Newly Overhauled Engine Somewhat Tight

wascator

Member
Hi, is it normal for a rebuilt engine to have a lot of drag at first? It seems to come from the rings, as the crank would turn nicely prior to installing the pistons.
I rebuilt an Allis-Chalmers B about 20 years ago, and the engine was so tight the starter would not crank it over. I could pull it through one compression with the hand crank and it would fire but it seemed to not have enough power to start running. I finally got frustrated and pulled it and started it. It ran great and very quickly loosened up so that the starter would start it nicely. It has run fine ever since with no problems.
Now I have a Lincoln welding machine, 1956, with the Continental engine, and it feels exactly the same way.
Is there anything I can do, like rig up a way to turn it some, so that it will loosen up, or is this necessary? Since I can't tow-start it, I wonder how I will ever get it started.
 
yes.. it's a bit normal to have more drag on a new rebuilt engine than a sloppy worn out one.

did you use assy lube?

did you plastigauge it to make sure the crank and bearings are matched up and correct clearance.

ring end gap correct?

you can run it over a bit with plugs out to cut the 90-130 psi compression to help turning it over.. parallel up some bats to help.. if it is 6v jump it with 12v.

run it with plugs out till oil pressure comes up.. then put em in and jump with paralleled bats / 12v bat on the 6v starter, if it is 6.. etc..
 
I don't know if I'd call it normal,but I've had to do it. Just recently in fact. I just overhauled an Oliver Super55 gas. I wouldn't even roll just towing it,I had to use the starter at the same time. After it started and ran for just a minute or two,it started right up with the starter without a problem.
 
Yes, all measurements were made and are correct. A well-qualiifed shop did the crank, which needed a polish only; installed bearings, cam and new bearings. Engine turned very freely until the pistons and rings were installed. Everything torqued correctly. Assembly lube, etc.
It's just amazing how much drag rings create until they wear in a little.
 
It is a something that adds up. The bearing have some drag then you add the cam and the pistons and rings etc it all adds up to a point that yes it can be hard to spin one over. As long as all parts including the rings are lubed like they should be all will be ok as long as the oil pressure comes up also
 
Did yo use Engine Assembly grease on all moving parts prior to installation?
Did you check your ring gaps before installing them on the pistons? Ring Gap is a big item!!!!
 
Hi
I had this argument with a know it all guy that worked in a local shop once. He said an engine if its done right should always start first time with a battery. I called BS and walked away.

6 weeks later he had done a motor, I was in there and he had flattened 5 new batteries and was boosting the last one. I told him if he towed it it would start in 10ft or less,the shop owner heard me and he told guy to do it. 8ft and it ran like a watch, stopped it after a few mins and fired next time with the starter. 1 in 10 I do wont start and we tow them first time, so this can happen from my and dads 50 odd years experience.
Regards Robert
 
I remember installing the pistons in this engine (Continental F-162): I did not have to drive them in or anything like that, but there was significant friction which obviously came from the rings. The oil rings are the type which use an upper and lower thin ring with an expander behind. They are designed to wear in very quickly. I checked the end gap of each individual ring in the bore where they were installed, but as I recall there is no end gap on these oil rings.
In short: I am not surprised at the amount of friction in this engine, given my experience installing the pistons.I've barred it around probably 25-30 revolutions, timing the magneto, etc. It has compression in each cylinder, and it does not have any particular tight spots. The block was bored and honed, and the crank was inspected and polished, in a professional shop long in business and of high repute. Since I can't tow-start a Lincoln welding machine, I wonder how I'll ever get it started.
 
If the starter, connected normally, with a charged battery will not turn it over then something is wrong. It can take quite a bit of effort with a bar to turn over a new engine.

If you still have the pan off, make sure the rods are not binding. The rods on my 44 were not reconditioned correctly, and caused it to bind. I got them fixed and it is fine.

What did you gap the rings to?
 
I'd be concerned about the end gap on the oil rings. The expander may not be in right or the thin rings not sitting right ?
I also go thru and check out the starters,alt. or gen.,water pumps & radiators on any engine job I do because the engine is going to crank harder and run hotter then when worn out.

I can't say as I have ever had trouble starting a fresh rebuilt engine. I crank them up without spark plugs or injectors to get oil pressure first too. Also use engine assy. lube on them when going together.
 

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