40 over pistons?

Heads, valves, pistons, rods, crankshaft, etc...

Moderators: Helpinators, Moderators

Post Reply
race_to_live
First Gear
Posts: 173
Joined: Fri Aug 08, 2008 5:16 am
Location: Pueblo CO

40 over pistons?

Post by race_to_live »

im looking at putting them in my leggy and was wondering if anyone has used them from wiesco and if you had any problems?
-91ss, 250,000mi rebuilt, tmic, tdo4, agx's w/groundcontrol, f/r strut bars, rust
-83 gl wagon...350,000mi custom dents
-62 honda 55, (moped)
-74 Yamaha rd 350
douglas vincent
Knowledgeable
Knowledgeable
Posts: 3336
Joined: Sun Apr 27, 2003 5:50 am
Location: OR, Portland
Contact:

Post by douglas vincent »

Are you forced to use 40 over? ie, are the cylinder walls damaged that bad?
Reddevil, Awaiting new heart, will it ever happen?
1990 wagon, EJ25 12.3 @ 116.5 FAST Family wagon getting new motor soon
1992 wagon, wifes daily, high compression
1992 Touring wagon, should I keep it?
race_to_live
First Gear
Posts: 173
Joined: Fri Aug 08, 2008 5:16 am
Location: Pueblo CO

Post by race_to_live »

no the cylinders are fine. the engine is in need for a rebuild and i was looking on weisco and they have 20 and 40 over. you can order custom pistons but i was just thinking about the 40 over. i don't really want tons of hp, i just like tq. im going to do the td04 deal at 14psi. i was just wondering about overheating because that sounds like a big piston and the block is a closed deck.
-91ss, 250,000mi rebuilt, tmic, tdo4, agx's w/groundcontrol, f/r strut bars, rust
-83 gl wagon...350,000mi custom dents
-62 honda 55, (moped)
-74 Yamaha rd 350
brand
First Gear
Posts: 170
Joined: Sun Mar 01, 2009 2:52 am
Location: Denver

Post by brand »

I've done a little bit of reading about stroking the 2.2 with either the .20 overbore or .40 overbore pistons and I came to the conclusion that it just doesn't make sense unless the cylinders need to be bored to make the block usable, you want a stroker to make your car unique, or you have compatible parts already and you want to use them.

By the time you're done buying all the components (pistons, rods, bearings, crank) and paying a machine shop, you'll have spent almost enough to buy a new 2.5L shortblock.
91 SS with a bunch of parts waiting on the shelf
94 SS with things and such
08 STI with stuff and junk
douglas vincent
Knowledgeable
Knowledgeable
Posts: 3336
Joined: Sun Apr 27, 2003 5:50 am
Location: OR, Portland
Contact:

Post by douglas vincent »

Just go .20 over. That way the pistons fit correctly (bored to fit) and you still have cylinder wall strength. The amount you gain in bore is MINIMAL. The only reason to bore out a subaru block is to fit custom pistons
Reddevil, Awaiting new heart, will it ever happen?
1990 wagon, EJ25 12.3 @ 116.5 FAST Family wagon getting new motor soon
1992 wagon, wifes daily, high compression
1992 Touring wagon, should I keep it?
GodSquadMandrake
First Gear
Posts: 199
Joined: Sat Mar 15, 2008 4:25 am
Location: Fairbanks, AK
Contact:

Post by GodSquadMandrake »

Yeah I put in the .040 bored over pistons. That's only like a half a millimeter difference so it doesn't really make a difference in displacement or cylinder wall strength. The cylinder walls are so thick to begin with and it's a closed deck block.

I guess it just costs more to have he block bored out that extra little bit. But I like to be like heh I have that little bit more than the other guy ;)

If you really want to increase displacement, I would go for the 2.35l stroker kit, that would be sweet.

Yeah I used stock rods because I wasn't planning on going much bigger than 300 HP. Stock crank of course, I just replaced the bearings. I kind of wish I used the gapless rings now though but meh.

Edit: I guess this board doesn't allow dynamic pictures so just click here for the pics:

http://www.god-squad.net/gallery2/main. ... temId=2757
-Doug Wilson
Post Reply