Rod Bearings - Hemi/Chevy

A lot of people over the years have mixed & matched various crank/rod attributes for custom design deals. A good typical example might go as follows.:

An Arias or MBR setup. Crank might have a splined Hemi style snout (RCD or PSI), Chevy mains, Chevy bore spacing (4.840"), Hemi rear flange, and Hemi rods.

I get why people would do this, for adaptability to certain off-the-shelf parts reasons, but the last item confuses me.

Why Hemi Rods (2.374" nominal) versus Chevy Rods (2.199" nominal)? What's the advantage, if any, with the Hemi versus Chevy rod bearings? Going the Chevy route might leave a little more rod material thickness in the big end of the rod where it might help a bit? Or does it boil down to simple bearing availability considerations and options? Blown alcohol.

Just curious..........

 

I had a bad ass Chevy engine that was a beast. It had a Bryant cranks for 5.00 in bore center engine with hemi rod bearings. Pure and simple hemi are sold in sleeves! Try buying a sleeve of Chevy bearings? You can’t. Only down side is hemi is .000 or .010 sizes. Chevy is nice because you can get +/- .003 bearings. But if your looking to make 14-1700 hp is prolly stay Chevy bearings as it won’t be hard on parts. But you start going over 2000hp go the hemi bearing route. IMO

 

You can’t buy a sleeve of uppers for the Chevrolet, you have to buy sets so you end up having a bunch of left over lowers kicking around. We went 5.40’s at 260 plus with old brooks rods and Chevy journals. Theoretically the more surface area of the bearing, the more load it can carry. Off on a tanget, when we purchased the billet block we also purchased a crank with hemi rear flange and Hemi Rods due to the availability reasons listed above. Shortly there after we switched to the hemi bellhousing pattern (the 481x has both) when we switched over to the titanium bell in an effort to shed some weight. Have you ever tried to sell a Chevy bell with no starter pocket? It’s next to impossible. That was the reason we initially changed patterns and it was a good decision as we now have a Hemi in the car and are running the same bell. If you run the Chevy rod bearings I recommend the “V” series. Your mileage may vary.

 

Thanks Jay & Rob.......

 

Aside from parts availablity, the larger journals also help to strengthen the crank by giving you more journal overlap.