KiwiKid

Hi All,

Has anybody successfully over-bored the cam tunnel on a GEN4 aluminum block to take a 60mm camshaft?

Obviously a larger diameter much stiffer camshaft core than standard is highly desirable for a high revving road race engine, so if anybody has been down this road before I sure would appreciate hearing from them.

Cheers,

Mark.

Hamrdown

iTrader: (25)

What the???? You are way over thinking your build buddy!

KiwiKid

Appreciate your thought's HD, however, this engine has to run at least 5,000 miles over 6 x 3 hour races, and is competing against Factory backed Ferrari's, Mclaren's, Porsche RSR's etc, so it has to have at least 750BHP and still be ultra reliable.

If you think we are "way over thinking" our build you should see the extent GM go to with their Daytona Prototype engines, just their billet block alone is $12K, and god knows what their billet cylinder heads cost!

We are trying to bring this engine in on budget [$40K] and still have a very stout reliable engine into the bargain, which is why I don't want to risk running the 60 mm diameter cam unless its been well proven in a standard LS block.

If I don't get any positive feed back from the various enquiries I am making, including raising the question on this forum, then we will settle for the standard 55 mm diameter cam.

Cheer's,

Mark.

Boostedhatch

This would be cool if you could run 60 mm bearings and a Chrysler style or bigger roller lifter.

Hamrdown

iTrader: (25)

I stand corrected! We're used to seeing posts like this for the average auto crosser or drift racer. Neither of which put the kind of abuse that you are inducing on their engines. Try posting this question up in the advanced tech section. You'll probably get a better response over there. I seem to remember reading someone doing this but it was many years ago that I read that.

Violence.z06

iTrader: (3)

Ive wondered the same thing. with a short stroke you do have a little more room between cam/rods ect. Not sure the block will support it or not. Either way i would like to know. Even in my build i would like to go 60mm or bigger.

Hamrdown

iTrader: (25)

I believe that's part of the reason the RHS block has a raised cam tunnel, in case you want to run a larger diameter cam.

lil john

Call Steve @ RED sure he could help.

KiwiKid

Hi LJ,

Thats the first call I made and Steve said he didn't know but thought the block should be capable of having the cam tunnel over bored from a strength perspective.

Cheer's,

Mark.

Violence.z06

iTrader: (3)

same with the LS Next block. dart even sells the 60mm babbit bearings for it. It can also run the 55mm roller bearings but i would never consider running those.

A.R. Shale Targa

iTrader: (2)

Call SAM (School of Automotive Machinists). I'd be willing to bet the Massengil fellas have done this as well as the keyed 1" bore Jesel lifters. In order for them to be making well over a thousand NA horsepower out of a 436 inch engine, surely they're pulling out all the tricks.
Texas Speed guys may have also played with this idea as you would be removing roughly .100" material to open the cam bore around .200"