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O.T Breaking in rebuilt engine

dman

Cast Iron
Joined
Feb 17, 2005
Location
NorthEast
I just got my 500 cadillac engine back from the rebuilder.I had it in my 1 ton and it served me well for many years.I use it to tow only and was looking for opinions on breaking it in.
 
Drive it around town for a couple of days, change the oil and filter. Then drive it like you stole it. I am of the opinion that lengthy break in periods server no purpose at all given modern ring and bearing materials.
 
Whenever we have rebuilt an engine we ran it for about 5 miles and made sure everything was working like it should. Then we would hook up to the jet boat and pull it up the hill (6 miles one way) a few times. Just don’t overheat it. And change the oil after about 500 miles. Friends and I have done this with many rebuilt and new pickups and have had powerful trouble free engines that last a long time.
 
I would ask the rebuilder what is the reccomended procedure. They are the ones that know what type of rings were used, what the cross hatch pattern is, and what finish they put in the cylinders. In piston type aircraft engines, the procedures vary depending on cylinders and ring materials, but generally speaking, you want fairly high combustion pressures on the rings for a while. We used to use straight mineral oil in our aircraft engines until oil consumption stabilized, and the switch to whatever the application warranted.
 
On initial start up, run at about 1500 RPM for 15 minutes or so, introduces cam and lifters to one another.
Then a top gear full throttle roll on from a low speed to about 60 - 70, then coast(in gear) to a slow speed.
Kinda seats rings.
I always wanted to stuff a 500 into a pickup, should be a torque monster.
 
Don't baby it, but don't abuse it either. Vary the engine load and engine speed frequently. Modern rings seat very fast.
 
I would add...Drive it 50 miles. Then change the oil and filter. Next oil & filter change at 1000 miles. Then onto your normal schedule, 3K to 4K or whatever.

I am a proponent of doing just normal city & highway driving, maybe use it to run errands and to work & back for a week. Then onto whatever you are planning to do.

My feelings on a hard fast break-in are that you get a loose engine that way which produces power but isn't a hi-miler. I recognize the differing schools of thought, though.

-Matt
 
I'll bet that thing pulls like nobody's business. I was going to stuff a 500 or 472 Caddy into my Step Van, but since I would have to swap out the tranny I decided against it. I wanted to keep the old heavy duty cast iron three speed manual for towing. Unfortunately, a manual Caddy flywheel doesn't exist and that's something I am just not comfortable making up (bang and there go your ankles, legs, or whatever is in line with the plane of rotation) and the crank has to be bored for the pilot bearing (not really much of a problem, either but just more hassle). I can get a custom made flywheel for $500, but that's probably more than the van is worth. Maybe the next truck I get will be a 400TH tranny so it will be practically a bolt-in.

The later 472 in the Coupe and Sedan DeVille actually had more torque than the big 500. I was going through my 66-73 Chilton manual and the 72-73 472 is rated at 565lbs/ft at 2400rpm! Funny thing is that the engine is rated 220hp at 4000rpm. It's putting out 260hp at the torque peak of 2400rpms!!! Add to that the fact the Caddy engines don't weigh much more than a small block Chevy and you have a killer towing motor.
 
........Never bought a rebuilt engine, but those I've done I'd coat the cam with EP moly grease, and then pre-oil using my granfather's old Milwaukee 1/2" drill motor driving the oil pump, until I had a good flow at the lifters.

Since it was all Ford and Chevy stuff, getting junkyard valve covers was no problem and these had a window cut down the center for rocker arm adjustments. After the distributer was put in I'd turn the electric fuel pump on to fill the carb.

Crank it up and run it at 1500-2000 rpms to keep the oil pressure up for 10-15 minutes. I used a 20wt oil. During this time the rockers were adjusted, and the radiator was topped and capped, and the valve covers replaced. Then it was take it out and drive it for awile with some moderate acceleration from stops, and a 10-15 minute trip on the freeway. After that it was drain the oil and replace it and the filter. I would watch my P's & Q's with it for 500 miles or so.

I guess it was in the early 80's I had a magazine with several articles in it and one featured the big Caddie engines in pickup for tow duties. Since they were designed to haul around big luxury automobiles, which was more or less cruising operations, they werent' really designed for performance. Mainly they loafed through life.

The article dealt with performance operations you could do or have done. Since ALL engine blocks are basicly the same thing (pumps), the performance aspect for any of'em comes from the heads. Naturally also parts associated with the head, ie: cam, intake-exhaust, and valves.

There was information of mods to the stock heads, and also oiling improvements. However there was a company that specialized in performance parts for the Caddie and Lincoln engines. I thought big block Ford parts were expensive :D ! I suppose the crowd doing these mods was very limited, but you could sure get some impressive HP and torque numbers from those big cube gas engines.

They featured a highrise aluminum intake manifold that looked about as big as my porch as one of their performance mods. It retailed a bit over $400 at the time.

Rick
 
I worked on cars professionally for 24 of the unhappiest years of my life before I wised up and got out of it, and I learned a few things. One is that a properly put together engine needs no break in except to maybe run it at a fast idle, say 1500 rpm, for about a half hour, and no amount of babying an improperly put together engine will save it from an early demise.
 
Jim and Pete are both right, Different boring methods produce different ring seating periods
but unless you prelubed the engine via the oil pump before starting it you have already started to create wear on everything.
Start it up make sure you have oil pressure run it the 10 minutes or five miles under normal load
then change the oil and filter.
 








 
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