[Vwdiesel] Bon Ami? Sauce or powder?

H.Hagar h_hagar at prcn.org
Fri Sep 17 15:10:26 EDT 2004

Mark Shepherd and all : sorry to disappoint you , but The Bon Ami trick was
only intended for NEW ring jobs  --that did not seat.

I think it was originally used on brand new GM engines.   The oil consumption
never got down to speck at break in.

Problem ? ---IMHO a combination of fancy new machining and additive oils 
combined with pussyfoot driving when new.

Your case sounds like wear or broken rings.    But I am going to let the mechanics
clear that one up.   Loren and Ferguson are your best bet.    Maybe James Hansen,
I have a feeling he is very sharp on this issue.

Last engine I had to break in was a 503 Rotax  ---and they supply a graph of rpm and time.
Full power for 30 seconds ----and so on.  Remember cylinder pressure --pushes
ring against cylinder wall ---so if you pussyfoot ? ring may NEVER seat.

I use leak down tester so I know exactly if rings are ok .   Absolutely amazing how well
some rings seal.   ----I have a compressor, like no way can you turn that flywheel by hand.
NO leak-by  that I can tell.


More information about the Vwdiesel mailing list