So I sold my 4 wheeler and after gettting everything with that worked out, used the money to pay off some bills. I have some money left over so I was going to order the rods and pistons for my future 355 build.

I am going to be using the stock crank and boring the block .030 over. Now I will be running a splayed 4 bolt main and LE3 package on the car. NA I'll be revving it to about 6900 and on the spray probably 6400.

I plan on at least spraying a 150 shot and then once I get the motor broken in upping it to a dual stage 150/150 shot. I will be running a dedicated fuel system for the nitrous with 110 in the tank.

I was looking at Diamond pistons because my friend has them in his 331 Mustang and really likes them. Also, I plan on running 6" rods. I would like something forged and either a H beam or I beam.

Any suggestions on the rods and pistons?

 

my vote is for the Scat h-beam rods with Mahle pistons. pretty economical set-up and from what I've seen, very good quality. Diamond makes a great piston too.

 

I agree, you will need some decent rods and Mahle makes some nice pistons. I hear those Diamond pistons are good too but have never run any. I run some Lunati n2o pistons with the ringland moved down a little which i think you may need if youre planning on spraying 300HP. Later

 

so scat h beams it is.

pistons? ive been looking at mahle and diamond.

 

Your going to ultimately be running a 300-shot (150/150) on a stock crank? Why are you lowering the redline 500rpm with nitrous?

 

I've talked to a few people on here and ls1tech and they have said that keeping the RPM's lower and keeping it from detonating, the stock crank would be fine. I don't really know if I will be running that big of a shot for sure or not.

I do know that I will be running a 150-200 for sure. If I can get into the 10's with only a 150-200 then that would be fine with me.

Fred, I know you have a lot of experience with this stuff. What do you think?

 

With nitrous, the lower the RPM, the higher the combustion pressures. There's a lot less strain on the engine at higher RPM. I spray from 5,000-7,000rpm. But NA, the cam is so mild there's no point in shifting much over 6,500RPM.

Sounds like you are shooting for something in the 650-800 flywheel HP range. Sounds awful high for a stock crank. That would be a good reason to limit the revs on nitrous.

 

Yeah that is what everyone was saying. Keep the RPM's low with the stock crank and spraying it. I wouldn't be spraying a 300 shot all the time either. Like I said, after I get the motor built I would stay with the 150 shot for a while and get my suspension and everything worked out. Then, if 10's were not obtainable, I would strap on a dual stage.

So Injuneer, what would you suggest for rods and pistons?

 

You can click on my Mod's List and get a complete list of everything that's in the engine. But Oliver Billet rods and custom BME nitrous pistons are not low budget parts. Nor is the Callies crank.

 

Mahle is not the right piston choice either for heavy nitrous use. You need to rethink your budget or lower your goals. I just looked in Diamonds catalog and didn't see any pistons that look right for a 300hp nitrous shot. Their "street/strip" flat top is described as "will work with small nitrous applications". The top ring is down 0.190", which is probably ok but may be marginal and the alloy is 4032 while the 2618 is preferred for heavy nitrous use. Rod length is pretty irrelevant for this application. A stock crank is not adequate. The least I would cosndier is Callies Compstar, ditto on the rods. Callies sells complete, balanced rotating assemblies at a reasonable price, that's the way I would go. JE makes a "heavy duty" SBC flat top that they descibe as: "Engineered for Extreme Duty Alcohol and Nitrous applications these pistons are perfect for drag race, ASCS and Sprint Car engines. Valve pockets are designed to work with Pro Action/Pro Topline 23º, Brodix 11X and angle milled cylinder heads and a 2.750” pin provides added stability to absorb heavy loading. Offered in .005” and .010” overbores to accommodate new aftermarket cylinder blocks. Ring grooves are machined for 1/16, 1/16, 3/16 rings." I have had good luck with JE over the years and I would consider this piston.

I think you need to seek advice of people familiar with using a large nitrous shot in a small block.

Rich

 

Mahle will make any application piston you want. Their power pack piston is good up to a 200 shot and even they advise against over that level. I missed the 150/150 part. If it was a simple or progressive 150 shot, then that's pretty reasonable.

Seeking advise of folks who run large shots is good advise in itself - even the best parts assembled for a large shot will end up a heap of wasted money if others things are not spot on.

Then again, if you're contemplating a 300hp shot of nitrous, cheap parts are not exactly an option anyway.

 

Did part of that come from a copy/paste of something I wrote on here or ls1tech? Thats my exact setup and seems like I wrote part of that awhile back.

I pushed my stock crank to ~850 crank HP, never had any issues. Had several hundred pounds of nitrous ran through it, lots of racing, and it's staying for the turbo build also.

I ran eagle h beam rods and wiseco pistons. The pistons finally gave up when it leaned it out one night, but they took a lot of beatings.

 

Yes, you were the one I was referring to when I said I talked to someone about their application.

I was looking through the SDPC catalog last night and came across a Scat forged crank for about 600 and some Scat forged I beam rods for about 300. Would these work okay? I'm still trying to make up my mind about pistons.

 

That's what I'm doing. I will admit, I have rebuilt engines in the past but they were all for daily drivers or just had a mild cam with some ported heads. I have NEVER built a performance motor and when it comes to nitrous I don't really know what parts will work. I have been looking into Callies Compstar but really can't find a website that will give me prices.

I have been looking at the Scat products and they look fairly decent.

Any sites where I can price this stuff out would be appreciated.

And thank you to all who have been giving me advice!

 

Also, do they make the Compstar stuff for a LT1. Everywhere I go just has the LS1 parts.