89 KAE pistons

[JJ240]

How do you tell if a set of pistons from an 89 240 are the high or lower compression?Used ones that came out of an engine, so I dont know what the part number is

[Aries]

the part number will be on the pistons...

[JJ240]

Ok, do you know where exactly so I could tell the person Im buying them from where to look for me?

[Aries]

they should be stamped on the bottom where the rod connects to the piston.

[JJ240]

Ok, great. One more thing, Is there any way I can figure out how much to mill off the top if these pistons are the 11.6:1 in the KA24DE ones? I would like to hit around 11:1

[Aries]

a good machine shop will be able to tell you...it is all based on head ports, bowl size/shape, and valve size as to what you will need to mill.

[JJ240]

Anyone here already know? I dont really feel like hauling my head and pistons into a shop just so I can find out how much I have to mill off

[Aries]

you should just be able to call the shop and ask...A good and reliable shop will give you a close estimate without needing to see the parts.

[JJ240]

Ok, sorry to bring this back up, but the pistons came with rods attatched and im going to be using these rods so i cant take them off to find the part number...they are flattops and ill try to get a pic up, but is there any way to tell if they are the 11.1:1 or the 11.6:1 without taking the rods off to read the part number?

[JJ240]

heres a top pic, have the camera so if you need a specific part or another angle i can get it

[JJ240]

Ive got till my rings and headgasket comes in to decide what C/R these are and wether I need to mill...then what C/R I want to make them if I mill

[sofast240]

JJ Talk to me next time your at the shop and we will find a shop to do it. I know of a couple.

Dave 96 S14polished lip

[JJ240]

I have a mill just need to figure out how much I have to take off

[Open4Cycle]

It s funny how people that don't understand how to do something can tell your incapableof it. Static compression ratio is simply the volume of the combustion chamber + bore stroke volume / combustion chamber volume. So lets check this out. Your engine has 2400cc displacement. We will divide that by 4 so that we are working with one cylinder which has 600 cc. Ok now we know that you have one clinder with a compression ratio of 11.6:1 and a swept volume of 600 cc. So now we need to know what the combustion chamber volume is. So CCV=600cc/11.6. CCV=51.72Now anything you remove from the top of the piston will add to the CCV which lowers the compression ratio.So now all you have to do is find the volume of what you remove from the top of the piston, which is a cylinder. I don't know how to make the math symbols here so the formula is Pi*Radius squared*length. So with a 89mm bore and you removed 1mm will yeild a 6.22cc increase in combustion chamber volume. 51.72+6.22=57.94600cc/57.94=10.35so thats 10.35:1 compressionAnd to make sure I bought a large syringe (sp?) and filled the combustion chamber with deisel fuel during mockup assembly. I was aiming for 11:1 and hit it right on the nose by doing the math.