Piston Ring Suppliers & Oversizes

Fri Aug 16, 2013 7:26 pm

I believe I'm coming up on a minor engine overhaul. I think I'm looking at a minimum of new piston rings, rod bearings, head gasket, and oil pan gasket. It seems that the suppliers for internal engine parts are a different group than normal Cub parts. I've looked on the internet and found Yesterday's Tractor, Bates, Stevens, Farmall Parts, and then eBay. Can anyone recommend a supplier based on the quality of their products? Which ones sell good American made bearings and rings? Prices all seem to $110 - $140 for the package, so they all seem comparable.

And I also notice that some suppliers offer 0.002" oversize pistons & bearings. Is it common to put in the 0.002" oversize on a very old tractor ( like 65 years old ). I'll be measuring everything before I order anything, but does anyone have any experience with a 0.002" oversize part? I am expecting to replace with standard size parts, but I'll be measuring very carefully to see if this 0.002" oversize might work better.

Re: Piston Ring Suppliers & Oversizes

Fri Aug 16, 2013 7:43 pm

Measure the engine. Make a list of all the parts and sizes needed. Then price the parts at your local auto parts stores, on the internet, local tractor dealerships- any make. You will find that there is a very large difference in prices of, for example the exact same gasket set for the engine.

.002 oversized bearings. Measure and plastigage the crankshaft. .002 could be to tight of a fit. Uncle overhauled one of his MM tractors and installed .002 oversized bearings. Tractor ran fine. When uncle turned off engine - stopped with a jolt. Local MM mechanic told uncle to remove the bearings and install standard.

Re: Piston Ring Suppliers & Oversizes

Fri Aug 16, 2013 8:21 pm

first. if you dont have a micrometer get someone that has one and knows how to use it. Plastic gage is worthless im my opinion. If you have .002 clearance in the crank journels. then you can be pretty sure they are out of round also. Mike to cylinders also.. in most cases you will find the wear in the cylinders to be tapered and out of round. If more than .010 wear then they should be bored,, Usually in a engine as old as these cubs you will need a proper valve job, this may include new valve guides.. Maybe new valves and seats also depending on how they are worn. As far as brand name parts.. you would do well going through a real autoparts store. such as Napa. Or old time real auto parts store. autozone and such parts stores sell nothing but junk, wont have a clue what your talking about. Most tractor stores sell aftermarket parts from TISCO and other such suppliers . they are mostly made over seas.

Re: Piston Ring Suppliers & Oversizes

Fri Aug 16, 2013 9:27 pm

Dennis, lets see. You are thinking about replacing the pistons, rings, bearings and gaskets. That's 95% of a complete rebuild. The only thing your missing is a bore and valve job. Maybe a crank grinding. Add those and you've got a new motor that will last another 50 years.

Remember the cylinders don't wear evenly. They wear more at each end of the bore, less in the middle. You have to set the end gap for the smallest portion of the bore. The end gap will open up at the bottom and top of the bore. With new bores the bore is even and the end gap remains the same through it's stroke giving maximum power and minimum oil consumption.

Now I may catch some flack for this, but if you don't want to pull the engine out and pay someone to bore it out, you can if you take your time and be careful, hone it out to the next over size bore. Using the correct hone makes the job pretty easy and starting out with coarse stones, you'd be surprised how quickly the material comes out. Switching to finer stones will leave a beautiful cross hatch pattern on the cylinder walls. I would recommend this over putting new rings and pistons in old bores.

This style of hone is what I would recommend.

Image

Over sized bearings are made for a ground crankshaft. If the crankshaft is worn chances are good it didn't wear evenly either. Pulling the crank and inspecting the journals is recommended and if wear is detected the journals should be ground.

So just by adding a bore job, valve grinding and crank grinding if needed (the last motor I rebuilt, the crank didn't require grinding and used standard bearings) you will have a new engine. To me that's a much better option than new pistons in tapered worn bores, new bearings on worn or scored journals so you can do it again in a few years.

Re: Piston Ring Suppliers & Oversizes

Mon Aug 19, 2013 11:25 am

Ditto to what Eugene and Clark said. Either measure it yourself or by someone who knows what they are doing before you order any parts. Oversize parts should only be used if parts have been bored or ground.

I also echo what Rick said about doing the valves. If the engine is worn enough to need a rebuild, the valves could use attention as well.

Re: Piston Ring Suppliers & Oversizes

Mon Aug 19, 2013 11:58 am

http://www.agkits.com/International-60-Cub-Engine-Rebuild-Kit.aspx

Re: Piston Ring Suppliers & Oversizes

Mon Aug 19, 2013 9:36 pm

Thanks all for the replies. As we all said earlier, the plan is to disassemble, then measure/inspect, and then order the parts and prepare the block for that size.

I've been perusing :eBay: for a bore gauge and it seems that they are readily available for a reasonable price. Do you think I could use a part of the cylinder that is below the piston travel to zero the gauge out? I looked for a master ring anywhere around 2 5/8" size, but they are few and far between.

Ricky, I'm taking a leaning to your honing idea. I'm 99% going to handle this thing myself, so the more I can do here, the better. I suppose there's a possibility of honing out to a round 0.002" O/S bore. Really would hate the thought of hand honing all the way out to 0.010" over. I hadn't thought of honing as I see it more of a finishing operation than a sizing one, but I suppose with rough grit stones and patience, you could get the desired effect. Did you use any coolant? How & what kind? I'm used to seeing powered hones getting flooded with coolant.

What is standard process for the valves? Lap the seats and replace the valves, springs, and keepers? I'll need to be sure and set aside some money for that as well.

Re: Piston Ring Suppliers & Oversizes

Mon Aug 19, 2013 9:39 pm

Thanks all for the replies. As we all said earlier, the plan is to disassemble, then measure/inspect, and then order the parts and prepare the block for that size.

I've been perusing :eBay: for a bore gauge and it seems that they are readily available for a reasonable price. Do you think I could use a part of the cylinder that is below the piston travel to zero the gauge out? I looked for a master ring anywhere around 2 5/8" size, but they are few and far between.

Ricky, I'm taking a leaning to your honing idea. I'm 99% going to handle this thing myself, so the more I can do here, the better. I suppose there's a possibility of honing out to a round 0.002" O/S bore. Really would hate the thought of hand honing all the way out to 0.010" over. I hadn't thought of honing as I see it more of a finishing operation than a sizing one, but I suppose with rough grit stones and patience, you could get the desired effect. Did you use any coolant? How & what kind? I'm used to seeing powered hones getting flooded with coolant.

What is standard process for the valves? Lap the seats and replace the valves, springs, and keepers? I'll need to be sure and set aside some money for that as well.

And what's everyone's opinion of reusing the head bolts? And what about the top of the block and the head? I guess I will just see how the pitting is around the water jacket ports and proceed from there.

I'd like to get this thing fixed good, but I'd also like to fix it quickly. It seems there's some inverse relationship between the amount of time something stays in pieces and the likelihood of getting it put back together.