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Re: Low Compression, 77 Midget 1500 cc

To: "William M. Gilroy" <wmgilroy@lucent.com>
Subject: Re: Low Compression, 77 Midget 1500 cc
From: Chris Kotting <ckotting@iwaynet.net>
Date: Thu, 08 Oct 1998 17:43:46 -0400
Bill -

1 and 4 don't sound too bad.  I'm betting that you've blown the head
gasket around 2 and 3.  You're going to pull the head anyway to assess
the situation, so I'd just pull the head and see what you find.

Chris Kotting
ckotting@iwaynet.net

William M. Gilroy wrote:
> 
> My 77 Midget (1500 engine) has an oil leak down low
> by the dipstick.  I thought it was the pan gasket.
> After I put in my new dizzy I found that I was leaking
> even more oil.  I found that the oil is not coming from
> the pan gasket but from the dipstick hole.  I checked
> the oil, it is full but not over full.  The valve
> cover vent is not plugged.  I still get the leak if I
> run the engine with the valve cover vent disconnected
> from the carb. at the valve cover.  Now I figure that the
> problem is excessive crankcase pressure even though the
> the crankcase is vent is work.  I then ran a compression
> test and these are the number I got:
> 
>         Cylinder 1:  135 psi dry / 155 psi with oil
>         Cylinder 2:  40 psi dry / 60 psi with oil
>         Cylinder 3:  75 psi dry / 90 psi with oil
>         Cylinder 4:  135 psi dry / 170 psi with oil
> 
> I ran my compression tests with all of the spark plugs in, and
> I squirted a couple shots of 20-40W engine oil into the cylinders
> for the tests with oil.
> 
> Now I am wondering what are my options.  I think they range
> from a complete rebuild to doing nothing.  I would like something
> in the middle.  First exactly what do these number tell me?
> Like cyl 4 is it just a set of bad rings and cyl 1 is a set of
> bad valves and maybe rings.  What is the correct answer?
> What are good numbers for compression?  What would I see on a
> newly re-built motor?  Could I get away with just re-ringing the
> pistons and a valve job.  I am trying to explore my options.  I
> would like to avoid a full engine rebuild at this time.
> I can see where that would lead me to many other things (hotter cam,
> paint the car since the engine is out, weber, headers, etc.) and
> I currently don't want to do all of this stuff.  Maybe down the
> road but not now if I can avoid it.
> 
> Thanks in advance,
> 
> Bill
> --
> Bill Gilroy
> 77 Midget
> E-mail:    wmgilroy@lucent.com
> Telephone: 732-957-4775
> Fax:       732-957-4775

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