Advanced Engineering Tech - Rods




View Full Version : Rods


Ari G
06-07-2007, 03:09 PM
Scat,Eagle ect.. when they rate rods like I beam 4340 at 7000rpm and 550hp

Is that the absolute max they will handle or what they warrant them at?Anyone have made much more hp then the assembly is rated at?

I´m thinkin about how mich the I beam can handle?


2002_Z28_Six_Speed
06-07-2007, 03:18 PM
You always can take them past what they are rated. The rating is the HP level you will get decent engine life for. You can make 500 HP with stock rods if you wanted to.

TT632
06-07-2007, 03:31 PM
I'm not sure what criteria the connecting rod manufacturers use when they come up with their maximum HP/rpm #'s, but I have never had a connecting rod failure that was the fault of the rod or the fastners. Oliver, crower, Lunati, Eagle etc. No failures and most of these rods were in engines making over 1000 engine HP. The failure mode was always found elsewhere, debri in the oiling system, lifter failure, loose windage screen, etc.
Hate to say it but, my current combination has Eagle H-beams at 1076 RWHP. They are being changed out for quality US rods as we speak, even though they look fine. My recomendation would be to use the higher quality rods and bolts when you start hitting the high triple digit HP #'s.


Ari G
06-07-2007, 05:44 PM
yes,that what i thought and have seen I beam rods rated at 500hp at 7000rpm handle 800hp at 8000rpm

jmalibuss
06-08-2007, 02:59 PM
As a machinist and engine builder I have used a TON of Eagle, Scat and some "no name" H beam rods. As much as I hate things that are "made in China" most of what I have found is they will hold up to just about anything you can throw at them. However if you are building a endurance engine such as high horsepower marine engine, circle track or road race engine I like to upgrade to a Crower, Callies, Carillo or maybe an Oliver.

Another thing I have found in the "made in China" budget H-beam & I beam rods is that most of the time you should have them resized and the wrist pins bore sizes checked. The rod housing sizes tend to relax once the caps have been removed and re torqued.

Ari G
06-08-2007, 03:40 PM
I was looking into the cheap ebay h beams but afraid of no name and "made in china"

About stock rods,like in the LT1 impala(not pink rods) what is the limiting factor and how high is the limit?

I like the idea of taking the stock bottom endi to the max

LSPerformance
06-10-2007, 11:07 AM
I wouldn't worry about the hp levels claimed, my main concern is the stress incurred when the piston is changing direction at/after overlap and the rod bolts/small end strap have to control the piston/pin/ring weight. The limiting factor on an rpm rating is piston/pin/ring weight, a lightweight assembly enough to do the job you are asking it to do is advantageous here.