My build:

sleeved GSR block with eagle rods
84mm 5.5cc Supertech All Motor Pistons 12.5 c/r

I had this build for a year with about 6000 miles on it and it ran great never smoked with no blow by. I finally saved the money to go turbo and pieced together a nice kit. I switched to E85 and boosted 10lbs for a week and my headgasket started to leak into my cooling system and I blew a radiator hose. My headstuds were suspect and combination of high comp turbo blew the gasket. Anyways long story short when I redo the headgasket I wanna switch to low compression supertech pistons. I was curious if anyone has experience swapping pistons of the sane brand and reusing their already seated rings on new pistons assuming I put them back in the same cylinders? If you think its a bad idea please give reason or rational to your claims.

 

I'd be more interested in the root cause of the failure in the first place. You should take apart the motor and assess everything first. E85 and that compression should be work ok on a mild setup. The deck and sealing surfaces should be checked, sleeve height is ok etc. Even if you did want to change the pistons, they come with rings anyway so what's the point.

 

If your swappiing pistons then a wall deglazing should be performed with at least a flex hone. That will promote a good seal for new rings. If youve gone as far as swapping out the pistons, then do the job right the 1st time and do what needs to be done. Fresh hone and new rings!

Ive done it myself and its not difficult.

Immediately tune idle for 14.7 on 1st start up while bleeding cooling system.

 

it is actually surprisingly easy. a drill, a flex hone,( i recommend 500-600 grit for a quick deglaze) and some atf/wd40. im sure there is a youtube vid of it. dont forget to clean the **** out of the block right away with soapy water. lots and lots of water. dry thoroughly and immediately oil or wd40 the cylinder walls

 

I was reading on the net about ring seating and I have come to the same conclusion myself. Supertech sells the rings and pistons separately but I ordered a set of rings. A buddy of mine has a flex honing kit. I will go ahead and do the hone.

 

I would like to know too. I had everything set right on the tune. I was running about 12-12.5 afr's and I was working on the ignition timing when I noticed my temp go up to 220F. I pulled over and the overflow was full of coolant and the hoses were rock hard. I am about to pull it apart now.

 

Overflow full, hoses hard? RIP head gasket.

 

I pulled it apart and I cant for the life of me find the leak. I felt like some of the head studs felt a tad looser than others. I bought a new set of ARP studs this time around. I for sure need to hone the cylinders they have a pretty good glaze on them.

 

The leak would be spent exhaust seeping past the HG and hot gasses pressurizing the cooli g system. So dont waste your time looking for a leak. Id make sure the deck is square before rebuilding/honing.

 

It almost looks like they're cylinder burn and head damage between #1 and #2.

 

So you're going from GE head studs to ARP? That is a step in the wrong direction....

I'd check the surface on the head and the block. I never liked the way GE decks a block. I always have it redone.

 

could have been head lift under boost, maybe caused by too much ignition timing. what steps and tq did u use on the headstuds?

 

I was just about to order some new ARP head studs. GE's are proven superior or just personal preference?

 

Both. GE stopped making them, so getting a set is now pretty difficult.

I actually bought a couple sets once I heard A1 (who actually makes the studs for GE) was going out of business.

The GE/AEBS stud design is proven to yield a better and more accurate torque compared to ARP head studs. It's all because of the material and the dimple at the base of the stud.

 

I questioned the GE head studs because they were used already at least 3 times maybe more and they state you should only reuse them 3 times. I used them because it was just an all motor build to begin with. Do you think they are still better than a new set of arp studs ?

 

I was running at peak 9lbs of boost and at that boost I was doing I believe 13 degrees of timing but I have to check again. I had started with 10 degrees and it lagged so I moved up 1 deg at a time to 13 and it was making more power.

 

I can already tell from pics that your p2w is too tight. that much scuffing tells me your motor is around .003-.0035 which is too tight for a turbo motor, much less a high compression e85 turbo motor.

it needs to be around .004-.0045 at minimum to avoid scuffing like that... .0035 might be fine for an NA motor but FI puts wayyy more heat into the motor resulting in increased piston expansion and stress on the piston which gets transferred to the skirts.

any turbo motor with forged internals I've ever had setup at .0035 scuffed skirts and walls bad, regardless of motor brand/model.

my sr20det @ .0035 making 350 scuffed
my vg30dett @ .0035 making 680 scuffed
my last ls/vtec @ .0035 making around 500 scuffed.

a lot of the high compression turbo guys here started out at .0035 and had scuffing issues, they've since gone higher, most around .0045 with no issues. it might slap a little more on cold start but that's about it. higher power/compression generally dictates a looser motor

but that's my .02

 

Man, seriously how can you call out improper ptw, from those pics. Why even speculate. Plus, those are low expansion 4032 supertech pistons. There is so much missing data and variables to consider I don't see how you can make any sort of an accurate diagnosis.

Everyone has different experiences. I did a good handful of drift car sr20's making 4-500 with cp's at .0035 and no scuffing or meltdowns to speak of. As well as countless b, h, f series with cp/wiseco in that range without issues. Sometimes, the pump gas gangsters and other applications, yes .004-.005 is a better bet.

 

If you want to be picky, it is actually scuffing more axially then on the skirts. That means there is a clutch/throw out issue. Chances are it touched the thrust bearings too.

It's impossible to tell the ptw from a pic. Scuffing or not.

 

My ptw is 0.032 . I will ask GE about my ptw with my new build. I am going to take the block over there because I need to have the deck checked out anyways. I hardly ran it boosted just a handful of times so I doubt I was getting it that hot. I did push it really hard on the dyno while back. I didn't have any throw out bearing issues it's got a brand new clutch and bearings from break in. My block was line boarded due to a spun tod bearing from the previous owner.

 

That could be what I was seeing. I was just noticing that the scuffing was extending way beyond the skirt area which could be ptw clearance or some thrust play issue.

 

I just disassembled my block and found a minor bearing issue so I am taking the block to GE tomorrow. My found that the scuffing was present in all cylinders but different in each cylinder. Some cylinders had more axial scuffing on just one side and another had scuffing on the skirt and sides. I also found that my clutch was coming apart . Well will see if Competition clutch will cover that. Pulling my motor apart was a good exercise and I learned alot.

I will post an update after consulting with GE about the headgasket sealing issue and the cylinder scuffing.

 

Seriously, does this not look like damage to anyone else?

 

looks like the headgasket could have been on the way out... or previous marks from a gasket failure.

who knows lol

 

The second pic just looks like burn damage from a dead head gasket. The first pic straight up looks like a crack in the head.