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MG TD TF 1500 - Ring 2

The project continues.
Taking the pistons out with the engine and crank in place was very easy.
I think I might have had a little bit of blow-by from number 4. The second ring down was shattered and a chunk of the piston was broken off. Not only did everything remain in place, there is no visible damage to the cylinder.
I assume it is proper to replace all 4 pistons and all rings rather than just the one bad one.
Also where is the best place to purchase pistons and ring sets?
All advice and sources welcome.
TIA,
Mort

Mort Resnicoff 50 TD (Mobius)

Photo 2

Mort Resnicoff 50 TD (Mobius)

You are very lucky that you did not score the cylinder.
I had a similar thing happen to my 1961 OSCA powered FIAT Spyder.
Getting parts for that car was a huge undertaking.
I went with replacing one piston. I only removed the one piston.
That cylinder was scored. Replacing the one piston and rings did seem to work OK. I dont think I could have gotten parts for a full rebuild.

If you go with one new piston you would want to match its weight to the other three.

Jim B.
JA Benjamin

Those are the pictures I was looking for. Were any of the rings stuck in their slots? How much "spring" did the rings have?
I usuaully buy from Abingdon Spares.
-David
D. Sander

None of the rings were stuck in the slots. There was some carbon buildup in the slots and of course on the piston heads.
I am not familiar enough with rings to give you an assessment of their quality. They all seem to have some "spring", could rotate.
BTW my cylinders are bored out +.040".
Are there different levels of quality to pistons and ring sets?
Mort
Mort Resnicoff 50 TD (Mobius)

Yes, Mort, there are any number of possible makers of your pistons. Any identification either on the crown or cast into the inside?

The general dimensions of any +.040 piston will probably be close, but there are many ring/spacing variations, not to mention weight. I would look for a single used piston by the same maker, but barring that, a new set of pistons. You might as well replace all the rings, as well, even if you keep the existing 3.

Tom Lange
MGT Repair
t lange

Mort,
I would also recommend having your new pistons and rods balanced.
-David
D. Sander

Mort

Somewhat depends on the condition of the cylinders. If not a large ridge at the top, you can get by with honing and going with oversized rings.

If you need to bore, then new pistons are the way to go.

I have some original pistons that are serviceable and also some 10 over that are in good condition. (3 with about 10,000 miles or so on them). Bruce dot cunha at charter dot net
Bruce Cunha

"D. Sander, Vermont, USA

Mort,
I would also recommend having your new pistons and rods balanced.
-David "


How are pistons and rods balanced?
Mort Resnicoff 50 TD (Mobius)

Mort,

There are some You Tube videos that explain it. Just do a search on balancing pistons and rods. I'm not sure how complete the videos are as I'm not an experienced engine builder. Hope this helps.

Kirk
Kirk Trigg

Mort,
Did you take the pistons out from the bottom or the top as I'm about to undertake the same as I have exactly the same problem?
Regards
Declan
Declan Burns

Declan,
Before you remove them make sure the connecting rods are stamped with the cylinder number or put a mark on them. This will get them back correctly. Also note the front and rear of the rods. Mine are stamped on the outer edge where the two halves come together.

I did it from the bottom. The crank was easy to turn using the flywheel.
I removed the bottom half of the assembly.
I pushed up on the rod and piston and brought it down on the passenger side of the engine.
I pulled the piston out of the cylinder.
I brought the piston down as I turned the crank and there was ample room to remove the piston without scratching it.
It went very quickly. I kept all my sets together.

After I purchase new piston sets I will balance the rods and pistons.
Kirk is right. I went to You Tube last night and studied the videos on balancing.

Thank you all.
Mort
Mort Resnicoff 50 TD (Mobius)

When you realize just how long the stroke is, and how fast the piston has to go to cover the distance up and down on every revolution, you realize just how fast the piston speed is. Thinking of four pistons going that fast, and stopping to reverse direction twice a revolution, you really want to balance them.
-David
D. Sander

Reamer is on its way. Bud
Bud Krueger

Thanks Mort-I'll follow the same procedure.
Regards
Declan
Declan Burns

This thread was discussed between 17/12/2013 and 19/12/2013

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