Factory Ford Forged 4v Crankshaft Question ?

[DOHC otto]

Does anyone know the forging process on factory forged 4v cranks ?

Are they drop forged or twisted forged ?

 

[darkside03gt]

Contact kellogg they make the cranks for ford

 

[DOHC otto]

Factory Ford Forged 4v Question ?

Does anyone know the forging process on factory forged 4v cranks ?

Are they drop forged or twisted forged ?

 

[san~man]

Please, only 1 thread next time.

 

[flstang65]

What is the twisted forging process?

 

[DOHC otto]

It has to do with the forging dies if they're single plane or two plane.

Some people say "twist forged cranks" are weaker because they are done with a single plane die and to index the crank throws at 90 degrees, the raw forging is twisted to offset the journals in two planes to create the final raw crank blank which is said to create internal stresses in the forging, as well as an poor grain flow in the metal.

Drop forged cranks are done with two plane dies and need no twisting to index, so when the are dies separated it "drop"s out a ready raw crank blank needing no twisting meaning improved grain flow in the steel and no stresses from the twisting.

However the best is billet forged cranks, meaning machined out of a billet of forged steel, way more expensive tho and I don't see Ford sending billet cranks out in factory cars.

So it has to be drop forged or twisted anybody know ?

 

[trinity_gt]

I think Kellogg was/is the forged crank supplier to Ford and I believe they used twist-forging.

 

[DOHC otto]

I think Kellogg was/is the forged crank supplier to Ford and I believe they used twist-forging.

Thanks man, I'll call them monday and ask for sure. I didn't see where the other guy posted it when they moved my thread.

 

[trinity_gt]

Why's it so important?

 

[DOHC otto]

I was told twist don't respond well to boosted setups, I was about to start my short block and I was going to use the factory crank if I could. If its twist then I'll just order an entire new forged rotating assembly.

 

[bdcardinal]

I was told twist don't respond well to boosted setups, I was about to start my short block and I was going to use the factory crank if I could. If its twist then I'll just order an entire new forged rotating assembly.

most of the rotating assemblies with forged cranks you see on the market for mod motors are actually Kellogg made factory cranks.

 

[trinity_gt]

I was told twist don't respond well to boosted setups, I was about to start my short block and I was going to use the factory crank if I could. If its twist then I'll just order an entire new forged rotating assembly.

The factory Cobra crank is a pretty stout piece easily capable of withstanding a thousand or more HP. And remember, the 2003-04 Cobra was factory "boosted" and responds very well to mammoth twin-screw blowers upping the power to insane levels with no internal reciprocating assembly upgrades at all.

Just how much power are you planning to make? Is this a daily-driver, street/strip, race only or ... engine?

If you're going to be making power that you believe will tax a factory steel forged crank, you're probably going to be looking at every aspect of the rest of the drivetrain, the suspension, the chassis etc too...

 

[DOHC otto]

I'm hoping to make around 650 crank, 550rwhp with a KB 2.6 . My concern was I would build it for that and then want more power using nitrous or turbo on top and have to take it back apart to put a better crank in it to handle the thousand or so hp.

I have the rest of the drivetrain planned out to handle the upgrades.

 

[Mustang92]

There have been plenty of guys making 1000RWHP on the stock Cobra crank with no problems so I don't think you have much to worry about.

 

[DOHC otto]

Slow on calling Kellogg but I finally did. They are twist to answer the thread, I'm still going to use it with my teksid and forged rods and pistons I'd say the bottom end is gonna pretty much bullet proof. If I don't screw it up putting it all together lol.

 

[twogts4us]

A Cobra crank won't be the point of failure...