I am looking at Molnor or K1 7.1 long hbeams for my new shortblock. Someone from Campbell enterprises said the Molnors would be on the edge at 1000 hp. I will have a stroke of 4.315 and flat top 4.5 bore 1.45 compression height Gibtech piston, lightened, and rpm will be 7500 or less. About 950 hp. 15/1 compression and alky. Is there a differance between Molnor or K1 in strength? Any other options for a 7.1 rod?

Not sure but I chose Oliver 7.1 I beams for my 553(4.5 bore 4.35 stroke ) build. Compression will be a tad less than yours and should cross the line at the same rpm. I just wasn't comfortable with the others given the cost of my KB block.

Not that Olivers can't fail but I think it would be less likely.

Only read posts you agree with

For a 1000 Hp I would suggest the Olivers. BUT keep in Mind that Molnar and K1 were both started by the same guy. They both come with ARP 2000 bolts. The Molnar also has the option for what they call Power Adder and Power Adder Plus where they add more Material to the beam. Actually they machine less. This makes the rod a bit heavier but also stronger. You could also look at the Pro Series from Manley.
Todd

Why not aluminum. BME, and R&R.

Is crank set up for Mopar or Chevy width rods ?

On the cheap Eagle with L-19 bolts
Not so cheap Oliver
Crower ?
and deep pockets Carrillo

Like it or not i may have to go with Manley or Oliver rods, about 850 more than the h beams i was looking at. I got away with running Molnor 6.86 Hemi H beams in the megablock, but what shakes my confidance in the 7.1 rods is the fact that the 7.1 rods are 11 grams lighter than the 6.86 rods.

Why not call Molnar and ask them? I talked to Tom Molnar at PRI two yrs ago and the guy is a font of knowledge. Honestly, I don't see your setup as all that aggressive. S/F....Ken M

HP means squat. What counts is reciprocating weight, rpm, and load if you run a power adder. The 7.100 rods are a modern design where unnecessary bulk was removed. Call Tom and ask. He'll give you an honest answer. Mine has Molnar 7.100". The bobweight is 2222. I was told my self imposed 7500 rpm limit was safe. Though it only runs to about 7300.
Doug

I know they are cheap and might need touched up but I don’t see the Eagles with L-19 bolts failing

They come standard with 190,000 psi rated 7/16 ARP 8740 (750 Horsepower rating) and 230,000 psi rated, 7/16 ARP 2000 rod bolts (1200 horsepower rating) or 265,000 psi rated 7/16 ARP L-19 bolts (1500 Horsepower rating) as upgrades. Each set includes Instructions and rod bolt lubrication.

I got a deal on these. If they check out ok I’m using them in my 572 Street Hemi.
They are old with Arp 2000s, but new

My friends rb stroker used the Callies Ultra I beam rod. Part no U15270
Very nice piece. Not cheap but supposed to be a pretty stout piece. Quality was very good and so was machining ootb.

Hey Greg,

I went with the Oliver pro billet option, and the peace of mind has been worth it to me...

Good Luck,

Arnie

Don't skimp on fasteners , which ever rod you choose.
I believe it was Barton who said it , in an article about the building of an AA/AH motor..............Use the best fasteners you can get.
Relative to all the other costs , it really seems like sound advice.
I would call Molnar and speak with Tom too. He has forgotten more about connecting rods that I ever knew.

L19 or SPS rod bolts are better than ARP2000

Oliver H Beams or GRP Alum.

7.05 GRP in my 604 B1
7.15 in my 540B1

Or these

Beware of L19 bolts. For a motor that sits a lot corosion could be an issue. My Molnars have over 400 passes.
Doug

Thanks everybody. I talked to Ed at Molnar, he said the 7.1 rods from Molnar would be fine. Two other things that will help- the new piston is going to be lighter and i plan to go to a clean neutral valvebody.