Does anybody know the weight of a standard sbc rod? I have searched everywhere and I cannot get an answer from anybody. I am assuming they are anywhere between 615 and 630 (weight in grams) If any of you know please let me know.


thanks a bunch!!!

 

The official super stock (2009) rules require stock pieces in all regards, and lists the minimum weight for 5.7 rods is 600 grams. The rest of the weights, and measures for engine bits can be found here http://www.monadnockspeedway.com/Sup...20-%202009.pdf. Good luck! What I'd like to know is what kind of latitude you can have before the engine starts to be to much out of balance. I'm looking at some after market rods which are 570 grams for one set, and 630 gms. for the heavier set.

 

Engine balance isn't just about total weight. The big end and small end also must weigh the same. You can have a set of rods that all have the same total weight but the big and small weights can differ.

When balancing an engine, all the big ends are weighed and all the big ends are adjusted down to the weight of the lightest one. Then all the small ends are done just like that. After that's all done, all the big ends weigh the same, the small ends weigh the same and the total weight weighs the same.

If you're limited to a minimum weight such as stock/super stock, you start with a heavy set and bring them all down to the minimum weight.

Most aftermarket SBC 5.700" rods are under 600 grams. Aftermarket rods purchased as a set are usually completely balanced.

 

You may be right. I know the 5.7 PM rods are right around 600 grams.

 

5.700" rod, pressed pin, I beam design. This would be close to a factory rod and it's 565 grams.

http://www.jegs.com/i/Eagle/356/SIR5700BPLW/10002/-1

This set is 595 grams.

http://store.summitracing.com/partde...8&autoview=sku

There's a set of powdered metal rods on Summit (pink rods). No weight listed but they do state that they are not weight matched.

There is no specific rod weight for a 5.700" rod. Rods from a 350, 305, 327 etc are all the same length but will all have different weights. Even different 350's will have different rod weights depending what pistons were in the engine. A low compression, deep dish piston will have a different weight rod than a flat top style piston. factory assembled engines are not as precision built as a custom engine. They just need to be within a specific tolerance spec.

 

In the early '70s, all the 5.7" rods were identical, strong, and heavy. By 1990, all the 5.7" rods were lighter and weaker, but still identical, except for the 4.3L V6. The later 5.7s usually come in under 580 grams, and are safe to 6000 rpm with ARP bolts. The earlier rods are usually over 600 grams, and are fine for extended use above 6000 rpm with ARP bolts, even okay for shifting from first to second as high as 7000 rpm if you are not using too heavy a piston. The PM rods are fine to 6200 rpm with stock bolts and stock LT1 piston weight. With ARP bolts they're good through 7000 rpm. The aftermarket cheap forged I-beam rods can be found in the 555-580 gram range, and are good to 7000 rpm.