Hi people ...

Curious to know if the EF 12-counter weight crank is better than the 9-counter weight AU type crank?

Why did Ford make the change, was it purely economic or was ther a real benifit in revs and smoothness?


Cheers

Possibly lighter and they used longer rods from AU on..Pin is higher in piston also...The sump is part of crankase strength as well...On AU...

See heres the thing ...

The way the story goes is ...

EA crank is a carry-over from the XC-XF 250c.i. ... Theory being this crank had stuff all in the counter-weight department and added to the engines inabiliity to freely rev (and make power) much past the 5000 mark (many say even lower like 4250) ...

Then EB-ED got a bit extra weight and that helped .. note that all these cranks were 9-counter weight cranks ...

The EF then got a 12-counter weight crank ... This further assisted in the rev/power combo .... again SO the story goes ...

The the EL-AU went back to 9-counter weights but more mass than the earlier cranks ....

I guess the question is ...

A) Is all of this info gathered over time in fact TRUE?

B) The change back to the 9-counter weight crank. Was it for economics and the EF was better, OR was it in fact found that 9-counter weights worked better?

Cheers,

I can speak from experience with regards to the XF and its inability to rev, but I would have thought it was more to do with overall engine design / pushrod type setup that killed its chances to rev. If it is the same crank in the EA, they tend to rev alot easier and smoother than an XF, which I think is alot more to do with the OHC setup.

My understanding is the counterweights are there to balance the engine to aid in getting rid of any harshness, but at a cost of being able to rev as your adding more weight to the overall drivetrain.

The EF's got the extra weights to help balance the crank better to make the engine less harsh.

I can tell you that an EL engine revs more freely than an EF, and is about as harsh overall. Considering everything else in the engine is the same apart from the crank, there must be something to it. I think the 9 counterweight just works better overall.

It seems to work best in the AU, however, the AU crank is different to the EL and is better balanced. This one would have to be the smoothest rever of them all. If you can get a hybrid block and crank, that would bolt straight into any E series and give all the benefits.

Dont hybrid cranks use the same main bearings as AU? If so they aint going to fit in other e-series

I understand that to be correct. Its a hybrid AU/EL crank where the mains are the same as an AU, but the big ends are the same as the EL, so it could use the EL rod and piston.

They wont fit in an e-series block, but they will fit in a hybrid block, as it is an AU block. I've yet had the joy of removing the sump on my EL, but I am told that the hybrid blocks have all the bolt holes there to accept the AU sump and its extra bolts.

I will know in the next 2 weeks when I get get in there to change my oil pump. So hopefully I'll have a better idea of what makes a hybrid bottom end.

What about slipping one of these into an "X" series 250c.i. block?


Hmmmmm

I dont think that there is any power to be had by swapping cranks. The problem with XF's not wanting to rev is more of a top end issue, not the bottom. Having said that, a set of 200ci rods and acl pistons will help get em spinning.

NON of the 6 cyl Ford cranks have had any issues...
I wouldn't worry too much....
Unlike the V8 crank below after block became 2 X 4 cylinders..

 

 

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I do also know that there were two different cranks in the EL's. Apparantly there was a crank that they used for testing for the AU's.
They were only used for a short while (apparantly i have one) and rev out more. Apparantly rev till 6400 without any troble. And i know this from experence


But i also do know the AU cranks rev more and are less likely to go bang then the E series.

yeha the au have the best balance and performance crank

I would have thought that was more to do with the extra rod length than the crank