dome size question

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two-stroke-brit
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dome size question

#1 Post by two-stroke-brit » Thu Jun 21, 2018 7:03 pm

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
350LC,Athena 392 big bore,stock porting,swiss cheese air box,stock reeds,spec11 pipes.(now TSA big bore pipes)
She might not be pretty but she will always be a fun ride


1982 YAMA RD350LC
98KDX 220R
1967 TRIUMPH TIGER
2001 TRIUMPH TT600

(F5)
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Re: dome size question

#2 Post by (F5) » Fri Jun 22, 2018 5:44 am

Depends on your gas.

Skim whatever you get to 0.8 to 1mm and then measure the com with fork oil in a syringe.
496 Cheetah. TSS PVs, PWK35s, Ignitech, RGV(ish) chassis

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two-stroke-brit
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Re: dome size question

#3 Post by two-stroke-brit » Fri Jun 22, 2018 1:41 pm

i will be running "E" free gas which i think is 93 octane.
thanks mark
350LC,Athena 392 big bore,stock porting,swiss cheese air box,stock reeds,spec11 pipes.(now TSA big bore pipes)
She might not be pretty but she will always be a fun ride


1982 YAMA RD350LC
98KDX 220R
1967 TRIUMPH TIGER
2001 TRIUMPH TT600

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T.RexRacing
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Re: dome size question

#4 Post by T.RexRacing » Fri Jun 22, 2018 1:47 pm

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.
There is only one difference between a madman and me. The madman thinks he is sane. I know I am mad.
Salvador Dali

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two-stroke-brit
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Re: dome size question

#5 Post by two-stroke-brit » Fri Jun 22, 2018 1:57 pm

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. :smt023
any recommendations for dome capacity size
thanks mark
350LC,Athena 392 big bore,stock porting,swiss cheese air box,stock reeds,spec11 pipes.(now TSA big bore pipes)
She might not be pretty but she will always be a fun ride


1982 YAMA RD350LC
98KDX 220R
1967 TRIUMPH TIGER
2001 TRIUMPH TT600

Darrell
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Re: dome size question

#6 Post by Darrell » Sun Jun 24, 2018 12:09 pm

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.
89 Canadian Spec RD-350
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evan_calgary
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Re: dome size question

#7 Post by evan_calgary » Fri Jun 29, 2018 3:39 pm

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.

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T.RexRacing
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Re: dome size question

#8 Post by T.RexRacing » Fri Jun 29, 2018 4:08 pm

I'd prefer a custom chamber made by the guy who ported it. OTS stuff has too many variables and compromise.
There is only one difference between a madman and me. The madman thinks he is sane. I know I am mad.
Salvador Dali

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two-stroke-brit
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Re: dome size question

#9 Post by two-stroke-brit » Tue Jul 03, 2018 10:33 am

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.
350LC,Athena 392 big bore,stock porting,swiss cheese air box,stock reeds,spec11 pipes.(now TSA big bore pipes)
She might not be pretty but she will always be a fun ride


1982 YAMA RD350LC
98KDX 220R
1967 TRIUMPH TIGER
2001 TRIUMPH TT600

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