TR2/3/3A pistons have 4 rings

[sp53]

So I bought a new project tr3. It has been exposed to the weather and the new engine was exposed also. It had new sleeves installed in the block, but the pistons were left out. The sleeves have some rust, but it looks like the rust will rub off. The pistons have 4 rings (2oil rings) is that good or bad? I guess I will try and get the sleeves out, but perhaps a machine shop would be best.

 

[Marvin Gruber]

Scotch brite the liners. Check the rings for correct gap. If good, put it together, tractor motor, they are tough.

Marv

 

[sp53]

Yea I hear you Marv. The inner block is surface rusty. It looks likethey had it degreased then painted the outside black put the liners in and leftthe rest bare cast iron for who knows how long. The liners fit nice and stickup just right. Most of the recites are from Victory B dating 1988. And yes apart of me thinks just leave it and change the oil few more times. It does lookhowever, that at some point they dropped it on the dirt/earth, but I should beable to flush that out. My old mechanist buddy once had me take the hot watertank water with a hose and blow out all the passages of a motor when it hadthat shot in it from cleaning.
Should I use a hone or use a Scotch bright by hand?

 

[sp53]

Yea I hear you Marv. The inner block is surface rusty. It looks like they had it degreased then painted the outside black put the liners in and left the rest bare cast iron for who knows how long. The liners fit nice and stickup just right. Most of the recites are from Victory B dating 1988. And yes a part of me thinks just leave it and change the oil few more times. It does look however, that at some point they dropped it on the dirt/earth, but I should be able to flush that out. My old mechanist buddy once had me take the hot water tank water with a hose and blow out all the passages of a motor when it had that shot in it from cleaning.
Should Iuse a hone or use a Scotch bright by hand?

 

[Marvin Gruber]

If you have a hone, definitely use it. There still will be some areas that you will need the scotchbrite. Some folks are going to fuss but I usually hose the whole block down with gasoline after cleaning. I do catch the gas with a pan and dispose of it properly.

Marv

 

[martx-5]

I believe that the four ring pistons are from the Vanguard motor. They have an 85mm bore which gives them 2088cc displacement.

 

[Foura]

I believe that the four ring pistons are from the Vanguard motor. They have an 85mm bore which gives them 2088cc displacement.

They are definitely Vanguard pistons. I used them in my first TR engine rebuild in the 3A in 1968. They were cheaper and as an impoverished student, that was attractive. I was later told the lower oil ring starved the gudgeon of oil in the harder use a TR was generally put to. I started work in 1969 and had the money to rebuild again with TR 86mm pistons and no lower oil ring.

 

[Don Elliott]

In 1988, I bought a new 1991cc set of pistons, rings and liners from Peter Hepworth in Yorkshire. The pistons have 4 rings. I re-did the engine in 2007 and after having an engine shop re-hone the liners, I put in new rings (4 per piston) from Hastings near Detroit. I ordered them over the phone and they arrived about 4 days later by mail. I've driven my 1958 TR3A over 113,000 miles with these pistons and liners.

 

[sp53]

Thanks you guys I have not seen the 4 rings before andthanks Don for easing my fears on using them. I have a ball hone that fits atr3 motor. The hone just fits in a drill and does not do a great job of gettingthat cross scratching I have seen done by machinists. I cleaned one up one cylindera little by hand, and I can see the original honing plus I did not see anypitting so far. I like to do what I can to keep coast down and be a hobbyistplus I am cheap. I do not have a much experience with motor building and I donot want to be so cheap I shorten the motors life by not having the correcthoning. Once on a new tr3 motor I did not get the oil ring to seat or somethingand oil would come up and foul the plugs. The fuel mixture might have beenwrong on break in or maybe the rings were made of the wrong metal likestainless or something. I final fixed it by replacing the rings and ball honingit, so I am not total sure what to do here.

 

[sp53]

Thanks you guys I have not seen the 4 rings before and thanks Don for easing my fears on using them. I have a ball hone that fits at r3 motor. The hone just fits in a drill and does not do a great job of getting that cross scratching I have seen done by machinists. I cleaned one up one cylinder a little by hand, and I can see the original honing plus I did not see any pitting so far. I like to do what I can to keep coast down and be a hobbyist plus I am cheap. I do not have a much experience with motor building and I do not want to be so cheap I shorten the motors life by not having the correct honing. Once on a new tr3 motor I did not get the oil ring to seat or something and oil would come up and foul the plugs. The fuel mixture might have been wrong on break in or maybe the rings were made of the wrong metal like stainless or something. I final fixed it by replacing the rings and ball honing it, so I am not total sure what to do here.

 

[CJD]

Most machine shops are reasonable for a simple hone job. They will also check your cylinders for taper. The finish you need depends on the rings you plan to use. Simple cast iron rings require a fairly rough cylinder surface, and take a correspondingly long time to break in.

If you are using molly faced rings, you want a very smooth cylinder wall, final honed with a cork hone, and break in time is usually a few minutes. With replacement moly rings in a decent cylinder that is round and not worn, you don't even need to re-hone.

Chrome faced rings usually take a medium finish.

If you follow me here, cylinder finish is an art. I am an avid "do it all" kinda' guy, but I leave the honing to my trusted mechanic to get the surface I need. The only exception is if I am just doing a ring change on a low mileage engine.

When you first said 4 rings, I was thinking like a diesel...with 3 compression rings and 1 oil. That double oil ring is interesting. I would think it is a heavy piston, looking at the picture, so you may want to limit RPM to whatever the Vanguard recommended. Just a thought.

 

[sp53]

Thank you John for your explanations and description, I willtake it in and see how much.

 

[CJD]

I just got bit with the 4th ring! Moss has the cylinder sets on sale for another week at $435, so I couldn't resist a set. Now, being a straight restoration, and not a performance rebuild, I went with the stock TR2, 83mm pistons. They arrived with the 4th ring below the pin. Truly weird!

I will weigh the pistons and compare to the originals before I use them. As long as they are close in weight, I'll keep them. If they weigh much more than original, I will likely swap for 86 mm with 3 rings. My thought...what's the point of staying with 83mm if they aren't stock anyway!?!

 

[TFB]

Thanks you guys I have not seen the 4 rings before and thanks Don for easing my fears on using them. I have a ball hone that fits at r3 motor. The hone just fits in a drill and does not do a great job of getting that cross scratching I have seen done by machinists. I cleaned one up one cylinder a little by hand, and I can see the original honing plus I did not see any pitting so far. I like to do what I can to keep coast down and be a hobbyist plus I am cheap. I do not have a much experience with motor building and I do not want to be so cheap I shorten the motors life by not having the correct honing. Once on a new tr3 motor I did not get the oil ring to seat or something and oil would come up and foul the plugs. The fuel mixture might have been wrong on break in or maybe the rings were made of the wrong metal like stainless or something. I final fixed it by replacing the rings and ball honing it, so I am not total sure what to do here.

I do my own cylinder work on motorcycles but basically the same.I don't think you will find any auto machinist using a ball hone.You can buy a glaze breaker hone,with flat stones for around 20 bucks.If you think your ball hone did a good job I think you probably did not look close enough.And my final wash before assembly is always soap and water,after solvents.
Have Fun
Tom

 

[CJD]

Sorry Tom...I dug up an old necro-post. Although it would be good to get a follow-up from Steve. I'm curious how he went with the pistons and all...

 

[sp53]

Well John the jury is still out on the 4 ring pistons. One of the machinists felt the fourth ring would help stabilize the piston and allow a more even wear on the sleeve plus help with oil that might find its way up. I will use them first and see what happens. Tinman did me cool and gave me a complete set of 87 mm to use if these do not workout.

 

[CJD]

I have been looking for info since I resurrected this post. All I can say for sure is that the 4th ring went out of vogue by 1960. Old flathead fords used them, and the jury on their forums are about 50/50 too. Some have run without the bottom ring installed, some cut the whole groove off the piston...and one guy, whose father was an old time mechanic recommended leaving the ring out...and adding it 100k miles or so later when oil consumption was starting to go up. Some call it a "stabilizer" ring, others an "oil control" ring.

I even called Moss...and they have nothing of use to say about it. VB doesn't know what they are selling, and TRF only list 86mm sets.

The only thing I can say for sure is that I would definitely prefer the modern 3 ring set up. Does anybody know if 3-ring 83 mm's are available anywhere?

 

[Don Elliott]

I have had 1991 cc pistons. rings and liners in my 1958 TR3A since I restored it and re-built the engine in 1990. My pistons have 4 rings as stated in a reply way above this one. I have driven 113.000 miles with this setup till 2007 when I put in new Hastings Piston Rings in 2007.

Since then, I am still running with good oil pressure with this setup in my TR using Castrol 10W30 an I can drive 3000 miles without adding any top-up oil.

 

[MLang99]

I picked up a set of 4 ring 86mm pistons off of ebay about 10 years ago. They came with one piece oil rings. After about 5k miles of moderately high oil consumption, I replaced the rings with the ones made by Hastings (the upper oil ring is a modern three piece design). I've now got about 20k of fairly hard driving on them with no issues. The Hastings rings solved the oil consumption problem. So far, I am pleased with the results.

 

[CJD]

OK...you guys are starting to sway me...!