Aftermarket Forged Cranks?

[~JM~]

Is there a thread that describes the various aftermarket crankshafts available, the specs, availability, costs, etc?

Also interested in learning the extent of machining operations required to prep the cranks & provide clearance for a stroker.

I'd prefer an internal balance crank suitable for a 3.8L or 4.1L production block.

Do the "long rod" combinations require a piston configuration where the piston pin intrudes into the lower rings? Are the piston skirts shorter?

What about flex-plate & harmonic balancer availability?

Thank you.

 

[dank GN]

This topic has been covered a bunch of times if you just search Forged crank I’m sure all your questions could be answered. There is no difference between the 4.1 Crank and 3.8 btw . Also if you are looking to buy a rotating assembly you can check out our cranks and rods Ect at www.boostedrps.com
And if you have any questions Tyler’s number is on the website and can help you pick the right setup for you

 

[~JM~]

Thanks. I've done several searches & read various posts. Some are fragmented, missing pics, old data, etc.

I understand that the same crank fits the 3.8L & 4.1L. I added that information to differentiate between stock OEM blocks vs. after-market or Stage blocks.

 

[TURBOELKY]

Is there a thread that describes the various aftermarket crankshafts available, the specs, availability, costs, etc?

Also interested in learning the extent of machining operations required to prep the cranks & provide clearance for a stroker.

I'd prefer an internal balance crank suitable for a 3.8L or 4.1L production block.

Do the "long rod" combinations require a piston configuration where the piston pin intrudes into the lower rings? Are the piston skirts shorter?

What about flex-plate & harmonic balancer availability?

Thank you.

The available 4340 forged stroker cranks for me so far have been spot on. The most work is getting the rod to cam clearance taken care of, and just a little clearance Work on the block where the oil galley is.

On the long 6.5” rod, you will have the pin in the ring landings which require ring supports that come with the ring set. It will have a smaller .927” (sbc) wrist pin. Not sure if the 6.350” rods get into the rings but I imagine they are close.
As far as flex plates and balances, they are available. BHj makes a damper, TA sells a steel balancer which can be used internal or external.
JW wheel makes a nice flex plate for both internal and external, as well as some Chinese flex plates that are pretty stout.

Nick Micale carries all this stuff and is always a pleasure to deal with. He also is good with getting a proper cam spec’d To your application, and anything that TA Performance sells he has available.

Hope that helps a little.

 

[~JM~]

Where does the rod & camshaft interference occur?

Is the use of a reduced base circle camshaft required?

 

[TURBOELKY]

Where does the rod & camshaft interference occur?

Is the use of a reduced base circle camshaft required?

Yes. Small base circle camshaft.
It occurs at the top thread outlet area in the rod, not the cap. I believe molnar rods addressed this slightly by making their rods with a little more clearance in that area, but I’m sure still require some clearance.

 

[dank GN]

If you look closely you can see where some material was removed . I took some off the treaded part of the rod bolt

 

[~JM~]

If you look closely you can see where some material was removed . I took some off the treaded part of the rod bolt

Compared to the rods laying next to the one you're holding, it appears that approximately +/-1/4" was removed.

Does every rod require modification, or just a few?

 

[dank GN]

Compared to the rods laying next to the one you're holding, it appears that approximately +/-1/4" was removed.

Does every rod require modification, or just a few?

It’s a motor by motor kinda thing bud . You would mock it up and see where your interference is and remove the material to get the proper runing clearance. And you would want to do all this before you take your motor to get balanced .

 

[~JM~]

Familiar with engine mock-up requirements/techniques.

Usually on a N/A V-8 though.

 

[dank GN]

If you understand engine mock up Ect. It is the exact same deal with the v6 . All the rods would require some trimming for a stroker setup aswell as some modifications to the bottoms of the cylinders . Agian all this will become aparent when you mock it up .

 

[marleyskater420]

OP, are you still looking for a crankshaft? I've had some family issues last couple days so I havent been able to post.

What can I do to help clear things up?