Borrow or buy a compression tester that screws into the head, otherwise
your just waisting your time.
On Wed, 4 Oct 1995, J. Michael Roach wrote:
> You could be right. The compression gauge is the rubber tipped kind
> that you force into the spark plug socket. There is plenty of room for
> user error. At least one cylinder had just under 100. They're not all
> exactly the same, just fairly low.
>
> I just did a valve job (about 20 minutes before I measured the
> compression), so that shouldn't be a problem. It made an improvement,
> but I'm not sure how much power this engine should have. It's the only
> one I've driven. It seems to have plenty of pickup for a 1500, but then
> again, no reference point.
>
> ----------
> From: Denise Thorpe[SMTP:thorpe@kegs.saic.com]
> Sent: Tuesday, October 03, 1995 6:07 PM
> To: mroach@socketis.net
> Subject: Re: '75 Midget Engine Rebuild
>
> > Randy mentioned in an email to me that 75 psi was rather low for an =
> > Midget. He also mentioned that rebuild was likely necessary (rings, =
> > head gasket, etc. could be the culprit).
> >
> > I plan to replace the head gasket within the next couple of weeks. I =
> > figure I can do that without tearing the entire engine out. Hopefully, =
> > it won't take longer than a day. Also, I have an engine rebuild planned =
> > already (along with a carb (tons of vacuum leaks) and front end (new =
> > shocks and king pin cleanup) rebuild) for this winter. I hope to drive =
> > it until it gets too cold, then disassemble her.
> >
> > My question is: is there a problem with running the engine with a bunch =
> > of vacuum leaks and low compression?
> >
> > j. michael
>
> I can't believe a Midget with only 75 lbs runs very well at all, but it
> won't hurt it to run it with low compression. However, running a car
> that's running too lean (vacuum leaks) will burn valves.
>
> The fact that all of the cylinders have the same low reading makes me
> suspicious. Engines don't generally wear out the rings at exactly the
> same rate. And head gaskets generally blow between two cylinders so that
> only two cylinders are low. Since your car still runs, I'd suspect your
> compression guage. If the compression is really that low, it would be
> more likely to be something that affects all of the cylinders equally like
> the timing chain. Or maybe the valve lash is adjusted too tight on all
> valves. A valve problem would explain your vacuum leaks too. If I were
> you, I'd look into it more before tearing the engine apart.
>
> Denise Thorpe
> thorpe@kegs.saic.com
>
>
>
>
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