VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1912-1928 28 Engine Experiment - continued

Hi All,
I wanted to bring you up to date on my 28 engine experiment which now has about 50 miles on it. I had some trouble today and although I was disappointed, I wasn't overly surprised that something like this could happen (note 'experiment' in the subject).

This morning I started the old gal up and let her idle for about 10 minutes before jumping in and heading to the corner gas station. I got about one block from home and noticed the engine lugging so I pushed in the clutch and the engine siezed up. I pulled over to the side of the road and hit the starter. Would not turn over. Engine was cool to the touch. After about 5 minutes, I hit the starter again and it turned over and started right up. No knocking, or other anomalous noises. Oil pressure was fine. I turned around and drove home, no problems.

I switched off the motor and pulled the plugs. I got out the hand crank and the engine turns with ease, no binding. I drained the oil, no visible contamination or foreign particles. I dropped the pan and did a visual inspection, everything looks okay. I pulled the head and examined the cylinder walls, perfectly smooth, no scars.

Now for the question. What next? I am considering whether to lift the motor and pull the crank bearing caps. I don't understand how a cool-running motor with good oil pressure would suddenly sieze and then correct itself after 5 minutes and run happily there after. Maybe I should I be running a lighter oil 5W-30 or 10W-30 for a new motor with inserts instead of SAE30.

At any rate, I am open to your suggestions. It's hard to fix what ain't broke huh?. :confused:

Thanks!
-R

Rusty: I'm no expert but could it be that the problem is not your engine at all. Could be a bad tooth in rear end that stopped the engine. (could be transmission too). When you described "seized up," meaning metal to metal? I found a bolt in the bottom of my tranny? Ricardo :eek:

Hi RustyFender,

Could it be that your problem was a result of the 10 minutes of idleing???

At idle, very little oil is "splashed" around in the crankcase. The two reservoirs for the mains and the wrist pins/cylinder walls depend upon splash oiling. At low idle very little oil is coming in and very little being splashed about.

I recommend you use a multigrade lighter oil. With the inserts, and the closer tolerances you have achieved with modern machining, the lighter oil would be much more appropriate.

Don't know where you purchased the pistons, but I had my engine seize as a result of omission of the oil holes to lubricate the wrist pins. A new piston and drilling the proper holes to lubricate all the wrist pins solved my problem. They had been overlooked in both the manufacture of the pistons and inspection prior to assembly.

I would recommend: change oil to lighter weight, and refrain from prolonged idleing until the engine is well 'broken in'.

Wish you luck with your project.

Hi Rusty,

It sounds like you dodged some real bullets on this one. The only incident I can recall that is even close to this was a newly built Dodge Hemi that seized immediately after a full power run on a dyno. It didn't show any power loss but as soon as it approached idle it stopped with a jerk. The main inserts were virtually welded to the shaft afterward and we had to clean the journals up with the shaft mounted in a lathe. The shaft was not damaged, however. Before tearing it down any furthur I would discuss the problem with the machinist and see if he has experienced such problems with similar engines. In any event I would examine the inserts for signs of turning in the block.

I would also re-read Antique Mechanics message a couple of times. Such items don't seem too significant until they jump up and bite us.

Herb

Just to add a bit to an already confusing story. The problem could be electrical. If the heat caused you to loose a good ground or the positive connection at the battery or starter the engine could run rough without power, stop and not restart. I have had a corroded positive battery terminal do just that on several occasions. My wife was driving both times and left the '68 Caprice Wagon on the side of the road when it died. When I got to it some time later it started right up and I drove it home. It wasn't until after the third time with me driving that it died and I found the culprit.

Thanks everybody for your ideas.

Has anyone tried removing the front and rear main bearing caps on a 28 with the engine in place? It looks like it would require a shallow socket and swivel setup and might be difficult to pull the 100 ft lbs torque on re-assembly.

Thanks!
-R

Rusty, how tight are your rod caps? If you recently rebuilt the engine it is possible your rod caps are overtightened. The bearing surface will get hot and expand causing the cap to seize. Especially sitting there at idle for 10 minutes. If this ends up the problem, the best thing is to loosen the caps until you can tap them with a hammer from side to side. Now I don't mean overly loose. Once the engine is running and warmed up the bearings will tighten correctly. You can also use plasticoat to figure how much to tighten them if you don't prefer using a hammer. You can't go by torque specs in a manual because those are babbitt bearings and no 2 are the same size.