Largest Bore size on FS-DE

[bvr_j_0969]

So I am going forged. Engine is Burning oil, even after New turbo, new head and head gasket.( dont argue with me its a good excuse to haha)

Seeing that this is my daily i need to minimize down time. So i need to order my Piston and rods before i pull the engine. I dont know if any previous owners have rebuilt this engine. So to ensure i have pistons that will work im going to order oversized. Whats the largest overbore you can go without risking reliability on the FS-DE.

Side note, the cylinder walls looked good when i had the head off, with what seamed like minimal wear around the top of the cylinder.

Looking to order them tonight or tomorrow so any help would be appreciated.

 

[bvr_j_0969]

anyone?

 

[01CrznMp3]

I have .20 over weisco's and wouldnt recommend any bigger. I have heard the cylinder walls are thin on the FS and any bigger can weaken it too much. Make sure whoever does the engine work precisely uses a micrometer on the cylinder walls and pistons to see how much over it needs to be bored. Mine wobble too much for my liking in the cylinder walls as if it really only needed to be bored .15 over.

 

[mazdaspeedp]

I got .20 overbore pauter rods weisco pistons

 

[bvr_j_0969]

My problem is I don't want to get. 020 over pistons and tear In To find out Its already been bored. 020

 

[Spiced MSP]

Well, measure it yourself or let a machine shop take care of it. Unless you have receipts or prior service records, the only way you are going to find out is to tear it apart. Plus, you should never buy pistons before machine work anyway.

 

[destineal]

My problem is I don't want to get. 020 over pistons and tear In To find out Its already been bored. 020

Just wait until you have the pistons out. I'm going through the same thing.

 

[LonBon]

Well, measure it yourself or let a machine shop take care of it. Unless you have receipts or prior service records, the only way you are going to find out is to tear it apart. Plus, you should never buy pistons before machine work anyway.

I know this thread has been dead for a year and a half,however, I feel it necessary to point out that you SHOULD buy your pistons before machine work. This allows the machinist to bore each cylinder to individually fit each piston with the lowest tolerances possible to ensure that there will not be piston slap, or excessive pressure put on the rings, etc... The opposite is also possible, however unlikely.