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Re: results of compression test

To: robert weeks <robert@woozy.com>
Subject: Re: results of compression test
From: Trevor Boicey <tboicey@brit.ca>
Date: Sat, 14 Mar 1998 16:33:46 -0500
robert weeks wrote:
> cylinder #1 no oil 190lbs/psi  oil 265lbs/psi
>          #2 no oil 175lbs/psi  oil 275lbs/psi
>          #3 no oil 170lbs/psi  oil 265lbs/psi
>          #4 no oil 185lbs/psi  oil 270lbs/psi

  Both numbers seem high indeed.

  My guess is:

  No oil readings are high because you have a slightly milled head
or non-standard pistons, somebody was likely going for more
horsepower. Could be a good thing.

  Oil readings are VERY high because you are putting in quite
a lot of oil, perhaps more than you should be for the test. Remember
that in a 1275cc engine with approx 10:1 compression the combustion
chambers are in the order of 30-40ccs, which is quite small. Adding
even 10ccs of incompressible oil can make the compression extremely
high for the remaining space.

-- 
Trevor Boicey
Ottawa, Canada
tboicey@brit.ca
http://www.brit.ca/~tboicey/

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