Farmall C263 engine piston orientation

[littlefarmer]

Ok---so now I'm trying to install the head on my Farmall 656 with C263 engine. I set the head on the block, and it won't go all the way down. It's hitting interference with the the step on the pistons.

Can someone tell me what is the correct orientation for the pistons in these engines? I've tried to find a picture, and I can't remember exactly how it was when I took them out.

All I know is that I installed them with the clearly "FRONT-->>" mark on the piston towards the front of the engine. (see attached picture).

I know that the stamped numbers on the rods go to the left hand (camshaft side) of the engine. The step on the piston is hitting the underside of the head on the side opposite from where the plugs are.

[i:7c448ac035]Is it possible that these pistons are mislabeled?[/i:7c448ac035]

Now I'm looking at the old piston. It has a different head configuration. I think they may have given me the wrong pistons!

What should have been a straightforward job, is turning into a real mess.

Any advice appreciated!

P.S.> Having major aggravations with getting this engine installed. And I've overhauled more Farmall engines, so I'm fairly knowledgeable about what needs to be done.

Here's a pic of the pistons that were in the engine:

This post was edited by littlefarmer on 08/20/2023 at 04:10 pm.

 

[Big Fat Herb]

I dont think the head gasket is the right one either

 

[used red MN]

I would have to say the pistons are wrong. A picture of
the piston at TDC kind of from the side with a
measuring scale by it would be helpful and a like
picture of the head combustion chamber as well. But
not sure what it would prove when you say it doesnt
fit. Just doing a quick search for c263 pistons it looks
like most have the center compression wedge like your
old ones. I see some that have the pop up more to the
side like yours are cut back from the edge to avoid
head interference. Where did you get the kit so others
can avoid this problem in the future? Cheaper is not
always better. Hopefully not from Yesterdays Tractors.
I also agree about that head gasket not looking correct
as well. Maybe with any luck ; > ) the Tractor Vet will
be along to smash any remaining hopeful expectations
you have.

 

[Mrfred54]

Those pistons are wrong. If you clean your old piston up on the top( narrow side of
the dome) I'm pretty sure you will find an arrow pointing to the front which puts the
dome on the new pistons on the wrong side.

 

[littlefarmer]

Found out what I did wrong. I ordered the wrong piston set.

Apparently there's a "Fire Crater" type, and a "step-head" type.

My engine had the Fire Crater pistons.

Apparently, they must not be compatible in the same engine. Something with the cylinder head (?). Because the "step-head ones I have have a clearance issues with my existing cylinder head.

A mistake I made. Going to have to live with it.

Don't know why there are apparently two different (and mutually incompatible) types of pistons for these engines. It's certainly nothing I've come across in the literature. Nothing about a serial number split or anything. And the IH parts book shows only one type of cylinder head for this engine.

The only thing I'm hoping now is that I can just get by removing the rod units and switching-out the pistons. I'm hoping I won't have to mess with changing out the sleeves also.

I will have to measure the new pistons to the existing sleeves. And check that they are correct for the .0045 clearance in the specs.

Regarding the head gasket being possibly wrong---a new head gasket comes with this fire crater piston kit. So I'm assuming it should absolutely be the right one.

Lesson learned---double check everything before ordering. Hoping my post/experience helps others in the future.

This post was edited by littlefarmer on 08/20/2023 at 06:28 pm.

 

[rustred]

Looks to me to be the wrong pistons. On the old ones the
dome has to fit into the combustion chamber. And valves
go in the valley. And the new ones it appears that high
spot is hitting the head flat spot ? Is that correct. ? and
that head gasket cant be correct. What does the old
head gasket look like , compared to this one. Plus a good
idea to shape a photo when unsure of stuff.

 

[rustred]

Yes exactly. Those pistons are for a different head, or
engine. And yes only need to remove pistons. As I asked
what did the old head gasket look like? Was the fire rings
round ?