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Re: regarding engine rebuilds

Subject: Re: regarding engine rebuilds
From: (Allen Bachelder)
Date: Thu, 23 Feb 1995 19:18:30 -0500

>a member of my local
>car-guy support group has cautioned me not to keep the engine at constant
>RPMs for a long time.  He says its good to vary the RPMs.  Why would this be
>true?  Rings seat better with RPM changes?  Or is he just passing oil?

When I rebuilt my Pontiac 326 in 1980 I was told to run for 20 min's
upon initial startup at a constant RPM to get the cam and lifters to
wear in correctly. Then I was supposed to do low speed (RPM) full
throttle acceleration in high gear to set the main bearings. I do not
know if this is correct or not but I did it and the car gave me great
service. Can anyone else confirm this? I don't Know about seating the rings.

- -Mark     = =o&o

I haven't heard of the main bearing routine, butI was cautioned - from two
different sources - not to let the MGB idle drop below 2000 rpm for the
first 20-25 minutes - in order to break in cam and lifters.  Beyond that, I
checked the MGB owner's manual on break-in instructions.   It said
something like keep it below 45 mph for the first 500 miles (if  I recall
correctly).  I interpreted this to mean roughly a 2500 rpm ceiling for

Allen "B"

Allen H. Bachelder, Associate Professor of Trumpet
Department of Music, Virginia Tech, Blacksburg, VA 24061-0240
E-mail:, Phone: 703-231-6713,  Fax 703-231-5034

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