Roadster62
Well-known member
Just wondering about the breakin in instructions on a rebuilt Model A engine. Seams like a long drawn out process, what did Henry have to say back when the A was new? Bob
REBUILT Engine BREAKIN
- Thread starter Roadster62
- Start date
Barry B./ Ma.
Well-known member
I started and ran mine on a test stand for several startups and retorqued the head, installed it in the car and ran it not more than 35mph for 500 miles never lugging it down or over revving it.
H. L. Chauvin
Well-known member
FWIW, many conflicting opinions on break-in; but just one (1) humble opinion based on experience with Model A's.
Remember for Ford's recommendations, in the early 1930's, it was a precise new car's engine with everything new; today, 80+ years later .................... it is now a rebuild.
If after exercising just a little care to avoid over abuse for about 500 miles after an engine rebuild, if one is pumping blue smoke at any time "soon" before or after this 500 miles, the amount of blue smoke is mathematically directly proportional to the degree of precision exercised by the rebuilder during the rebuild.
Remember for Ford's recommendations, in the early 1930's, it was a precise new car's engine with everything new; today, 80+ years later .................... it is now a rebuild.
If after exercising just a little care to avoid over abuse for about 500 miles after an engine rebuild, if one is pumping blue smoke at any time "soon" before or after this 500 miles, the amount of blue smoke is mathematically directly proportional to the degree of precision exercised by the rebuilder during the rebuild.
Patrick L.
Well-known member
Everyone has their opinion. Maybe our resident rebuilders will chime in with their recommendations.
I've liked to run them at a fast idle [1500-2000] for 1/2 to 1 hour. Let it cool [ retighten head on an older engine] and do it again. Then when on the road vary the speed without abusing the engine.
Change the oil at about 100 miles and then again at about 500.
I've liked to run them at a fast idle [1500-2000] for 1/2 to 1 hour. Let it cool [ retighten head on an older engine] and do it again. Then when on the road vary the speed without abusing the engine.
Change the oil at about 100 miles and then again at about 500.
CarlG
Well-known member
This was (supposedly) in the window of every new car:
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Mike V. Florida
Well-known member
Follow the rebuilders instructions no matter how long and drawn out you might think it is.
Roadster62
Well-known member
Ok, Lets say a rebuilt Model A engine costs $5,000, wouldn't it be in the rebuilders best interest to do all this "Break In" at his shop rather than handing it over to Joe Adverage, who may or may not know what is going on? Bob
Chuck Sea/Tac
Well-known member
Running an engine under load is different then running it unloaded on a stand.
Mike V. Florida
Well-known member
Like Chuck sea/tac said, does anyone really think a rebuilder is going to place an engine in a car and drive it around for hours to break it in? ANY rebuilder worth doing business with will give detailed instructions on what to do with the engine once you receive it back from them.
BILL WILLIAMSON
Well-known member
Chuck,
My thoughts are that an engine on a test stand is under a certain amount of stress, from rings settling in & other parts "limbering" up, etc. Why add extra stress of hauling the weight of the car, fighting wind resistance, generating more heat, etc. to the process? An engine on a decent test stand can also be monitored much more closely.
Would breaking it in while driving lead to a "BETTER" more "COMPLETE" "LONGER LASTING" break in? I DON'T THINK SO! BUT, the majority of engines of all sorts, are usually broke in, IN the car. The main thing is just use common sense & don't run the snot out of them for awhile & do an early oil change & everything will be cool.
Bill W.
(These thoughts are from many years of my own experience, NOT from "Jim did this"---"Rob didn't"---"Hank should have"?---"That engine lasted longer"---"He should have broke it in on a hill"----"NO, he should have gone DOWNHILL with the choke 1/2 ON"---B.S stories ABOUND!!)
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Jwilli
Well-known member
Just researching the best way to breakin a newly rebuilt engine. From reading this thread, it appears that common sense and care would be a good approach. I appreciate all the replys make by the experienced A people. I think I am learning more from the Barn than from the books. Both are valuable. Thanks Guys.
tbirdtbird
BANNED
Patrick L from Geneva has it.
He has described the techniques used by most modern day builders. My nephew went to McPherson college resto program for 4 yrs and that is how the engine building department did it. Run at about 1/2 the max acceptable RPM.
We run at about 1200-1400 rpm here. I might not go to 2000
We also re-torque several times along the way, hot. Not to start that drama all over again. And we are always able to take up the nuts the first couple times. By the time we do it the 3rd time all the stretch is gone and they won't take up any more
He has described the techniques used by most modern day builders. My nephew went to McPherson college resto program for 4 yrs and that is how the engine building department did it. Run at about 1/2 the max acceptable RPM.
We run at about 1200-1400 rpm here. I might not go to 2000
We also re-torque several times along the way, hot. Not to start that drama all over again. And we are always able to take up the nuts the first couple times. By the time we do it the 3rd time all the stretch is gone and they won't take up any more
kingbee
Senior Member
My (well known) rebuilder said to just drive it like you're going to drive it, don't baby it.
In order to not get run over by traffic, most of my starts in my heavy Town Sedan are at or near full throttle, with shifts at 3,500 - 4,000 RPM. I do kind of take it easy for the first 100 miles. My engine is fully inserted, large intakes, Stipe 340 cam, oil filter, Lion 6.9 head, Chevy pistons and Burlington crank. It typically takes 1,500 miles for my oil to get dark enough to change. My engines don't use any oil or make any bad noises, and are daily drivers spring through fall. Hot water heater and A/C help make that possible.
Perhaps a babbit engine without a filter has different requirements, but I'm comfortable with my routine. My engines are running all modern moving parts, so I feel they should be able to take the same abuse that modern engines do.
In order to not get run over by traffic, most of my starts in my heavy Town Sedan are at or near full throttle, with shifts at 3,500 - 4,000 RPM. I do kind of take it easy for the first 100 miles. My engine is fully inserted, large intakes, Stipe 340 cam, oil filter, Lion 6.9 head, Chevy pistons and Burlington crank. It typically takes 1,500 miles for my oil to get dark enough to change. My engines don't use any oil or make any bad noises, and are daily drivers spring through fall. Hot water heater and A/C help make that possible.
Perhaps a babbit engine without a filter has different requirements, but I'm comfortable with my routine. My engines are running all modern moving parts, so I feel they should be able to take the same abuse that modern engines do.
glenn in camino
Well-known member
When I first start a rebuilt engine, I rev it up and down several times to seat the rings. Then re torque the head to 55#, drive it around the block a few times, Then torque the head again while hot. Its ready to go. I hardly ever drive faster than 50 mph.
Rowdy
BANNED
I agree to break it in like you plan to use it. A local mechanic here that used to rebuild tractors would always encourage his customers to plow with a tractor for atleast 10 hours during its break in time. His rebuilds had a good reputation of lasting longer than most and overall having more power when broke in as he recommended. Rod
RonC
Well-known member
Your engine should be good to go right out of the box. If an engine needs to "wear in" then it can't be machined properly. You will have to retorque the head and I would change the oil after 500 miles to remove any debris. However follow the rebuilders directions for the warranty
MrBruce
Senior Member
I agree with Mike. But today's parts namely rings and inserts are better than they were 83 years ago. After 26 years with Clevite I break them in like I'm going to drive them. You don't what to take it down the freeway 60 mph for hours but you do want to go through the gears and get the rings to seat. Any engine builder will tell you (dependent on what he did to the engine) how he would suggest you break it in.