glenb1991

Goals: @ 400rwhp @400+torque N/A with a good tune.
@ 550rwhp @600+torque Boosted with a good tune.

My build so far is consisting of Forged 5.7" H-Beam Rods, and Keith Black 18.6cc Forged Dished Pistons 4.030". Heres the decision im still trying to make.

Stock Crank, 3.48" stroke, netting a 9.25 SCR with the above pistons.
or
SCAT Cast Steel Crank, 3.75" stroke, netting a 9.89 SCR with same pistons.

my question here, which should i go with? im looking for the above goals, both with n/a and boost.

PS. heres the set-up for each. im tryin to not have to replace parts while doing this, as the turbo and everything will just be "added" on in the future.

N/A- 355(9.25 SCR) or 383(9.89 SCR), Cast Crank, Forged Rods, Forged Pistons. LE1 Heads with 1.6rr, LS7 Lifters, Comp Cams Pushrods, Lloyd's 228/235 .560/.560 109 LSA cam, Cast Manifolds, to 2.5 inch piping,to y-pipe, to cut out, to hi-flow cat, to muffler, to tips. I will be adding a 3200 Stealth Stall in the future, probably right before the turbo gets dropped in.

F/I- 355(9.25) or 383(9.89), Cast Crank, Forged Rods, Forged Pistons. LE1 Heads with 1.6rr, LS7 Lifters, Comp Cams Pushrods, Lloyd's 228/235 .560/.560 109 LSA cam, Cast Manifolds to crossover pipe, to borg warner s475, to 2.5" intake piping, to intercooler, to water/meth nozzle, to intake, to ??" downpipe, to cut out, to hi flow cat, to muffler, to tips. Stealth 3200 Stall.

Im looking at some delphi 60 # injectors, off a new 255lph pump, to cover any fueling i will need for future boost increases.

So whats everything think, ill prolly catch some crap from people for trying to do this but i just wanna see where my "FAIL" points are in this plan, BESIDES, trying to set-up for a turbo build with my initial rebuild.

If all this is too much and no one thinks it can be done without a 8 or higher on the hassle scale, then ill just stick with a nice 383 with the same heads/cam/stall and run some nice hooker headers.

ford

If its just to see the fail points why replace the crank? Atleast you would be at a lower CR with the stock crank.

I can't say i agree with purposely blowing it up if you plan to use the pistons/rods later in the future. If it was a bone stock LT1 and you were building a motor on the side right now I would say go for it.

It's hard to say whether to go 355 or 383, when we know nothing about your FI setup. You say turbo in the future, but does that mean you have an S/C for what you mention now? If so which one? What turbo do you plan on using? There are still a million questions to ask here.

But to be honest if you just want to find a breaking point... I wouldn't spend any more money on stuff than you have already.

camarobird92

Can you use the same pistons for the 3.48 and 3.75 stroke cranks? I always thought that different pistons had to be used.

94SLUG

I just dont think its going to be economical to shoot for 400 na rwhp with desired compression, further more why? Not like your going to ever run na when you get your power adder.. Your tune will be set for one or the other... I would forge the entire lower and shoot for a cr around 8.5 to 1...

boosted-lt1

NO. A piston is designed for a certain stroke, rod length, and block height. Imagine going from a 3.48 crank to a 3.75 with all else equal. You would end up with the piston more than an eighth inch into the head!

Glen, if you stroke the motor you need new pistons.

I'd either run the stock crank setup or go to an Eagle or Scat 4340 3.75.

Stud the main caps either way.


EDIT: Why would you care about an NA goal?


-Scott.

glenb1991

because the turbo wouldnt be on the car for another 6 months probably but i want to drive it once the motor and heads are done thats why i asked all this, and i can get pistons for either crank with a 18.6cc dish hence the reason for the same number. so i can get those pistons for a 3.48 and a 3.75 stroke. that checks out.

boosted-lt1

Thanks for clarifying. If you are dead set on that piston/dish, then the stroker puts you pretty high as far as static compression. What piston material is that?

To put one thing in perspective 383-355 = 28 cubic inches. That's a 7.9% increase in displacement over the stock crank setup (ie. not very significant). You can hit your goal with the stock crank and will have less money in the motor (I mean 550 turbo goal).

Now if you think you want a forged crank, might as well go 3.75.

To assemble a setup for 6-months of driving, and then have to tear the whole thing back down to go turbo is huge pain in the a**. Do you really want to drive the car that bad NA for 6 months?

ford

This is kinda what I was hinting at. I could see if he had a bone stock already running LT1 he just did not give a crap about blowing up while he built his stroker on the side. But building a cheap motor just to then rip it back out and build it again seems like a huge pain in the ***. Regardless of budget it just seems like a waste of time.

It kills me to have 90% of the parts I need just laying around, but the do it right the first time method works on more than just blower motors.

jay_rich

My motor makes... 415RWHP thru a moser 12 bolt and a 4l60e 3K stall at the wheels. Here is a quick rundown

383
splayed 4 bolt mains
je -28cc pistons
6.0 roads (eagle h-beams)
Eagle 3.75 Crank
LE2 heads
custom 234/242 Cam
58mm TB
Ported/welded intake
1 3/4 long tubes
Electric water pump
Deep pan
high pressure pump

ETC thats at 9.78:1 compression

IM gonna run 10-12lbs with meth I should be around the 600-650 wheel i think

Jay

boosted-lt1

Ford,

I think he means he wants to run the boost motor NA for 6-months.

He mentioned a cast manifold kit, so I suppose you could get the whole thing together and running, then keep the manifolds in place and add the turbo system 6 months later. I'd try to pull ahead timing on the turbo kit and do it all at the same time.

Who recommended an S475? Just curious. Isn't that turbo for bigger motors (98lbs/min ~ 800plus). Might spool slow.

-Scott.

glenb1991

Yea to clarify, im not building a motor to blow it up, just to rebuild... i honestly dont think the dumbest ricer in the world would do that to his honda hatch. I want to build this set-up, with all BOTTOM END parts made for a turbo set-up. the only thing i want to even tempt to mess with again is the cam as i know a n/a cam can be different from a turbo cam. Like ^^^ stated, im gonna have everything run the same, all thats gonna happen is theres gonna be a turbo placed at the y-pipe.... hence the reason the majority of the set-ups, were identical.... dont see hwo that didnt pop out but sorry ahead of time for seeming like an a hole about this.

glenb1991

so if i get this right... your not running the turbo now??? correct me if i got that mistaken. seems like an n/a set-up, so i just wanna see what your driveability is like with a motor built for turbo running n/a.

glenb1991

Thanks, you hit the nail on the head, during the next six months the last thing i want to do is blow the motor.... and i would pull ahead the timing of the kit but its taken me about 6 months to save up for the motor build. im at the point now where i have the money to get the bottom and top end done, not much else so im gonna have to straggle just to get an exhaust put on the car if i stick with n/a, i have all these parts laying around for a turbo build, but no good turbo to run with it. the s475 was recomended i believe on another thread on here, recomended for the 383 build tho. and im still debating on running a clone sts kit with some nice longtubes to the turbo to allow for a faster spool. if i can somehow get my beat up 1989 jeep from ohio to florida sometime soon i can sell me current dd and get the turbo set-up started off pretty well.

glenb1991

like stated above, if i build it for a turbo now, EVERYTHING, except the turbo, intercooler piping, and crossover pipe will be on the car, therefore i wont have to "tear the whole thing back down to go turbo". I just want this car on the road, and as stated originally, if i can do so, SAFELY, with a build 90% made for a turbo, yet still be able to run N/A til i get the appropriate money saved up, then i would like to do so. So is this possible??? my question still stands unanswered but thanks for asking the questions because now everyone can understand better what i meant by my original post( i tend to misword and not kno how to ask questions originally, lol.)

ford

Yes you can run the car at a lower CR N/A without any problems, you would naturaully have 2 different tunes. It may not break any land speed records with a lower CR.