hand lapping prior to break-in

[sweetdiesel]

I have a friend that suggested it to me prior to break in of a new engine. The way he explained it was to drop about an ounce of castor oil down the head and hand turn the engine about 75-100 times. After doing this the oil should be real dark or black. This is supposed to smooth out the piston and shorten the amount of time required for break-in. The engine also needs to be cleaned out with DA after this is done and relubed with some oil before starting break in. Another method I had heard about involved using lapping compound and a lapping tool. Anyone doing this?

 

[Monkey Wrench]

Ah, that thread title had me confused for a bit! Thought maybe you were on the wrong forum there for a bit!

I've never even heard of this method, but I'd be really interested in learning more about it.

 

[vbgagnon]

IMO it doesn't really take that long to break in an engine the "old fashioned way" The heat cycle method is a proven method of doing a breakin and there is no guess work to it.

 

[Plaidfish]

I clean em all out anyway....no honing metals or whatever but I do break it all down now and clean and seal em real good.....I don't see what is so hard about getting them started....I have yet to have any real issues starting a new mill and I've helped or broken in a lot of different ones.....

 

[olds97_lss]

If your trying to speed things along, that doesn't sound like a "quick" way to do it. If it enhances performance or extends the life of the engine, then I'd think it was worth it.

 

[sweetdiesel]

I read on rctech that handlapping using lapping oil and a lapping tool can extend the life of the piston/sleeve by 30-40%. Still looking for more information to back up this claim.

 

[Rotorxhead7]

IMO it doesn't really take that long to break in an engine the "old fashioned way" The heat cycle method is a proven method of doing a breakin and there is no guess work to it.

Aint that the truth!!! by the time ur done rebuilding the engine trying to cut corners vbgagnon and myself will be rippin long b4 ur ready...my

 

[Plaidfish]

Aint that the truth!!! by the time ur done rebuilding the engine trying to cut corners vbgagnon and myself will be rippin long b4 ur ready...my

I rebuild mine when they are brand new.....after seeing a few high end mills ahve shavings inthe case It's just a safe thing to do.....but reaming the sleeve w/ the piston head and oil sounds a lil hokey to me......stand breakins til I diiieeeee booyyeeee!
lol.... my truck body is painted so I'm all giddy inside...

 

[sweetdiesel]

When I heard him explain it to me I was also very skeptical, but I respected his words because he works for a major engine importer and has been modifying engines for over 20 years.

I will ask him again since he went through the process fairly quickly and I may have missed some details in his explanation.


edit: here is the thread from rctech on hand lapping. If anything it is interesting reading.

http://www.rctech.net/forum/showthread.php?t=41183&highlight=hand+lapping