28 cc domes pump or race?

[rubbertoe]

just ordered a set of 28cc domes to replace the 30cc domes on my ada set up.my question is this will i still be able to use 91 octane or will race gas be manditory?right now i have a wet pipe ,flywheel ,6degree timing advance.my compresion with the 30 cc domes was 175 psi .i do mostly freestyle.what up

 

[Nefarious]

I've got 28cc domes on my ski and there is NO WAY I could run pump gas (200psi in each cylinder)

 

[redsxr800]

i have been running pump gas on mine with 28 cc r@d head sense it had been new without problem. been four years. never did do compression test tho :ugh:

 

[Nefarious]

I should have added that I race so there's no way I could get away with pump gas on 200psi but if you're not hittin' WOT for any length of time you might be able to get away with it.

OP,
Let me know if you want to sell those 30cc domes.

 

[Superjet112x]

29cc domes in my 08 superstock is 210lbs comp NO WAY on pump gas

 

[Superjet112x]

i have been running pump gas on mine with 28 cc r@d head sense it had been new without problem. been four years. never did do compression test tho :ugh:

would maybe check for pre det!

 

[Shonuff]

What flywheel are you running?

 

[redsxr800]

What flywheel are you running?

not sure who your asking but mine was stock fly wheel, only things i did were, wet pipe with rejet and timming advance, reed spacers, 28cc r@d grudled head, better reeds ,removed air horns.
i had that cheap cdi from ebay on it but that died so been running stock.

this year im adding vforse reeds and lightened fly wheel. mybe good cdi
ps i cant spell

 

[redsxr800]

i`m thinking bore size changes compression when were talking cc . im thinking 701 would get little more compression out of 28cc then my 800

 

[redsxr800]

ada Dome sizing and readings were performed on non ported cylinders at sea level. Also please note when compression ratings are increased, premium pump gas and / or higher octane fuel is required.

Kawasaki 750 domes

30cc 150 psi

28cc 165 psi

26cc 180 psi

24cc 195 psi

22cc 210 psi



Kawasaki 800 domes

32cc 180 psi

30cc 190 psi

28cc 200 psi

26cc 208 psi

24cc 216 psi

22cc 225 psi

this from z force racing (( new R&D CAST GIRDLE RACING HEAD.this head is 28cc and good for a nice gain power.and still use pump gas.this is a must with the girdle kit if you are using the factory pipe dry type pipe.))

all in all i guess i have been pushing my limits a little

 

[cmeripper26]

Just for reference i have an 05' SXR which i just gutted and built the stock motor up a bit, i run the stock case and crank and bore with NOVI dual 42's, factory wet pipe, v-force reeds, r@d polished intake, JSU head with 28cc domes and i wired up the Advent Tempest T3 programable ignition. This setup pulls hard and runs good with a little exhaust tuning. I have not had one prob. with running 93 octane. I can get back to u with compression ratings. my tester is f'd up by my friend. Hope this helps out.

 

[Superjet112x]

Just for reference i have an 05' SXR which i just gutted and built the stock motor up a bit, i run the stock case and crank and bore with NOVI dual 42's, factory wet pipe, v-force reeds, r@d polished intake, JSU head with 28cc domes and i wired up the Advent Tempest T3 programable ignition. This setup pulls hard and runs good with a little exhaust tuning. I have not had one prob. with running 93 octane. I can get back to u with compression ratings. my tester is f'd up by my friend. Hope this helps out.

Don't think Novi ever made 42mm carbs

 

[Matt_E]

i`m thinking bore size changes compression when were talking cc . im thinking 701 would get little more compression out of 28cc then my 800

Bigger bores make more compression with identical sized domes than smaller bores.

You can't compare dome sizes between different skis/motors (i.e. SJ & SXR) and draw any conclusions on compression.

 

[redsxr800]

Bigger bores make more compression with identical sized domes than smaller bores.

You can't compare dome sizes between different skis/motors (i.e. SJ & SXR) and draw any conclusions on compression.

i knew sj and sxr would be night day , more from piston set up and what not.
i was thinking ccs spead out would be less, but i think your write:grumble:

 

[Scorn800]

I've used R&D 28cc on a mild drypipe limited & had 190psi on stock bore.
I use a TBM 29.5cc standard dome on wet piped limited and have 185 on stockbore.

 

[Shonuff]

Rubbertoe, what flywheel are you running?

 

[cmeripper26]

Novi did make dual 42's they are converted from Mikuni's 38's

 

[Scorn800]

Novi did make dual 42's they are converted from Mikuni's 38's

Novi did mod the stock 40i carbs & make them 42. Tim no longer makes them.

 

[Proformance1]

On my 05 SXR 28 cc domes are 185 psi on Frosty's gauge, JSU said 174 psi and 93 oct was fine, but I don't do any long full throttle pulls because of my advanced timing curve from my Mitsu ign. By the way they say 29cc domes are 168 psi for reference. Oh yeah and by the way this combo hits really hard and I still have a stock bore and flywheel.

 

[SXR-FOREVER]

With my R&D 28cc Domes I was running 178 in each cylinder in MN. Not sure how much elevation matters?

But I ran the same domes in FL on pump gas with no problems.

Does it change between manufacturers? I just for an ADA head with 28cc domes to replace my R&D one..