jmann

picture

Leafy

iTrader: (1)

Thats only a thing for rotaries.

AlwaysBroken

I'll post pics tonight when I get home. Long story short, I'm gonna strip and clean the block, send it good local machine shop to bore/hone.

The more I look, the more problems I find with the pistons. At this point it looks like I'm just going to be getting a new set.

So far:
#1 ingested a screw or a circlip maybe after the last time I had the head off. Not sure. The gouges were pretty small and hidden under carbon so this might have happened a while ago. My instinct is that they're potential hot spots for detonation, but I never got any detonation so maybe lucky? My oil temps have always been super cool due to my oil cooler/fan setup (even with the sprayers), so maybe that helped.
#2 looks perfect in every way. Would reuse without hesitation.
#3 sprayer wrecked it, as reported earlier in the thread.
#4 that #3 sprayer definitely took a few swings at it from below, there's shallow dents and gouges on the bottom near the wrist pin, but no cracks and the crown and the thin parts of the bottom look fine. I'm sort of on the fence about this piston.

My gut says machine shop for the block, new pistons and rings when it comes back.

patsmx5

iTrader: (16)

Sounds like a plan to me.

Landrew

iTrader: (2)

I used red locktite when I replaced my squirters with bolts.

Then I cranked it to the left soldier boy quite a lot foot lbs.

Savington

iTrader: (31)

Machine shop will want the new pistons to set P/W clearances, and you should send the rods to them to be checked over as well. Replace your oil pump and bearings as well.

AlwaysBroken

Yeah, this shop already went over that with me. They will look at the bore first and then we can go over piston sizes once it's good. They were recommended to me by the guy who built this engine the first time around.

Since I'm already at 84mm, is there a point at which I should just buy a new short block and swap over the rods with new bearings? I would think it's probably safe to go up to 85mm bore but 85.5 + boost seems like a bad idea to me. 84.5 seems as safe as 84 to me, just slightly less commonly available. Thoughts?

Also, what is this issue I heard about with wiseco pistons not working with 99 heads? I've been running these pistons with a 99 head since 2003-2004 and never had issues with valve clearance. Or is it something to do with the newer piston designs or something? I suppose I could ask wiseco. I know the FM ones are fine with 99 heads, but they're only for 84mm bore size.

codrus

When I was building my current motor, the cost difference between 84mm and 84.5mm pistons was larger than the cost of getting a new block, so that's what I did.

--Ian

jmann

FM can order 84.5mm for you. One thing of note here is when I rebuilt my motor the Wiseco sheet under general info. had the bore size at 3.3070" with a suggested clearance of 0.0035". I called wiseco to ask if that was over the 3.3070 suggested bore size and the guy said no that the clearance was in the piston and not to measure the piston as the coating on the skirts can vary a couple thousands as it is there just to help with startup the first time. I wanted .004 clearance so I had them bore it to 3.3075, just thought I'd let you know.
Mine is a 99 also, no head clearance issues but I have FM pistons. Theirs also have 1mm oversized valve reliefs in the piston.

AlwaysBroken

I just added everything up, looks like I'm going to be coming in just under 2500 bucks to do pistons + block/head refresh + pump + harm damper. Make it 2900 if I go for double valve springs (these are the original 16 year old valve springs).

codrus

Do the valve springs. My 17-year-old original valve springs with 94K miles (and a lot of boost and high revs) are floating at 6900 RPM.

--Ian