WS Sick

Most tend to agree that the 6 inch isnt needed on a 350, the extra piston dwell from the longer rod most people cannot justify. So to save cash on the piston the 5.7 would probably be the better choise, now a 383 is a differnet cookie, the 6 inch rod would be better.

lethal bird

iTrader: (12)

That's what I was thinking but wasn't sure.

OutlawZ

iTrader: (4)

not 100% accurate. The 6" rod 355 offers the best piston/rod ratio in the SBC world. less side loading on the pistons, less friction, less heat.... the increased dwell equals a more efficient burn. I ran a 6" rod 355 for awhile until it smoked the thrust bearing but it performed very well and was a loud powerful beast of an engine.... 422 RWHP thru a 6 speed all motor on it's first dyno trip not even really tuned all that well.... setup was very close to what you're thinking about. 236/242 hydro roller cam, ported intake, 58mm TB, Stage II heads.. very similar to your build. It went 11.7 on motor and 10.40 on a 150 shot. they are very efficient motors and they can make alot of power. put a 6" forged h-beam in it and call it a day...

WS Sick

Thanks for the input Outlaw, I myself have ran a 355 with 6 inch rods, but I really didn't feel that I was making that much more power than with a 5.7 rod motor, now I have nothing to quantify that statement other than comparing my results to others, and in the motors defence it was far from optimized camshaft wise.

OutlawZ

iTrader: (4)

Yeah the results of another .3 worth of rod length will definitely not be noticed in the seat of the pants.... really it comes down to efficiency and longevity... John Lingenfelter himself was a SERIOUS supporter of the long rod 355 and wrote a huge article about it at length. Horsepower not withstanding there are other gains to be had with the rod length increase like the oil temps and the side loading of the piston....

NOW on the other hand some do not like the fact that the wristpin gets moved up into the ring pack causing you to lose some of the piston crown strength on a heavy HP n2o/blower/turbo application. It's tough getting a thick top ring land needed for heavy doses of nitrous and still having the extra rod length. Several builders have told me to "always opt for the longest rod you can stand to have and still retain the piston top ring land you are comfortable with at xxxx hp level"..... however it's not impossible. I have 6" rods in my 383 and my pistons are spec'd for a 500 shot. They will live at those hp levels provided the tune is SPOT ON.... The longer rod is always worth looking into cause while maybe the HP levels will be unchanged from 5.7, 5.85, 6" but the oil temps, side loading, and rod/piston ratio will always improve as you step up thereby theoretically increasing engine longevity by decreasing wear and tear on the pistons and bores...

95mysticta

iTrader: (4)

I went with Forged Eagle 6 H Beams as when the time came i could reuse them if i went the stroker route down the road.

nitrous2fast

iTrader: (2)

There are a few reasons to go one way or another with rod length.

5.7"
1 can use the stock rods
2 can use stock pistons (generally)
3 wrist pin doesn't interfere with any of the rings.
4 sometimes can find 5.7's for a few bucks less (same company)

6.0"
1 longer dwell time, causing timing to be more optimised
2 less side loading, causing less wear on the side walls of the engine
3 better rod to stroke ratio, causing a non forged piston to be able to hit higher rpms.

good thing about a 6.0" is if you were really on a budget you could opt for a hyper-eut piston and still hit 6800 rpms safely. The longer dwell time at tdc and bdc allow for less stress on the pin and pin bosses.

lethal bird

iTrader: (12)

I'm learning a lot here guys thanks for the info. Looks like 6" it is.

gregrob

iTrader: (8)

"Most people" don't have a clue how to tune nitrous. Done properly a nitrous motor will last as long as anything else. No need in leading him to believe that spinning rod bearings comes with the territory because it certainly doesn't.

355z28

iTrader: (8)

on a 355 a 6" rod is the way to go for sure. Its not a power things that you notice but its optimal for the reasons states above.

I still say run the 7/16 scat rod, its 100 grams lighter then a H beam and along with a lighter piston (like Mahle or CPs Bullet pistons) will rev super fast. The Scat I beams will support 600-700 horse power spun to 7k rpm. Most likely your going to turn yours 6500 and make 400rwhp. Why add unnecessary weight to the rotating assumbly the costs power and et?

If you run Mahle powerpack pistons I wouldnt think you plan on running more then 150 shot which puts you in the clear.

lethal bird

iTrader: (12)

Stock forged rebuild.
Scat 6" I beams
Mahle pistons (still don't know which ones yet)
Clevite rod and main bearings
Durabond cam bearings
Arp rod, main, head, intake, exhaust bolts
Millings standard duty oil pump
Lt4 Ed timing set/Cloyes stock chain and crank sprocket
Svo 30lb injectors

355z28

iTrader: (8)

Looks good, I wouldnt bother with the lt4 ed chain its a good piece but is over priced for what it is. Just a stock replacement 3 piece set will work fine.

Here is about exactly what you are planning on building.

http://www.ellweinengines.com/Ellwei...Kit/355Kit.htm

lethal bird

iTrader: (12)

Petty much. Only difference it that's a 355 and I'm staying 350.

gregrob

iTrader: (8)

Might I suggest not going the cheap route like everyone else does?

Heres a rough suggestion for you
CP Bullet series pistons
Compstar H beam rods
Clevite H bearings on the rods
P series on the mains

Food for thought. You get what you pay for.

lethal bird

iTrader: (12)

I really wish I could but I don't think some of those things are in the budget.

lethal bird

iTrader: (12)

And for what I want to do with the car I just can't justify it. I just want a meanish street car with the occasional track days where it might see some nitrous. Now if I was going more strip than street I would be all over that setup but for now I think I can just make do.

WS Sick

Yes, after I reread my post about rod bearings it does sound like I'm saying it's inevitable, I should have added that the tune is important to avoid detonation.

FormulaJoe

iTrader: (5)

Anybody try King bearings here?

I'm also building a 355 but not so much on the budget side.

lethal bird

iTrader: (12)

http://www.summitracing.com/parts/MLE-SBC125000F05/
http://www.summitracing.com/parts/MLE-SBC550000F05/
Which one of these pistons do i need?

FormulaJoe

iTrader: (5)

Not sure but the only difference between the two is the compression distance.

Also, I got my srp pro series pistons from cncmotorsports.com for about $100 cheaper then summit.. They usually beat summits prices on most everything they both have. Though the difference varies..