Im just trying to put together a budget plan for my stroker. You guys have pretty much beat into my head go with the longest rod you can. So Ill probably go 6.0 but whats the Differance between "I" and "H" beam rods. I mean I can see the physical differance in looks but whats the performance difference. I think I heard someone say something about having to do more clearancing with H beams? Is that true?

 

I've read that h-beams spread the bearing loads over a larger area than i-beams. H-beams are also a bit narrower and I'd think that they may have an advantage aerodynamically.

As is obvious... we're talking things you'd never see on a dyno with a moderate level performance engine but you asked.

Clearance-wise (strokers), it depends on the rod maker as some are better than others whether specified as "stroker clearanced" or not. Some h-beams give more clearance than others... same with i-beams, so it's not a clear-cut thing.

One of my favorite I-beams is Howards, lightweight (weight choices) and not too expensive, plus have good clearance designed in. Don't go hog wild and buy a rod you don't need though.... a Scat I-beam is good enough for most builds... just depends on what you're after power-wise.

-Mindgame

 

H-beam v. I-beam is an unresolved issue, AFAIK. Clearly, there are good rods in all price ranges with each design. Something I wouldn't sweat over.

I test fitted a number of different moderately priced rods for my last buildup and found the best stroker clearance of the ones which I tested were the Lunati Pro Mod. I looked at Crower and Lunati I-beam and Eagle and Scat H-beam. But they all can be made to work. The Lunati's have been good to me so far. Good rod bolts are a must. If you are on a budget, I recently saw a set of Scat 4340 6" I-beam forgings with hi-tensile 7/16" cap screws for <$300 bucks that looked good. But I have no direct experience with them. The Lunati Pro Mods go for ~$700.

Rich Krause

 

You mean the difference would be so miniscule you wouldnt notice?

And I was looking at the eagle rods in my Herbert Performance catalog they are within my price range. And another set I dont recall which ones that specifically said they are stroker clearanced.

Also how big does a weight of the rod play into performance, and how much power do you gain in going from a regular pressed pin to full floating?

 

I went with the Eagle stroker-clearanced H-beam rods on my 396 primarly because of their additional clearance.

Once again, it seems that Mindgame is able to exactly what I was going to, with regards to distribution of the load over the rod bearing

Frankly, if money is tight, this is probably not the place to spend a bazillion dollars in search of every last 0.1 HP.

 

I agree but neither are very far away from each other in price, thats why I asked.

 

I'm at the shop so I gotta do this on Old SStrokers account...

Anyways,

I've never seen a very lightweight H-Beam. Mid to high 600g's for a 6.0" plus rod. The Scat I's that Rich mentioned are a very good choice. They are usually around 590-600g so they are pretty light. Spend the money where it makes HP, Eagle H's are good, they are durable and come in alot of lengths for cheap but are never really light. The top rod builders in the world make both types. Carrillo is a H beam company, Oliver is a I beam company and Arrow is a A beam style, which if you are going all out on a circle track engine a Ti Arrow is the way to go, but that has to be a $30,000 engine to do that. 475g or less for a 6.0" Circle Track rod! That's just the steel ones, but they are like $400 a ROD!

I've heard good things about Howard's. I gotta get their catalog, just to check their stuff out. They seem to be more of a West Coast company, cause alot of guys in SoCal run their stuff. Good lieghtweight rods though. Under 600g for a 6.0" Forged I beam.

Bret A.K.A. SStrokerAce

 

I bought 5.7 I beam rods for my 383, from a well known Ford supplier that has yet to be tapped by the GM crowd. Coast high performance, AKA Probe Engineering they were right at $425 with cap screw ends. I wanted 5.7 rods for the piston speed, my ports are a little large.

WWW.PROBEINDUSTRIES.COM

David

 

Another example of reading too much into things, brought to you by the number 3 and the letter...triple u.

1)StrokerAce says that your engine budget needs to be $30K, thus you can justify Ti rods and make all of us jealous.
2)Mindgame says that you should go with I-beams unless of course, you go with H-beams.
3)Its a general consensus that the Japanese Direct Market Tungsten rods are probably not good, at their 2,400 gram weight.

Eric Bryant, is that 0.1hp per rod or total? If it's per rod that would suggest almost 1hp, which if you calculate by the difference of the Eagles H vs. I means you're only paying $300/hp which some of us on here, can almost justify.

 

I wish I could own a $30K engine! The other caveot of that is the rulling body allows Ti Rods!


BTW sorry about the spelling mistakes in the post above.

 

Titanium rods would be to harsh on the rod bearings for a street application would they not? Seems like they are so hard they would not absorb any shock and transfer all the load in a detonation situation directly to the bearing, also I think I beam rods would be better than H beams, seems to me oil would puddle in the cavities and cause drag, I beams are sleak. JMO.


David

 

Ok so its pretty much undecided? Ill just buy the lightest ones I can afford that are already stroker clearanced. But that leaves my other question. How much better is a full float rod/pin/piston that a regular pressed pin. And just so Im sure when a rod says bushed that means its for a full float pin right?

 

Bret, Howards is a bit more popular with the circle track crowd than drag race. Their rods are light, about the only forged rod on the same level is the Crower Maxi-lite billet series. The 6.0" 93-4 Maxis for instance are on the same hp rating and weigh ~605 g. Howards midweight rod is ~595. They are rated at up to ~650 hp but I will tell you I've ran them in a 392 race engine that made well over 700 hp 7,300 rpm and never had one fail, nor show abnormal elongation. Bushed and ran them for 3 seasons. Good stuff that not many people are aware of except for the circle trackers it seems.

On titanium vs forged and shock loads. You have just as much problem with that in good hard billet and 4340 forgings. Detonation will kill bearing no matter the connecting rod. If it's a real concern (nitrous hits etc.) then go aluminum for a drag car... either that or use an aluminum main cap. I think the shocking is about the same.... either way you look at it, it's a no win situation.

Bushed = floating. No real performance increases noticable on a street app, so don't sweat it one way or the other.

-Mindgame

 

Ok well its not a street application. I cant afford insurance on two cars so my Dad and I are turnig my 3rd gen into an all out drag car. Is it a noticable difference in race only applications?

 

For a race only app, you'd be better off going full-float. Providing adequate pin oiling and the proper clearance, you'll see better pin bore life. Not to mention, in a race engine where you're constantly tearing things down for inspection, full float is much easier to disassemble/reassemble and inspect. That's a big plus with race engines!
If you're going that route, make sure the pistons are machined for Spirolox. Also watch for excessive rod side clearance. You want to stay within spec or to the low side. You also want the pin to retainer clearance to be as near "zero" as possible. Both things help in keeping the pin from moving back and forth, smacking the retainers.

HTH.

-Mindgame