SPEED750

I need a set of forged pistons but not sure what to buy. I have LE2 heads, LE1 cam, the motor won't be turning over 6700rpm and I have a NX wet kit. 150 hp would be my max n20 jetting. CNC motorsports has KB forged for $340ish, these are flat top with -4.7cc reliefs. Are the cheap KB any good? Anybody know of a killer deal out there??

SPEED750

ANYBODY!!!

firetird

how much are you wanting to spend?

SPEED750

Well most of the forged I've seen are 5 or 6 hundred. So anything less than 5 is kinda low. As far as my budget, I want the cheapest that can take a 150 shot and last along time. If that means I gotta drop 6 hundred then I guess thats what I'll do. If guys are spraying 150 on stock cast pistons with no problems, then it would seem like any forged would do the trick. I dunno.

CCCCCYA

KB's are hyper pistons. You will want to avoid them for a N2O application. Your going to want to pony up and get a nice set of SRP flat-tops. You'll be looking at 6 cc "eyebrows" (valve reliefs). You can spray your 150 shot on THEM till the cows come home with no issues (given a safe mixture that is). You might want to think about upgrading to stronger rods too while your in there, but the stock crank would be just fine as would your 2-bolt caps in this application. Oh, and make sure you don't cheap out on the rings. I've had good luck with ZG (Zero Gap)rings, but opinions on them vary. Some like 'em some don't.

Hope this helps..

Dave C.

I burn rice too

I used the Sealed Power pistons from Summit. You can get the whole rebuild for about $530.00. I had good luck with them on my last car, but I didn't get a chance to spray with these. I did drop one pretty hard on the concrete during the rebuild and it didn't even ding.
Like you said, a in-expensive forged is better than a hypereutectic. If you were running more than a 150 shot then I would be concerned.
Good luck on your choice!

SStrokerAce

Personally I love the Mahle Pro Pack pistons. The pistons come with the rings in the set and it ends up being less than a SRP kit and the quality is better. They take spray, come with coated skirts and from what I have seen make more power on the dyno.

Bret

darkangel95

What do you think the limit of the Mahle pistons would be? I have been thinking about using them when I build another motor and I was wondering what I could saftley spray with them. 200-400 hp if the whole bottom end was built for it?

LT4orbust

do a search on using stock pistons with nitrous, from what i've seen... stock pistons and rods handle 150 with no problem.
i was going to do the same thing, but decided to just change the cam and port the heads with a little less n20

SS Mark

I think a big problem with stock LT1 pistons is the ring lands are weak, might as well replace them if it is going to be apart.
-Mark

SStrokerAce

Stock or aftermarket?

Most times pistons go with N2O due to the rings closing up to much from the heat and breaking off the part of the piston above the ring land or you lean it out and burn a hole in the thing. Other than that they hold up well to decent N2O shots.

Bret

izzyz28

Ditto! This is what I used and it works great. Plenty stout for the 125 shot I'm running, and the skirts are coated. Just make sur you get it balanced, as they're not the lightest pistons in the worls, especially compared to the "lightweight" stock pistons.

darkangel95

What do you mean by stock or aftermarket?

I always look out for and read your posts and I was just curious what your opinion of these pistons may be. Does Mahle make a specific Nitrous piston? I have seen that quite a few of the LS1 guys were using them in forced induction setups but haven't heard of very many LT1 guys using them (I could just not be looking enough) My final question for this post is would it be better to run another piston in a heavy nitrous application, specifically one with thicker top ring lands ( The Mahle's may have them I am just unsure)

Thanks for your help, Bret

SStrokerAce

Actually Mahle makes the stock LT1 and LS1 pistons, all the way up to custom Next Cups stuff and F1 stuff.

If you want to run a HUGE shot then a custom N2O piston with the top ring land farther down from the top of the piston is the way to go. We are talking about over a 300shot here.

Most times guys kill pistons due to the two things I mentioned. If you build the motor with this in mind it's really not that big of a issue.

Bret

1-bad-z28

remember that running that much juice (above 150 shot) will need some higher octane to keep it from detonating and make sure the timing is adjusted properly. I just saw an article about how far they can juice a 383. This motor have a firged crank, 4 bolt main, h-beam rods, and forged pistons. They said 150 shot was about max on pump gas before it started detonating. They went all the way to a 215hp shot and destroyed the engine.