F-20 stuck pistons.

[Chris NW Ind]

I'll find out soon enough but my understanding is the piston will clear the crank. But not if the crank won't rotate.

 

[rustred]

no you dont pull the crank, just turn the throw out of the way. do you know how big these cranks are.

 

[rustred]

the only way they will come out the top is if you push the piston out with the sleeve.

 

[Chris NW Ind]

no you dont pull the crank, just turn the throw out of the way. do you know how big these cranks are.

Understood. Thanks for all the advice. I am determined to get this thing going.

 

[Chris NW Ind]

Quick update. Got the pan drained and removed. Bad news is 2 gallons of water came out followed by 2 gallons of oil. Good news is the crank and rods seem unharmed.

Just finished spraying the crankcase with diesel and drying it out.

I'll try for the rods later.

Also, a quick straight edge check shows the head is indeed a bit warped where the gasket was discolored.

 

[Chris NW Ind]

Does the oil pump simply drop down with some twisting after removing those bolts? Kind of like the M I think.

 

[Chris NW Ind]

Underside of 2 and 3.

 

[kshansen]

Underside of 2 and 3.

I understand better now! Seeing that picture and also looking at another site about the F-20.

 

[Chris NW Ind]

Made the briefest of progress today. Got rod #4 undone, but it won't clear the crank as is.

It's also apparent the block has a significant amount of corrosion and scale in it. Once the sleeves are out, I can clean it out better.

 

[rustcollector]

Chris,
I would start with a cylinder hone or coarse steel wool, Kroil and a hand drill and clean and oil the cylinders (all 4) then try to move the crankshaft forward or back. Doesn't look too bad to me. Would appear that exhaust valves on #2 and #3 were open letting the moisture in. Check these valves for being stuck. Open a side port on the engine and measure the width of the rod at the cap (diagonal across the rod). If less than 3.75 inches it will go out the top. If it ran good before it sat and stuck, then it should run as good without disassembly once freed up.

 

[Chris NW Ind]

I'm pulling the pistons and fully expect to find stuck rings. More water got in there than I guessed. Seems to all have been down those pistons--I haven't found any other damage. One valve was stuck, I forget which cylinder. It's already freed up. The head will be going to the machine to get planed soon enough.

 

[rustred]

Made the briefest of progress today. Got rod #4 undone, but it won't clear the crank as is.

It's also apparent the block has a significant amount of corrosion and scale in it. Once the sleeves are out, I can clean it out better.

did u get them 2 pistons loose so the crank can be turned ?

 

[Chris NW Ind]

did u get them 2 pistons loose so the crank can be turned ?

Ran out of time. I'll get back to it when I am off work again.

 

[Chris NW Ind]

Here's the F-20 sitting in my garage. Serial # FA-148239 which is about as late as I've seen.

 

[RobRightmyer]

Looks nice. I would have to say it's well worth the effort.

 

[Chris NW Ind]

Progress. All the rod caps, shims, inserts, etc. are out along with the 2 loose pistons. I'll start on the stuck ones tomorrow.

 

[rustred]

Progress. All the rod caps, shims, inserts, etc. are out along with the 2 loose pistons. I'll start on the stuck ones tomorrow.

View attachment 150219View attachment 150220View attachment 150221

I hope you’re keeping all shims in order as they were removed. It is standard procedure to stick the caps and shims back on the rods with the Shims in the same order. Then no chance of mix up.

 

[Chris NW Ind]

Oh yes. That board is marked 1-4 mag side and manifold side, all in order.

 

[Chris NW Ind]

I had to take them all off first to get the crank loose.

 

[rustred]

Oh yes. That board is marked 1-4 mag side and manifold side, all in order.

It’s not the way I would do it. No dought they have to be plastiguaged on assembly. But I still keep things in order. What if some one or kids started playing around as an example. Best is to stick the caps back on with the shims. Just saying.