taylorham5842

I have a 94 pickup with a LC engineering 22re w/ 40k miles. Bought it off a buddy a while ago.

Problem #1. I pulled the head off beacuse I found antifreeze in my oil.

Problem #2 SO inspecting the block I found the #1 piston had a 3/4" long piece missing on the outside. I could see the ring easily. Lots of carbon build up on piston and head. Very light scoring or cylinder. Now someone told be that piston might of burned up from too much fuel being dumped into #1 cylinder or timing advance to far.

Now measureing the piston i removed it is 3.683 or 93.54mm. Stock is 92mm right? So mine is bored over .060? I havent miced my cylinder yet but will today.

Got some work to do....

The MAN

could be a 94mm bore

MudHippy

94mm = 3.7007894", so no, it couldn't be. 3.683" = 93.5482mm, so 93.55mm is closer to what it really is(which it isn't). LCE calls them 94mm forged pistons...but they're not really though(obviously).

And it's also bored atleast .061"(1.5494mm) over. Stock is 92mm(3.6220492") + .061"(1.5494mm) = 3.683"(93.5482mm). But if you leave room for piston to cylinder clearance the bore should be ~3.684"(93.5736mm), so it's probably closer to bored .062"(1.5748mm) over in reality.

The engine is supposedly a 2.5L according LCE. But if the bore is 3.684"(93.5736mm) x 3.5039389"(89mm) stroke = 149.39698547055744 CID = 2449.1309093534004 cc = ~2.45L

Oh you want to know why the piston blew up, that I don't know. Might have something to do with the design, or install process, of the pistons. Seen something like it happen not too long ago with somebody's Keith Black pistons. I'd atleast want to know who makes these pistons myself.

EDIT: Displacement calculation revisions: bore & stroke = 3.687"(93.6498mm) x 3.5039389"(89mm) = 149.77279322747282 CID = 2455.2916922536528 cc = ~2.46L

taylorham5842

Thanks for the reply. Cylinder is about 3.687. but thanks for the helping me understand it better.

taylorham5842

Anyone know if wiseco 94mm pistons would fit? used them for years in my dirtbikes but never a car...

MudHippy

As far as I can tell, no they won't. Not without boring + ~.015"(~.381mm) over.

3.701"(94.0054mm) piston size
+ ~.001"(~.0254mm) optimal piston to cylinder clearance
~3.702"(~94.0308mm) optimal bore size
- 3.687"(93.6498mm) current bore size
~.015"(~.381mm) difference in bore size


BTW 3.687" - 3.683" = .004" and is considered excessive as far a piston to cylinder clearance specs. The FSM states it should be .0005"(.015mm)-.0014"(.035mm), or ~.00095"(~.025mm). If those really are correct measurements the pistons are a mismatched size, and that's what caused the failure.

EDIT: bore & stroke = 3.702"(94.0308mm) x 3.5039389"(89mm) = 150.86045741016092 CID = 2473.1222526255892 cc = ~2.47L

xxxtreme22r

Why not just take the engine to a machine shop and ask them. And with the broken piston I am sure your gonna have to bore an additional amount.

engineshoppa

Could you see the ring from the top with the piston in the cylinder?
Pics?

taylorham5842

Did take it to machine shop. Honed it a bit. there was no real damage thank god.

taylorham5842

peow130

Disagreed. Evidently theres a guy out at our racetrack with a 22R in his subaru (yes, subaru), running a 4" bore, with chevy pistons.

But hey, LCEngineering knows everything right?

taylorham5842

Agreed... The more I work on Yotas the less I believe in LC. They weren't to knowledgeable but they did try.