90 gsx rebuild cylinder questions

[dj99877]

Ok so, I just got my block back from the machine shop. decked and honed. after I checked each cylinder carefully with a light I found a strange ring pattern in the two middle cylinders. Being as how this is my first motor rebuild I have ever done I figured I would ask you smart guys what you think. now the ring looks to me like it was from one of the piston rings, the 3rd cylinder markings are slightly worse than the 2nd cylinder and when i put my fingers down in I can feel a slight dip where the marks are, NOW my questions are, what could have caused this, and more importantly will it affect the motor in any way, and if so, how would i be able to fix it. Would I have to bore it out and get new pistons or is it not that bad? here's some pictures, thanks for the help!

 

[BogusSVO]

thats your oil ring seperator, must have had water in the cylinders at some point and it rusted......

rule of thumb, if you can feel it, it needs bored

But if you can live with a little blue smoke, you should be fine. if its a basic stock build up. when the shop saw that, they should have stopped and called you about it.

 

[Rob10_99]

Hey bogus, I've got a block sitting in my backyard for the past 4 or 5 years. Think it would be good with a 20 or 40 over?
What exactly are those marks, is that rust from the ring, or from the cylinder wall?
Dissimilar metal corrosion?

 

[whe3ls]

idk those walls dont look very good, one of them looks rather ruff

 

[dj99877]

rule of thumb, if you can feel it, it needs bored

so, another time honing it wouldnt do any good even though the indend is very small? and if i was to get it bored 20 over what other modifications would i have to expect?

 

[bluegs03]

if you bore it .020 over then you would need new pistons, depending on which ones you get you might also need new connecting rods. For instance some stroker pistons need different rods to become a stroker etc.

 

[dj99877]

if you bore it .020 over then you would need new pistons, depending on which ones you get you might also need new connecting rods. For instance some stroker pistons need different rods to become a stroker etc.

so lets say I got it bored and went with a pair of lets say ross or wiseco .020 over sized pistons would i be able to keep my rods and everything else stock?

 

[tim4g63fast]

if you bore it .020 over then you would need new pistons, depending on which ones you get you might also need new connecting rods. For instance some stroker pistons need different rods to become a stroker etc.

i thought 100mm crank with stroker pistons made it a stroker, not the rods.

 

[Turbo Talon DL]

so lets say I got it bored and went with a pair of lets say ross or wiseco .020 over sized pistons would i be able to keep my rods and everything else stock?

You should be able to keep the stock connecting rods and use them with forged .020 over pistons. A shop will need to press the wrist pins into the rods though. You should return that block to whomever 'claims' to have machined it. Ask them to bore it and re-hone WITH A TORQUE PLATE!!! When you drop the block off make sure they use a torque plate. And when you pick it up ask them if they used a torque plate? Do they know what a torque plate is? Make sure they torque the torque plate to whatever PSI your head bolts/studs require.

 

[dj99877]

Ok. i will go and ask them about it. not sure if I'm gonna bore it yet or not though, I don't really want to if I don't have to I guess. I got it machined at United and it didn't seem like they did the best job. I might take it to another place once I ask them about it! thanks for all the input I will keep you all posted

 

[BogusSVO]

Rob 10_99 Hey bogus, I've got a block sitting in my backyard for the past 4 or 5 years. Think it would be good with a 20 or 40 over?
What exactly are those marks, is that rust from the ring, or from the cylinder wall?
Dissimilar metal corrosion?

well how bad is the block for sitting out sode? I am sure it needs to be bored by now. what over size I do not know, It needs to be looked at and measured.

The rust pattern looks like the oil ring seperator rusted to the wall.

Dj, remember, for every .001 you open the bore, you will gain 3.141 on your ring gap, if you hone that mark out you will also have more piston to skirt clearance., you may even get piston slap till the engine warms.


Bluegs03, sorry, the rods do not make it a stroker, that is based of the stroke of the crank.
Now if you went with longer lods, and moved the wrist pin in the piston, you would have a "long rod" engine, the longer rods would let the piston dwell at TDC longer, and low the flame front go further across the piston before it started down on the power stroke.

DJ, yes you could hang the ross/CP/wiseco pistons on stock rods, But why? if you go to the expense of good forged pistons, spend the cash and get a set of H-beam rods to, and balance it all.

Like I said , you can run the block "as is" but you stand a good chance of burning a little more oil than normal, the oil will sit in the pits and burn off.

 

[dj99877]

DJ, yes you could hang the ross/CP/wiseco pistons on stock rods, But why? if you go to the expense of good forged pistons, spend the cash and get a set of H-beam rods to, and balance it all.

As of right now I don't have a lot of cash to be putting into this motor. My goal is around 350 horse when I'm all done so I would like to stay with the big rods if possible, unless I stumble across a small fortune in the near future (not likely)! I was wondering since I'm probably gonna bore, could I buy a decent pair of used bored pistons or just spend the little extra and get brand spankin new? keep in mind that I'm kinda on a tight budget as of right now

 

[My1GLaser]

As of right now I don't have a lot of cash to be putting into this motor. My goal is around 350 horse when I'm all done so I would like to stay with the big rods if possible, unless I stumble across a small fortune in the near future (not likely)! I was wondering since I'm probably gonna bore, could I buy a decent pair of used bored pistons or just spend the little extra and get brand spankin new? keep in mind that I'm kinda on a tight budget as of right now

Well, we all eventually grow out of our "current" build and need more power. If you feel confident that you can live with 400-450 max, then look into a set of NPR pistons, which are stock replacements. Slowboy has them for about $200.

 

[BogusSVO]

if the cash is tight, get some of the oe replacements and hang them on your stock rods, weather they will hold 350hp is going depend on how well you can tune.

 

[dj99877]

if the cash is tight, get some of the oe replacements and hang them on your stock rods, weather they will hold 350hp is going depend on how well you can tune.

i was kinda leaning twards ross pistons and then just saving money for a while longer?

 

[BogusSVO]

i was kinda leaning twards ross pistons and then just saving money for a while longer?

if you hang the ross pistons on the stock rods, then save some more cash, and want to swap to the H-beam rods, you run the risk of breaking/distorting the ross pistons when you have them removed from the stock rods.

stock rods are a press fit, the small end of the con rod grips the wrist pin

H-beam rods are a bushed full floating rod, the wrist pin is kept in place by retaing clips

 

[My1GLaser]

i was kinda leaning twards ross pistons and then just saving money for a while longer?

Like Bogus said ^^^ above. Plus, if you go with forged pistons then you are over halfway to a complete forged bottom end and might as well spend the $350 on rods too.

I had to make that decision last year and I just ante'd up and dropped the $900. $200 would have gotten me a 400hp capable bottom end, which I haven't exceeded yet. I plan to one day so I just built it forged...as long as I did a good job building it and its still holding up when I slap on a Holset next year.

 

[bnr32_coupe]

There's the possibility of losing some compression because of that.
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[BogusSVO]

There's the possibility of losing some compression because of that.
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how so?

 

[dj99877]

ok well, i found a pair of pistons that i want to get, now i just have to go talk to the machine shop and talk to them about it. these seem like pretty good pistons don't you agree?
ROSS PISTONS FORGED .020" 8.5:1 DSM 4G63 ECLIPSE 6 BOLT:eBay Motors (item 200333613110 end time Aug-17-09 16:54:46 PDT)

 

[BogusSVO]

they are a "name brand" and ross has been making pistons for decades, so I do not see why they would give an issue. Just make sure the block it bored and honed with a tourqe plate and the main caps torqued too

 

[dj99877]

they are a "name brand" and ross has been making pistons for decades, so I do not see why they would give an issue. Just make sure the block it bored and honed with a tourqe plate and the main caps torqued too

well I talked it over with my machine shop guy and he said that he has no torque plates for 4 cylinder cars and there is no one else around either, and I know the reasons for using a torque plate is there a better answer to this or should i just have him bore it without, he said its not THAT big of a deal considering he has worked with alot of dsm's and Honda's or should I look into a mail in place or something?

 

[dj99877]

does anyone have a tourque plate i can borrow or rent because the machine shops around my area do not have one and i dont really feel comfortable doing it without one. otherwise does anyone know of a good machine shop around the La Crosse, WI area, I live In La Crescent, MN which is right by there. thanks!