4.2?

schwalbe

Registered User
Found an f-150 2004 that's being parted out. Would the crank work in a super coupe? If so what would be a good price? Any other parts I should look for? It also has 63k on the motor
 
Yup, there are probably 10 or more of us already running them....including some of the big dogs....of course you have to also get some compatible rods and pistons to make it work.....not the stockers out of the 4.2 either. they are good for a normally asperated engine but cannot handle boost....Dan
 
Price

As far as price goes I got my brand new one for $100.00 on the internet. It was the same one Dave D uses I believe he said.

Smitty
 
I believe there are also block modifications needed to do a stroker motor.

Nope, don't have to touch the block because of the crank change....
My first exercise was to keep the stock SC rods and use some stock replacement 98+ Mustang 3.8liter pistons...this required taking some of the center counter weights off to clear the piston skirts (cost me 100 bucks to mod the crank) the crank still 0 balanced without Mallory metal so it was a cheap build. and I believe if I had used some forged pistons for that model mustang it would still be running....I cracked a piston due to detonation (I suppose).
I built it to compete in the "fastest stock appearing" class we ran for a couple years and it won...it made 271 hp and 375 torque with a 94/95 blower (unmodded) a stock intercooler and a slightly worked stock MAF, throttlebody and breather box. It did have a little cam in it with some home ported heads. I drove it to work and back daily for nearly a year before the piston cracked so it could have been made to live with minimal changes (meth, or double intercooler, slightly different tune etc.) Dan
 
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Lol I know this ;-) but would anything have to be changed on the block?

Just the bore....the crank does NOT require any changes to the block. You do however have to get the main bearing to match the crank, an SC crank has the rear main ground undersize but the 4.2 crank does not.
As with any stroker situation, you need to be extra careful during the assembly to make sure the parts you have chosen to complete the assembly doesn't require some clearance, such as rod bolts and the bottom of the cylinders, but that would be more due to rod choice than crankshaft. The parts I chose fit just fine.
 
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Ok why cant you just use the 4.2 short block? or mb rebuild the 4.2 with forged pistons?

You can, but most here are starting with a 3.8 SC motor. If you have an early model SC, you may also have problems with the crank sensor mounting, because 89-93 the sensor bolts to the block, and the 4.2 block may not have provisions to accept the early model sensor. Late model SC motor uses a timing cover mounted sensor and you should be able to transfer the timing cover without any issue. You just need to be sure to use the correct vintage 4.2 motor that has a netural balance crank.

David
 
Nope, don't have to touch the block because of the crank change....
My first exercise was to keep the stock SC rods and use some stock replacement 98+ Mustang 3.8liter pistons...this required taking some of the center counter weights off to clear the piston skirts (cost me 100 bucks to mod the crank) the crank still 0 balanced without Mallory metal so it was a cheap build. and I believe if I had used some forged pistons for that model mustang it would still be running....I cracked a piston due to detonation (I suppose).
I built it to compete in the "fastest stock appearing" class we ran for a couple years and it won...it made 271 hp and 375 torque with a 94/95 blower (unmodded) a stock intercooler and a slightly worked stock MAF, throttlebody and breather box. It did have a little cam in it with some home ported heads. I drove it to work and back daily for nearly a year before the piston cracked so it could have been made to live with minimal changes (meth, or double intercooler, slightly different tune etc.) Dan

I remember your build. Interesting. One question for you: Why did you use the Mustang pistons instead of SC pistons?
 
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