aluminum rods

[ACKERSON]

Is there anybody out there that has first hand experience with Groden aluminum rods?

 

[92redman]

Try Shep. I don't think you will find anybody using them on the street because an aluminum rod will stretch and it's length and big end and small end holes change quite a bit as they heat up. I have been told by several experts that aluminum expands at least 2.5 times as much as iron.

 

[ACKERSON]

That's what I have always been told until a few days ago My cousin spoke with somebody over at ffwd and they said that the groden aluminum rods were ok for street use. I told my cousin that was very unlikely and he should contact the manufacturer. So he called Groden and he spoke directly with the owner. He said that they were fine for street use and he would warranty the rods against breakage on the street. The car won't be running until the spring though because we are doing a complete buildup on the car. I'll be sure to let everybody know what happens. I'm keeping my fingers crossed.

 

[yoshimitsuspeed]

That's what I have always been told until a few days ago My cousin spoke with somebody over at ffwd and they said that the groden aluminum rods were ok for street use. I told my cousin that was very unlikely and he should contact the manufacturer. So he called Groden and he spoke directly with the owner. He said that they were fine for street use and he would warranty the rods against breakage on the street. The car won't be running until the spring though because we are doing a complete buildup on the car. I'll be sure to let everybody know what happens. I'm keeping my fingers crossed.

Did you ask how long they would be warrentied against stretching and breakage?
And how long they should last.
I don't know any thing about them myself but those are the questions I would ask.
You could have rods deform at 40,000 and they could be like yeah they are fine for street use but you are supposed to replace them every 20,000 miles or something like that.

 

[Akarimotorsport]

waste of money from everything i have read. Besides most aftermarket rods can handle enough power for street driving.

 

[ACKERSON]

Why do you say it is a waste of money?

 

[92redman]

waste of money from everything i have read.

What is a waste of money? Having the lightest possible rotating assembly?

Besides most aftermarket rods can handle enough power for street driving.

What makes you think a street driven car makes more power than a race car?
Nobody is debating if aftermarket rods are strong enough, he is wanting to know if aluminum rods will last long enough with the amount of miles a street car will put on them.

So far it looks like the company thinks they are okay for street use. I doubt they will warranty a "race" part as the nature of the environment they were designed to run in.

 

[ACKERSON]

The manufacturer claims that the rod will handle daily driving and racing without any failure. Apparently they are suppsoed to be able to handle 800+hp however, I am skeptical considering the reputation of aluminum rods. I guess I wil just have to wait and see. Thanks for all of the info guys

 

[GRNDSM]

Those are definitely some pretty big claims! I am all for experimentation and new stuff, I just wouldn’t want to be the first one to try these on MY engine . So I guess what you are doing is a right thing, keep trying to find someone with some FIRST HAND experience with this particular product.

The problem is that if this product is new, it might take a year or so to come up with time tested results.

 

[oddrob]

We ran the same set of aluminum rods all year in the Talon and were satisfied with the results. We made more power than ever and they handled it. As to street applications, that I wouldn't be sure of. We had a Toyota that broke an aluminum rod last year and I will say they make a hell of mess when the go.

 

[92redman]

We ran the same set of aluminum rods all year in the Talon and were satisfied with the results. We made more power than ever and they handled it. As to street applications, that I wouldn't be sure of. We had a Toyota that broke an aluminum rod last year and I will say they make a hell of mess when the go.

Rob, did you measure the rods after the season to see how much they stretched or deformed etc..? How many runs would you estimate you made on the set? Do you know how much power you were making or have a good estimate?

 

[greycar]

I also used aluminum rods this last season and they worked great. I made enough power for mid 10s @137mph and had no abnormal problems at all. I was using GRP rods, I don't know how they compare to groden but I would recomend them for racing, I didn't get much street driving in this year so I can't comment on that factor.

 

[98talonAWD]

aluminum rods are cool and all.. but you have to tear down the motor every like 10K miles or so. totally not worth it unless your sponsored and or have way too much money and time!

i know this from experience... and not just something i have heard! if you drive it on the street... dont use aluminum rods. as for trying new things, go for it.... just not aluminum rods.

 

[ACKERSON]

Groden claims that these rods have a different alloy than other brands of connecting rods and they will last. We'll find out soon enough.

 

[deth2u]

I have first hand experience with Pauter's trademarked "E-beam" rods. They claim to handle 900+hp and 35+lb of boost. I doubt you can see that with even 100 octane, I could be wrong. They're cromemoly and come with some sort of exclusive ARP bolts. These in my opinion are the most quality rods you can buy for the street/race application. I slammed my 6G72 in 2nd at 100mph numerous times to get the fastest, ungodly entry speed into corners and sent my engine screaming into the red numorous times. Not very safe mechanically you'd think, but my engine never had a qualm about it. This is hell on the rods. Also, I've heard nothing but good things about Pauter from other guys. Definately worth the extra money if you're hell-bent over the strongest rod on the street possible. I couldn't reccomend them more.


My machinist saw my rods when the block was getting worked, he's been building engines for 50 years and they even made him stop what he was doing to give them a once over.

 

[VKill]

Some of the most powerful drag motors in the world are using aluminum rods putting out well over 3000 horsepower turning over 10,000 RPM. Aluminum rods should be just fine for street. However they do present some problems. Clearance can be problem sometimes because they are so large. I have actually had to cut them to clear cam lobes and have had to cut blocks. They do fatigue when used on really high horsepower engines. So I used to change mine every race season. I don’t think you will be stressing them much on the street with a streetable engine. Also their bearing clearance changes more with temperature change. Your engine should always be fully warmed up before stressing them.

Aluminum falls right in line with titanium. Titanium fatigues with time under high stress too but takes a little longer. I found out the hard way a few times.

 

[nukefission]

The car won't be running until the spring though because we are doing a complete buildup on the car. I'll be sure to let everybody know what happens. I'm keeping my fingers crossed.

Bringing this thread back, are there any update on this situation? I'm in the market for some rods and am thinking about these Grodens.

 

[Scrymerr]

Just a thought- people say aluminum rods stretch and cannot be used very long. Understandable. However, I don't see how this information can pertain to both 1000hp motors and say 500hp motors. If said aluminum rods are supposed to last say 20,000 miles at 1000hp, would you not expect them to last a lot longer than that if you were making half the power? I imagine it would also depend not so much on power, but revs. Would a 2.0@9000k making 500hp not stretch the rods a lot more than a 2.3 revving to 7500?

Dan

 

[nanokpsi]

Just a thought- people say aluminum rods stretch and cannot be used very long. Understandable. However, I don't see how this information can pertain to both 1000hp motors and say 500hp motors. If said aluminum rods are supposed to last say 20,000 miles at 1000hp, would you not expect them to last a lot longer than that if you were making half the power? I imagine it would also depend not so much on power, but revs. Would a 2.0@9000k making 500hp not stretch the rods a lot more than a 2.3 revving to 7500?

Dan

It's not a matter of power, it's a matter of metal fatigue. From my undertanding the rods also stretch around the rod bolts which definately deosn't qualify as a good thing to me.

Groden claims they installed them in a shop truck and it ran just fine on the street for 100k miles. I don't believe that enough to use them in my motor and I am willing to bet that most people win't either.

 

[ITSME4G63]

Groden claims they installed them in a shop truck and it ran just fine on the street for 100k miles. I don't believe that enough to use them in my motor and I am willing to bet that most people win't either.

what did they do, strap the truck on a dyno for a few weeks?

 

[Scrymerr]

It's not a matter of power, it's a matter of metal fatigue. From my undertanding the rods also stretch around the rod bolts which definately deosn't qualify as a good thing to me.

Groden claims they installed them in a shop truck and it ran just fine on the street for 100k miles. I don't believe that enough to use them in my motor and I am willing to bet that most people win't either.

Maybe you didn't understand what I was saying. The rods are not just going to stretch from sitting there, things need to make them stretch. A few things I can think of that would cause the rods to stretch over time is the power the motor is producing, the amount of time the motor is spending under load, and the rate at which the rods are moving. Now if you put an aluminum rod in a stock motor and drive it "normally" on your weekday commute it will not stretch as much as it would if it was in a 1000hp drag car making multiple passes each week, that is a given. Now I am wondering specifically what factors lead to the stretching of the rods more: power, rpm, mileage, or other.

 

[nanokpsi]

what did they do, strap the truck on a dyno for a few weeks?

Shop truck, AKA thing empoyees used to run errands, etc in.

 

[nanokpsi]

Maybe you didn't understand what I was saying. The rods are not just going to stretch from sitting there, things need to make them stretch. A few things I can think of that would cause the rods to stretch over time is the power the motor is producing, the amount of time the motor is spending under load, and the rate at which the rods are moving. Now if you put an aluminum rod in a stock motor and drive it "normally" on your weekday commute it will not stretch as much as it would if it was in a 1000hp drag car making multiple passes each week, that is a given. Now I am wondering specifically what factors lead to the stretching of the rods more: power, rpm, mileage, or other.

I do get what you are saying amd I am convinced mileage is an important factor. The rods may or may not have logged 100k miles in a work truck. Either way that isn't a 5-600whp street car.

It all comes down to piece of mind. Is the little bit of money you save on rods and the slight performance benefit (at the level a majority of the community is at) worth the possible catastrophic damage? A vendor built shortblock with auminum rods and other good compents is going to cost you 2500-3k, all of which would be pissed away in the name of science if somthing were to go wrong.

 

[Jon Lane]

Shop truck, AKA thing empoyees used to run errands, etc in.

Exactly, and which is why the truck test makes sense. It's the fatigue and hot/cold cycling -- and what they do to rod bolts as well as the rods themselves -- as much as anything. Peak HP numbers for 1/4 mile blasts aren't nearly as pertinent as 100k miles on the street would be for a street motor.

On the other hand, if Shep gets 250hp out of each rod at 10krpm's, I think the race test has already been proved...

 

[nanokpsi]

Exactly, and which is why the truck test makes sense. It's the fatigue and hot/cold cycling -- and what they do to rod bolts as well as the rods themselves -- as much as anything. Peak HP numbers for 1/4 mile blasts aren't nearly as pertinent as 100k miles on the street would be for a street motor.

On the other hand, if Shep gets 250hp out of each rod at 10krpm's, I think the race test has already been proved...

I was just merely saying that even if the test did occur, the rods in a daily driven DSM would see a lot more abuse. I'm sure the rods in the work truck saw very little power and verly little/no detonation. Both of which are going to be factors in metal fatigue as well as all the heat cycling. The small gains are defiantely not worth the risk to me. I am all for you to try it though