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Re: results of compression test

Subject: Re: results of compression test
From: Ulix Goettsch <ulix@u.washington.edu>
Date: Sun, 15 Mar 1998 10:17:05 -0800 (PST)
Cc: Spridgets@Autox.Team.Net
In-reply-to: <v03007800b130934d42ef@[206.240.43.75]>
Reply-to: Ulix Goettsch <ulix@u.washington.edu>
Sender: owner-spridgets@Autox.Team.Net
Robert,
I think your readings are caused by an optimistic gauge (and using too
much oil). But since
repeateability is more important than accuracy in this case, I would look
at the differences between cylinders.  You have a little more than a 10%
spread dry and less wet.  If you are happy with the engines performance
and general demeanor, I would change the rod bearings.  Take a good look
at the crank surfaces.  If they are scored, plan on a rebuild in the
future.

Ulix


On Sat, 14 Mar 1998, robert weeks wrote:

> Hello,
> 
> I've been trying to decide whether to do a full rebuild on my engine
> or just replace the bearings and leave it at that for now. Unfortunately,
> I think Uncle Sam is going to want any spare cash I have come April 15th.
> So money is getting a little tight for a rebuild.
> 
> I went and got a compression tester to see how the rings are and here
> are the results:
> 
> 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
> 
> This makes no sense to me as the Bently book says 120lbs/psi is the
> proper reading for the 1275 series A. I took all of the measurements
> twice and came up with the same thing both times.
> 
> Does anyone have any insight to these readings? I'd appreciate any help
> I can get.
> 
> TIA,
> 
> Robert Weeks
> Durham NC
> 1969 Midget
> http://www.woozy.com/midget/
> 
> 

    Ulix                                                    __/__,__        
.......................................................... (_o____o_)....
                                                           '67 Sprite


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