I am looking at going with either a 355 or 383, but that isnt the focus. The goal is around 400rwhp NA and after some time, a shot of nitrous 150 at the most. Real world goal of low 11's motor, and giggling into the 10's. I am going to be running a TH400 and when the 10 bolt poops the bed, a Ford 9". Probably run the old junky CC306 or GM847 and some 28Xcfm/19Xcfm ported stock LT1 heads.

Taking into consideration my goals..why would you choose a...

355 vs 383 [Remember its going to have a heavy drivetrain]
Cast or Forged crank?
2 or 4 bolt main caps?
5.7" or 6" Forged Rods
I or H beam?

Mainly just wanting to see why you would choose one vs the other.

-Dustin-

 

I'll toss out what I'm thinking to get the ball rollin'

- 383ci [To keep RPM's in check for longevity, less stain on parts, street manners, no worries on the PCM, and TQ available lower to help power up the heavier drivetrain?]
- 6" Scat Forged I Beam Rods [Buddy has brand new ones laying around for cheap [$100-150]
- Forged Scat Crank [I'd rather have it and not need it, than need it and not have it] [Not sure if cast would hold]
- Mahle Power Pack Pistons

2 bolt vs 4 bolt mains...I have no clue...again I may use the same reasoning as with the crank. Just not sure if the lower RPM's would warrant 4 bolts, although I'm thinking the nitrous might.

One question I have is only shooting the crack to it occasionally would I be able to get away with a cast crank and 2 bolt mains, what about nodular iron?

-Dustin-

 

Well, I'm all about overbuilding stuff because you never know what you may throw at it and high quality stuff has a habit of lasting a long time...I like Callies, Oliver 5.85" billet rods (the 5.85" offers a good compromise between the 5.7 and the 6.0" for rod angle in the bores and having enough piston to handle goodly amounts of whatever you throw at it) and JE pistons... I have heard good things about Mahle pistons, but I have no experience with Scat stuff...

My 383 shortblock with the Callies, Oliver JE combo has been in the car for 12 years without a hiccup and the set up just keeps getting faster...

--Alan

 

my opinion?

383 for the same reason - I like the torque curve over that of a 355 in a heavy car.

6" H-beams. I have never seen an H-beam fail without circumstances that would not have killed any other rod. You, like me, are not running a big shot of gas, so the I-beams may suffice, plus the price is right for those. I chose the H-beams though.

Scat forged crank - this would be a requirement in my book, and I have one. This, with 4-bolt mains, was an extra margin of reassurance that I was willing to pay for. Plus, if you get the urge to spray more, or god forbid should it go a little lean, the potential for part failure is significantly less. How much reassurance you'll need really depends on how willing you are to replace and rebuild when it breaks. All HiPo stuff is on borrowed time - that's just reality.

The Mahle pistons are awesome pieces for the money, and will suit your application well.

 

TOUGH CALL on the 2 bolt vs. 4 bolt and cast vs. forged crank

Many people do it just for the piece of mind. But you VERY RARELY ever hear about mains or cranks breaking (I have never even seen it personally on an LT1).

More than likely, on a performance motor - The pistons, rings, bearrings, rod bolts, etc. will break instead. That is where you hear the most stories, so those parts should be top notch. I guess it all depends on what kind of a budget your on if you wanna do the crank and mains also. People spray 100-150 shots on stock internal LT1's all the time - but you must remember that you will have a more aggressive cam, etc.

ME, PERSONALLY: I have a 2 bolt main and stock crank car that is supercharged with around 500-550 RWHP. It has held up great now for around 2 years. BUT - it was properly tuned, and has good forged pistons/rods, good bearrings, etc....

But ultimately it is your decision...

 

Since you're buying a rotating assembly there is no reason at all not to run a 383 unless you're just really lazy or you like a high rpm screamer. theres a few extra steps in making a stroker work, and either you wanna deal with em or you dont its that simple.

I would for sure go with a forged crank with nice big radii off the journals. Just for the piece of mind and the prevention of cracks. by the same token i would run a 4 bolt main cap setup. you wont see a main failure and rarely a web failure unless something is screwed on the RA balancing. the big reason i would run 4 bolt mains is because with higher rpms and the dope hitting you're probably going to see some fretting of the main caps. when you take the engine apart you've been running you will probably see it there anyways. I really dont like things getting loose enough to move around in my bottom end ya know.

H vs I beams, i choose H beams plenty of people running i beams and they are light and strong. In the case of a nitrous motor or a setup where i would run a forged crank and 4 bolt mains i think the rods need to be as beefed up as possible.

 

2 bolt block with studs, 4340 forged crank, 6" h beams, forged pistons. Mahle pistons are better for an NA motor but the SRP pistons have the top ring down a little more so if you were going to spray it I'd use those. Trick flow or AFR heads both have thicker decks than stock LT castings and will help you keep from popping head gaskets under the spray. The trick flows flow about 255 and the AFR's about 265. With some mild porting the Trick flows can easily beat the AFR's and still come out right on price.

 

Here's my setup....

stock crank
eagle h beam rods and wiseco pistons
splayed mains
le3 heads/cam/intake
full bolt ons
th400/4000 coan converter
150 shot single stage currently
All 91 pump gas

Dyno'd 365rwhp n/a and 520rwhp on the 150 jets with a bad opti
New opti and 8 degrees timing taken out and it did 377rwhp right off the street in the hot weather on the motor

It'll be getting a 2nd stage soon, 200-225rwhp total, shooting for 600+ rwhp through the th400 and high 9's. No track times yet, lots of street runs through. This is my daily driver, gets raced every weekend, and I average about 200 miles per week on the car.

Here's some recent vids of taking out some 600+ rwhp cars...

http://media.putfile.com/2300rwhp-racing

http://media.putfile.com/skinniesvsmoddedr1

In my opinion if you keep the rpm's down(I shift at 6300-6400 on the bottle) and have a good tune a stock crank will be plenty fine. This winter I do plan on a better crank and a 350+ shot for next year.

 

im pretty much where your at as far as goals and mods.


Right now im gonna be using forged pistons and rods (not sure if the are H or I)

the crank is gonna be a stock resurfaced one with 2 bolt studded mains. My builder says i shouldnt have any problems at all.

I will be running a 125 shot til next year when i may upgrade to a 175-200

the stock crank can handle A lot of abuse b4 it goes.


MY builder has been in the 10s for a while spraying on a stock crank

 

Think about like this, if you have an addictive personality your probably not going to stop at the 150. So in this case go forged crank/4 bolt main.
If your more laid back and can be happy with what you have, save your extra money. Theres guys with stock bottom ends,h&c, and a 150 shot that hold. How long is going to be a good question. Sooner or later a weak spot is going to arise. But that may be 10 passes or 100 later.
I would ask yourself how many track pass will it see a year, would you consider rebuilding it 4,5 years later, how hard are you on it on the street, etc.

 

Which is why I am wanting to spend the extra cash and go with high quality parts so this is the last bottom end I have to put in this car. Your car never ceases to amaze me so learning from your setup would be a wise move. Sounds like I might have to go all out on this one. Definately not the area to skimp on, this isnt vinyl inserts and neon bulbs.

Other than the rods, I'm not saving that much going with Chinese stuff anyways

I live about 15 minutes from Golen, so perhaps I'll have them do my block work and assembly just to make sure its right. Hopefully start out with a Vette LT1/4 block with 4 bolt mains. I like to use supporting venders when I can

-Dustin-

 

Hey, thanks! Yeah, the damn car amazes me most of the time, too. My motor was originally built by LPE in 1995 and the quality of the stuff they use plus the meticulous attention to detail in their machining and assembly are second to none. John was all about durability and I think they succeeded in my build. When I went with the Joe O. cam it was only to go faster. The motor has never had any issues with anything in 12 years...

Good luck with your build. It sounds like its going to be a fun ride!

I'm going to continue to push my set up and see what happens..Just opened a box of QA1 springs/shocks...Got 4.10s and a spool in the garage, and some 275 60 R15 M/T DRs...mmmmmm...

--Alan

 

if you look on ebay you can find
6.0 hbeams for $250
4340 1pc.rear seal crank for $330,3.48 or 3.75
mahles for $500.also avalible from flatlander
ive bought about ten forged bottom ends and all the low buck stuff is the same.the crank and rods are the same as the ones eagle sell.

 

IIRC the vette 4 bolt mains arent splayed

i mean splayed is not necessary but u said u want the best lol