93 black t/a

I was told by a friend that going with a 383 that you can't run a 6 inch rod, and that you'll have to clearance the block so much that you'll end up hitting the water jacket. Is this correct?? I thought there was quite a few people running 6 inch rods on 383's with no problems.

ss.slp.ls1

iTrader: (36)

Ask your buddy where he is getting his information from...
You can build a 383 with .030" over bore (4.030" pistons), 3.75" crank, and either 5.7", 5.85", or 6.0" rods depending on which style pistons you choose. You want to go with the longest rod you can get away with.

93 black t/a

Well as it stands now i'm planning on ordering forged eagle crank and h-beam 6 inch rods with forged srp 16cc dished pistons.

96lt1m6

iTrader: (31)

there are too many horror stories out there and a ton of success to disprove those stories.

93 black t/a

I clearanced my block when i built my 355 and used a 6 inch h beam rod and didn't have a problem. Granted, I didn't have to clearance that much.

RamAir95TA

iTrader: (2)

I haard from a friend whose friend heard from another friend's room-mate's inlaws that your friend providing the information is retarded.

There have been countless 383 builds with 6" rods. Including mine. Anyone who tells you that it can't be done is downright assinine.

shbox

From pics and threads I have read, some rods require more clearancing than others. Educate yourself and choose wisely.

James Montigny

iTrader: (13)

Yes, you can run 6" rods.
Yes, you will probably have to clearance for most rod designs.
Yes, you are likely to hit water with H-beams and big bolt heads.
No, it's not the end of the world, you can weld it closed again without a problem.

This is my 383 with Eagle 6" Forged H-beams
We hit water several times and welded to repair.

Puck

iTrader: (17)

Depends on your block, rod choice, and rod bolts used. If you use 6" Eagle h-beams with L19 rod bolts you WILL hit water in more then one spot.

If you go 6" rod I would half fill it no matter what rod/bolt combo used just in case. Also note that there are some other cons besides just clearance - less PTV(not usually a problem on most builds but worth checking), smaller piston choice, and a higher chance of needing a small base circle cam to name a few.

93 black t/a

Is there really that much of a difference between a 6 in and 5.7 in rod, to spend that kinda money on having the block filled and welded?

fergymoto

iTrader: (129)

The general consensus that engine builders I have discussed it with have said that it is mostly theory and there have been no solid proven gains/benefits of going with a 6" rod over 5.7"

Another thing with 6" rods is the wrist pin is often located partially in the oil ring land which has been said to cause more oil usage.

I would stick with 5.7" or go to 5.85" if you want a happy medium.

BlackTA96

iTrader: (3)

Damn.
This thread makes me wanna rethink going with a 6" Hbeam.
hmmmmmmm....

93 black t/a

Well i just found out that the connecting rod bolts are the 8740 chromemoly steel ones. Will these require as much clearancing and hitting of the water jacket?

myltwon

iTrader: (1)

depends on the design of the bolt head more than the material

MadMike 97 Z28

iTrader: (3)

bigger rod = smaller piston, smaller piston = less rotating mass, less rotating mass = more HP, more HP = FUN

ss.slp.ls1

iTrader: (36)

Also...
Longer rod = less side loading of the piston = less friction & less heat = more HP & cooler oil temps

BlackTA96

iTrader: (3)

ok...so maybe it'll be worth it...
lol

ABA383

iTrader: (1)

And just to add to this John Lingenfelter did extensive durability testing in conjunction with the rod angle/side loading in the bores and determined that the 5.85" rod is the optimal choice for power/durability in the 383...Lingenfelter built my shortblock in 1995 with a Lunati crank, Oliver 5.85" billet steel I beam rods and JE pistons...14 years, countless 1/4 mile passes, and 52,000 miles later it just keeps getting faster...and there was minimal clearancing needed...

--Alan

fergymoto

iTrader: (129)

^It keeps getting faster because it's just getting broken in Alan

OutlawZ

iTrader: (4)

6" oliver rods, 383 half filled block here. custom nitrous pistons with buttons instead of wrist pin spirolox so that my top ring land is still thick as ****.... pistons are setup for a 500 shot.....

never hit water.... but probably because my engine builder sits at the right hand of god.....

if your guy knows what he's doing you won't have a problem.... I run huge rod bolts and didn't come close to water...