Learning to make fast go fast!

[Bud]

well, poop

 

[rcm90]

I have an 8bolt kellogg laying around. Needs turned down, but it's yours for shipping if needed.

 

[05stroker]

I have an 8bolt kellogg laying around. Needs turned down, but it's yours for shipping if needed.

Thanks for the offer! Is it a 3.75 stroke?

 

[rcm90]

Thanks for the offer! Is it a 3.75 stroke?

Crap, thought you were standard stroke..

 

[05stroker]

Well, I tore down the motor yesterday and not real sure what happened. The balancer bolt came out by hand as y'all know, I have a crack on the rear crank journal, a bent I beam rod, and two pistons that hit the deck due to the fact that there was no bearings left on the number 4 and 8 rods. I will post some pics later after I get my computer hooked up. Good news is the valve train cams and heads all look good. So do all the other bearing, well as good as the can for that much metal floating in the oil. Oil pump gears are in tact as well.

 

[lito]

The rest of the bearings are good?

 

[05stroker]

The rest of the bearings are good?

Yes, they have some debris but are not starved for oil.

 

[lito]

No scratches like they knocked?

 

[05stroker]

What do y'all think, what happened first? Rod bearings are moly coated and the mains are not.

 

[05stroker]

This picture is the one I most want some answers on.

 

[lito]

OK, first theory, crank broke, rod bearings sized/spun, pistons hit chamber, this wore mains and bolt freed because of this banging.

 

[05stroker]

OK, first theory, crank broke, rod bearings sized/spun, pistons hit chamber, this wore mains and bolt freed because of this banging.

Exactly what I was thinking! I am open to other suggestions though.

 

[retfr8flyr]

I have to agree with Litto. I think the crank broke first and started all the mayhem.

 

[D98GT]

Any other carnage on the crank?

 

[05stroker]

Any other carnage on the crank?

No, just on the one broken journal.

 

[46Tbird]

This picture is the one I most want some answers on.

I have never seen a crack like that through a rod journal.

Second theory - I think you may have had a rod bolt let go, causing a piston to contact the head. Inspect and measure your rod bolts.

Now normally I would expect a rod to deform before transferring a shock force to a rod journal like that. But maybe those were just "really good" rods and the angle was right.

Do you mind if I put that photo up on another site or two to fish for answers?

 

[05stroker]

I have never seen a crack like that through a rod journal.

Second theory - I think you may have had a rod bolt let go, causing a piston to contact the head. Inspect and measure your rod bolts.

Now normally I would expect a rod to deform before transferring a shock force to a rod journal like that. But maybe those were just "really good" rods and the angle was right.

Do you mind if I put that photo up on another site or two to fish for answers?

Feel free to put it out there. All of the rod bolt where still torqued tight when I disassembled the sb. I do have one bent rod on #8.

Theory three could be that I lost a bearing on #8 allowing the piston to make contact with the head bending the rod and cracking the crank.

 

[travelers]

Theory 4 is it possible that the front pulley support you had made was/is out of balance with the crank and the harmonics took out the oil pump and the rest is history. The cranks I have seen usually sheer around a main journal not crack across the rod journal.

 

[05moneypit]

I know of two different stroker cranks that broke the exact same way yours did. Both were in a big HP heavy car and broke at the drag strip under load.

The only thing I can think of on the balancer is maybe the bolt was tight but the hub had galled and wasn't pulled all the way down and then loosened up under load?

Anyway it sucks. I admire your dedication to your car!!

 

[swflastang05]

Damn that sucks. It's difficult to speculate what caused the damage, I would lean toward theory #1 or #4 above though. Maybe time for a billet crank?