What is the difference?

[KAlder]

I have a 383 stroker that I put together in high school. The kid that has had it for the last 6 years sold it back to me. It has a broken crank, but every thing else is in great shape(the snout broke off). All the cranks I can find are for either 6 or 5. 7 inch rods. What does the crank care what rod is bolted to it? Balancing? If so, should I care (because I am going to have everything rebalanced anyways). It has the 5. 565 inch 400 rods.

 

[Dl5treez]

I have a 383 stroker that I put together in high school. The kid that has had it for the last 6 years sold it back to me. It has a broken crank, but every thing else is in great shape(the snout broke off). All the cranks I can find are for either 6 or 5. 7 inch rods. What does the crank care what rod is bolted to it? Balancing? If so, should I care (because I am going to have everything rebalanced anyways). It has the 5. 565 inch 400 rods.

Easy answer... any 3. 75" stroke 400 crank will work just dandy.

"old school" 383 stroker:
... I'm guessing this is what you have.

350 block, relieved at bottom of block for crank clearance.
350 pistons with relieved skirts
400 crank, flywheel/flexplate/balancer, main journals turned down from 2. 65 to 2. 45.
400 rods 5. 56"


"new school" 383 stroker:

350 block, relieved as above.
custom pistons with higher pin heights
400 crank, flywheel/flexplate/balancer, main journals turned down from 2. 65 to 2. 45
standard every-sb chevy-'cept-for-the-400 5. 7" rods.


"new school v2. 0" 383 stroker:

same as above but with:

super long 6. 0" or longer rods

custom pistons with super high pin heights and rings high up on the piston. sometimes the pins are so high, they intersect with the oil ring and require ring support rails.

Also, the long rods sometimes have clearance issues with the cams, so the rods have to be clearanced on the bolt shoulders and/or reduced base circle (smaller diameter) cams need to be ran.


Ideally, the longer the rod the better. Your old school short rod 383 has a max rpm of around 5500... . the 5. 7 rod 400 can go about 6500, the 6. 0 rod 400 can eclipse 7000 all day long... .


SO..... tear it down and build a long rod engine. :-laf

 

[KAlder]

Oh trust me, That is what I WANT to do! But thats not in the budget that keeps me in my bed and not on the couch. It's going into my jeep that mostly just idles around anyways, so high R's don't work. What is the difference between the cranks though?Why would Scat sell one for 6 inch rods and one for 5. 7 inch rods?

 

[KAlder]

Oh, and I like your signature, same boat.

 

[Dl5treez]

I'm looking at the Scat catalog and see all the various options. For a regular 383 stroker there should be no difference, unless the cranks are offset ground or some other minor adjustment...



Best thing to do would be to call them at 310-370-5501 and ask.

 

[Wayne M.]

A short rod chevy stroker really isn't a good engine because, as mentioned, the rods are optimally too short. The rod ratio is way off. In other words, the angle of the rod is too great, and this is not good. Kinda like having the seat too low on a bicycle and having to power your leg down from full fold. The 6 inch rod is the way to go.

This is where small block Mopars excel. Their stock rod was always 6. 125" and with a higher deck- that's a good motor to stroke!