The Stovebolt Site Forums The Shop Area Engine Shop 235 not cranking

I have a 1955.1 3100 with a 235 inline six. I drove her around the neighborhood, pulled into the driveway and shut her off. The next day I went to crank her up and she made a noise like somebody threw gravel in a blender. I had my son come out and crank her over, while I was under the hood, looking things over. When he tried to start her, there was no noise, but she didn't start. I verified that fuel was getting to the carb. I then pulled the distributor cap off and had him try cranking her again. This time I heard the noise again and noticed the distributor wasn't rotating.

So since I am only a YouTube mechanic, I have decided to get some thoughts and advice. I looked online and found this forum. So here I am to collect and advice and thoughts you all care to provide. My initial thoughts are gloom and despair. It sounds like the gear on the distributor may have broken, If that's the case, what's the possibility of being able to just replace the distributor? If it broke, does that mean I have a bunch of metal that I now have to get out of the engine? Are we talking just dropping the oil pan, cleaning it up and put it back in place? What's the odds the cam gear is broken as well? How do I check, bore scope?

I have not pulled the distributor yet, it' just too cold out. But the next time we have decent weather, my plan is to pull it out and have a look. Which brings me to another point, what do I need to know about pulling the distributor? The oldest engine I had before this was a 1968 327. It had one screw holding the clamp that held the distributor in. Not sure on this old girl.

Thanks in advance for any help.

BH

Could be a couple of things but might be that the fiber cam timing gear may have self destructed. That would explain the distributor not moving because the cam is not moving. It happens, and when it does it can sometimes cause the intake valves to hit the piston bending them so I would not try to start the motor any further until you sort out what is going on. Its a big pain though because to check the timing gear as you have to pull the pan to access two bolts that secure the timing cover and are only accessible by removing the pan.

I think Mike is right. You'll also have to remove the cam and that's a little involved, too.

Pull the valve cover and have your son spin the starter while checking to see if the rockers are operating. If the cam gear lost some teeth you'll see problems with the rockers.
Unfortunately as has been suggested that's what it sounds like but always check 1st. No need to go deeper than necessary.
Good luck
Dave

BH,

What is the engine serial number for your 235?
It is stamped into the block on the "ledge" to the rear of the distributor.
That will ID the engine as from a car or truck.

I think that the fibre timing gear was used on passenger engines and the truck engines had aluminum timing gears?
Nonetheless, the timing gear might be your problem.

Group 0.736 GEAR-SPROCKET, Camshaft Timing

I suggest before you take anything apart is verify if the starter is spinning the flywheel. Was the crank spinning when you tried starting? You said the distributor was NOT spinning, so that could mean a few things. A) The distributor gear is broken, or B) The timing gears are broken. Answer that and then you will know where to go searching for the broken link next. If neither the crank or dizzy are spinning, then may be the starter or ring gear on the flywheel are bad? Good luck!

Thanks for all the feedback. Snowing here and expect freezing rain and rain through Sunday. I will try and get the serial number to the engine, and verify flywheel is rotating.

BH

I'm old school but I think a good check of the engine actually turning over via the starter is a viable option here. Its rare but not uncommon for a distributor gear roll pin to shear. These old birds are pretty tough. I would definately check to see if all that grinding is coming from a bad starter or even a solenoid thats frozen and the starter is spinning with no load. How cold is it there?

Good Luck
RK

RK - It's been in the high 20's at times. Currently snowing with around 4" on the ground. Since I don't have access to the wifes garage I work outside on her.

Here is the thing, and why I would suggest not starting with the starter. I agree, its possible the distributor gear broke apart. In all the years and all the early 6 motors I have ever messed with in 42 years, I have never seen that happen. But no way would I ever say I have seen it all, lol. However, If the cam gear is a fiber gear, and if it did come apart, the cam will maintain the valves in whatever position they were in when the gear let loose. If any of the intake valves were open, using the starter to rotate the motor will cause the piston to come into contact with the intake valve instantly bending it. that may have already happened, but if not, no sense in causing any further damage. I would probably just pull the valve cover, then all the plugs, and then turn the motor over by hand at the fan, or at the flywheel with a flywheel turner. If the crank turns but the rocker arms are not moving then its the cam.

Dragsix, that is exactly what I will do.

Hang on, lets start with the simple stuff before we pull cams, and valves..........

Check the connections of both ends of both battery cables. Are they sound and free of corrosion? Is the starter connections clean too? Often times when we try to wake a truck from a long nap the battery cables are a mess. If they are, nothing will happen when you try and start the truck.

How fresh is the battery? is it fully charged?

I have a charger on the battery. I will go over the cables as well. I assume it was good since I started the day before and it was turning over when I try to crank her now. My son reminded me that the fan was turning when we tried to crank it. Just some additional information, hopefully helpful.

BH

BH,

"My son reminded me that the fan was turning when we tried to crank it."

If you have an original style fan/belt, it turns when the engine turns; and, the engine turns when it is cranking on start-up.

Do you mean that the fan was turning before you cranked the starter/engine?

They key was in the on position, and when I stepped on the floor starter, the fan began to turn. Am I answering your question? I believe it's all original as far as fan/belt is concerned.

BH

Good, the fan should turn as soon as the starter starts turning the engine.

That means your starter is turning the flywheel. That's good. Pull the distributor cap and see if you can turn the rotor by hand. If you can then it's time to pull the distributor and investigate further. Hopefully it's just the roll pin holding the gear on. Next step would be the removal of the valve cover and see whats going on with the valves when turning the engine by hand with the spark plugs out. Good luck.

Good copy on next steps. Pull distributor cap off and try to turn it by hand. Pull valve cover, turn engine by hand no plugs an see how valves react. If I disconnect the battery, do I still need to pull the plugs, or is there another reason to pull the plugs?

Takes all the compression away making it much easier to turn by hand.

Doh! Makes sense. Thanks!

I can lead you to the water . . . , lol. Yes, as above, makes it much easier to turn the motor over by hand.

Here's one possible source for the noise- - - -the camshaft has some flat spots between lobes for connecting rod clearance. Yes, it's that close down there at times. If the cam isn't turning due to a stripped timing gear, it's possible the rods are hitting the cam as the crankshaft spins. Is the 235 actually an "interference" engine where pistons and valves can come into contact with each other? I sort of doubt it unless the head has been milled and/or a high lift cam has been installed.
Jerry

Yep, it’s an interference motor. In 85 I had rebuilt a 235. Got a bad timing gear set where the dots for tdc no. 6 were mismarked, badly mismarked. I was using a stock sealed power cam (which did not come with a cam card) and did not put a degree wheel on it to confirm the opening and closing events. Tried to fire that motor up and promptly bent all 6 intake valves. I keep the receipt to remind me of why I use degree wheel, even on my stock rebuilds.

I came down with a sinus infection, so no work done this weekend.

ok, the antibiotics are doing their job, and I am feeling a lot better. Today the weather was good enough, that I had no real excuse not to get out and pull the distributor. As you can see by the pictures, it's as I suspected. Two teeth completely missing, and two other teeth missing half. I was able to pull one tooth out with a magnet and one, half tooth.

Can I get away with just replacing the distributor and hoping for the best? What's the odds the cam gear is shot as well? I am looking for opinions on how to move forward.

Thanks,
BH

P.S. I tried to get a couple of different angles, so you can see the extent of the gear damage.

See if you can shine a light down and see if there is any visible damage to the gear on the cam shaft. Maybe rotate the motor by hand to make sure you can see all of the gear teeth.

The only number I can see on the block are top right of distributor

B35 913
241
570

Something caused those teeth to shear off, and the most likely culprit is the oil pump. At a minimum, I'd suggest spinning the pump with a cutoff straight blade screwdriver shank in a 1/2" variable speed drill motor, and/or pulling the oil pan and the pump for a detailed inspection. The broken gear just might be the result of another failure, not the primary cause. The cost of an oil pan gasket and a couple of hours of labor time might be cheap insurance.
Jerry

Another possible cause of the distributor gear failure could be from a mismatch of the distributor gear and the camshaft gear. There was a change from cast to forged camshafts at some point in time for Stovebolt engines. The distributor gear material changed at the same time. If someone just threw a random distributor into the hole just because it fit may have caused the mismatch and resulting failure.
Carl

BigHog, look for a machined pad just aft of the distributor and sort-of behind the dipstick. There should be a stamped engine serial number on that which will help ID specifically what the engine is. The casting number that definitively IDs the block is low on the passenger side, between (and below) the distributor and fuel pump, and is usually obscured and hard to read (so the stamped engine serial number is the next best thing). There will also be a cast-in date code (in the form of something like E 10 5, which would decode as May 10th 1955, as an example) on the passenger side, just above and a little in front of the starter.

If you can ID the engine, that will help with a few questions, such as fiber vs aluminum timing gear and whether the cam is cast iron or steel, and what distributor gear should be used to match (as well as what the distributor PN should be, which is stamped on the breaker plate). For example, if it's a '55 235 first series truck engine and not modified, it would have a cast iron solid lifter cam (not the early steel cam, and not hydraulic lifter), and would have a Delco 1112388 distributor, per the parts manual. Hope this helps as you get farther into determining what caused the distributor gear to fail.

But, I'll echo some earlier comments - I've never seen a failed distributor gear in a 216/235/261 before your photos, and even in very worn distributors, the gears generally look fair to good, with some wear patterns visible. I'm thinking, similar to Jerry, that something had to have seized or nearly seized on the distributor/oil pump side of the distributor/cam gear combo to have the distributor gear shatter like that. Normally, there isn't a huge amount of resistance to rotation. Can you easily turn the distributor shaft in the distributor body, now that it's out of the engine? It should turn with light resistance. If that turns freely (and the shaft isn't so worn/loose that it might tilt and bind), then I think Jerry probably hit the nail on the head. I know it would mean the pickup screen would have had to fail, but perhaps something hard was sucked into the oil pump, locking it?

Forged (or machined) steel cams need to run steel or bronze distributor gears. A steel cam will machine away the teeth of a cast iron gear, not cause the teeth to break. Check the undamaged teeth (if any) on that broken gear and look to see if they're heavily worn. If not, something has locked up either the distributor shaft or the oil pump. I'm betting on the pump. However, something in the centrifugal advance system under the breaker plate could have come adrift and jammed the distributor.
Jerry

Been a while, so here is the update. The cam gear look good, and the oil pump was good. So I replaced distributor, points, condenser, rotor, and cap. She is back up an running. That's all for now. As the weather gets nicer, I plan to do more, just not sure what I will tackle next.

BH