Bench break-in? Car not ready for driving

thebanjoman

thebanjoman

Senior Member
Now that I have the engine running in the chassis I'm following my instructions for engine breakin. I'm running it at 15 minute intervals and letting it cool down and repeating this process for two hours running time. Then onto 30 minute intervals for the 3rd hour according to the instructions.

I'm months from completing the body and driving the car but I do want to continue properly breaking in the engine.

Instructions say 200 miles, not exceeding 35mph then change the oil.

Now the math comes in.

I should be able to calculate RPMs at 35mph and distance to equal 200 miles and run the engine on the frame for this period.

Do I need to simulate driving by running at different RPMs for this time or would a constant speed be OK, not exceeding the builders recommendations?

Thoughts are that I can multi-task and continue to breakin the motor while I work on the body. I'll still have to make sure my work on the rest of the drive train is good but that can come later.

Good idea?

Bad idea?

I should call the builder but constantly get sidetracked at the office and forget to call.
 
The problem I see with that is not being able to load the engine. When you accelerate, you create higher cylinder pressure and some of the pressure goes under the compression rings and expands them outward. This helps seat the rings quickly instead of glazing them. Chrome rings are the worse, moly and regular cast iron, not so bad.
 
The engine requires a load for proper break-in. Without this load the rings will not seat properly, resulting in improper glazing of the cylinders, which will result in blow-by.
 
DITTO!!!!!

After an initial run in of the cam, apx 15 Minutes, You need to get some load on the engine.

I feel excessive No Load running will do more harm then good.

Definately DO NOT allow the engine to idle for any extended period of time. This can really do harm to the engine as the internal parts do not all receive proper lubrication.

This is MY OPINION!

Chris
 
This string shure helps me also. I need to start up my B engine just to loosen it up but I sure follow your thoughts about putting a load on it. I was figuring of running it for about an hour on and offbefore shutting it down and checking. No car for it yet and still looking for a pickup.
Pete
 
Good opinion Chris! A new engine should be broken in by accelerating from approx to approx 40 under full throttle, and allowed to return to 25 slowly, so as not to pull high vacuum. Repeat 10 times and the engine is ready to go. These are instructions from several ring manufacturers in the past.
 
Glenn C. said:
The engine requires a load for proper break-in. Without this load the rings will not seat properly, resulting in improper glazing of the cylinders, which will result in blow-by.
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Makes sense,

I'll continue to follow the builders instructions up to the 3rd hour and then refrain until I can properly load the engine.
 
O.K. just curious here. When I got my engine running we let her warm up and cooled her down and did the retorque thing twice. Then I just got in her and drove her around the block a few times not exceeding 25 mph. Then I bumped the speed up to 30 mph for awhile and kept her there. I finally got her up to 40 and backed her down to and drove like that for several miles. I put about 25 miles on her that way going up and down and constant driving. Nothing hard but I got her out and about.

My question is this. Who comes up with these break in instructions? Are they using Ford's original instructions or someone elses? Are they instructions from the 50's/60's?

Mike
 
1930 Artdeco, I learned it from several old time mechanics that started in the 20's and worked their whole life as mechanics. I have seen engines that were driven too easy at first that acted as if the rings had not seated. I honestly believe if you put on enough miles they would be bound to seat in eventially.
 
Richard in NC said:
1930 Artdeco, I honestly believe if you put on enough miles they would be bound to seat in eventially.
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These blocks get hard with age and usage. Sometimes, If the rings are not properly seated, the cylinders will glaze and then the rings never really seat in.

It is also very important to NOT use synthetic oil, especially during break in as the rings may not seat at all. Load on the engine will increase combuston pressure which loads the rings out against the cylinder walls. This is what helps to seat the rings.

Do not run the engine at WOT or very high revs during break in but drive the car at light to med loads and up a few hills. DO NOT overheat the engine or allow it to just idle.

This is how I have been doing it for more then 50 years.

Chris
 
I have always been told ( over the last 25+ years ) that best break-in is done on the road, after car has run at fast idle for five-ten minutes to check for leaks & other issues, then run down the road, with periodic acceleration in high-gear followed by off-throttle deceleration, which "loads" the rings against the cylinder walls, and helps them "lap-in" with the cross-hatched honing pattern in the bores. After about an hour's operation, the honing marks are pretty much smoothed-out, and little additional ring seating takes place.

All that said, I have also read pre-Depression auto service literature ( such as the Dyke's Manuals) that talk about "running-in" a fresh motor in the shop, either from a line-shaft or an electric motor... this is supposed to run-in and burnish the babbit bearings without destroying them... I wonder if they did this before honing the cylinder bores and installing the rings, or on a completely assembled engine ?

Anybody know ? Herm ?
 
Years ago, in Britain, one would occasionally see a sign on the rear of a car that read "Running in, Overtake". It seems best to drive normally, but not at high speed, until run in.
 
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