Aluminum connecting rods

[Unchained]

When I assembled the 540 Arias in spring 2000 I got the best set of aluminum rods I could find.
The Bill Miller units that were 7.25" long.
Now it seems a lot of guys I talk to tell me that aluminum rods are only good for a season or two and then you have to toss them. Is this true or is this a throwback from aluminum rod failures from decades ago? :confused:
The rods are real beauties and I would hate to have to toss them. Can you just check your deck height after running them for a season to see if they stretched to determine the condition?
Mark

[nitro557]

check the roundness of the big end ,also most rod manufactures make a thread guage to run into the rods and check if the threads are pulling out and yes running alu rods for 2 or more seasons is pushing your luck

[West Coast Dave]

The guys I know that run aluminum rods in their drag stuff keep a log and after X amount of runs they toss them away. You can't mag them and the fatigue stress will finally get you.

[Hotcrusader76]

Diddo...
I have heard they aren't good for extended periods of use due to the tensile strength of the rods...
I have never run them, but this is what I have gathered from a few racers.
~Ty
[ December 17, 2002, 02:31 PM: Message edited by: Hotcrusader76 ]

[Jrocket]

Well atleast you have some of the best ones on the market.Miller makes some sweet ones.I think the rods will have a longer life in a boat for sure.I wouldnt be afraid to run them.Ive ran them before,just not in a boat motor.I put alot of normal and drag racing hours on mine.No problems.I was once told that its the down revving that kills the big end of the rods.Kills the big end caps.I dont know if this is true but its what I have been told.......Run'um :D

[Unchained]

JRocket, I've heard that before too. That it's the decelerating that stretches them. In a jet boat there certainly is no decelerating. It's a consistent load.

[Cole]

This brings up a question that i have always wondered,i have a blown 540 that makes about 700 hp and did not go with alum rods but H-beam instead.the motor was in a jet and is now going into a 26'cat,i have always thought the rods were my motors weak link,is this true. Cole

[Jrocket]

Cole:
This brings up a question that i have always wondered,i have a blown 540 that makes about 700 hp and did not go with alum rods but H-beam instead.the motor was in a jet and is now going into a 26'cat,i have always thought the rods were my motors weak link,is this true. ColeWhat brand of H-beam's?

[Cole]

its been about a year...i dont remember what brand....they were fairly expensive. Cole

[Jrocket]

Actually theres alot of good brands out there.Some are made in the same factories just have different brands on them.I think theres other things to worry about in your motor than your rods.They should hold up for quite awhile.An H-beam rod is plenty strong with in reason for 700hp.The majority of most hp motors on the street and in boats probably have a good h-beam rod......
Bad lubrication,detonation and water hydraulicing are more of what will kill those rods first..
I hope something I said helped ya......I know something but not everything! :D

[DUCKY]

I was told that aluminum rods are only for nitro motors where the violent combustion is hard on the crank. This came from George Striegel and I pretty much consider him to be GOD.

[Jrocket]

DUCKY:
I was told that aluminum rods are only for nitro motors where the violent combustion is hard on the crank. This came from George Striegel and I pretty much consider him to be GOD.Thats true,somewhat.They are very soft on the bearings and crank but their not just for nitro motors.Being soft on parts is a good thing. :D
Hey Ducky,hows Havasu treating you?

[Fiat48]

Bill Miller told me the best way was to change the rods one run before they break. I have not broken a rod since doing so. jawdrop

[sgdiv7]

What I always did was when I broke the bolts loose if you could not take the bolt out with your fingers the rod had stretch beond the service life and it is time to replace them. When those rods brake they put holes and brake everything.

[SchellSchock]

What about using dye penetrant inspection. Not the spray on yourself kind but through a qualified Non Destructive Test or plating house. We use this process all the time on aircraft parts to find stress cracks etc. and pretty cheap. maybe $50.00 for a set. BTW better to go with Titanium rods IMHO

[Unchained]

Sgdiv7, Good idea, I can try that.
Schell Schock, Titanium rods!! jawdrop
What do those cost?
I bet their indestructable.
Well if I have to throw these in the dumpster I would have been better off to have paid a lot more for rods that would last a lifetime.
Thanks for the input.

[Clown]

Mark
I was looking into titanium rods for my motor
Until I was told that they are indestructable!
If any thing else fails like a piston pin ,That rod just holds together and beats the living ****
Out of any thing that is left , Because of it being so strong!
P.S. Did you buy that boat yet?

[baracuda]

had aset of bm al.rods in my jet boat, ran them for over 10 yrs
rebuilt it last yr, put the same rods back in it.still running strong.
i heard the same thing about the rods being throw aways after
about 2yrs that was in 1986.thougth it might put your mind at ease
alittle.

[Unchained]

George, I'm ready to send in the deposit to Hi-Tech Performance to order a new 19' Edge Stealth. I didn't scope out the exact graphics that I wanted yet. I better start pouring over some pictures.
Barracuda, Sounds like the Alum rods held up fine for you. How much HP were you putting to them?

[baracuda]

it's running about 750-800 horse,with the nos.that
was a ford engine.429 SCJ.

[Fiat48]

I run aluminum rods because I run blown alcohol. Otherwise I would not run them. We raced a Blown Gas Hydro at 9 seconds on Chevy 7/16 steel rods for 5 years with never a problem. The motor turned 8500 rpm. Currently, I built a Blown Alcohol 510 with Lunati's Pro Mod rod to be raced in PE class. So far, no problems but it has only run about 20 passes. If I don't see the bearings hammered, I will convert my Blown Alcohol motors over to Lunati's rod. The only reason to run aluminum rods is weight and the cushioning effect for the crankshaft. I beleive boats are easier on Crankshafts than drag cars so I think aluminum rods are not required unless you run fuel or hammer it to death. Just my opinion. :)

[565edge]

I use eagle h-beam with the L-19 bolt in my 565",i would either buy these for 625 a set,or buy oliver's.Hey unchained p.m. me about the price on that edge.thanks allen.

[DUCKY]

Fiat48:
Bill Miller told me the best way was to change the rods one run before they break. I have not broken a rod since doing so. jawdrop LMAO!!!
and Jrocket, Havasu is cool, I love it here, other than the wages...
Left the insulation place today and start at Sterlite tomorrow. I didn't see how I can bring home enough to pay the rent at $0.03 per square foot. That's 18333 square feet pe week to clear $500 take home, or roughly 9 houses per week. OUCH!!!

[Jrocket]

Hey Ducky,whats Sterlite???? That sucks about the insulation job. eek!

[DUCKY]

Sterilite is the company that makes all that nifty plastic stuff you buy at Wal-mart (Storage bins, Garbage cans, Laundry Hampers, etc...) Their main operation is here in Havasu. Huge Plant, coming down Kiowa from my house, it looks like their roof takes up a square mile!!!

[Flat Screwd]

Ok heres the skinny on alum rods. Rod stretch is harder on them than comp. So in a blowen application the piston is somewhat under comp. at TDC when the intake valve is open so decreceing the stretching force imposed by the piston as it comes up on TDC. Also heat soak kills them. So after you blast a hot pass ilde untill your oil temp cools before you shut down. I have talked to guys that have run them for as many a 5 years and only changed them just because. I run a set of BME rods in my flat.