MyGreenBabyZ

I've recently come into a Callies Stealth crank for an LT1 with 3.750 stroke and a set of 6.0" Crower Maxi-Light 94 Series 3 Rods for a small journal crank.

These rods retail for over 1500 dollars and I'm sure the crank runs over a grand.

Now I got them both for a SCREAMIN' deal and I feel it would be a shame if I couldn't use these rods. They don't weigh but 560g each FOR A 6.0" ROD and crower claims the rods are good for 800 HP!

I've also had the crankshaft and connecting rods checked at my machine shop and they are in perfect shape ready to run.

On to my question:

I wanted to know if I could use these rods successfully with my crank if I have the crankshaft reground?

I was quoted about 200 dollars for grinding the crankshaft and 175 dollars for re-hardening and nitriding. Are those acceptable prices?

What about power handling? I know that taking .100" off the crank must weaken it but I have been told that for my goals it would be insignificant. Will this drastically weaken the crankshaft?

I've heard that small rod journals are good because the slower bearing speeds, ect.

I only plan on making 450-475 Flywheel horsepower and I MIGHT put about a 100 shot of nitrous if and only if I cant reach my power goals.

Should I use these rods? Or should I try to sell them and buy a set of eagles or something? I am running on a tight budget and it would be great if I could use these rods, because I already have them.

Thank you guys for the help,
T.C.

SStrokerAce

T.C.

Regrinding a crank is not a bad idea at all. The Max Lites are great rods and if this all comes out significantly less than the sum of the parts anyways then it's a good idea.

The concept you are talking about with "weakening" the crank by grinding the journals smaller is journal overlap. You can go thru some pain in the *** calc to come up with the area of two intersecting circles. Or the way I like to do it...... 1/2 stroke (3.750=1.875) - Main Journal Radius (2.450 = 1.225) - Rod Journal Radius (2.000=1.00) = (Amount of overlap)

1.875-1.225-1.00= .350" (Yes this is a negative number just change it to a postitive)

The higher the number the stronger the crank is due to journal overlap.

For a 2.100" rod journal you would have a overlap of .400"

This is a simple way to do it and the areas would definatle change more than this number when comparing cranks, but it gives you an idea at least.

To compare a Cup crank to that.....

3.25" Stroke, 2.30" Mains, 1.850" Rods = .450"

That's 600+ miles, 9500rpm and 800+hp

Another thing to think about.....


You could increase the stroke of the motor too 3.850" since when you make the rod journals smaller you can offset grind the crank and take advantage of the smaller rod journals byt moving the centerline of the rod journal out the same distance as the reduction in journal size. You will also weaken the crank when doing this.... just plug in the formula.

As for the re-hardening..... It's not 100% needed. I've checked some stock cranks tha go for miles and take lots of abuse and we are looking at a consistant Rockwell hardness on every surface of the crank. From the middle of the journal to the bearing surface to the counterweights..... A Callies Stealth is induction hardened on every journal which helps wear but doesn't keep the crank from breaking in half due to too much power or too much RPM and recipricating forces on the crank.

On a side note..... Howards has those PM 6.0" Rods that are 585g's, 800+hp and cost $600 retail. So if you wanted something similar in a standard journal that would be the way to go.

Bret

sheppard00

yes definatly cut the crank and run the small journals cranks usual break in the hmmm I'll call it webing between the 2 journals no at them. the bearing speed will be alot slower so the crank and rods recieve less wear per revolution and this makes 5000rpms only have the friction of like 4000rpms. use what you got and he is correct you don't have to have a crank re hardened it just make's them last longer.

OldSStroker

Bearing speed is proportional to circumference which is directly proportional to diameter so reducing from 2.1 to 2.0 dia. would make 5000 feel like 4762 to the engine. If you get down to 1.85 rods, 9500 rpm is more like 8400 bearing speeds with a 2.1 journal, and 5000 is about 4400.

FWIW, decreasing the overlap gives less metal to resist the bending loads from the rod journals, so the stress (lbs/square inch) in the web is higher. That may be why the cranks break there. The journals are loaded fairly evenly by the rod, so they don't often fail in shear, unless the radii at the ends of the journal are sharp or have stress risers.

arnie

No! You certainly don't need them. Waaay overkill, AFAIC. If ya got a 'screamin' deal on them, it should be easier to make a buck on them, when you sell them, and get what you really can use, and need. Someone here has a motto, regarding using components, that complement the others. I see this particular component, as a good example. I don't consider this component, a very good match, to the rest of the engine, and for it's intended usage.

Birdie2000

Taking them to Moldex? If so that's what I paid for mine earlier this year.

MyGreenBabyZ

By screamin deal i mean A SCREAMIN' DEAL, for both the crank and the rods and my AFR 195's and as far as I'm Concerned why look a gift horse in the mouth. If i can go WAYYYY overkill then why the heck not!?!

I feel that these rods, being as light as they are and plenty strong coupled with the Callies forged crank and a nice light set of forged pistons set into my four bolt block will give me the ability to upgrade as far as i could want or need in the future or even leave it alone at the power I plan on making and have it last a lifetime. Not to mention the fact that the light rotating assembly should free up a few horses too.

Matching components can cause problems for many people that might want to expand in the future, one setup might work great at one set power limit but what if you want to go bigger?

Unless you want to buy these rods for 1200.00 dollars arnie? I think im going to go ahead and use them.

Thanks everyone for the advise, I'm going to send the crank and rods out to be setup this week.

Thanks so very much!!!
T.C. Stachowicz

MyGreenBabyZ

Actually i think my machine shop deals directly with them, and im pretty sure thats where they are sending them. Jack at automotive machine does great work for me. He did my honda short block and its been handling the abuse I hurl at it with no problems, 220HP/192TQ at the wheels out of a 1.6L and low boost (cant wait to crank the wick!).

stealthblack

On another side note..
I saw an ad for those and was wondering how the 4260 steel compared to 4340.they have a little chart extolling the virtues over different steels with tensile and yield strength,etc. but its an ad, not a study.I know theres some metallurgy gurus floating around this board//Im gonna stick to olivers or lunatis or just put some good bolts in my ESPs when im freshening the motor soon, i was just curious.Word on the street was that GM factory PM rods werent real fond of nitrous hits,--any truth to that?anyone used a set of these yet?

SStrokerAce

We got into a big panty fight over this a while ago......

PM is not as dense as most setups but the powder they use in the Howards rods is close to 300M which is very pricey in a off the shelf Billet. I know Manley and Arrow make rods out of that and you don't want to know the cost.

ESP's with ARP2000's are more than most guys here even need, so that's a good choice man.

In the times I have talked with old boys such as Joe Sherman, the old school parts and rods are actually pretty dam good. One reason I like Scat I beams, they are basically a cheaper, stronger setup than the old stock rods and most guys could get away with them in about 90% of the motors out there.

Bret

1racerdude

If you do turn the crank to 2",make real sure they put a generous radus on the journals and buy the brgs that fit the radus.

stealthblack

Im not quite old school but i agree old tech stuff takes a beating.We ran "pinks" and Sportsmans far past recommended in the old days [waay back in the mid-late 90s ] More revs than juice though which helps a little.Now ive got more cash its hard not to over-rod a motor,but it wont hurt anything but your wallet.
speaking of high $$ rods, I was looking at some CP pistons and saw the Pankl rods,i'm scared to ask how much;probably up ther with LAE and Lentz and Arrow like you said.
Thanks for the info on PM,ill search for that debate.


ps..I dig Joe S.'s stuff in big way.