Requirements for forged pistons...

[yamahaSHO]

What we're getting at is that you'll be able to make more power than the car can handle or put down.

You can order the pistons to fit a completely stock motor if you wanted. You pick your bore, compression, wrist pin size, etc (just go through Josh as he has it all figured out if you tell him what you want). It would be a VERY GOOD idea to have the rods resized and new bushings pressed in if you're going as far as to rebuild the motor. A rebalance and with a micropolish are a must. You'll also have to fit the rings to each individual bore yourself (or pay a shop). A machine shop will have to do all the crank and rod work.

I would start by just getting the tune and adding more boost before you really decide on the built motor. Pat has run since 2001 (IIRC) on a stock motor with 15 PSI and has tracked the crap out of it. He has broken 3 piston ring lands, but he admits that it was his own fault.

You'll be much faster sinking the money into "non-breakable" driveline parts and a way to get the power down than you will with just making a ton of power. Given that you like the quarter mile, really high top end power isn't going to do you much if you're spinning 1st, 2nd, and part of 3rd.

 

[twr]

So building another shortblock is the plan, basically? Forgive my ignorance but, how exactly does a machine shop balance a rotating assy?

How they do it, not for sure the exact way it's done, but I know they will need the crank, rods, rod bearings, wrist pins, pistons and piston rings to do it properly.

 

[nik97]

Pat has run since 2001 (IIRC) on a stock motor with 15 PSI and has tracked the crap out of it. He has broken 3 piston ring lands, but he admits that it was his own fault.

Can you elaborate on this? Fuel issues?

 

[yamahaSHO]

No charge cooling (water injection went out), plus stock fuel rail setup (#4 and #5 run lean first), and a day on the road course cause enough heat to detonate the crap out of the motor.

With all these questions, a search may be in order to get caught up

 

[yamahaSHO]

Give up that quick?

 

[1995SHO9]

Can I get some advice on this. I asked a couple of months ago but lost the responses. Toolman, yamaha sho, fogsho, sho nut, texan toney?...

I am getting the forged pistons from sho nut soon. What would happen if I just droped them in. I'm planning on doing this. I know its recomended to balence the crank but what COULD happen if I don't? Can I get away with just dropping them in safely?

I already blew 2 pistons out on 12 psi so I think it is time to grab some forged. Opinions please. Also which ones from sho nut do I need to buy to just drop in a stock 3.0 block? part number would be greatly appreciated.

Thanks everyone,
Johnathon

 

[ManySHOs]

Do a search on the forum about engine balancing and then do one on google. It'll give you enough reading material for awhile.

The bottom line is that I would not install mismatched rotating assembly parts or lighter pistons without having everything balanced as an assembly. It should only cost $150-$250 depending on where you go. It's worth it and it's the right way to do it. I'm not sure why anyone would spend nearly $1000 on pistons but not $200 to balance everything correctly.

Ian

 

[1995SHO9]

Do a search on the forum about engine balancing and then do one on google. It'll give you enough reading material for awhile.

The bottom line is that I would not install mismatched rotating assembly parts or lighter pistons without having everything balanced as an assembly. It should only cost $150-$250 depending on where you go. It's worth it and it's the right way to do it. I'm not sure why anyone would spend nearly $1000 on pistons but not $200 to balance everything correctly.

Ian

Because I can't afford to have someone tear my engine totally apart and rebuild it to do this stuff and be without a car for a month while were doing it..... Tearing the whole engine apart is above my head right now and I don't have the tools or facilities to do it at. And while Brian from the PA sho shop is my freind and hooks me up very good on prices, it would still be expensive.

 

[BlackonBlack89]

My suggestion is build your L/C motor out of the car slowly. (or have someone do it slowly) Then when the time comes install the new High HP motor in. This way you can save some money and get the right parts to do it. This way you can still drive the car. Plus you can do some smaller stuff like making the engine look better. Ie paint the block, powder coat mics metal stuff, heat wrap wires for reliability and do it the right way and even better your way. And why not just rebuild and get the tranny parts gas nitrided. it would only cost 1500 or so...........LOL



Thats wat I'd do. if I had lots of money

 

[yamahaSHO]

Can I get some advice on this. I asked a couple of months ago but lost the responses. Toolman, yamaha sho, fogsho, sho nut, texan toney?...

I am getting the forged pistons from sho nut soon. What would happen if I just droped them in. I'm planning on doing this. I know its recomended to balence the crank but what COULD happen if I don't? Can I get away with just dropping them in safely?

I already blew 2 pistons out on 12 psi so I think it is time to grab some forged. Opinions please. Also which ones from sho nut do I need to buy to just drop in a stock 3.0 block? part number would be greatly appreciated.

Thanks everyone,
Johnathon

Well, I'd say you got yourself in a tight spot on this one... If you've already blown two pistsons in this short time on 12 PSI, you're got a problem (be it mechanical, tuning, not enough cooling, etc). If you can't afford to build the motor or go without the car, boosting a stock SHO motor at 12 PSI probably wasn't the best decision. Actually, that boost on a stock motor really does require more than just the standard user/maintainer/modder.

You can't just drop in pistons, especially lighter pistons that may or may not take different rings. Running without a balance will beat the crap out of your rotating system. Something is likely to fail (rod bearing, rod coming out of the block etc.). In addition, you're going to LOSE power with a balance so far off. I won't even get to the point of sizing bores, with pistons as well as making sure you still have a true usable bore.

My suggestion is to get another short block and build it when you can pay for it. This way it won't be a huge chunk of money at one time and you won't be without a car for a long time. It sounds like not only do you need to read these forums for SHO specific information, but you could REALLY benefit from learning a little more on building engines, how they work and boost.


BTW, how do you know you blew to pistons?


If you do go through with this and want to buy pistons from Josh, talk to him directly on what you want to do with it.

 

[ManySHOs]

Because I can't afford to have someone tear my engine totally apart and rebuild it to do this stuff and be without a car for a month while were doing it..... Tearing the whole engine apart is above my head right now and I don't have the tools or facilities to do it at. And while Brian from the PA sho shop is my freind and hooks me up very good on prices, it would still be expensive.

How are you going to install the pistons without tearing your motor apart? They are installed from the top and unbolted from the bottom so the entire thing needs to come apart anyway. At this point, removing the crank is only a few extra bolts.

As others have suggested, I'd build up a spare engine and drop it in when you can. That's what I ended up doing when I built my 3.2.

Ian

 

[SASHO91]

Because I can't afford to have someone tear my engine totally apart and rebuild it to do this stuff and be without a car for a month while were doing it..... Tearing the whole engine apart is above my head right now and I don't have the tools or facilities to do it at. And while Brian from the PA sho shop is my freind and hooks me up very good on prices, it would still be expensive.

Then your'e in the wrong game.....

 

[1995SHO9]

How are you going to install the pistons without tearing your motor apart? They are installed from the top and unbolted from the bottom so the entire thing needs to come apart anyway.Ian

I do realize what is involved with replacing pistons. It is an 8 hour job. I watched paul while he replaced my broken ones.

 

[SASHO91]

Wait.... so you have allready done this once?

 

[1995SHO9]

Wait.... so you have allready done this once?

Yah I had 2 pistons go out on me already, correct. Paul was awsome and he replaced it in a day. I don't believe it was because of the tune. Ashley assured me it wasn't and I have total confidence in her. Besides I was in the car while we were tuning it and the computer wasn't showing any knocks and the airfuel was staying awsome. The pistons wern't melted but the rings did break. We just believe it was because of being a high milage engine at 12 psi. I know other people have broken piston rings at that level of boost, so its not to far out of the ordinary. If it happens again I will question that there is somthing else causing it.

 

[yamahaSHO]

I don't care how confident you are, you had some awesome KNOCK. This was NOT related to high mileage. Pat was running 15 PSI running ******* a road course everytime he broke his pistons. It's not a "high mileage" motor, but I'm willing to be it has more wear than your newly boosted motor.

Out of curiousity, what pistons did you break??

 

[SuperchargedSHOguy]

You have some serious issues you need to address if you have broken piston rings already.

With Tim, forged should be a no brainer...if you want to boost you should start with upgrading the heart of the operation, the engine. If you are not forged you need a good tune with some charge cooling if you want to boost double digits. People have done without in the past but it is just a ticking time bomb....tick tock....tick tock.... unless of course you have boosted in the past and have learned from experience...

 

[K-Dawg]

Listen to what these people are telling you. Rings don't just break for no reason.

 

[somedude_001]

I'm just throwing this out there, but maybe your boost gauge is off and you were running more boost than you thought?

your rings broke or ring lands broke?

 

[twr]

My understanding when I was on AIM with him yesterday was both. I have to agree with everything that has been said. Rings and lands don't just break, they break because of knock.

I have hard time believing that the pistons had any cracks before the turbo went on. In N/A form, there's not enough cylinder pressure for a knock event to crack pistons. Not only that, the stock pistons are a very robust pieces. I've been feeding mine 10 to 14psi on premium fuel for 3 years and 20k miles and I used 3.2 pistons with unknown history to boot.