Well my oil pressure is slowly going, about 10 at idle now, and the car is smoking blue. So I already know the car is gonna need a rebuild SOON, so these are my goals. 355 to save a lil money, maybe keep the stock crank and get it turned and checked. Get really good rods/pistons that could take a 250 shot but will only see a 150 for a long time. I just want them to be able to hold it if I ever do decide to move up the nitrous. What would you guys suggest, and if anyone has any other suggestions on the motor im open. I want to see about 400rwhp N/A, then whatever I can do on bottle. Also I already have the LE2 setup on the car now.

 

400rwhp NA, and a 250 shot will put you at 650rwhp. Thats pushing it for the stock crank (i know people have done it, but im lookin at the "build it once" moto). Honestly, if you have the cash, do a 383. Call up combonation motorsports, get a good rotating assembaly, or part one together like I did, came out to be about $500 more and was well worth it. I am going with Callies Dragonslayer crank, Callies Comp Star 5.7" rods, and a set JE custom -16cc nitrous pistons w/ hell fire rings. I also went with a custom cam from Bret Bauer. I am HOPING for 450rwhp, we will see....If you have the money, go for it! If you dont, still use the same mind set, build it once. 250shot on any more, espeicaly a streetable one will test it to the limits. I wouldn't worry to much about the internals, pretty much a good forged piston/rod/crank can hold it...i'd worry about blowing the head gasket out.....i dont think a standard felpro gasket will reliably handle a 250 shot...i'd go with a cometic MLS gasket.....I'd use the heads still also....on my 383 im going with a set of TEA lt1 casting heads that flow 276/246(with a pipe) @ .600 lift....which is prob what those flow, mine mite flow abit more on exhaust though.....

 

I'm interested to see what you do, too. I'm looking to get a low-revving and torquey motor for street. 400rwhp/tq. is what i'm hoping for too.... without revving to 6900 rpm.

edit: oh yea, and the bottom end has to be inexpensive - why go forged when you're NEVER going to use it? I just want a fast daily driver....

 

You might want to change your cam while the car is down. An LE2 cam is setup to make NA hp. It has a narrow LSA and such. Look into something with more LSA and a wider split toward the exhaust (you make a lot on the bottle). It isn't as easy to make NA hp with a nitrous cam. And an NA cam will sacrafice a good bit on the bottle.

Bottom end:
250 is a big shot. For something like that you will want nitrous pistons and good rods. A forged crank really isn't that expensive either. 4 bolt mains are a VERY good idea for that much nitrous or at least studs and a progressive shot.

A ten second motor for a 200 or less shot on a healthy NA motor doesn't require as much work but won't be as reliable/safe on the bottle. Forged rods and good forged pistons with studded two bolts is pretty stout if your not spinning high or spraying too much.

Just some things to think about.

 

i was thinking of spinning it to maybe 6600, also the car is still on stock gears, so it shouldnt be AS hard to get 400rwhp.

 

Some of this is good some of it is well old wives tales....

First off... N2O cams do like exhaust duration, but most NA cams have way to much anyways from what I have seen from people out there. A narrow LSA not fitting with N2O is not the case.... I just did a N2O cam that had 35+ degs of overlap at .050 and it will love N2O. Nitrous motors work just like NA motors in the sense that they need overlap too, not as much as a NA motor but it still needs to use the help of exhaust scavenging to fill the cylinder at high RPM. On a 150 shot you really don't have to change much on a LE2 cam, it works as is.... A bigger shot would like a different cam setup but a small shot will still get a lot out of it.

Secondly.... Like Nick said above.... a bottom end is paramount to a big shot of N2O. Now you can build a setup to take 150-200 shot with a stock crank and 2 bolted studed mains... just keep the RPM down. Even them you might have evidence of fretting on the main caps. I would stick to a set of Forged Flat Tops, Scat 7/16 Bolt I Beams or Eagle H's with standard bolts and polish the crank unless the journals are junk then just put a nice filet radius on it with a .020 or .030 grinding....


Bret

 

How bout this, Golen racing 383 competition short block $3499

Specs:
Block: Thermally cleaned and Stainless-Steel Shot. Inspected by MPI process. Decked, bored, honed with torque-plates and pressure washed. Clevite cam bearings and pioneer brass freeze plugs installed. 4-bolt main caps.
Crank: Eagle 4340 Forged Steel
Rods: Eagle Forged 4340 H-Beam, 6" Length, Floating Pin
Pistons: SRP Forged
Rings: Speed-Pro Plasma-Moly
Bearings: Clevite Main and Rod Bearings
Core Plugs: Brass Pioneer Core Plugs
Dynamic Balancing: Full Rotating Assembly Dynamic Balancing
Main Studs: ARP Performance Main Studs

 

I'm gonna head up there this summer when I'm in Boston to check them out actually.

I guess you are thinking stroker now huh?

Well make sure you know your displacement is going to change the cam and heads.... kinda sucks don't it?

Golen also has a 355 setup..

bret

 

Lemme tell ya light weight is the key. I made 365 with basically stock heads, 233/239 cam, 1.6 rocker, LW 3.48 crank, shorty headers, LW 6' rods, forged pistons, bout 11:1 compression, ect. The kicker is it was on valve springs that was way unmatched for the cam! So the valvetrain was very sloppy. Id say with a completly LW 383 with le3 heads, a gm 847, and full boltons 450 rwhp is instore. Throw some gas to that 700 with a huge shot. Now if i could win the lottery? HAHA.

 

Hell I'd take a better intake and some good flowing heads over the 30-40 some pound cranks I've run anyday of the week. $1200+ cranks aren't worth nearly as much as $1200 heads.

BTW I've seen touched up stock bottom ends with stock heads make over 375rwhp....

Bret

 

Well the only reason im considering them is because i have seen first hand what that 383 will take, i would rather have a 355 and rev to 6800 because its better for me with an M6 so i can hold each gear a lil longer and make full potential of each one. On there site they only showed a 350 long block and then the competition 383, im positive they have a "competition" 355 shortblock if I just call them. It prolly will be about 500 less than the 383 just because thats what i have seen elsewhere. And there competion package is just basically forged internals. But countrymusicz28 has the 383 in his M6 vortech T-trim car, that puts like 530 to the wheels, he turned the boost up to 16lbs now so i dont know how much he's putting down. I watch him race people every week down here and is constantly beating on it, so i know they can take some abuse.

 

if the setup is done correctly 355 or 383 should be able to take a lot of abuse. If money isnt a prob go stroker, you wont be sorry

 

Ok guys sad news, lost all oil pressure, checked to make sure the oil pump drive gear was alright, and it is. So im assuming i lost a bearing as the motor was making quite some noise. You guys have any good sources to get these parts? I want to stick to a 355, scat 4340 crank, scat I-beams, and i dont know which pistons and rings to use for nitrous, theres so many of them. Do you think i can find them cheaper seperately or all as one rotating assembly, and where would you buy your parts from?

Edit* found these from strokermotor.com

Internal Balanced Part #IB3555

* Crank: 4340 Nitrided Forged Steel 3.480 Stroke
* Pistons: SRP 4032 Alloy Flat Tops 10.3:1 CR w/64cc
* Rods: 6.0 4340 Lightweight Forged Steel I-Beam w/ARP bolts
* Bearings/ Rods & Mains: Clevite 77 'H' bearing
* Balancer: Pioneer SFI approved steel style 6.25" diameter
* Flexplate: SFI approved, 168 teeth
* Balance: High performance street/strip,
* Piston and rods matched +- 1 gram

$1,650.00

Internal Balanced Part #IB3554E

* Crank: 5140 Forged Steel 3.480 Stroke
* Pistons: Probe Forged Flat Tops 10.8:1 CR
* Rods: 6.0 4340 Forged Steel H-Beam w/ARP 7/16 bolts
* Bearings/Rods & Mains: Clevite 77 'H' bearing
* Balancer: Pioneer Street Performance Steel 7" diameter
* Flexplate: 350 SFI approved, 168 teeth
* Balance: High performance street/strip,
* Piston and rods matched +- 1 gram
* This kit will take 200HP of NOS <--- I like this

$1,495.00

ill just keep posting them as i find them gofaststuff.com

Kit #SBC6 SBC 4340 Rotating Assemblies - 355, 383, 396, 406, 420, 434ci, Eagle 4340 Crank, Eagle 4340 H-beam rods, ROSS pistons, Plasma moly rings, Clevite H Race Main and Rod bearings. Please provide piston compression with payment.
Kit #SBC6 SBC 4340 Rotating Assembly Unbalanced $1549.00
Kit #SBC6 SBC 4340 Rotating Assembly Balanced $1699.00
Kit #SBC6 SBC Dome Pistons Option $50.00

 

also i read something about a main girdle or something that connects them all together that supposedly makes it stronger than a 4-bolt main. possible to use on an lt1?

 

im pretty sure that a splayed main bearing is stronger