who ( sucsessfully )runs a 330 on pump gas ??

[lee37vernon]

i have just bought a 330 kit from a member on this site . been talking to a guy here in the UK that swears hand on heart you cant get a pro x top end to last the distance without running race fuel ( its equivelent to $8 a liter here ! )

so who here is running pump gas ??, its worth noting that the pump gas i will use is approx 95 octane according to USA scale ( 99 ron )

punker has already suggested using a 33cc dome . anyone else got a take on this ??? :confused:

[sandspanker]

check your compression. if it above 180 psi get a different dome cut. anything 180 and under should be ok for pump gas. my wife's 330 with 200 psi would not start with pump gas. fires right up with some race fuel.;)

[lee37vernon]

anyone else have any experience with this , also anyone got a suitable dome for sale ??

[sandspanker]

what kind of head do you have? esr,duncan.

[lee37vernon]

its a pro design cool head . its still waiting to be shipped to me as i want the dome thrown in the box . i'm just having no luck getting straight answers , ESR responded as if i was speaking a foreign language , didnt know if their domes fit , no clue what size i may need . maybe i spoke to wrong person ? duncan would not help at all , all i got from them was ' what compression do you have ' like . i dont know its sitting in abox several thousand miles away !! like banging my head against a wall :mad:

[300excrazy98]

when you get it just look at the dome, should have a # stamped into the top... I would then invest in a compression gauge. If the dome says ''17'' then your definately going to need race fuel. if there is a ''23'' stamped in, then you have alot better chance of running pump fuel, but without that gauge there is no telling what is ok...

Hope i have not made a mistake!

[lee37vernon]

i have a compression guage , thats not the problem , i just cant believe that i cant get a ball park dome volume from any of these guys ...WITHOUT having to assemble the whole thing first .

i know from here i've had the suggestion of 33cc , i just wanted to confirm that with one of the companies , check their domes will fit and order it up .. should be easy , so i thought .

cannot find a website for prodesign anywhere either .

remember also this is a 330 pro x so its a 76.5 mm bore . i believe your 17 - 23 cc domes are for std 250 cc .

[georgedoggy]

hi

i have a duncan 300cc barrel and i run a 22 or 23cc dome and i run 98 pump gas and it runs fine. according to my guage i run 230pounds of compression. which is quite high, but just could be my guage.

it does prefer race gas though, i find race gas makes the power snappier. i dont think it gives me more power, just more responsive. so if you can afford it run race gas.
Can you get avgas? thats a good alternative ive found. 250r's love a bit of lead in the fuel !

[sandspanker]

:) get ahold of (Big~Dan at Patriot Racing) he should be able to answer your question. (www.patriotracing.com)

[peeping TOM]

try some lead replacement additive......and av gas ,,,costs the same as normal petrol ,,but the best quality

[lee37vernon]

where are you getting av gas ?? are you actively running it in your 330 ??
i was going to run some millers octane booster in the mix just as a bit of insurance . dont know if anyone else is doing this ?

[peeping TOM]

just find a local air field,,,, they,ll glady sell u ava gas for £5 a gallon,,,, other answer;s yes ...

[lee37vernon]

thanks :D

[imprezkid]

bump this up,
who is running av gas, i heard the head is bad on the motors. Also still looking to figure out what dome i should run to run a 330 w/cool head on 93? How much would i gain running race gas? its expensive btw

[Pro1200]

call pro design and ask them..very helpful for me i found..good luckk

[thedeatons]

Yep, Tom at Pro Design is very helpful. Don't expect to call him and throw out a ballpark piston size and have him give you answers. He is very precise, and will have you measuring things. At first I was annoyed, but he is trying to be accurate, and protect his reputation.

He needs to know:

Has the head been machined?
Has the cylinder been machined?
Which piston brand?
Size of piston?
Size of current dome?

I had no idea whether anything of mine haad been machined, so i had to measure the piston in relationship to the top of the head, so Tom could tell me whether anything had been machined...

Take care of him, and he will return the favor. New domes are ~$45.

[C-LEIGH RACING]

Lee,

The Pro-x cylinder has its own head, a two piece just like the Prodesign cool heads, but are made a little different from the Prodesign.
Prodesign could probably cut you a dome to fit the Pro-x head & I'm sure they have probably done it before.

LA Sleeve, CT Racing, Eddie Sanders Racing, LED, will have the Pro-x brand cylinder kits & should be able to cut a dome out for you like you need to use.
LA Sleeve & CT Racing, their Pro-x heads have a small locating notch on the inside mating surface of the dome that you have to aline when putting the dome & outter part of the head together.

ESRs outter part of the head is different, their design different from the Pro-x, but the dome they have is the same measurement as the Pro-x head.

Only difference in the domes from either company is that little locating notch on the inside.
The ESR heads dont have that locating notch inside, so you can use an LA Sleeve or CT Racing dome inside it, but you cant use the ESR dome in the LA Sleeve or CT Racing Pro-x head.

I suspect the problem your having, calling the companys, is from you being across the waters & add to that how everythings going in the world today & people are just a little standoffish thinking it could be a scam or flimflam of some sort. You need to assure them your ligit.

Now for the dome, a dome cut anywhere from a 33cc to say a 35cc, that should put you in the prem pump gas range & you need a progressive squish.
In other words, the angle of the dome squish would be smaller size out next to the cylinder bore & progress wider as it goes to the center of the head.

Getting & cutting a head dome for a cylinder not as easy as one would think. When building an engine from the crank up, the head is about the last thing you do & its size & shape it is cut, is to match up with all the things you just done to the crank & cylinder. Things like the porting, a bottom end ported engine will trap more after the piston covers the exhaust port than say a drag ported cylinder, so the head dome needs cutting to match that.
This is another reason your having trouble when calling trying to get a dome, because most any of the builders, that being the last thing they do, have no idea what the rest of your engine is built like.

Find out what porting is in that cylinder your getting, find out what head is on it if its a stock Pro-x head or another brand & the crank stroke, & then call & give them that info.

If I'm remembering right, some time back you needed something & your problem was solved at CT Racing, best I can remember.

33 to 35cc, progressive squish for pump gas, but you need to know what porting & what head.
Neil

[imprezkid]

Is there any way to tell if a cylinder has been ported? identifying marks? If not should i just post up a ton of pictures of the cylinder, i bought the bike already with a 330, now im trying to rebuild, and still trying to figure out what i have