First off, has anybody ever CC'd their U-20 head? If so what kind of
numbers did you get?
Here are the measurements needed for calculating CR. I improved my CC'ing
setup http://madmadscientist.com/cyl_head/ It's the first picture on this
page.
Combustion Chamber volume = 38.0 cc
Bore = 3.460 "
Stroke = 3.235"
Deck Height = .025"
Compressed Head Gasket Thickness = .04"
I know my head is probably thinner than it should be ~4.450" (I think that
was not as easy of a measurement to make as I thought..)
If I plug these #'s into this online CR Calculator
http://www.turbofast.com.au/Tfcomp.html I get a CR of 11.37!!!
That's a little high I think. Playing with the calc a bit I see that if I
use two head gaskets for a thickness of .08" my CR drops to a more
reasonable 10.19 If I want to get down to the lower CR that a supercharged
engine would require (~8.5) it would require a head gasket thickness of
.16"
Do these numbers seem way wacky to y'all
I really really want to try to get the engine together before Shasta this
year..
Thanks in advance,
Daniel Neuman
Oakland CA
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