Crank failure

[lance flake]

A pass on a crack test of course doenst mean a oart wont develop a crack later on in use but at least you know you are starting with a good piece and have the peace of mind that you at least tried to make sure everything was good.

Craig do you know anyone else that makes a crank with 4.25 stroke and the 3" main? Most I've seen run the cleveland main.

Eagle used to make one. Not sure if they still do

[cjperformance]

A pass on a crack test of course doenst mean a oart wont develop a crack later on in use but at least you know you are starting with a good piece and have the peace of mind that you at least tried to make sure everything was good.

Craig do you know anyone else that makes a crank with 4.25 stroke and the 3" main? Most I've seen run the cleveland main.

Steve, as Lance mentioned Eagle did make one in 4.250", the last one . As far as im aware 4.170" is it thses days.
Which does make for a WAY easier clearance job compared to 4.250" !

[1972ho]

You might want to check with Tim Meyers website I’m sure he has a 4.250 crank just not sure if it’s 3.00 mains.

[midnightbluS10]

Probe makes/made a 4.250 stroke x 3.000 main crank

https://www.coasthigh.com/Probe-4340-Cr ... -14672.htm

[Steve.k]

Thanks guys. Tim does have these 4.25 and now molnar 4.35.

[cjperformance]

Thanks guys. Tim does have these 4.25 and now molnar 4.35.

Nice, what size big end on the 4.35 crank?

[Steve.k]

Thanks guys. Tim does have these 4.25 and now molnar 4.35.

Nice, what size big end on the 4.35 crank?

3" on main 2" on jornal.

[MadBill]

Not much journal overlap there!

[cjperformance]

Not much journal overlap there!

Yes Bill, very scary looking ammount of material on these cranks in this area!

[Steve.k]

Not much journal overlap there!

Yes Bill, very scary looking ammount of material on these cranks in this area!

Do you think the cleveland journal size would be better?When u think of a 460 crank with same kinda stroke theres alot more beef.Im not sure why they went 2.0. This one that broke is cleveland size.

[Walter R. Malik]

Not much journal overlap there!

Certainly a lot more than a "Mountain Motor" Pro Stock crankshaft having a 5.750" stroke with an even smaller main.
Those throw arms are not thinned out and the lightening hole is not so large like these cranks, though.

The big engines made a whole lot more torque and horsepower, too.

Most people don't think of it this way but, engine bearings are "consumables" to be replaced often, if need be.

[Steve.k]

Broke her off the rest of way. Some interesting lines.

IMG_4057.JPG

IMG_4056.JPG

[Steve.k]

Couple more.

IMG_4058.JPG

IMG_4059.JPG

[1972ho]

Kind of just like my v-6

[Ken_Parkman]

Sure looks like fatigue to me - which makes X2 on the damper not doing its job. Not tuned for the combination.