I can set the ring gap in at the end of the rings.
The rings seem to be tight in the piston grooves. The manual states between .001 and .002. I would assume this would be for the cast iron pistons. What should the clearance piston grooves for aluminum pistons?
Here is the picture of the new piston and how tight the rings are.
Rings in grooves.
Are you sure those rings are not for use with cast iron Pistons.
Min on a aluminium piston (modern gas engine) would be .0008" to .0012" Diesels up to .004"
T's are happy with .001" to .003".
The description for the rings is:
"Hastings brand rings for Aluminum Pistons"
How can I tell if they are for cast iron or aluminum pistons?
Looks like 1/8" thick rings, so they're for aluminum pistons for sure. Old original cast iron pistons has 1/4" thick rings.
Mark, Can't you see from the picture they are for aluminum pistons??
Never used that brand before. The large Oil ring is very different than the one I'm used to using.
Used lots of Hastings rings, way old US company, in Hastings Mich. Always good product. Dave in Bellingham, WA
The smallest feeler gauge that I have is .0016.
How do I verify that the piston gap clearance is .001 or just above it?
Before you put the rings on the piston you need to set the gap. Place each ring in the cylinder about where they would be when the piston is at the bottom of the stroke. Make sure they are square with the bore. Measure the distance between the ends with a feeler gage. File off what you need to meet the spec in the Ford manual.
You should borrow a hone from the auto supply or a local auto enthusiast and hone the cylinder. This will allow the rings to seat and should give you a little extra clearance as it is likely the piston was fitted with too little clearance and that is why it galled in the first place.
The machine shop that bored the block may have left a burr on the bottom of the cylinder so be careful and if one is there remove it.
As I recall from way back, the end gap clearance for piston rings is .001" per inch of the cylinder bore, so that would be .003-.004".
I have set the ring gap before. The last time I did a rebuild the piston ring groove was not as tight as it seems with these rings. I need to get the ring groove clearance good then I am going to set the end gap. The last thing I would want is that the piston expands and does not allow the rings to do their work or worse. I guess I am being a little over paranoid.
Don't over think the gaps........just make sure there is enough.
If the oiled rings spin freely in the grooves you're fine.
No matter what aluminum alloy it will still have a much greater coefficient of expansion than cast iron.
By the way, any corner chamfers on the rings face UP.
I'm sure the ring set would have fitting directions but it does make a difference for right or wrong fitting of rings with chamfers/bevels.
From Hastings, correct ring installation.
I took Craig's advice.
The rings do have enough groove clearance.
I was able to start checking the end gaps.
Just one needed just a tad bit of filing.
I moved the rod over from the old piston to the new one. I set the new piston in the hole with the arrow pointing forward.
It seems that the rod is backwards.
Could the old piston being put in backwards have caused the issue?
I am going to swap the rod around.
and tests it again.
Now I am thinking I need to swap the other three pistons.
Here is the picture of the wire through the bold and around the rod. Does this look ok?
Sorry, No that doesn't look OK, wire has a bad habit of breaking and ending up in the magneto, a cotter pin is all that is required, as for rod, the wrist pin bolt always face the cam shaft.
Steve, did you remove one of the other pistons and weigh it to compare with your new one? If they are within a few grams, you shouldn't have to change the others - unless they have any cracks..
If they do differ significantly in weight you may be able to remove weight on the heavy one(s) to match the lightest? Bad luck if the three old ones are significantly heavier than your new piston - that would be a cause for buying four new ones for me. It's hard to remove a large amount of weight without risk for the integrity of the piston - grinding along the bottom of the skirt only takes a few grammes.
The orientation of the rod wouldn't be able to cause any issue - not cracking a piston anyway.
I agree with Frank that a cotter pin is enough for the clamp bolt. (Hard to place it with the hole in that direction, though..)