TravisBiggie

My goal is 400-450WHP. My block is torn apart, and I am installing eagle rods and arp rod bolts. I would like to use the stock pistons, and ceramic/thermal coat them. I recently read a post on here talking about 400-500+whp builds on stock pistons.

Anyone have some input on the integrity of the ls piston, or know the thread i'm speaking of? I've even considered NPR pistons.

Thanks

Muckman

iTrader: (2)

Stock pistons? Dont even waste your time.

TravisBiggie

after reading some more, Id have to agree, thanks

yungkhmer

Dont do it. You should have hit up one of our sponsors for a combo deal of rods and pistons.

TravisBiggie

I already purchased eagle rods. I'm going to wait for a set of low comp pistons with stock bore. I'm under the assumption that if I bore out my stock sleeves it will weaken em. Should I say stock bore or ??? I rather have the sleeves keep their strength rather than make more power with boring and possibly weakening them. I will eventually go to 500+whp on stock sleeves once I get upgraded supporting mods.

rich7777

You need to check the cylinders to confirm they're not out of round or tapered. If you can't, then consider what the majority are doing - reboring to 81.5mm. You need to understand that most B series engines (except the ODD few) have covered a lot of miles and gone through a lot of wear and tear.

wantboost

iTrader: (2)

Coatings don't make things bulletproof.

Will it help protect the piston and the ring lands? Yes but only to a point, as you're still dealing with a cast part with relatively low strength compared to an equivalent forged part.

You're going to need forged rods and pistons. I recommend Manley turbo tuff rods and cp pistons, I'd still have the domes, sides down to the first ring land, and the skirts coated.

I'm trying probe I beams in my current build, from contact with probe, the rods I have will support 9000+ rpm and 800-900hp. Plus they are super affordable. While I'm not aiming for 800, the reduced mass of the rods will make the motor more responsive and it will also free up power and torque that would normally be absorbed by the combustion process having to overcome the weight of the rotating assembly.

Now the numbers I got were straight from Probe's import tech, so we'll see how they work. Still debating on aluminum rods.


But again no, stock cast pistons, coated or not, will not survive the power you desire. And assuming those are wheel horsepower figures. You need to take in mind how much crank horsepower it will take, assume 15-20% drivetrain loss (I think that's the correct number) but the drivetrain losses depend on things like rotating assembly weight, flywheel and clutch weight, fluid used in the transmission, drag from bearings, say wheel bearings for example. Plus the weight of the brake rotors as well as the weight of wheels and tires


My main question is this, why attempt/think that coated stock anything will support those power figures

TravisBiggie

Thanks for the reply. I do not think the coating alone will allow it to sustain a lot more horsepower, I was simply doing it for good measure and to disperse the heat and prevent hot spots etc. I am angry I actually thought stock pistons were good for such power, I think I was reading about the nippon pistons instead..

Anyways, I'm in the market for forged pistons now. Thanks

Turbo-LS

iTrader: (4)

Don't go low compression and you should bore it to 81.25 or 81.5 mm. A half a mm overall isn't going to weaken the cylinder walls and its best to have a clean perfectly round bore to start with

Wiseco are cheap and will work with the standard wrist pin option

TravisBiggie

I'm thinking 9:1 or stock compression. I was told to stay away from wiseco pistons because they are "loud" ?

wantboost

iTrader: (2)

also the current/new wisecos already have coated skirts (if you get them and they aren't coated, you got old pistons)so all you would then have to do is have the domes coated

I wouldn't recommend anyone but Swaintech to do the coating

got-vtec?

iTrader: (4)

They were probably taking about the piston to wall clearance. If your on a tight budget go with SRP pistons. They're the cheapest priced set out there i believe and will help safely meet your hp goal.

Turbo-LS

iTrader: (4)

wisecos are the cheapest piston no SRP. You can get a set for 450 bucks and they will get the job done just fine. There all going to be noisy at start uyp but wiseco's arent bad. I was running SRP pistons and they worked fine for years till i blew a sleeve apart and killed the pistons.