school me

so school me on billet rods and headstuds.. ive seen a few diffrent brands, crower, cunningham, and theres a couple others.. are they the same? whats the big diffrence? also head studs... whats the major diffrence in arp's vs H11's?

I cant help you on the rods, id like to know myself though. As far as studs go, the h-11s have more clamping force then the ARPs do.

Choupique108 said:

I cant help you on the rods, id like to know myself though. As far as studs go, the h-11s have more clamping force then the ARPs do.

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And they are less likely to stretch so can be used over more times than the arp's. They are made out of h-11 tool steel. I am not sure what the arp's are made of.

Hypermax (i think) are the only 7.3 aftermarket connecting rod to used forged metal instead of a billet chunk of metal cut out. It is made the same basic way stock forged rods are, however a much stronger grade and stronger shape. Some believe forging is stronger than billet.... Steel has grain similar as wood has visible grain in it. In the machining process as the holes at either end of the rod are simply cut out of a billet chunk it cuts right through the grain. Forging the rods keeps the grain flowing out and around in the circle as the molten steel is poured in, and some people believe it makes a difference. The two big billet rod makers for 7.3's are hypermax, and crower. Either will take any hp your dinosaur can muster up

Is it not basically true that all the popular aftermarket rods used in our 7.3 are stronger than what a filled block with a plate can take so as far as that goes its rather moot?

I have to agree PJ. On a number of fire receivers testing the ones that handled the highest pressures before failure where those that had the basic shape from forging and then the final dimensions were milled. Some added in cryo from there but that was not part of the testing.

I know some of the engine failures I saw pictures of with hypermax rods hanging out and still checked out perfectly striaght and GTG was impressive. IIRC one survived not one but two devastating grenades and still checked out OK. IMO how ever they are made its working LOL

I still see Crowers in build lists more than any other though for what that is worth.

But as far as hands on knowledge I got nothing for ya with the 7.3 and these rods.

TARM said:

I know some of the engine failures I saw pictures of with hypermax rods hanging out and still checked out perfectly striaght and GTG was impressive. IIRC one survived not one but two devastating grenades and still checked out OK. IMO how ever they are made its working LOL

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Yes, remember Cale's spectacular engine failure? I think Brian said that was 3rd engine those rods were in, and although they'd prolly spec out ok - they didn't want to use them again. That block was in pieces and the crank/rods were holding the pieces together!! Brian said something about 105psi of boost was fine, but 107psi was too much! lol.

So, at what power level do y'all think aftermarket rods would be a good idea?

I've personally had Crowers, Hmax forged, the early and late versions from Wipe Out, and a set of stainless steel rods from back in the day through my hands. the early Wipe Out rods were WAY overkill and WAY heavy- that is one reason they were redesigned into the new style. The early stainless rods were great for competition rigs of the day - but day to day use was disastrous.... All the rest of the offerings that I have seen in person - I wouldn't be afraid of using - I think they pretty much all are capable of handling anything we throw at them on a factory block. My personal choice is Crower - they have worked out well in the builds that I have done.

thanks guys an thanks HRT i like real world experiance, it will really come down to price and availability. i want to buy as much from one vendor as possible so i have some searching to do. it will be another 8 months or so yet till i can save enough for a good rebuild.