gtuturbo

Could anyone tell me the width of a 330 rod at the crank journal?
I kept one rod and piston for my rebuild and for the life of me can't find them!😞
Trying to use 6" SBC rods and 4.00 pistons instead.

joe_padavano

Should be 0.935" - 0.937"

cutlassefi

Chevy Rod will be .940 or so. But look for an LS style Rod as they're centered like an Olds. Std sbc stuff is offset.

gtuturbo

Aha! So they are very close.
I saw something about the offset of normal SBC rods.
LS rods it is. Thanks!

cutlassefi

What piston? A standard Chevy piston will be way too short.

gtuturbo

You tell me, brother!
From what I have read, you have done this before. I am open to ideas.

I wanted the same 6" length rods, but it seems I have to go a little longer with LS rods. Looks like 6.1250" ?

Pistons? Good question. 4.0" bore and forged so far.
Stock 330 has a 9.33" deck height, and stock assembly is 9.3075" ?
That makes the stock deck clearance at -.00225.

So my new compression height for my pistons needs to be 1.49" to keep the same deck clearance?
Problem is they dont make any pistons with that, do they?

olds 307 and 403

I know one member off set ground his 330 crank for a 3.5" stroke with I believe 6" sbc rods and 4" bore sbc 350 pistons. I know 6.2" rods are out there, start calculating.

RocketV8

Yeah, this was my recipe: Scat Pro Stock sbc rods and KB hyper pistons.

cutlassefi

No, not off the shelf that I know of. However you can do the 6.200 rod with a 1.425 cd piston. Only thing is they don't make a centered rod in that length so you'll need to mill .050 or so off one side of the pin end depending on what piston you use. You can use offset rods, it's just easier if you can get a centered one.
Rocket V8 - a better combo would be using a 6.125 rod with a 1.425cd piston. I'm doing one now and that rod is available as a centered one.

GOSFAST

This was a very common build years ago but in "reverse" of your build.

We did a small number of SBC builds with the 6.000" Olds conn rods. No crank work, there were rod brgs available back then to make it a bolt-together deal.

They were known as "conversion" brgs, came in Std, .001", .010", and .020", and the "domed" pistons utilized the .980" pressed pins.

Thanks, Gary in N.Y.

P.S. The pistons (cast only) were available as a stocking part number. I may have a set on the shelf still, not sure??

RocketV8

I started building my engine 10 years ago and didn't know about LS rods at the time. The parts I used fit my goals and budget but I agree - if you can use a centered rod you should do it! It's just good engineering.

However, many stout engines have been built with offset rods - is it really a big deal? Has anyone taken one apart and found anything bad?

gtuturbo

Looking at these LS Eagle rods:

H beam CRS6200O3D 6.2"

ForgedPistons 4.0" bore :

ICON IC9226 1.433" CH 18cc Dish
8.64:1 CR

RocketV8

I zero decked my block to get good quench with a 0.040" gasket. I know the effects of quench are debated but I figured if I can get it why not? My pistons have D-shaped dishes that correspond well with the Olds head "quench pads".