Hi Peter,
----- Original Message -----
From: Peter Ficklin <pficklin@qnis.net>
To: <spitlist@gte.net>; Spit List <spitfires@autox.team.net>; Glenn Trunnell
<trunnell@mindspring.com>
Sent: Thursday, February 17, 2000 5:37 AM
Subject: Re: head shaving
>
> Glenn...
> STOP!
> DON'T SHAVE IT YET!! I screwed up in my calcs as I went back over
> them, and found I'd messed up somewhere - Sorry... 8^( If it's
> already too late you'll end up with 11.5:1 or something! Ping city. I
> hope your machine shop isn't open this time of night anyway! I think
> the correct amount would be around 0.048" and assumes flat-top pistons.
> You may or may not have dished ones. The best way, is to cc the head
> after all the polishing takes place, and then determine how much you
> want to take off. Sometimes, if the block is "decked", you will end up
> with "pop-up" pistons, and that'll throw these basic calcs out the
> window. Joe Curry sent me the following note, so your results may
> vary...
>
> Joe Curry wrote:
> >
> > Peter, did you take in to consideration that his engine apparently
> > already has the higher compression pistons instead of the stock "dished"
> > ones?
> >
> > When I first built Huxley's engine, I used a head that had been shaved
> > an incredible amount (best I could tell about a quarter of an inch had
> > been removed). I was using flat top 9:1 pistons and the result was
> > about 260 pounds of compression all the way across. I could not find a
> > fuel with enough octane to keep it from pinging, even with the timing
> > set much further back than it should have been.
> >
> > As a result, I got a stock head and had it recone and now I have about
> > 180 psi across.
> >
> > I also discovered since then that the stock 1300 head is something on
> > the order of 1/8 inch shorter than the 1500 head. I suppose it is to
> > compensate for the shorter stroke, but it sere seems extreme. I have
> > often wondered what effect that particular head would have on a 1500
> > engine without any shaving.
PING PING PING PING
A friend of mine tried it to avoid the costs of machining, it cost him
another gasket ad a few hours putting the old head back.
Graham.
> > Regards,
> > Joe
>
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