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#Post#: 47023--------------------------------------------------
Compression and exhaust port
DIR By: The Ripper
Date: September 24, 2014, 8:09 pm
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Bought a R16 partner and couldn't resist removing the base
gasket and compression jumped from 155 to 176psi, question is
this compression jump acceptable for a working saw using 87
octane ? The gasket was .027,so how will this effect the timing
and power outcome when removed?
On the exhaust port there seems to be some casting flaw that
protrudes slightly up from the floor,should this be removed
flush with the floor and then slightly radius the bottom edge
inward. Also the bore is 44MM so would opening up the E/P to
29MM be acceptable, don't want to push it to the edge.
#Post#: 47026--------------------------------------------------
Re: Compression and exhaust port
DIR By: farmboy
Date: September 24, 2014, 8:55 pm
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You need to check the squish too tight is bad news detonation,
etc. 44mm I'd suggest .020 no less than .018 squish. Rule of
thumb on widening ports for work saw is bore x .65 yours is 44mm
x .65=28.6 29 should be fine. The casting on the floor of ex
port is anti reversion ridge. Porters are actually cutting them
in on some saws. I've seen that ridge in Partners, Jonsered,
and Husky. Having said that I'd leave it. 87 is OK. Most of
us run premium non-e (if available) @ 32:1 w/synthetic mix oil.
Shep
#Post#: 47028--------------------------------------------------
Re: Compression and exhaust port
DIR By: Gatekeeper
Date: September 24, 2014, 9:08 pm
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87 has worked fine with up to 230lbs of compression.
#Post#: 47081--------------------------------------------------
Re: Compression and exhaust port
DIR By: The Ripper
Date: September 25, 2014, 8:14 pm
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Double checked the squish and it comes in at .035, Which I
prefer as I'm not a big fan of those super tight squishes. As
for the anti ridge,I just worked the corners when widening and
didn't touch the middle. Opened the port from 23.5 to 27mm
mostly on side as the other side was already a straight shot.
Hope to fire it up this week-end. Thanks for the mix ratio tip.
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