Building a good engine first time.

[garputo2]

I am building my 1995 eagle talon tsi 7bolt. the block is okay had it honed no need for boring. I have a new crank so everything will be oem spec on sizing. What my issue it I want to build a nice bottom end that will be good for upgrades later. The kit for the pistons and rods are what i have in question. I want a good set but not too heavy on the wallet I have found a decent deal but the listing shows the options below either 8:3:1 or 9:0:1 but oem spec is 8:5:1. I am wondering what to do please anything will be helpful. i guess its becaise Wiseco only offers these sizes so my question it of I go to 831 instead of 851 will it make a difference?


7 Bolt 93+ Eclipse (Evo1-7)

Part #
Application
Bore Size
Compression Ratio

K548M85
4g63 7bolt
85.00mm (Standard Bore)
8.3:1

K597M85
4g63 7bolt
85.00mm (Standard Bore)
9.0:1







WISECO PISTONS MANLEY RODS EAGLE TALON 1G 2G DSM 4G63 : eBay Motors (item 120515400005 end time Jan-18-10 06:16:43 PST)

 

[tenn-gsx]

Depends on what boost level you plan to run. The higher the boost the more prone to knock the engine will be. Keep in mind that you need to match your bore to the pistons you purchase. You say you were able to hone the cylinders already. Be prepaired to re hone them if needed to make them match the specs on the cylinder to piston gap.

 

[BogusSVO]

if you want the stock compression, run the 8.3:1 pistons, by the time the head is done and milled, you should be closer to the 8.5:1

the 8.3:1 is an estamate of what your static compression should be, think of it as a "best guess"

there are may varaibles that can change the compression of the engine, HG thickness, combustion chamber CC, piston to deck clearance, also having the big ends of the rods resized can lower the compression....

 

[garputo2]

I am rebuilding the block because of rod spun. I was planning on not doing much to the head. I plan to possibly do some head work maybe now not sure will be using a 20g turbo not sure on how much boost but the more the better so i want the block to be able to hold up. My plan was to keep everything stock so it will hold up to large numbers of boost. they have a good ross set at 8:5:1 but if I go with the 8:3 or 8:8 even 9:1 which are my different options I will probably be looking changing the head