New 7" Forged 500 rods and 7.100" 472 rods are her

[Al from MTS]

The new 7" forged rods we had built for the 500 Cad engine are starting to arrive. We have a few sets here now. The rest should be here in 3-4 weeks or so. The forged pistons for use with these rods are in production as well. The 500 forgings will give 10-1 with 76cc heads. A 9-1 will also be available for the 120cc heads.
I was also able to scrape together the cash to do a run 7.100" of 472 rods as well. Both the 500 and 472 rods will be available either bushed for floating pins, or no bushing for press fit pins.
The 7.100" rod will allow the shorter and lighter 500 Cad piston to be run in your 472. You will also be able to build your 472 with either 120cc or 76cc heads, just by using the proper 500 piston for the heads you use. The new forged pistons we are building for the 500 will also fit your 472 when used with the 7.100" rods.
Rods are priced @ $575.00 per set for either engine.

[~JM~]

Good deal Al.

It's nice to see some thought being put into 472 parts also.

Thanks
~JM~

[Vern]

Al that is great news. I hope a lot of people take advantage of this. For clarity you will not be able to use the 7.1 rod in a 500 correct?

[DOC]

Al,

Using the 7 inch rod and matching forged piston, what kind of horsepower and rpm are they good for?

DOC

[Al from MTS]

Vern: It would be possible to use the 7.100" rod in the 500. Would require a custom piston. There is still room to move the pin in a 500 piston to accomodate the 7.100 rod. I just could not afford to build a 2nd run of pistons for that combo to keep here in stock.
The 7.00 rod and piston combo will be in stock.

Doc: We are going to have to bust, stretch, or twist a rod first (Ouch thats gonna sting!) to get some ideas on the real limits of these new parts.

[campagna]

What rod journal size are the two new rods?

[cadfor]

Al,
Will these new rods be a direct bolt in with the 500 piston in a 472? The heads on my motor are the 950 series, are they the 76cc chamber heads? What would the assumed compression ratio be? If it's 10 - 1 or a little less it sounds like a really good upgrade.

[STDog]

Will these new rods be a direct bolt in with the 500 piston in a 472? The heads on my motor are the 950 series, are they the 76cc chamber heads? What would the assumed compression ratio be? If it's 10 - 1 or a little less it sounds like a really good upgrade.

Fom Al's message, it would depend on the piston. So if you have pistons for a 500 w/ 76cc heads you get the same compression you would have got with a 500 crank and rods. So if you get a early 500 piston, you get that compression.

I think this is a great Idea. A rod to allow for the compression height difference so all the 500 pistion will work with a 472 crank. No more need for 472 and 500 pistons to be designed, just use the correct rod. Cudos to Al for specing it out.

I never really understood why the pistons were different anyway. Cadillac should have just used a different rod for the stroke change, and kept the same pistons.

[Al from MTS]

As I read my post I realized I wasn't real clear with it. What I should have said is these rods are meant to use the new forged 500 pistons we are building. We have pistons for the 120 and 76cc heads in progress.
Both the 500 and 472 long rods are designed to work with a piston compression height of 1.645". We are also using a .990" BB Chev pin in the new rods and pistons.
A quick peek @ the KB piston site shows several part numbers that could also work. I also saw a stroker 460 Ford forging that looks like it could work with the 7.100" rod in the 500. Again this is just scribblin numbers on a pad. Have not tried it yet.
The new rods are not meant to swap stock compression height Cad pistons from 500 to 472.

[MilesO]

The 7.1" rod can be used with the 500 crank by using a piston with a compression height of 1.548 and a deck height of 10.800.

KB site has a few candidates as well as Probe. Al can get them for you.

Thanks Al for making the 7.1 a reality with stock size rod bearings !!

The 425 cranked 472-498ci engines are coming.

Miles