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question for any engine builders out there

3K views 7 replies 6 participants last post by  MAHRKEAU 
#1 ·
On another forum someone asked the proper way to "break in" an engine. Someone posted this link.

http://www.mototuneusa.com/break_in_secrets.htm

Has anyone heard of or done anything like this for engine break in?
The engine he refers to is an air cooled motorcycle engine, but he states this is the way to do it on any engine.
I was always told to break in the cam by running up the RPM's right away for a few minutes then drive the car from anywhere from 500 to 1000 miles before any hard driving. I'm not talking about an engine from the factory like from a new car or crate motor, I'm talking about engines you rebuild.
What are the opinions from any of you experienced engine builders out there.
 
#2 ·
I agree with what hes doing. Put a load on it then let engine braking slow you down that will create high vacuum in cylinder to pull some oil up there then get on it again. Do that a few times. Drive it normally and change oil after a couple hundred miles.

I bet theres going to be a lot of different ways on this. :mwink:
 
#4 ·
That's similar to the method I used for any forged piston engines, The first part is to seat the rings, after cam breakin, I take it out and do almost full throttle runs from 50-80K and back, about 10 times, but then after that, (you guys are gonna say, WHAT?) I do full throttle runs till the valves float, 3-4 times.
It's broken in.

You can tell I've never built a 10000$ engine, but I learned this from a top builder in my area, And haven't experienced a rotating assembly failure on any of the 10 odd street-strip engines I've built.

I know I'm an amatuer, So please don't try this. I'd hate to get blamed for anyones engine failure.
 
#5 ·
I Prefer Synthetic Oil But Not For Break In So I Put In Enough Regular Detergent Type Oil To Be Safe. Start The Motor Check For Leaks, Time It, Level Out The Carb, Kill It. Drop Out Oil And Filter Go Back In With Fresh Same Type Oil And Filter. Take It Out And Drop The Hammer. Give It Hell For A Day Or Two. When I Am Satisfied It's Broken In Then I Drop Out Whats In There And Go Directly To Same Brand Synthetic At The Viscosity The Weather Dictates. The Old Timers Used To Use Non-Detergent For Break In But I Feel Non-Detergent-While Being Conducive To Ring Break In- Would Not Have Enough Anti-Scuff And Anti-Shear Qualities, Both Of Which Would Negatively Affect Cam/Lifter Break In. Also I've Heard The EPA Has Mandated Removal Of Zinc Oxide From Oil Causing Premature Cam Wipe Out. Wouldn't Want That Now Would We? This Would Bear Investigating! I Understand Some Cam Manufacturers Are Including Zinc Oxide Additive With Their New Cam Kits. Me Thinks The Zinc Oxide Would Need To Be There For The Life Of The Engine If One Wants The Cam To Last As Before! The Highest PSI In An Engine Is Where The Cam Lobe And Lifter Meet. Even More So With Flat Tappet Cams. MD
 
#7 ·
My dad and grand father have told me that for ever. Every motor we have built they run it just like they are going to drive it every day. When we put the engine in my truck we spent about 30 minutes checking everything over then I jumped in it and drove it home about 230 miles from their house. That was 6-7 years ago the thing still runs like a scalded dog.
 
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