Mystery

[unbeam]

Thought I'd post my engine problem to get the feel of the group prior to finding our the answer. 6 bolt 289, rebuilt about 10 years ago, largely stock, iron heads/hydraulic lifters, assembled by the machine shop. Sat on engine stand for years, periodically turned over with a socket. Reinstalled in car and gotten running, but sat for several more years. Would start it periodically until one day it would crank but not start. Finally had it taken to my mechanic, who found a broken push rod in #7. Rockers and head looked OK. Drained oil, and coolant in the oil....
Head off, no obvious damage there or to piston. Removed piston, no visible damage to cylinder. Now it goes to the machinist for exam and magnaflux. Any thoughts or predictions? Anyone ever seen this on an engine with 0 hours? Thanks, David

 

[Austin Healer]

sounds like a failed headgasket let coolant into a cylinder. the engine hydrolocked, bending a push rod....

 

[0neoffive]

sounds like a failed headgasket let coolant into a cylinder. the engine hydrolocked, bending a push rod....

DITTO

 

[michael-king]

sounds like a failed headgasket let coolant into a cylinder. the engine hydrolocked, bending a push rod....

Yup.. Maybe HG failed as engine was only turned over and periodically started.. So assume the head never got torqued down as the motor never got run in... But did heat cycle.. Probably have been better to never started it .. Just turn over by hand and have oil and assembly lube in it.

 

[unbeam]

The head gaskets looked OK. Would love for that to be the issue, as any other options are much higher $$$

 

[Austin Healer]

The head gaskets looked OK. Would love for that to be the issue, as any other options are much higher $$$

There is only one other possibility, and it depends on what type of valve guides you had installed. Cast iron valve guides are dimensionally stable. Bronze valve guides are not. Bronze valve guides require more clearance, or they can seize on a valve stem when hot... I've had this happen on a couple of engines coming through my shop. It's why I always specify cast iron valve guides on engines I am rebuilding.

 

[unbeam]

Thanks, engine at the machine shop now. Also not sure if the block was magnafluxed the first time around