641 ford

[jr1983]

Ive got a 641.sn5775. It sat for a couple decades behind my in-laws house. I was trying to get it running and it would pop here and there but wouldnt start. I had oil pressure when cranking. I replaced the oils pressure gauge and it hasnt had an oil pressure reading since. I didnt think a lot of it because it hadnt started yet. After a while of cranking on it the engine started slowing down regardless of battery charge. I was thinking about stuff and pulled the valve cover. The whole underside is quite rusty. Valve springs etc. it wont turn over with the starter now though it doesnt appear to have a stuck valve. Probably going to have to overhaul it if I had to guess. Anything I should be aware of going into this? Common problems etc?

 

[old]

Good chance it has a broken ring or 3 due to you spinning it over with out doing an ATF treatment to free up the sticking rings it is likely to have. But there is still a little hope that it is just due to rusty cylinders and an ATF treatment may help

 

[jr1983]

Well at the very least Im gonna pull the head on it. Ive never heard of broken rings locking the engine up but thats not to say it cant happen.

 

[old]

A broken ring can get wedged between the cylinder wall AND piston and score the sleeve badly and lock things up

 

[jr1983]

Well that makes sense. I cant imagine the thing breaking a ring no more than it took to get it spinning. It wasnt stuck at all and you could turn it over by hand originally. Time will tell once I pull The head on it. The way its acting Im almost wondering if it was oil pump failure.

 

[Keith-OR]

It is almost impossible for a broken ring to get wedge between the piston and piston wall(sleeve). The only way that could happen if by chance a ring land broke, there is not enough clearance between piston and sleeve wall.!!!
IMHO, ATF is a joke, was manufactured for transmissions not rust remover or penetrating oil!!! Use Kroil or BP Blaster, or any good penetrating oil..

 

[Keith-OR]

1st thing I would have done, is drain the oil and put in fresh oil, 2nd the minute I lost oil pressure I would have pulled distributor cap and made sure the rotor was turning, as distributor is what drives the oil pump!!. I would pull the oil pan and check the pump pickup, might be plug with sludge.

Buy good shop service manual!!

Good luck

 

[jr1983]

It had oil pressure when cranking then I changed the gauge. Not uncommon to have it take some time to fill the line at low rpm so I didnt think about it. Thanks for the dist tip. It was still turning when it stopped.

 

[Keith-OR]

All the indications is that the crankshaft run dry of oil, I would figure out how to turn the oil pump, after pulling the dist.

 

[Eman85]

Pull the plugs and turn the engine by hand and see if it is hard to turn. Been sitting for decades electrical system might not be in too good condition.
I don't get the it had oil pressure so you changed the gauge part.

 

[jr1983]

I just replaced all the gauges. It had oil pressure till I
changed the gauge. I was thinking the line just hadnt
bled out yet. Now not sure