OUPSSS the block

Wotland · Post by **Wotland** » Wed May 07, 2008 10:27 am

Hi,

The P38 4.0 of one guy here suffered of overheating, after removed the valley gasket he discovered this horror

:

Do you have an idea of the origine of this particular block failure ?

kiwicar · Post by **kiwicar** » Wed May 07, 2008 11:00 am

I think getting a head off may reveal a piston/ valve contact situation. Otherwise it could be the tappet momenterily siezing in the bore and kabang as it lets go.
Mike

ian.stewart · Post by **ian.stewart** » Wed May 07, 2008 11:01 am

1st guess, is it a reground cam? on a used core, I am wondering if the cam has been reduced to below its minimum base circle dia, which can exert side loads onto the lifter.
Dosent look like the pushrod is bent, is the rocker gear broken??, If not it indicates to me its a cam/lifter problem,

Wotland · Post by **Wotland** » Thu May 08, 2008 10:46 am

No broken rocker gear or bended pushrods.
I think me too it is an tappet momenterily siezing in the bore due water infiltration because valley gasket failure...

kiwicar · Post by **kiwicar** » Thu May 08, 2008 2:27 pm

Another thought, could the edge of the tappet have dug into the ramp on the cam, unlikley I know but if a big enough hollow had formed on the face of the lifter it could result in the cam jamming the lifter in the bore and it breaking out from the side load as the ramp came around

Whatever it was it must have generated some spectacular forces as it happened.
Mike