How much tq/hp can connecting rod handle?

[SuperB70]

Is here any hardcore engine builders?

I'm again building an force induction engine and

After talking to my dynoservice friend I have been asking myself do I have strong enough rods. I got so expencive block and crank that I just cant blow them.

I know it is sum of many things like rod length, piston desing and so on but I would like to know:

Has anyone here found the torque-/Hp-limit for forged H-rod?
I know a guy, he's running twin turbo bb mopar witk K1 crank and K1 rods and has 2000Hp/2000Nm-1470 lb ft, been running 4 years now no problems.

Another bbc tt running around 1000Hp with stock LS6 crank and rods. Nowdays it's w/forged aftermarket stuff.

Any numbers? My rods are promised to handle 1200hp. But been thinking that should I just save more and buy a set of Oliver's.

Maeby then I can sleep at night

Any ideas anyone?

And please dont say: buy Oliver's and be done with it. If I could throw that kind of money now, I would not be doing this.

[ccm399]

So are your rods K1's?

There is more to it that "a forged H rod". Eagle is different than SCAT, SCAT is different then CAT and so on.

Having said that, nothing wrong with a good H-Beam rod. We set the IHRA BB/AA running 6.125 Eagle rods. That was a 354 SBC running 32-35 pounds of boost and 8100 RPM shift points... I think she used to go out the backdoor at 8300.

Sure this was a Drag Race application but RPM and cycles are the biggest killer of rods. Cylinder pressure (Torque) is a compressive loads. RPM (HP) is a tensile load.

What kind of RPM are you planning on turning?

My LS engine for the Firebird will probably have Eagles in it. I am shooting for (planning on) 1000-1100 HP with twin turbos.... And I plan to sleep very well at night...

Chris

Oh, but get the Olivers....
I had them in my personal engine race engine and MAN are they NICE!!!!

[camcojb]

I'm not a hard core engine builder. I have used Oliver, Howard, and Eagle rods in forced induction builds, never had an issue with any of them. I did upgrade the Eagles to the L19 bolts, but they were fine in a 900 rwhp combo.

[SuperB70]

I got Eagle rods, they came as package deal with the pistons.

6.2" w/arp2000 bolt upgrade. CRS6200B3D2000

My engine is not going to turn more that 6500rpm and boost level around 25 psi.
What I know, these engines delivers more than 1000hp and killer tq and that is what kills these rods cos they are thin (less than 1/4") in the middle of H.
They are more than 1" wide other way.
And my pistons dont have much skirt to give much needet support.

My dyno friend has seen cases where H-rods have twisted because massive tq.

[ccm399]

I am very familiar with the Eagle rod as we used them in lots engines.

Not many were boosted to be completely honest though. Like about our IHRA record setter, we beat the CRAP out of those rods and they took everything we threw at them. Again, this was a drag race situation, not street (std Eagle bolts for what it's worth).

6.200 is a long rod for sure (ours were std 5.7 Chevy length rods) I believe they will live. I don't think the statement about the thickness makes much difference though as an I-beam Oliver is thinner than a 1/4" in the I-Beam (again I am very familiar with this rod too).

It sounds to me like you want someone to talk you into buying the Olivers not out of it? To that end, you absolutely cannot go wrong with an Oliver rod!

I think either will work to be honest. I plan to use Eagles in my LS when I get to that point. I built race engines for 15 years before my career change if that helps... PM me if you want to discuss that further.

Chris

[SuperB70]

Thanks Chris for your input. I see you know your stuff...

I know that Olies are the king.

I would like to buy them but just cant afford.

I feel that I need to tell what I'm building,

Many know so: Ilmor (Viper) 8.3 V10 with 4.2L liquid cooled twin screw. I've a brand new engine from competition coupe program. We have made our own billet main caps. Just got from States a another crank (turned to sbc spec) and pistons/rods.

One I did build was 525 BBC with 8-71 useing same kind of H-Eagles. Dyno it 736hp / 1065Nm- 785 ft lb of tq at 7psi. On our premiun pump gas. We have 95 and 98 oct.

Juhani

[GregWeld]

Juhani --

I know you said you "can't afford it" --- but can you afford to build a whole new engine if you bend or break a rod?

I'm not saying which way you should go -- I'm just saying that if it's a "I can sleep at night" decision.... I'd save up and go with what your guts are telling you.