Thread: Crank Question?????????

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I am trying to build a 383 how emportant is it to go with a 4130 crank I know it is stouter but is a 5140 that much less than the 4130.

Thanks
ChevyDave

I am trying to build this on a budget but I dont want a piece of junk.

4340 is very good but there is 300m and that is the top of the line 5140 and 4130 are good and about the same some of the cheap cranks i seen both ways 4130/5140 and there not sure what they sell? if your going very hi hp and rpm you want 4340 i have used all of them even stock iron cranks . has alot to do with what your looking to do

4340 is a stronger and tougher (as in fatigue resistance) alloy than 5140.

Kitz

If your on a tight budget,your not gonna twist it over 6500, and your not putting it in no more than a medium weight car, a good seasonded stock crank will work just fine...You do need to have it checked by a knowlegable crank shop..

Originally Posted by kitz

4340 is a stronger and tougher (as in fatigue resistance) alloy than 5140.

Kitz

yes your right and 300m it better yet. better know as 300M timken $$ they are all alloys of steel with a mix of many thing .the first number indicates class like the 40 in which the steel belongs in like carbon molybdenum steel and fine grain after carburizing are at there maximum physical properties THE 5140 steels are chromiun alloy and may interchangealby with alloys of 2340 3140 if you want to know more about steel the machinerys handbook is handy i have other books on make up of steel and iron but this stuff falls out of my head

Its going in a chevy short wide bed about 4200lbs. I am looking to buy new and I am "probably" not going to exceed 6500 rpms.

Originally Posted by HWORRELL

If your on a tight budget,your not gonna twist it over 6500, and your not putting it in no more than a medium weight car, a good seasonded stock crank will work just fine...You do need to have it checked by a knowlegable crank shop..

yes your right we would go over the stock crank iron or steel round off sharp spots and smooth any machine marks wrap the main s and rods with duct tape and thin cardboard and many rolls of tape over the main and rod pins the shot peen the hell out of the crank before any crank grinding was done then you have a very nice looking crank and over all better then in it stock form

Originally Posted by ChevyDave

Its going in a chevy short wide bed about 4200lbs. I am looking to buy new and I am "probably" not going to exceed 6500 rpms.

on or off road ??on road new scat cast steel . on and off road then the 4340 with power adders or 4130.will work you still have not told us much on max hp or use. any of the alloys will work in time they all can fail running the crank out of oil and quality of oil and trash in the bearings along with oil clearances will make the best crank fail

I've read where David Vizard has buzzed a Scat cast steel crank to over 550 hp repeatedly on dyno pulls without a failure. Now, that's CAST STEEL, not cast iron.

I am not sure on the horsepower I want as much as I can get on a budget. See my biggest issue besides money is I have never raced or built a motor so I dont know what horsepower does what. I just know bigger is better. It is for on road use street/strip. Its going in a 4200 lb pick up. Not sure about rear gears and thinking about a turbo 400 or 700 R4. Keep the info comin I appreciate every bit of it.

i would think a cast steel scat crank will do along with a set of speed pro hyper pistons would do.you will save some money here and put your money in the heads and a roller cam .if you were going in mud pits or pulling and any Nos with hi rpms then i would tell you 4340 and forged pistons and some block pre work

Agree with Pat.