Piston rings.????

[supraleed]

I'm doing a rebuilt for a 87 7mge with about 124k with little knowledge of previous owners treatment to the car. The head gasket was kooked and the water pump barring blow out. I'll be sending the head to get re-done and ported. I want to do the work on the block, how ever this is the first 7mge Ill be rebuilding. I found a set of rings but I'm not sure what diameter to get for a proper compression seal. I found a set with following description:

Standard Diameter 83.00 mm
1st Group 1.50
2nd Group 1.50
Oil Ring 4.00

Is this a proper size to get Or a different size. Now the car will not be ran a as animal better yet just a sleeper for weekends only. Any info will be greatly appreciated...

 

[AJ'S 88NA]

I'm doing a rebuilt for a 87 7mge with about 124k with little knowledge of previous owners treatment to the car. The head gasket was kooked and the water pump barring blow out. I'll be sending the head to get re-done and ported. I want to do the work on the block, how ever this is the first 7mge Ill be rebuilding. I found a set of rings but I'm not sure what diameter to get for a proper compression seal. I found a set with following description:

Standard Diameter 83.00 mm
1st Group 1.50
2nd Group 1.50
Oil Ring 4.00

Is this a proper size to get Or a different size. Now the car will not be ran a as animal better yet just a sleeper for weekends only. Any info will be greatly appreciated...

Depends on what you're going to have to do to the block. May have to be bored a little, sometimes just cleaned up a little, but usally bored + .010 or more depends on what the machine shop finds. You shouldn't buy anything until the shop checks it out.

 

[supraleed]

I was also reading up in the haynes book about the honing the cylinder with a bottle brush. The cylinder walls are good shape how ever I did find a few streaks on 2 cylinders. The streaks are about 3/4 of an inc wide and there is no ruff spots. It feels really smooth over all. So as far a sending to a machine shop I'm trying to hold up that. If I were to measure the cylinder walls, that would help out right? but ether way how would I know what size of rings to get. How Would I match one size (cylinder) to another (rings). Basically If my cylinder is (FOR EXAMPLE) 4 3/4 of an inch in diameter how much smaller should the rings be? 1/8 smaller or so.?? like I said This is my first 7mge I re-build. I am mechanically incline I've rebuilt honda's and mazda's before. But never a 6 cylinder. I read the book back and forward and still no mention about size match up.

 

[cuel]

Click Me...

Go to Toyota and order the 1988 Toyota Service Repair Manual(TSRM) for the Supra. Haynes manual is ok for general repairs, but not very useful for the technical aspects.

 

[AJ'S 88NA]

I was also reading up in the haynes book about the honing the cylinder with a bottle brush. The cylinder walls are good shape how ever I did find a few streaks on 2 cylinders. The streaks are about 3/4 of an inc wide and there is no ruff spots. It feels really smooth over all. So as far a sending to a machine shop I'm trying to hold up that. If I were to measure the cylinder walls, that would help out right? but ether way how would I know what size of rings to get. How Would I match one size (cylinder) to another (rings). Basically If my cylinder is (FOR EXAMPLE) 4 3/4 of an inch in diameter how much smaller should the rings be? 1/8 smaller or so.?? like I said This is my first 7mge I re-build. I am mechanically incline I've rebuilt honda's and mazda's before. But never a 6 cylinder. I read the book back and forward and still no mention about size match up.

You need to read a little farther. It tells you how to check the cylinders to see if they are within spec. You should check the old rings and pistons to see how they measure according to spec. (Ring end gap)
My old rings at 129,000 miles were still within spec.
Was there a ridge on the top of the cylinders?

 

[Setheroo]

Odds are, that if you have any sort of streaks, it would be best to get that thing to a machine shop to have it bored at least 10 over from stock. A machine shop will know what to do with it when you tell them you want it prepped for 10 over piston rings... all it leaves you doing is buying rings that are 10 over from the stock size.

I haven't ever rebuilt an engine just by rehoning... I don't ever feel that it does enough... I like a new cylinder wall, it just gives you piece of mind. Plus - when you take it to the machine shop, you could have the top of the block lapped - just to make sure that you have a really good flat mating surface for your head gasket.