Inliners International
Posted By: CircleFan GM 270 - 11/23/04 04:15 PM
Hi all. New member, first post. Am involved in circle racing with old time cars. Are turning a 250 at 6 to 62 on 1/4 mile track, with a single barrel carb as that is the limitation. Also CI limit is 310. Need to build new motor this winter and was wondering about the 270, or did the four main crank pose a problem. As a kid, I can remember that they were very dominate, but that was then.
Any opinions would sure be appreciated. Thanks
Posted By: Twisted6 Re: GM 270 - 11/24/04 02:57 AM
Hello and Welcome to the Inliners World. find a 292 bore .060 =302 that should work out better then the 270 even stock for stock. hope this helps
}[oooooo]
Posted By: CircleFan Re: GM 270 - 11/24/04 05:32 PM
Twisted6: Thank you very much for the reply. Yes, I agree that to give away 50+ CI isn't a good idea, but the concerns that we have are the limitation on carburation. We are limited to the one single barrel carb, stock intake maniford and know of nothing, that would comply with "stock" that is bigger then the 1 5/8th venturi that we are running. We already are running in the area of 12:1 on compression. Would this carb really be able to feed the additional volume of a 302, or would you anticipate that we would have to really reduce the combustion area. Hope I haven't sounded too ignorant on engine building. Thanks again, really appreciate the help.
Posted By: Twisted6 Re: GM 270 - 11/24/04 06:07 PM
well something some have done is take the secondary butterfly out of a Qjet carb bore the 1bl carb out cut done the buterfly some How much I have no idea. And install it in the 1bl carb. JAck somers is one man who has been doing this type of mods for some time now.. about the only other thing I can come up with is make sure You have the carb For the 292 Then make the mods to That one.

Running a 194 head On a 292 with a true flat top piston can Net Compression Better then 12-1 Hope this helps }[oooooo]
Posted By: CircleFan Re: GM 270 - 11/26/04 07:52 PM
Hi Twisted6: Is this "Jack Somers" in the carb business, and if so, how would I contact him? Thanks for all your previous help.
Posted By: samwise68 Re: GM 270 - 11/26/04 10:51 PM
how about running one of the big GMC 302 straight 6's? i've seen one or two that really cranked out the horses..and "stock" would be an even bigger carb. so..maybe just a thought? otherwise, definitely the 292. granted, i have no track experience..so hey. just my 2 cents.

SamWise
.for every 1 mile of road theres 2 mile of ditches.
Posted By: CircleFan Re: GM 270 - 11/26/04 11:21 PM
Thanks for another post. You guys really seem to know engines. My concerns are that, with very limited knowledge, it seems that short stroke, large bore beats small bore long stroke. I hope I haven't opened a can of worms with this statement but I think of F1 and Indy engines. It just seems to me that the more bangs per minute means a faster car. I'm sure this will be subject to objections, but this is my current inexperianced thought. Granted, not as much tork, but at the end of the straight away, it seems like the high winders are in the lead. This is why we are trying to turn the 250 so tight and put 4 in pistons in it. As a further example, we can beat the 300 Fords and the 292's are having crank problems. Really appreciate the come back....
Posted By: Twisted6 Re: GM 270 - 11/27/04 12:11 AM
this is his web site But i think it is down right now but try the link http://www.megalink.net/~jsomers/index.html I'll try and Email you his #

hope it helps }[oooooo]

Ps One thing someone Once told be when I first started to build my 250. Was to use the 194 crank for a high winder????? Had me woundering But I didn't want to lose The Cubes of the 250.
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