advice on oversize high comp pistons

[comhosa]

I am rebuilding my 4age engine, large port, 7rib block. I have it bored one size over to 81.50mm.
I need to get one set of 81.50mm pistons and oversize rings high compression from 10.4:1 to max 11:1 compression.
Please advice me on which brand has the most bang for the buck.
From the most economical to around $500.00
It will be a daily driver and occasionally spirited driving.

much obliged

[yoshimitsuspeed]

What are the details on the rest of your build? What cams? Stock ECU? Any other mods?

This piston would most likely be my suggestion but it depends on the rest of your build. You could get it to 11:1 with a thinner headgasket and a light skim on the head.
http://www.matrixgarage.com/products/ar ... 051-piston

[comhosa]

no mod, stock cam, stock ecu

[yoshimitsuspeed]

A cam would do a lot for you performancewise. Is there a reason you aren't going with one?

What octane do you have available? Where are you located?

[oldeskewltoy]

I am rebuilding my 4age engine, large port, 7rib block. I have it bored one size over to 81.50mm.
I need to get one set of 81.50mm pistons and oversize rings high compression from 10.4:1 to max 11:1 compression.
Please advice me on which brand has the most bang for the buck.
From the most economical to around $500.00
It will be a daily driver and occasionally spirited driving.

much obliged

You didn't mention WHICH 4AGE you have... if it is a largeport you will need to look inside it to confirm which crank it has BEFORE you order pistons.

ASSUMING you have the "big" crank it means you can just buy OEM high comp 10.3 to 1 pistons(13103-16121) and add a thinner head gasket, or machine the head a little to get over 10.3. As to rings, it has been reviewed a few times, a certain Honda engine (don't recall right now)uses similar rings. This would be your middle of the road cost... $350ish

You MIGHT be able to find an aftermarket set of stock type 4AGE "high comp" pistons on ebay... This set of standard bore high comp pistons is $45.00... yes high comp piston set for $45. It'll be a bit tougher to find 1/2mm oversize, but they are likely out there.
http://www.ebay.com/itm/224-2989-020-91 ... 67&vxp=mtr


If you do decide to boost compression and keep the stock cams, you will need to do some combustion chamber de-shrouding/polishing to ward off pre-ignition. The 1990+ smallports used a knock sensor to pull timing.

This is chamber de-shrouding

[gotzoom?]

And, if you have the smaller crank, Supertech makes 11:1 overbore pistons that take 18mm wrist pins. The cost will be a bit over your budget, since you'll need to have the rods machined slightly to fit the pistons. They include rings, as well.

[Rogue-AE95]

Also, Orion Engineered made custom rods to use 20mm wrist pin pistons on the "smaller crank" (40mm rod journals).