"Hemi" style rods for small block?

[gzig5]

Is anyone familiar with P3614514 small block rods? Found a couple references online and an may have located some. The literature say that they are heavier than a regular rod and he weighed one at 2 lbs, 0.5oz which converts to 762 grams (Edit..That conversion is wrong, would be ~922Gr) . but the boxes have numbers on each end that look like weights and when added come up different. 182.1 + 432.4 = 614.5. I thought a stock 340 rod was more like 750g? Not sure what to make of that.
I'd imagine these should be as good as a modern Scat or Eagle I-beam rod. I'm putting my '71 340 back together with the stock dia OEM high compression pistons and forged crank, so I don't want to have to make a big balance correction.

 

[Locomotion]

These will be heavier than OEM rods. You'll likely need Mallory metal for balance and the extra weight will hinder rev-a-bilty. Lighter rods are plenty strong, like Scat I-beam and H-beam rods. Not sure if you'll have any clearance issues.

 

[gzig5]

These will be heavier than OEM rods. You'll likely need Mallory metal for balance and the extra weight will hinder rev-a-bilty. Lighter rods are plenty strong, like Scat I-beam and H-beam rods. Not sure if you'll have any clearance issues.

The weight is what's confusing me. I didn't do the conversion on the scale reading correctly 1lb = 453.6 gr. and he shows just over 2lbs which would be 907gr, which seems way too heavy. The weights on the boxes may be from other parts and the packaging re-sued. I'll have to weigh one of my stock rods tonight. I like the idea of the lighter rods but these are new and would be strong and not need a rebuild or bolts. Just comes down to what I can get them for.

 

[Locomotion]

The weights on the boxes are a little on the higher end of "advertised" numbers shown for Scat I-beam and Eagle SIR rods. Summit shows Eagle H-beam rods at around 695 grams. OEM rods are heavier and it wouldn't surprise me if the rods you're showing are actually around 2 lbs. I had a set many years ago, They are "bulky" and have heard the term "Hemi-footprint" associated with them.

I'm sure they are stronger than Scat or Eagle I-beams. But they are very likely for sale because they simply weigh too much to be practical for 99% of applications. As mentioned, Mallory metal and possibly 340/360 cast crank balancer/flexplate will be needed with them. That may negate the cost difference between those rods and an aftermarket alternative. (It's cheaper to take weight out of a crank using lighter rods.)

Just my opinion, but with OEM pistons, OEM rods or H-beams would be plenty. Scat I-beams would also work for milder applications. It's just that the crank counterweights would require a good bit of lightening and the OEM pistons are on the heavy side.

What the application for this engine? Street, street/strip, race?

 

[gzig5]

Sounds like these may not be for me then if they’re that heavy. The car will see a lot of Street and road course and then occasionally on the dragstrip. Once on the road I plan to drive the **** out of it. I’ve got a second block build a stroker out of it with some aluminum heads when I get the money saved up but the 340 that came in it has 2.02 J heads and ran pretty good but the rod bearings were toast. Going to tweak it and put as big a cam as I can stand and play with different cam, intake, and carb combos.

 

[crackedback]

Those are good for assaulting someone...

Use in an engine today, not so much anymore with the other better lighter rods available.

 

[Rat Bastid]

Those rods aren’t near as good as what you can buy today. No serious connecting rod is built with that architecture. And no serious connecting rod is built with a bolt and nut. They use cap screws for a reason. I also don’t think those rods are 4340 either. IIRC they are still 1018 or something.

 

[toolmanmike]

I wonder how many used 273/318 rods back in the day to lighten things up. Plenty strong.

 

[Rat Bastid]

That happened more than most people think. I used to buy every 273 crank I could find. Several were given to me. Then I’d turn .100 off the OD and use a couple of sticks of Mallory in there to balance it. Vroooom vrooom. It makes a difference at racing RPM.

 

[Bewy]

I would use new H or I beam rods, Scat Eagle etc, that use the cap bolt for any serious 'work'. Cutting the factory rod bolt head clearance seriously weakens the rod in an already critical area.