Built Motor...identify Crank

[BradleyMustang3]

so i bought a motor ant t5 wc trans for my Cobra and i was told the engine was rebuilt with an e cam but when i called the shop that built it i was told that the motor was built all forged internals with a 347 stroker crank....is there any way to tell what crank is in the motor while its still out of the car? ive read that you can take off the oil pan and get the serial numbers off the crank and rods...anyone know if thats valid or any other way i can confirm internals without tearing the motor down?

 

[revhead347]

There should be a stamp on the front or rear of the crank.

Kurt

 

[Rick 91GT]

There should be a stamp on the front or rear of the crank.

Kurt

Depending on the brand it may have a casted in logo or a stamp on the front counterweight or a pt#. If you can post a picture I have pretty much seen all the aftermarket cranks and can I'd most brands. Also get a good pic of the rod.

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[revhead347]

Also if you know the imbalance, that's a good start. Their is currently no forged crank that I'm aware of designed for the factory 50oz imbalance. Scat and Eagle offer forged cranks in 28oz imbalance and neutral balance. If it's a 50oz imbalance, then it's probably a cast crank. Most of the cast cranks are made in China now.

Kurt

 

[BradleyMustang3]

I took the part number off the harmonic balancer its a ford oem balancer. Does that help?

 

[BradleyMustang3]

Can I see that stamp on the crank with the motor together and flywheel attached...I looked I didn't see anything just a part # on the harminc bal.

 

[revhead347]

I took the part number off the harmonic balancer its a ford oem balancer. Does that help?

Yeah, run the number on the stock balancer. Ford only made 28oz and 50oz imbalance balancers. If it's a 28oz imbalance, then it could be a forged crank. If it's a 50oz imbalance it's a cast crank.

Kurt

 

[Rick 91GT]

Can I see that stamp on the crank with the motor together and flywheel attached...I looked I didn't see anything just a part # on the harminc bal.

The stamp or marking will be on the front counterweight of the crank

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[BradleyMustang3]

E4te a3a 50oz does that rule out 347 or just forged vs cast? I know I can pull tue water pump and ger the numbers off the cam to identify that

 

[revhead347]

I would normally say it rules out a forged crank. There is a way to force balance a forged crank to make it work with a 50oz imbalance, but there is no reason to do that. It would meaning over drilling a $700 crank shaft to make it work with a $70 balancer. It's highly unlikely. They do make a 50oz imbalance cast crank though. I think SCAT makes it. Don't let that get to you too much, a cast crank is still rated to 500hp, which is almost as much as a stock block will hold anyway.

Kurt

 

[BradleyMustang3]

So if that's the case where does that leave me with identifing the crank without taking it apart or measuring displacement?

 

[Rick 91GT]

I'd be more worried about if it is a 347 or not. I would pull the oil pan off the motor look at the crank and rods pictures will tell me everything...

Pulling the water pump will not give you access to the cam numbers you would also have to pull the timing chain the cam retainer, the pushrods the lifters and slide the cam out to look at the rear of the last journal.

Is the motor still out of the car? Are the heads off?

Like Kurt said nobody would balance a forged crank to 50oz it turns the crank into a piece of Swiss cheese. Nearly every engine builder balances stroker motors to 28 ounce or 0 internal

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[Gearbanger 101]

If the motor is out of the car, you could punch out the rear frost plug at the back of the block and just shine your flashlight into the hole. Most manufactures will stamp of engrave the part number on the rear of the cam. I'd rather knock out and have to replace a $2 frost plug than changed $50 worth of gaskets?

At this point I'm with Rick and suspect that it's not actually a 347. Most engine kit manufactures push the 28oz balance strokers over then 50oz balance units....forged or cast.

 

[BradleyMustang3]

Yes its on my garage floor. Ill drop the oil pan tomorrow(12 hour shift today) and post up some pictures. I'm hoping it is a 347 but if its just a 306 with a cam I'm still ok with that...either way I have a fresh motor which is my blank canvas to build upon...for 600 $ with a trans It was a steal.