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Author Topic:   360 inch rule motor
dukeboyz
Dirt Newbie

Total posts: 4
posted April 05, 2005 01:03 AM  
What is the best bore stroke combo when building one of these? We ARE allowed full roller, any compression, any carb on gas, any length rods, any steel aftermarket heads,any exhaust and any intake. 4.125x 3.330? 4.125x 3.250? 4.00x 3.50? 4.00x 3.48? What length rods work best for the best bore stroke combo? 3/8 high momentum track, 2900lb car.

dgb
Dirt Full Roller

Total posts: 70
posted April 05, 2005 07:41 AM  
If money were no object, I'd say to maximize the bore for just about any situation- especially in a non restricted carb situation where you'll probably be seeing alot of rpm. Since I'm sure money is an object, I'd stick with the tried and true 4.030 x 3.50 and spend your money on good heads and valvetrain. I guess I don't think there is enough of a difference either way with bores and strokes to justify the expense. Smokey Yunick would tell you to go with a 3.50 stroke and put the longest rod in it you can, (6.125 probably) and spend your money elsewhere. Some will disagree I'm sure, but I guess I'd stick with that advice. It all depends on your budget and how many rpm you plan on running.

dukeboyz
Dirt Newbie

Total posts: 4
posted April 05, 2005 10:57 AM  
$$$ not an issue

KSGerry
Dirt Freak

Total posts: 376
posted April 05, 2005 11:47 AM  
Best flowing non-aluminum heads...
One new pair of high flowing STEEL 18 degree high-port GM heads similar to the GM aluminum 24502569 (cast number 10134363). 255cc runners with 51 cc chambers. Fully CNC machined. Experimental design as GM does not offer steel 18 degree high-port heads...$1800. Can be purchased with new Ferrea titanium 2.15 intake and 1.620 stainless steel exhaust valves...$800.

Buy the complete package for $2400.

These were intended to be used on a 360 cid Sprint car. However, our sanctioning body now permits ASCS engines with spec aluminum heads.

Regards,
Gerry Dedonis "KSGerry"
dedonis@kans.com
785-655-3862

dirtbuster
Dirt Forum Champ
Total posts: 2007
posted April 05, 2005 12:00 PM  
Id go with the bigger bore(4.125) and 3.33 stoke as well,with at least 6"+ rods. Plan on turning it about 8000+ rpm. Put a good set of heads on it with matched intake, something like the 14 degree pro heads if you can find them. IF not maybe go with a set of 49cc iron eagles, cut to like 35cc or whatever and fully ported etc. then get an intake matched to them. Squeeze some flattops in there cut just enough to clear the vavles and try to keep compression 14:1 or higher.

dgb
Dirt Full Roller

Total posts: 70
posted April 06, 2005 06:18 AM  
yep, if the $$$ is no problem, then dirtbuster has it right. Plan on running alot of rpm.

chomme
Dirt Freak

Total posts: 300
posted April 10, 2005 11:50 AM  
pro 14 degree steel heads will blow any 23 or 18 degree head out of the water. i'd also go with the big bore short stroke. small bores shroud valves.

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