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Author Topic:   engine builders help!!
unlucky13
Member
posted June 14, 2003 10:31 AM
7/16 stroker-350 crank offset ground to 3 7/16 stroke w 2"crankpin.

9/16- same except offset the other way.
NO other special machining required, both need custom compression height pistons.
The only reason to build one of these is if you need an odd displacement.


unlucky13
Member
posted June 14, 2003 11:34 PM
If your motor took a standard 350 piston your crank was not offset ground.A 2" crankpin is 283-327 size,350 is 2.100".Small journal cranks have less friction because of smaller bearing area. Winston cup and others even use Honda size (1.88")journals.


unlucky13
Member
posted June 15, 2003 09:59 AM
It simply makes a 359ci engine if you use a +.030 bore . The piston needed would be a custom built piston . This combo will produce decent torque number's , but will be severally horse power limited . This combo is something that was played with a long time ago , and abandoned by most everyone . I'd back up and use the bigger bore combo with the shorter stroke .

Steve

------------------
Hendren Racing Engines
Rutherfordton , NC
(828)286-0780


unlucky13
Member
posted June 19, 2003 11:21 AM
Yes , the 3.480 , 3.500 , 3.562 , and 3.625 X 4.125 or bigger bore will make your best all around combo if your looking for an engine in the 377ci - 393ci range .

Steve

------------------
Hendren Racing Engines
Rutherfordton , NC
(828)286-0780


unlucky13
Member
posted June 20, 2003 09:03 AM
That is an extremely heavy piston .With a 625 gram piston on a 305 crank , you will more than likely be adding weight to the crank to get it balanced . I would look at JE's , SRP line of forged pistons . I believe they make a shelf stock domed piston for your application . I'm not sure on the weight , but I'd imagine about 100 grams lighter or so , and probably around $450.00 for a set with pins . Maybe even look into Weisco's Pro-True pistons as well . No matter what you use , you will have to balance this rotating assembly .

Steve

------------------
Hendren Racing Engines
Rutherfordton , NC
(828)286-0780


unlucky13
Member
posted June 24, 2003 10:48 AM
I'd still look elseware for piston's . The ones that you are looking at are depth charges . Do you have to run a 4 valve relief piston ,and 76cc heads ???

Steve

------------------
Hendren Racing Engines
Rutherfordton , NC
(828)286-0780


unlucky13
Member
posted June 25, 2003 10:32 PM
just for kicks I toyed with the idea of the 307 block and 400 crank and came up with a jeeep 4.0 litre piston that only needs the rod pin end honed .004 (chev pin diameter=.927,jeep=.931) and valve reliefs fly cut to work.never tried it though because I figred the .125 smaller bore(vs. the 350) would shroud the valves too much to take advantage of the stroke.

rod length 5.565(400 rod)
stroke 3.750(400 crank)
bore 3.895(.020 over for 4.0 litre jeep,.020 over bore 307)
CD 1.581(stock 4.0 litre jeeep,piston is a 11.5 cc dish)
0 deck=9.025(supposedly stock chev, when .004 is milled from top of piston)
cubic inches=354
copression=8.933 (before milling .004 from piston and fly cutting valve reliefs,might cancel each other out?) with 76 cc head,.020 thick head gasket
silvolite part#2228 for piston
piston dish is shaped like (_) with closed top(couldn't find symbol to fill it in)
pins are also offset

the little air pump would be starved too much but it is still an interesting idea for a low rpm mill,like for a hauler?

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