deep scratched cylinder

[billyvang05]

i am doing an engine rebuild on my 1g 4g63 and when i took my block to the machine shop the guy tells me that cylinder #3 was deeply scratch and i would have to bore it and would have to use bigger pistons. my question is that i am plannig to put 2g pistons on and how much i would i have to bore in order to get the scratch removed and for the piston to work

 

[ZmanIV]

It will have to be bored out enough to remove the scratch.
You may want to consider just getting forged pistons and aftermarket rods. They are just a bit more than having the 2G pistons and 1G rods machined to fit your application.

 

[billyvang05]

the machinest suggested to bore it .030 to .040 over to get rid of the scratch

 

[Cs4g63]

If your machinist says to bore it out that much than thats what you are going to need to do.
When replacing the pistons choosing which ones to get will depend on how much money you are going to want to spend.
These guys are a good basis on what the diferent pistons will cost you from a well known store.
http://www.slowboyracing.com/shop.p...38&PHPSESSID=a8a9bb5b45a48223fd04a857ab196693
https://secure.buschurracing.com/ca...4_123&osCsid=825ea2cd53511c89ab5643956e5cb585

 

[billyvang05]

is 85mm pistons good enough for a .040/.030 bore on the block

 

[ZmanIV]

Check with JE looks like 86mm is for a .040 overbore. 85.5 is a .020 overbore

 

[4g63t]

You can get oem 2g pistons in a bigger boar that can hold 500hp.
http://www.slowboyracing.com/estore/product.php?productid=1714&cat=559&page=1

 

[ZmanIV]

However you still have to have the rods and pistons modified to use them. Machinists dont work for free.
If you are already in there just upgrade to forged and new rods.