Evo 8 pistons in 1g

[David Boyd]

Okay guys so I bought some eagle rods for my 1995 eclipse gst. It has a 1g swap so I got the rods for a 6 bolt and they came with the 22mm wrist pin. I have to make a decision fast would I be able to use evo 8 pistons? My motor is bored .20 over so would I still be able to use the evo 8 pistons and just get them .20 over?

 

[90laserRSfwd]

Just to be sure I'm following correctly, you bought 6 bolt eagle rods with the 22mm pins? Eagle part number (5900MC3D) and you want to use stock (or stock replacement) EVO 8 pistons that are .020" over)? Is that correct?

If so, be aware of the following 2 issues. 1st: Eagle rods use floating wrist pins (evo 8 pistons I'm fairly certain are press fit, last I remember researching), and 2nd: why are you set on using an EVO 8 piston to begin with if you already are upgrading connecting rods?

Just trying to understand fully before answering..

 

[90laserRSfwd]

Also, if your motor is already .020" over, is there a problem with it that you are trying to correct? Are you sure the bore is able to be honed and still be tight enough to remain at .020" over bore? Your missing a lot of information (for example you don't have your profile filled out) and we have no idea what you use your car for or what kind of power your making? Do you have a budget? I foresee this thread getting locked quickly if you don't add a good amount of info to help us help you...

 

[David Boyd]

Okay I bought the car about a month ago and about 1 week ago it spun a rod bearing. So I had to tear the engine down and do a full rebuild. Once we got it tore down we didn't know it was .20 over until I got a rebuild kit with standard size pistons. It had a gap so we took it to the machine shop the get the JE pistons that was already in miced. He said they were .20 over so that's when we figured that out. Also when I ordered the rebuild kit I figured I might as well upgrade the rods so I went with eagle h beams. Well my mistake I didn't pay attention to the wrist pin on the rods I ordered and they are 22mm and the rods are longer. But I've been reading threads on here about how people just use the evo 8 pistons. The JE pistons don't have a identification number on them so I can't reorder them. So basically I assumed I'm just gonna need a bigger piston for my eagle rods that I got. Is there any other piston I could use? If so what kind? Car has 14b turbo, CAI, pacesetter headers, aftermarket exhaust(not sure what kind) the guy said its pushing like 340 to the wheels on the dyno but I'm not sure how true that is. The car is also my daily

 

[90laserRSfwd]

If you got longer eagle rods (I assume 156mm), then you don't have the 5900MC3D's. What is the part number on the rods you have. I would recommend at this point you forget the EVO 8 piston as an option. The machine shop needs to measure the bores and tell you if you can still use a .020" over piston (Wiseco, Manley, Mahle, JE, Ross, etc. etc.) and if not, can the block go .030" over or is it that bad that it needs to go .040" over? Brands like Ross offer .030" over while others, like wiseco, only off .020 and .040 overs. Also keep in mind if you do have 156mm rods (as opposed to the standard 150mm stock length rods, you'll need to use a stroker piston that moves the wrist pin up 6mm to match the longer rod. With this in mind, you may want to not use those rods either. Your scenario happens more often then you might think, don't worry though, we'll help. We just need some more info! You need to take your block, crank, and other parts to a GOOD machine shop. Someone that knows what they are doing and does thing correctly. There are a lot of local machine shops that, while they can machine v8's with no issues, somehow can not manage to complete work on a 4g63 without Fing everything up. No one knows why, it just seems to happen a lot. So I caution you about choosing a machine shop wisely. There are a few things we need from you (and the machine shop). We need to know IF your crank and block are ok to reuse (have them mic and magnaflux the crank, and measure and magnaflux the block. They might also need to hot tank, or vat tank, or "clean" the parts before measuring, this is normal.

Is the crank re-usable? Does it need cut? Was is already cut? Will it balance out? is the keyway slot messed up? Can they micro polish it correctly? etc.

Is the block re-usable? How egg shaped are the bores? Were they bored / honed correctly from the last machine shop? How warped (if any) is the deck surface?

If you don't know these things, included what the ACTUAL parts are you have (pistons and rods), don't bother putting the engine back together, as it will just fail again. I'm not trying to come off as a dick, just trying to help, but reinforce that things need to be done in the correct order by competent people. Whether that person be yourself or a machine shop. Search youtube for "Jafromobile" and watch the engine build / tear down video's to get a better understanding of what needs done.

 

[90laserRSfwd]

Car has 14b turbo, CAI, pacesetter headers, aftermarket exhaust (not sure what kind) the guy said its pushing like 340 to the wheels on the dyno but I'm not sure how true that is.

Don't take this the wrong way, I'm not trying to insult you or anything like that. Whom ever you purchased the car from is lying to you. I am 99.99% sure your car is not making 340whp on a 14b. Especially without larger injectors, pump, a tuning solution, and a serious tune. Next, (again not flaming here, just trying to help), DSM's don't have headers, they have a turbo manifold, of which, Pacesetter is probably worse then the factory manifold. I assume it has no heat wrap or shield around it either, which is also not helping. The exhaust brand isn't important. Don't let big names fool you. 3" pipe is 3" pipe. It doesn't matter if Jesus made it or (more likely) it was made by a 3 year kid in china. The exception here is wall thickness and alloy grade if your exhaust is stainless, and mandrel bent or press bent.

We will gladly help you. That's what we are here for. Make sure you keep up with the routine maintance as well. These cars can be tons of fun or piles of junk depending how you keep after them. Not just oil changes either. Timing belt, balance shaft belt, water pump, oil, fuel filter, exhaust leaks, etc. There's a lot more work to keep these cars happy then most other cars. Keep posting your questions and we'll keep answering..

 

[David Boyd]

If you got longer eagle rods (I assume 156mm), then you don't have the 5900MC3D's. What is the part number on the rods you have. I would recommend at this point you forget the EVO 8 piston as an option. The machine shop needs to measure the bores and tell you if you can still use a .020" over piston (Wiseco, Manley, Mahle, JE, Ross, etc. etc.) and if not, can the block go .030" over or is it that bad that it needs to go .040" over? Brands like Ross offer .030" over while others, like wiseco, only off .020 and .040 overs. Also keep in mind if you do have 156mm rods (as opposed to the standard 150mm stock length rods, you'll need to use a stroker piston that moves the wrist pin up 6mm to match the longer rod. With this in mind, you may want to not use those rods either. Your scenario happens more often then you might think, don't worry though, we'll help. We just need some more info! You need to take your block, crank, and other parts to a GOOD machine shop. Someone that knows what they are doing and does thing correctly. There are a lot of local machine shops that, while they can machine v8's with no issues, somehow can not manage to complete work on a 4g63 without Fing everything up. No one knows why, it just seems to happen a lot. So I caution you about choosing a machine shop wisely. There are a few things we need from you (and the machine shop). We need to know IF your crank and block are ok to reuse (have them mic and magnaflux the crank, and measure and magnaflux the block. They might also need to hot tank, or vat tank, or "clean" the parts before measuring, this is normal.

Is the crank re-usable? Does it need cut? Was is already cut? Will it balance out? is the keyway slot messed up? Can they micro polish it correctly? etc.

Is the block re-usable? How egg shaped are the bores? Were they bored / honed correctly from the last machine shop? How warped (if any) is the deck surface?

If you don't know these things, included what the ACTUAL parts are you have (pistons and rods), don't bother putting the engine back together, as it will just fail again. I'm not trying to come off as a dick, just trying to help, but reinforce that things need to be done in the correct order by competent people. Whether that person be yourself or a machine shop. Search youtube for "Jafromobile" and watch the engine build / tear down video's to get a better understanding of what needs done.

Okay, I looked on the box earlier today and it is actually the 5900mc3d part number so we're good on that. Also I bought a new crankshaft with the rest of my parts. Cylinders and everything looks good on it we looked it over many times

 

[90laserRSfwd]

Looking at is doesn't tell you what info you need. You need to have the block cleaned, mag'd and measured with an actual bore gauge, at the 6 correct spots. Otherwise your just guessing. Putting an engine together isn't that hard, but not doing it correctly will cause $1,000's of dollars in damage in no time. If you bought a new crank (new, not another used unit) you still want to get it mic'd and balanced for the best performance and longevity. I'm just trying to help save you some frustration down the road. As a reference. I paid $1,450 to have my short block machined (not including already having a good block and crank, or any of the parts (pistons, rods, bearings, ARP's, kiggly main girdle, fluidampr, etc.)

Do it right or do it twice, as the saying goes..