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dome size question
Posted: Thu Jun 21, 2018 7:03 pm
by two-stroke-brit
Hi All
how do i work out what cc dome i need to use with a cool head for my athena 392 setup.
i have athena head but the squish is about 1.5mm
i would like to get a cool head but unsure what size cc dome to get
thanks mark
Re: dome size question
Posted: Fri Jun 22, 2018 5:44 am
by (F5)
Depends on your gas.
Skim whatever you get to 0.8 to 1mm and then measure the com with fork oil in a syringe.
Re: dome size question
Posted: Fri Jun 22, 2018 1:41 pm
by two-stroke-brit
i will be running "E" free gas which i think is 93 octane.
thanks mark
Re: dome size question
Posted: Fri Jun 22, 2018 1:47 pm
by T.RexRacing
Octane is octane regardless of ethanol content. Tuning requirements are different by a little but the resistance to detonation is 93 octane ethanol or not.
Re: dome size question
Posted: Fri Jun 22, 2018 1:57 pm
by two-stroke-brit
T.RexRacing wrote:Octane is octane regardless of ethanol content. Tuning requirements are different by a little but the resistance to detonation is 93 octane ethanol or not.
thanks for that.
any recommendations for dome capacity size
thanks mark
Re: dome size question
Posted: Sun Jun 24, 2018 12:09 pm
by Darrell
I'm thinking of putting a replaceable-dome head on my Canadian-spec RD-350, and have wondered the same thing.... which dome is right? Didn't the head come with some information, or perhaps a call to the company would be worthwhile? Keep us posted, please.
Re: dome size question
Posted: Fri Jun 29, 2018 3:39 pm
by evan_calgary
How do these heads work? As in, is the dome itself determining squish or is the head? I would assume the dome but I don't know. If dome, you would think you could buy a different shaped chamber with a specific cc for your octane. It seems crazy people have to skim the domes themselves when they come from the aftermarket 'performance' company but I suppose at the same time the road, crank, and piston will impact the squish. Just curious.
Re: dome size question
Posted: Fri Jun 29, 2018 4:08 pm
by T.RexRacing
I'd prefer a custom chamber made by the guy who ported it. OTS stuff has too many variables and compromise.
Re: dome size question
Posted: Tue Jul 03, 2018 10:33 am
by two-stroke-brit
evan_calgary wrote:How do these heads work? As in, is the dome itself determining squish or is the head? I would assume the dome but I don't know. If dome, you would think you could buy a different shaped chamber with a specific cc for your octane. It seems crazy people have to skim the domes themselves when they come from the aftermarket 'performance' company but I suppose at the same time the road, crank, and piston will impact the squish. Just curious.
yes the dome sets the squish dim.