Which Connecting Rods do you like or prefer and why? This is a subject I am not very knowledgable about. I would like more opinions because it seems to be an opinion issue. Which is lighter? Which design is stronger? Would it matter what type of application (n2o, na, or fi)?

Please vote and give your opinion on the qustions above.

My application - 347, Stock crank, Callies Rods (I or H?), JE pistons, 224/228, full bolt-on (Fast 90/90, Lid, SLP MAF, Hooker Headers, elec cut-out, TSP ORY, Hooker Catback and pullies), AFR 205 Heads 64cc, and a 150 wet shot.

 

H-beams are supposedly structuraly stroger due to the H design. H-beams are usaully a bit heavier due to more material being used. For your application, I'd use the Compstar rods, which are H's I believe.

 

H beams are definately stronger, and usually a little heavier. I beams can also be very good rods, and usually allow for a little extra clearance. Sometimes handy with real tight stroker applications. Usually a little cheaper too. I prefer h beams for their strength.

 

The quality of the rod is key....Ive seen killer versions of both. Metal integrity, quality control, machining tolerances, and obviously including a good rod bolt make for a good (and sometimes expensive) connecting rod. Its more of a personal preference amongst engine builders IMHO, and the reality is that a quality piece of either design will get the job done. The Callies Comp Star you mentioned is an excellent rod for the money....I just installed a set in the 383 I just completed dyno testing with. It had nice machining and was repeatable from one rod bore to the next when I checked them all with a dial bore guage.

Lunati, Manley, Eagle, Scat all make good stuff for the dollar spent. Some are a few bucks more but any of them (if assembled correctly) can reliably put up with alot of power and make a good upgrade over a factory rod even if you put in the better bolts (which certainly helps the stock piece put up with more power and RPM before failure).

I'm not voting because I dont feel one design is necessarily superior to the other....

Tony M.

 

I was under the impression that you wanted to have lightweight rods as well as other engine components.

 

you do, but it is a balancing act.....

too heavy = loss of HP
too light(too little material) = big BOOM


the question of just "which connecting rod, I or H" really is useless......thats like asking "what is better, a jet aircraft or a battle ship?"

for what? are you building a stock daily driver/24 Lemans car/ProStock car/etc? how much do you want to spend? etc....the list goes on....


for most people, the eagle H-beam is cheap and indestructible.....it is not the lightest (not really HEAVY by any means.....) or the strongest but Mustang guys are running them past 1000HP and 8000+RPM.....and at $450-$500 a set, makes the $1200 Lunati rods kind of pointless......

 

Well, thanks for the votes. I have told you guys what my application is. I am going with the H Beams because I know they are usually a littloe more if bought outright and the shop where I am buying from will do the H-beams for the same amount. Callies is the brand I will be going with. The comparison between the carrier and the aircrft is a little extreme don't you think since I did include my set-up. I will probably be in the neighborhood of 450-475 w/o n2o if I am thinking correctky with a mild tune. It may see 200 n2o but if it does it will be rare. I just want a tight motor that I don't have to worry about on the bottom end of things.I feel that I have some of the best heads around, don't you agree Tony? A mild stick, and bolt-ons ahould get me probably a little higher than I am expecting but hey if you expact less and come out more, that's a good thing. This motor is not for track use only, I have a 408 for that. This is cruising, street racing, drive to and from the track and a few passes, etc. Reliability is the key to this new motor. Just wanted some opinions, thanks guys. Keep voting and sharing your ideas/theories.

As far as comparing quality between 2 companies, I'm not trying to. I am comparing design, strength, weight, and reliability between the I-beam and H-Beam rods. I am going with either Callies or Scat in any application I use. That is my personal preference. It's what I have used every since and I have had no problems to this day with rods, knock on wood.

 

don't know how but I missed the part where you said what you were doing.....guess I got rapped up in reading everyone else's replys......

 

lol! He was caught up with light and heavy off my post!

 

I've worked with iron most of my life (ironworker go figure). An I-beam is stronger than a H-beam. The reason why is that a I-beam has bigger web than a H-beam. The web is where all the strength needs to be not the flange like in a H-beam setup. At least thats how things are in my line of work. I vote I-beam.

 

hmmm ibeam being stronger is what an old timer here told me and for the same reason i think

 

I always heard I-beam is stronger under compression and H-beam is stronger under tension.....

 

Then if that statement is true....n2o would need an I beam then, right? Since n2o usually comes with higher compression engines. Althouggh my engine will be in the neighborhood of 11/1 cr.

 

well i say I-beam. the reason is after long desgin methods we found that the I-Beam has less stress points and fatige fractures at high durations than the H-beams. also the material selections plays a big part in the strength of the rod

 

so for a Mild H/C 200 shot set-up lookin for around or over 600rwhp a I-Beam rod would work great?

 

I have heard that the largest number of rod failures actually happens on the up stroke (as the piston reaches TDC)....the rod actually stretches and snaps as the piston tries to keep going out the bore while the crank tries to yank it all back down.....

 

in conclusion, either rods work for MOST applications. Wouldn't you agree? I know there aren't many that have over 800~ rwhp so any of the companies, Lunati, Callies, Scat, would work for these applications. Now, how much hp are the factory rods worth? I have heard 450-500rwhp. Would anyone here agree? I personally would start worrying around 400. What do you guys think? Assuming you have ARP rod bolts as well btw. I know that would be the first question or comment.

 

I wouldn't have any problems using stock rods with ARP bolts to about 450-500rwhp.....anything above that I would move on.....

 

wasnt about to read all the above so if my opinion is off or repeated than sorry. I belive the h-rods are a lot stronger,heavier also but not something you want to compromise with when building a strong engine... just my 2cents

 

Very interesting, got any ore info on the test you did? Ive always heard the H was stronger, but im up to be re-educated...