Opinions for 47 Engine?

[ctltmp]

I figured I would do some evaluating for later. I found the following.

The cylinder bores measure out of spec (except at the bottom where they are nominal). I'm getting 2.630-2.635 1-1/2" down depending on what cylinder. The pistons are std. and had .20 over rod bearing installed. The rod work looks pretty recent.


The bores still show some crosshatch on the ring wear area and very visible below that.


I have to wonder why someone would go to this extent and not fix a rear main that is leaving badly.

Door number one is what to do with the block. The tractor will see very little work. It will serve as a demonstration tractor for local events with a hammer mill on occasion. Probably will never even have a mower on it.

Any thoughts appreciated!

[Eugene]

Since you are not planning on working the engine hard, I wouldn't go to the expense of over boring the cylinders.

Spend a lot of time on the internet looking for .010 oversized rings. Or get .020 oversized rings and file down the ring ends.

[ctltmp]

I spent a lot of time as well. I don't think they exist. I never thought about filing. 020 over rings. Never done it so and hints I'd appreciate. How do you deal with the oil rings?

Thanks

[tst]

they never made .010 rings, IH said use standards on .010 pistons, that is a bad thing, filing down rings is NG either as the right is not kept "round" when compressed

[inairam]

If you are going to spend the time and the money you should get the machine work done and use the proper positions and rings. There is no sense putting money and time is new parts that will not last long.

"Do or do not there is no try" as Yoda says.

[Eugene]

viewtopic.php?f=1&t=26195&hilit=filing+piston+ring+ends

Piston ring end gap and available piston rings has been discussed before.

There are custom piston and piston ring manufacturers. Used them before to find piston rings "not available" at the auto parts store.

[BigBill]

I use this adjustable hone to bore with, you need a dial bore gauge too. They have rough stones and smoother grit stones. It’s not hard to do.

https://www.enginehones.com/lisle15000.html

https://www.enginehones.com/m50160.html

I believe in doing it once and doing it right don’t skimp.

[ctltmp]

I have a bore gage. Can you accurately hone the length of the bore to .020 over with just a good quality cylinder hone?

A little update. The rods are. 020 under and the mains are. 010 under. I pulled one main lower. It doesn't look so great. I'm very curious why the cylinder walls still show some crosshatch remaining like little wear but the bearings are showing much heavier wear.

[BigBill]

Yes, use the hone I listed above, rough stones to open the bore up. The hone will feel tight on one end if there’s a taper in the bore stay where it’s tight till the bore feels the same then mic it, as you get close to the bore size you want switch to the fine stones. Keep it wet with honing oil. Chrome rings, tight cross hatch, castiron rings looser cross hatch.

[ricky racer]

If you are going to spend the time and the money you should get the machine work done and use the proper positions and rings. There is no sense putting money and time is new parts that will not last long.

"Do or do not there is no try" as Yoda says.

[BigBill]

I do all my own boring. That hone is gear driven adjustable. It’s the same as the sunnen hone I had. I don’t trust anyone doing my machine shop work. I had one automotive machinist mess up boring and pressing the wrist pins. No more trusting anyone.

[ricky racer]

I'm very curious why the cylinder walls still show some crosshatch remaining like little wear but the bearings are showing much heavier wear.

20200622_165211.jpg

That happens because someone previous to you did a lousy attempt at fixing a worn out motor. The reason there is some crosshatch in the cylinders is it was apart recently for a "rebuild", but they didn't want to do it right, they wanted to cheap out, throw in some new rings and say, "that's good enough". Obviously it wasn't because now you've got it and pulling it apart again. In my opinion, if you pull a motor apart because it's worn, you have two choices, throw it away or fix it. Putting new rings in is a waste of time and money as far as I'm concerned. If you can do most of the work yourself, it doesn't cost that much to rebuild an engine. Shop around and get estimates on charges for machine work and look for the best deal. I was looking between 3 engine shops when I rebuilt my last Cub last fall. That build is in the link below. I hope this helps.

viewtopic.php?f=1&t=105338&p=834090&hilit=cost+of+rebuilding#p834090

[ctltmp]

Rick your block looks fantastic. Prices seem reasonable. Think I'll make some calls. I have to split it anyway.

Electrician at work has 2 47's in his barn he's been wanting me to look at. I know they run and that's about all. May have a better motor in one of them.

[tst]

A hone is made for finishing cylinders, not designed to bore, yes you can do it but if the cylinder is worn to a taper it will not correct the taper, tapered cylinders need to be bored

[Crimson Tim]

I’ve just been pondering the last few weeks about how much engine work is really practical to DIY and how much you really had better contract out to not make a mess of it. It seems we are getting close to an answer here.

If I had a dollar for every time I was stewing over a question in my head only to have someone else on the forum ask almost exactly the same question... I could afford to buy more Cubs!