thewinner

im building a forged 383 and the machinist has the kits in the book, and the only one that would get me close to a high 10 low 11 CR has i believe an 11 cc dish in it.

This should be fine to run in an n/a and nitrous application right? he said that it will promote better flame b/c of the dish.

also goin with a 5.7 rod. and lastly, lt1 CC size is about 53 right?

thanks

PNYKILR

If the heads are stock they are 58cc's. That is a great setup for NOS, as it allows you to run bigger shot's(300 ) if you choose to do so.

treyZ28

nitrous likes compression unlike blowers and turbos..


go to 11.5:1 and use longer rods

then again static compression is meaningless if you aren't concidering dynamic compression

thewinner

how come long rods, wont that put the pin right up in the heat?

11.5 seems like a lot of compression? stock is 10.5 right?

and what the hell is dynamic compression?

treyZ28

to much explainin

dynamic compression takes into concideration the compression after you bleed off some from your cam- in a nut shell. reall compression because after all, your car is bleeding compression.

static is all valves closed and piston goes up. 10.5 cc's of air got compressed into 1 cc of air.

longer rods allow for more dwell- in a nutshell

JordonMusser

i would let somebody tha tknows LT1 put this setup together.

I agree, more rod, 11.5:1 or so.

thewinner

so im not gonna run into any knock problems with running the 11.5 n/a?

treyZ28

you explained the nitrous thing to me way back when jordan

thanks

::::smacks jordan a highfive::::


so long as you run 93 octane youre fine-

i would skip on the 87 though

thewinner

i always run premium, 91 up here, so 11.5 should be easily taken by the motor?

so compression ratio doesnt effect the amount of nitrous you can run?

thewinner

ok back to the original question hehe, will a dished piston be as strong as a flat top? is it appropriate for an n/a nitrous motor?

rskrause

Lots of issues raised here already. But most pistons designed for forced induction have a dish. As long as the rings aren't so high as to limit the thickness of the crown there is no problem. If you stick with a good piston manufacurer and specify that you will be using a big nitrous shot you should be fine. Don't get a "lightweight" piston for this application.

As far as CR goes, the whole package and what fuel you use needs to be taken into consideration. But as has been suggested, nitrous does not require low compression like a SC, especially if you are running a big cam. Optimized cams for nitrous are a big topic. But suffice it to way that they are somewhat similar to SC cams in that overlap is bad (though less so than with a SC) and a fairly big split between the intake and exhaust duration is desireable. Head work emphasizing exhaust flow and a good exhaust system will also opitmize nitrous gains.

Rich Krause

thewinner

are 4 bolt mains NEEDED with a max of 200 shot of juice? i assume ill push about 425-450rwhp n/a. i'll probably run 150-175 most of the time on juice, but maybe try a 200 sometime. highly doubt ill ever try the 200shot anytime though.

I see lots of people pushing some good amounts of nitrous on teh stock bottom end and wondering if ill be ok with the stock caps and some arp studs?

Rich, ive got a 230/236/112 .544/.555 that i am going to be using for the car. not teh best for the juice but its what i have to work with.

so if these are SRP pistons, i should be just fine using the dished?

Is the difference of .5 or so in teh CR REALLY gonna make a difference? stock CR is 10.5 right? and how about the rod length? 5.7 vs 6? any real big difference? what is the power gain from the extra dwell time?

rskrause

I think you will be ok with the stock caps, but be aware that they are likely to move a bit under nitrous leading to shorter bearing life. If you run nitorus a lot, don't expect the bottom end to last forever but it should be ok for quite a while. The studs are an excellent idea.

The 1/2 point of compression is not a big deal, same with the cam. Will cost a few hp, but it should still run pretty damn fast. SRP is a good piston. The JE isn't that much more $$$ though and it's a tougher alloy. The JE/SRP "nitrous series" rings are a good choice for this application.

Rich Krause

thewinner

so it should be a reliable motor running a 150 shot or 175 every once in awhile? im not gonna be on the nitrous always, just at the strip and for the occasional street race if im behind

Rich, do you honestly think it is worth it for me to switch to a flattop and a 6" rod?

so an eagle 4340 crank, 4340 hbeam rods, and srp pistons should be a very good setup? does eagle have a freaking website?

rskrause

The switch would absolutely not be worth it. I wouldn't give you a warrantee on it, but it should be fine for occasional use.

Rich Krause