Back from the grave....

[95_GSX]

Well I know its been a while. But I hope to have my GSX up and running again in May of this year. Its only been 3 years since she has ran . A LOT has changed in those 3 years though all for the better except for not having my car. I almost had it running a couple years ago but I made a mistake. I bought a 6-bolt and swapped into it and did some minor mods. Long story short I mixed up the timing belt tensioner brackets on the used motor I swapped in and toasted a head. Pistons 2 and 3 hit the valves leaving some small dings in them. Here is my question, can I sand them smooth and not worry about the small dings in the pistons and just replace the head or do I need to do a top-end on the block? I am worried that the dings make create "Hot Spots" on the pistons and melt them. I am not sure if that is a legitimate concern or not. But that is why I am asking. Also if I have a new decked head, am I safe to put it on the old block with a new head gasket and ARP studs or is there something that needs done to the block surface before the new head? I appreciate the help.

Sorry if this should have gone somewhere else, this seemed like the most appropriate place to me.

[gthompson97]

It depends on how big the dents are I guess. If they're just little marks where they hit, I wouldn't worry about it, but if it made a decent size dent, I would replace the pistons that are bad. Pics would help. As for the head/blck mating surface, as long as the head is flat, a new headgasket is all you should need as long as the block surface is clean (no gasket material/dirt/grease/etc)

[95_GSX]

Right on, it checked the pistons pretty good. It isn't just a mark where they hit. It actually moved material on the piston surface. I suppose it would just be safest to order a new set of pistons, rings, and wrist pins. Unfortunately I don't have any pics nor can I get them for a couple weeks. I have the car stored in my parents garage about 220 miles away. I am going up there on the 12th and I can post pictures after that.

[gthompson97]

If it left a groove then I would just replace the pistons. 2 pistons shouldn't be that expensive so it'd be safer to just replace them.

[95_GSX]

I will probably just do all 4 cylinders. With my luck if I only replace 2 and 3, in 6 months I'll loose the rings in 1 or 4 and be down again. I would rather just do all 4 at once and be done with it.

Edit----> Plus cylinder pressures should stay more even this way.

[SilvrEclipse]

Wow that sucks. I couldn't imagine going that long with out having my car run. I have only had my car for three years and 1 day. Good luck on getting it running again man.

[95_GSX]

It looks like it will run me about another $440 for another set of pistons. Here is something for some discussion....I am looking at the Wiseco 9.0:1 pistons to help liven up my little t-25. Is this going to be a disadvantage when I upgrade to a 20g? Or is the 9.0:1 still going to play to my advantage? Also take into account my normal driving elevation is between 5000-8000ft.

[gthompson97]

I wouldn't waste the extra money on them, plus forged pistons take forever to warm up or they slap like crazy. The stock 6-bolt internals are good to over 500hp. You also don't need a whole set of 4 pistons, just 2. And while you're doing them, you might as well re-ring pistons 1 & 4 too, hone the cylinders, and be good to go for a long time.

[Blackcrow64]

Wow... Welcome back dude. Long time, no see!...

It sucks that that happened to ya. I think I would replace them with some more stock pistons just for the peace of mind. Like Garrett said, they are good for over 500hp... Which is what I should have done instead. Oh well, live and learn!

Oh and now you guys can't rag on me for going 2 years without my car running since we have a 3 year streaker here. lol

[95_GSX]

Sitting here this morning I am coming back in to my old DSM'ing self of being a cheap ass. I have a seven bolt sitting in my garage with perfectly fine pistons in it. If I just order a new set of rings for those they should work out great. I will still get to bump the compression up a little and save some money. Now I know there is an issue with the wrist pins and connecting rods when using 6-bolt rods with 7-bolt pistons. So I will have to do some research on that, unless some one has those little facts memorized and would like to post them .

[Thor06]

Hey man, welcome back! Good to see old faces around again.

The 2g pistons use a 22mm wrist pin whereas the 1g ones only use a 21mm... that means the 1g rods have to have the wrist pin hole taken out an extra millimeter to accept the 2g pistons. I talked to a couple machinists and they say the best way to do that is with a hone, but as you'd imagine that would take FOREVER. Back before I got my good motor and was thinking about rebuilding one, I thought at length about the 1g rod/2g piston combo and thats really what I wanted to do. Only problem is machining costs of taking that hole out an extra mm is enough to where you might as well just get forged pistons. Now here's what I started thinking.... what if you just bought the hone and did it yourself? I think its kind of risky, but you should be able to get a brake cylinder hone for like $20 at a parts store, just hook that bitch up to a drill and check it often. You'd have to look into tolerances and all that too, but I thought it might just be doable. Hope that helps.

[95_GSX]

If it is only 1mm it shouldn't be that bad to hone out, I am a patient person. But I also know a guy in the town where my car is that is a machinist and literally has a full machine shop in his personal garage. So he might be able to hook me up for a 12-pack or something. I will have to talk to him.

On this note though, can I reuse the crank bearings or do I need the crank turned and use oversized bearings?

[gthompson97]

Depends on what it looks like. If it's not scarred up or out of spec, then just throw some new bearings on it, maybe have it polished or something. If it's pitted/scarred, then you'll need to have it turned and oversided bearings put on.

[95_GSX]

Well here is my current parts list that I am looking at let me know if I overlooked something:

From SBR:
Reman 6-Bolt Head
OEM Stock MLS Head Gasket
OEM T-Belt
ARP Head Studs
OEM T-Belt Tensioner
ACL Rod and Main Bearings

From Mitsu Dealer:
Stock 7-Bolt Piston Rings (4)

From Parts Pile:
Stock 7-Bolt 8.5:1 Pistons (4)

[gthompson97]

Why are you getting a rebuilt head from SBR? You can find a perfectly good working on from somewhere else for a fraction of the cost I bet. I'm not sure how much the rebuilt SBR heads run, but if it's like the rest of their parts, it's not cheap.