Stroking over 4 inch
- Thread starter dusmon
- Start date
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stroked340
Well-Known Member
Haven't started it yet but planning on a build using the 4.25 stroke crank..
6pkScamp
Well-Known Member
Lovin my 4.25.
SRT_DSTRHOLC
Well-Known Member
I plan on the 4.25 but with turbo!
Marcohotrod
Well-Known Member
what bore size are we talking? I think going undersquare is overrated. more friction, a very short piston, for what-a little more low end torque? when car craft built a 440, a 460 ford, a 454, and a 455 buick and a 455 olds and a 455 pontiac, all with similar carb,intake, heads, cam, comp. ratio etc. - the 440 had the shortest stroke - 3.75" - and made the most torque. when wally booth went pro stock raceing, and the rules were pounds/cubic inch, they tried 340 cu. in., 350, 360, 370 and over 5000 rpm they all made the same horsepower
Ditto. Getting my heads done first. Once there finished and paid for, it's on to the 340 block. Off to the machinist to check it out.
Do tell...
Small & focused crowd here. Many have the 4.0. The relatively new 4.25 has t been done much here. DJV did it. He has a thread on it from start to finish. I am planning on it now. It will be awhile until completion.
Macho, the answer is; more torque and less rpm. HP is not a consideration so much over what the 4 inch arm makes because we know about your HP example above. You make a good point about a long stroke engine and the friction though with any bore and stroke combo, one could argue and point out short comings. It really depends on what and how your doing. Shorter stroke engines have there merit no doubt. Then Again, high reving engines are high stress engines vs. big stroke low rpm engines.
I've had a few 3.31 stroke high rev combos and there great fun. Love a high rpm screamer.
Ohhhhh that sound @ 7K+!
Same as the 3.58 combo. Had a few. Again, great fun. Same HP with more torque at a lower rpm.
EL5DEMON340
Well-Known Member
I haven't done one yet but plan on a 4.125 in a hopefully .020 over 340 for about 427ci. I think when you go to the 4.25 you MAY have to notch or modify the oil pickup. I haven't heard of anything wearing out quicker than a standard stroke build, in fact with the shorter pistons and light rods the whole rotating assembly is much better and lighter then the old heavy sb TRW dome pistons and stock rods that were the norm 20+ years ago.
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