The Stovebolt Site Forums The Shop Area Engine Shop mysterious 235 behaviour

Dear Stovebolt Comrads, I have a 1953 3600 that I have driven and kept running for my entire working life. About 30 years ago I replaced the original engine with a rebuilt 235 that I took out of a '50 sedan automatic. It ran well until about a year ago when some teeth broke off the bakelite timing gear. Bent several pushrods in the process. I had the head completely rebuilt and replaced it along with new pushrods and replaced some worn lifters. Also new ignition components and factory rebuilt carburetor, set ignition timing. I was expecting wonders when I started it up. Instead... no power, blackened tail pipe and plugs, awful gas mileage, bad oil burning , and gradually declining compression and vacuum. I thought I may have been been a tooth or two off on the timing gear, took the cover off and that wasn't it. Valve and ignition timing were in sync. I was hoping one of our vast fraternity might have some insight into what the heck happened.The old 216 that I took out 30 years ago is still lying on the barn floor. If all else fails I'll have start from scratch on it. Thanks, DaveB4

I'll swag a couple things together are causing your problems.
1) blown head gasket. A compression and/or leak down test will verify the innards.
2) Carb float not adjusted right. I know you said factory rebuilt carb but that doesn't always translate into a carb thats 100% ready to go. What carb do you have?

Sometimes it's all too easy to misadjust the valves after a Head R&R. Triple check your adjustments to make sure they are fully closing and not being held open. Also possible that whomever rebuilt the head didn't put those little seals on the valve stems. Without them you could get alittle too much oil into the cyl when running.

Good luck

Factory
Rebuilt
Carburetor

I'll make a pretty large wager you have an incorrect carb for the 235 engine. If it happens to be calibrated for a 216 instead of a 235, it will run very rich, and if the power valve happens to be stuck in the open position, you will use massive amounts of gasoline and have very low power. Do you still have the carb it was running before the head rework?
Jerry

I have to comment on the great history that you have with your truck. That it is and was your working truck for the last 30 years is just awesome. I hope that it serves you for many years to come!

Thank you Truckernix, HotRod Lincoln, and Volfandt. Actually I've been driving tnat truck to work and wherever I had to go since 1972. I will check out the carburetor. I still have the old carburetor but it had it's own peculiarities. Do you think enough carbon might have formed in the cylinders to prevent the valves closing all the way? Your's, DaveB4

Just a stretch here - you said the engine was originally in a powerglide car - and that you replaced the lifters when you had it apart recently. Is it possible this was a hydraulic lifter engine and maybe you put solid lifters back in it by mistake? This would have profound effects on the valve timing which would affect all of the symptoms you describe.

There's an old carbon removal trick that I'll just mention (not necessarily recommend) that involves running the engine at around 1500-2000 RPM and dribbling a Coke bottle full of HOT water down the carburetor throat a little at a time. It supposedly steam-cleans carbon out of the combustion chambers. I've had mixed results with it, but engines I tore down after the procedure did have pretty clean combustion chambers.

If lifters were worn, there would have been corresponding wear on the camshaft lobes. Rig up a magnetic base dial indicator on the adjuster side of the rocker arms and compare cam lobe lift from one cylinder to another. Intake and exhaust lift numbers will probably be different, but all the intakes and all the exhausts should match closely with each other. If you're still running hydraulic lifters, it might be necessary to remove the rocker shaft assembly to get an accurate measurement of cam lift, since valve spring pressure could cause the lifters to leak down during the lift measurement process. When I was building race engines I had a pair of solid lifters with tall extensions for the dial indicator to contact when degreeing cams- - - -solid and hydraulic.
Jerry

As a youngster working in a gas station we were told that slowly pouring a can of STP down the carb while the engine was running was a cure-all for a number of things including carbon removal. I did this a number of times because we got 25 cents for each can we used. In retrospect I think the only we accomplished, besides selling STP, was creating enough smoke that it looked like the whole gas station was on fire.

STP- - - - -the answer to a bunch of nonexistent problems! I used to use it for engine assembly, until I realized every engine I built with the stuff was having premature, oil system related failures. I built one more engine, just to convince myself I was over-thinking things. WRONG MOVE!
Jerry

Worked on a friends 63 Ford pickup with a 223 engine and single barrel carb this past summer. It too had no power, and was blowing black smoke out the tailpipe. Disassembled the carb. Everything was clean inside it. Checked the float setting, it was way off. Reset it, reassembled the carb. Problem solved.

Rick

My dad was a Ford Dealer mechanic when Ford
switched over to OHV engines in 1954. They hadz problems
with the engines carboning up. The Ford factory rep told
my dad to get the engine hot then slowly poor a bottle
of hydrogen peroxide down the carburetor. I saw my
dad do this a couple of times when he was working on
a car as a kid. Jeffrey

Casite used to make a carbon blaster treatment they called "P.D.Q." It was used by attaching the 8 ounce can to the carb inlet with an adapter block and blocking off the incoming fuel line. Then the engine was run at a fast idle on the contents of the can and repeatedly snap-accelerated. The engine would cough, snort, and rattle, sort of like the worst case of detonation anyone could imagine. Huge clouds of carbon would fly out of the tailpipe!

In the early 1950's our family race car ran on an alcohol/Hydrogen Peroxide mix, but instead of the 2% by volume peroxide used for first aid, Dad used technical grade stuff at 20% concentration. It was so corrosive he used a stainless steel pony keg for a fuel tank, ran stainless fuel line all the way from the tank to the carb, and ran the carburetor dry between races to keep from eating the bottom out of the float bowl!
Jerry