[speedball1969]

Im in the process of building a 406 small block and need all the help that I can get. Someone posted here "help me to build a killer 406" and I have read this over and over again. I was curious though as to the differnece, and the pros/cons of "I" and "H" beam rods. Thanks in advance.
And just for kicks, do you think that a Scat or a Eagle engine kit (including crank & rods, I will be using Ross pistons also , I understand there extremely good and reliability) would be possible of supporting 500-600 h.p.?

Thanks guys

[dnult]

In my limited experience, H-beam rods are stronger, but overkill for most applications. However, they can afford you some clearance between the cam and cap bolts if your doing a stroker motor.

-dnult

[CamaroNOTcamero]

All the top manufacturers use I beam rods, or A-beam.
For the money, Crower Sportsman Cap screw rods are the lightest and highest rated, as well they are made right here in the USA!

[chicane67]

H beam rods are (In theory) stronger and more stable at higher RPMs with lower rod ratios and have been considered overkill in most streetable applications. Personally I dont know if I can swallow the overkill part, but whatever, I use H beam rods in street engines.

H beam rods are a good consideration where ENDURANCE is and WEIGHT is not an issue. Although, the I beam rods are normally a little lighter than their H counterparts.

So for a streeter, I think the aspect of weight to cost is the biggest PRO/CON issue. This and the total bob weight can be a concern for some engine combinations as well.

The Eagle kits are good for 500-600hp comfortably.

[Busted Knuckles]

Eagle H-beams are so beefy on the rod cap end that you'll have to grind quite a bit on the pan rails and take a chance of hitting water. Check out Scat's new 4340 I-beam Pro series rod. They use a shorter rod cap screw and according to my machinist, they'll clear the cam on the top and pan rails on the bottom with no grinding at all in most cases. I have a set for my 406 and they look pretty impressive. Machining is not quite as pretty as Eagles, but he's built engines hitting 600 on the dyno without problems. HTH.

[Rayzor]

Check out this link! This site has a lot of info!!!

http://www.grapeaperacing.com/GrapeA...h/rodtypes.cfm

[chicane67]

Hitting H20 !?!!

[pdq67]

Somewhere I read that there IS a street application aluminum rod out there that lasts close to the stock steel rods but I don't remember where I read it or who makes them.

I am wondering if these are made out of a refractory grade ceramic fiber filled aluminum matrix material for extra fatigue property increases b/c I do know they are using this kind of material now for diesel engine pistons, or at least I think I do???

And, somebody, I think Crower, is making a magnetic Titanium rod, again if not mistaken, that will pass a Tech. magnet check that is really light although can work-harden and eventually become brittle if I remember my metallurgy here?? Plus, these fall into the "unobtainium material" money range if you get my drift!!!

You know I think all Briggs & Stratton lawn mower motors have aluminum rods in them AND the little abused suckers very seldom throw one!!!

pdq67

[Eric68]

"refractory grade ceramic fiber filled aluminum matrix material" !?!?!! Holy crap Scotty, the antimatter containment field is collapsing . . .

Seriously, there is some debate over which is better H or I beam. Both have been used in very high HP race motors with success. I don't think you would have a problem with the Eagle SIR rods in a 500-600 HP motor that sees an ocassional 1/4 mile blast. They are rated at 500 but can handle a little more than that I'm sure.