanks for any help!!!!!!! 1-262-392-2989 or mribbich@wi.rr.com

The 1962 Chevy 235 would have had a timing gear (fiber) driven by a smaller crankshaft gear. Knowing the design as I do, it is nearly inconceivable to me either of those gears could have jumped a tooth or two. At least I'll say in 60 years I've never seen this happen, although I have seen a couple of fiber gears break and when that happens often a couple of even more serious problems follow.

If there is any way to remove the radiator and gain enough access to the front of the engine, you could remove the harmonic balancer (you'll need a puller), remove the front cover (you'll need also to remove the oil pan as it is likely you'll have 2 bolts/nuts that can't simply be unscrewed from the front...the two at the bottom) and rotate the crank by hand until you can see if the two dots...one on the cam gear and one on the crank gear...line up. But I wouldn't do this yet. A backfire is simply a spark plug igniting fuel at the wrong time...usually in the intake manifold or the exhaust manifold (which actually should be called something like after-fire but many folks still call it backfiring)...that is to say unburnt fuel is being ignited at the wrong time. Could be a valve stuck open or not working correctly. Could be ignition timing but if it is that far off, often the engine won't start at all.

Remove the valve cover and start the engine. See if all the rocker arms are working and if the valves are also opening and closing. Check your manifold vacuum with a gauge. If you have a valve sticking open or not closing, you'll see it clearly. The needle will drop every time the event occurs...vacuum fluctuations of a couple of inches could indicate ignition or ignition timing trouble and fluctuations of 4 or 5 inches could indicate a sticking valve. Let's start there and see where we go.

I would check the static timing first. Trace the number 1 plug wire to the distributor cap. Get a silver sharpie and make a verticle line on the distributor body directly under the center of the no. 1 plug wire tower.

Pull the plugs. Hook up a remote starter switch if you can, if not, just use the starter button or ignition switch. Cover no. 1 plug hole with a finger. Bump the motor until you feel compression. Then grab the fan and belt and rotate the motor counter clockwise, little at a time, until the bb on the flywheel is right at the pointer on the bell housing.

Now pull the cap and see if the rotor is pointing at the silver line you marked on the body. If not, loosen the screw on the octane selector plate, not the hold down bolt, and rotate the distributor until the rotor is aligned with the sliver mark. Tighten the screw. You are pretty close, if not exactly on, TDC.


Look at the plugs, if carbon fouled or oil fouled you need to clean and regap them. If they are clean, check the gap just to be sure.

Next, rotate the motor by hand if necessary, so the rubbing block on the points is on the highest point on the distributor lobe. Check the gap and adjust if necessary.

Install the plugs, cap and wires. Now you can start the motor and check final timing with a timing light. That will at least answer the question of timing.

I suggest that since the engine does run (though rough and spitting back) that you start with the basics before tearing in, I’m sure others can add a few more “non invasive” things to check before going in. You may get in there soon enough but observation, checking settings, and being METHODICAL is a sound approach to chase any problem, less expensive too᠁

The coil if looking leaky is certainly high on the list to replace, fresh gasoline alway a good idea after sitting

My list follows (choose the order and feel free to add items):

-are we getting good fuel supply? And air supply?
-sequentially pull each spark plug wire to check for idle drop and check for spark from each wire (inspect spark plugs and check gaps)
-inspect/(file)/gap the existing points (I’d use dwell meter if available) inspect rotor and cap
- use timing light to set timing (preferably one with programmable advance)
-compression check

After that I would probably pull the valve cover to check valve lash, and observe valve operation (when was that done last?)
Complete Tuneup with known good condenser
After this I think you will have solid information, or questions᠁.

Chuck

Are you available for a phone call this evening? I can walk you through some basic diagnostics in a short 2 way conversation that will make more sense than multiple pages of forum talk. I'm homesteading a motel 500 miles from home with nothing better to do than shoot the bull with another stovebvolter! LOL! I'm picking up about five stovebolt engines and a stash of parts early tomorrow morning, then I'm headed back to Tennessee.
Jerry

Jerry
Send me your phone number and a good time to call Central Standard Time. Thanks!!!!! mribbich@wi.rr.com

Marv.

PM sent.
Jerry