Farmall H oil pressure

[boomer1025]

SG: thanks for the input--valuable stuff as usual.

I'm facing a ring job on my 1948 Farmall Cub. Lapped the valves but the compression is only about 60 psi (wet) now. Should be about 100 psi on a 6.5:1 compression engine.

Question: when you do a ring job on your Fords, etc. do you put in oversize rings (0.020" etc) assuming that there's significant wear on the cylinder walls? Or do you just use standard size rings?

I want to do the ring job on that Cub in my shop without having to send the block to the machine shop if I can avoid that.

You'll have to check the taper in the cylinders to find out if you need to have it bored and use oversize pistons & rings. I'm not sure if that engine would have sleeves or not. Maybe someone else would know about weather it's sleeved or not.

 

[Soundguy]

SG: thanks for the input--valuable stuff as usual.

I'm facing a ring job on my 1948 Farmall Cub. Lapped the valves but the compression is only about 60 psi (wet) now. Should be about 100 psi on a 6.5:1 compression engine.

Question: when you do a ring job on your Fords, etc. do you put in oversize rings (0.020" etc) assuming that there's significant wear on the cylinder walls? Or do you just use standard size rings?

I want to do the ring job on that Cub in my shop without having to send the block to the machine shop if I can avoid that.

i'd make the judgement on ring size based on cyl bore...

soundguy

 

[Soundguy]

Maybe someone else would know about weather it's sleeved or not.

if an engine has sleeves, you should see them from the block deck..

 

[BobG_in_VA]

You'll have to check the taper in the cylinders to find out if you need to have it bored and use oversize pistons & rings. I'm not sure if that engine would have sleeves or not. Maybe someone else would know about weather it's sleeved or not.

Cub engines are not sleeved...you would need to re-bore the block. BobG in VA

 

[art]

The only oil that should be ran in those old farmalls a non detergent oils straight 30w if you use modern eng oil it will wash out ur bearings

This is not true! I have more of an issue with putting diesel oil in a gas engine then to use a detergent oil. Diesels require more ash in the base then a gas engine would need which will wind up on the valves normally to burn them.

 

[Soundguy]

This is not true! I have more of an issue with putting diesel oil in a gas engine then to use a detergent oil. Diesels require more ash in the base then a gas engine would need which will wind up on the valves normally to burn them.

that's almost as bad as the ND comment.

As long as the 'diesel oil' in question carries the correct 'S' rating, it us fine for a gas engine. likely higher ZDDP as well.

I have only rarely seen 'C' rated oils that did not also carry an 'S' rating..


soundguy

 

[flusher]

if an engine has sleeves, you should see them from the block deck..

No sleeves in that Cub 4-banger. I did check the cylinders when I did the valve job--no ridges at the tops of the cylinders.



I may just do a poor man's rebuild (rings, rod bearings) and replace the valves and guides also.

 

[Soundguy]

from the factory it had none.. but I always advise people to check. as you never know what's been done to it in 50+ years.

are the valves bad or can you hand lap them?

I just did a poor mans upper on a 63 4000...

soundguy

 

[flusher]

from the factory it had none.. but I always advise people to check. as you never know what's been done to it in 50+ years.

are the valves bad or can you hand lap them?

I just did a poor mans upper on a 63 4000...

soundguy

Lapped them. Compression test (wet) showed about 60-70 psi on the cylinders with the lapped valves up from about 40 psi before lapping. Should be around 100 psi (6.5 compression ratio). Figure I'll be doing rings next.

 

[Soundguy]

hmm... methinks seats as well...