systalis

My engine will be built next week. I have almost everything except the pistons. The engine is a '97 350 block bored .040 over and I'm looking for about 425hp at the crank on just the engine with an additional 100 shot of N2O. I'm looking for about a 10-10.5:1 piston and I know that forged is a must for nitrous. Price isn't really an issue, but I don't want to pay alot of $ for something that is an overkill. My builder says that he wants to find something on the lighter (weight) side. I'm running 5.7" rods.

Which brand do you guys run and what would you reccomend? My budget is around $500 if you guys think that is what I need to spend. If I could get the job done for less, thats great, But I don't want to skimp on the pistons since I'm gonna spray the ***** off of it.

BTW, this car will be driven about 30 miles per week and will rarely see track use.

Thanks

Toby

systalis

Oh yeah, I could go with 6" rods too but I may have to talk a friend out of them which could be pretty tough. I'll probably go with a 5.7" rod though.

Sonix

iTrader: (1)

TRW / speed pro forged pistons are the best value pistons out there. The brand still prices their stuff reasonably. Once you get into the "racing" brand stuff like SRP, KB, etc, the price basically triples.
Flat tops with a small valve relief, 64cc heads, and a slightly decked block will probably put you right where you want to be, CR wise. I wouldn't bother with 6.0" rods.
I'd also stick to a 5/64" ring set, rather than the significantly more $ 1/16" size.

systalis

Thanks sonix....Which type of rings? I think I heard him say something about "moly" rings?

Sonix

iTrader: (1)

yep, "moly" rings are kinda the norm, for everything aside from REEEEAL basic CHEEEPO stock rebuilds. He just means "moly coated iron rings". The "top" surface has a moly coating. You can get chrome moly, and plasma moly, depending on how much you like to spend. Plain jane moly rings in a .040" oversize should be just fine. Be sure to gap them wider based on your nitrous ambitions!!!

systalis

Yeah, I believe he said "chrome moly" and he knows about the gaps. I will spend as much as I need to spend to be able to spray and not blow the engine up in three months.

He did give me a guarantee though. He guaranteed I would blow the thing up!

systalis

Where's the best place to get TRW's sonix?

Sonix

iTrader: (1)

everybody and their dog sells TRW/speed pro, etc. They're federal mogul, however you want to call them. Your builder doesn't sell them?
Summit would have them, Ohio crankshaft, PAW, etc etc. You're getting it balanced?

Well, gapless rings, plasma moly, anything like that is just harder on your wallet, for the average guy. I don't think it'd stand up to nitrous more. I'd watch your head bolts and deck (head and block) flatness most. Use a good head gasket set, etc.

systalis

Nah! My builder doesn't sell anything. He's an old dragracer with an offshore job and does this on his spare time. He's got plenty of friends in the racing and engine building buisnes that he uses at his disposal. He's going to call me with his piston suggestion in a couple of days, but you know how it is... I gotta check him out. I know he won't try to screw me cause he's a friend and he's working for free!!!

BTW TRW\speedpro are the same company or just two good ones?

Sonix

iTrader: (1)

yep, all part of the big ol' federal mogul chain: (check all the brands at the bottom...)
Federal-Mogul - Speed-Pro Pistons

"speed pro power forged pistons"
I know I sent you that link with the compression ratio calculator before, so run the #'s, given the cc volume of the piston head (from speed pro), then keep those part#'s you find, and ask your builder about those. You usually need the block to be finish honed specifically to your pistons so...
TRW-L2256F40 comes to mind.
TRW-L2403NF40

systalis

Yeah you sent me the link and I had it saved to my favorites, but my hard drive crashed and I had to replace it. I'm in the process of recovering all of my info from my past threads......Thanks again for the info!

systalis

If I had the extra cash, would I be better off springing for the srp's over the speed pro's or would they be overkill for around 420hp plus a 100 shot of nitruos?

Sonix

iTrader: (1)

I think that's more of a brand thing, then a quality thing. But I'm not the one to ask about that.

systalis

Well, I asked only because I've read stories on this board about piston slap on cold starts and cracked skirts. I don't want to build this thing twice because of one bad link in the chain.

Sonix

iTrader: (1)

piston slap is something you'll have to live with. Forged pistons expand more than the others, so they need more space on the sides when cold. I don't know about cracked skirts though.
Maybe i'll leave that particular question to someone else, it's getting rather lonely in this thread...

systalis

Yeah I know, it is lonely in here, but as always sonix, your expert advice is always appreciated.

My builder is offshore now for another week and a half. I guess I'll wait until he gets back and see what he says.

Thanks dude

BadSS

Flat-top Wisco with plasma-moly rings $525 - very good for the money – probably a little over-kill on your build,, but that's close to your $500 budget and includes rings.

Wiseco Pro Tru Forged Piston Kits: WIS-PT003H4 - summitracing.com

Keith Black Forged $366 – never seen em,,, don’t know of they’re any better than the TRW-LW2256s or not,, that I know will handle what you’re building.
Keith Black Forged Pistons: UEM-KB717040-8 - summitracing.com

TRW Light Weight $304 – worth the step up from the standard 2256 and I’ve sprayed over 250 horses on a 460 horse engine before.
Speed-Pro Power Forged Pistons: TRW-LW-2256F40 - summitracing.com

Standard Forged TRW slugs (heavy) $265 – the extra $40 for the weight difference and 1/16 rings for the LWs is worth the step up
Speed-Pro Power Forged Pistons: TRW-L2256F40 - summitracing.com

You might can find them cheaper,,, but that’s a quick-pick for you.

acidpad

I recently just bought some forged probe pistons and couldnt be happier with them. Check them out, they are cheaper than the rest and seem to be on par with craftsmanship.

systalis

Thanks guys, thats exactly the kind of feedback that I was looking for. Any other advice will be greatly appreciated since I will probably be purchasing them sometime next week.

systalis

What about SRP? Are they overpriced or overrated? Are they worth the extra cash?

I do like the wisco's in your link badSS.

ditchbangr

iTrader: (1)

The TRW/speed pros are marketed/priced for the average joe, but they are not the lightest.

I'd take the Probes 2618 alloy over the SRP's 4032 alloy. Mainly because your planning on nitrous in the future and the 2618 is more forgiving. Wisecos are also extremely nice and they probably win more championships than anyone else in the business. Mostly preferences and applications....

systalis

Man, those probes look prettycool. Does anyone here run them?

matt_p

2618 alloy pistons expand more under heat than 4032 pistons. The 2618 is stronger, but because of the exspansion the piston to wall clearance has to be even greater than 4032.

You'll definetly get piston slap with 2618. Piston slap on 4032 pistons isnt as bad as everyone says. I doubt you'll even notice it

systalis

But the slap goes away once the engine is warmed up right? This is just a cold start issue?

systalis

Right?

ditchbangr

iTrader: (1)

From what Mork O Neal(one of probes owners) told me the probes can be run tighter because of their skirt design, believe what you want he wants to sell his pistons. With 2618 you may hear it for the first 30 seconds, pretty much every new truck I have been around has noticeable piston slap once the temps drop below 20 degrees and they run 200K. If your going to spray you want 2618, my arias 4032's are only recommended for a 175 shot, most hypers will take that.

systalis

I'll only put a 100 shot or so, but I may go bigger in the future so I definitely want forged over hyper. I don't think that piston slap will bother me much if its only for the first 30 seconds or so.

Thanks