Groden Rods?

[DeadlyEclipse95]

I was looking into getting a set of Groden Rods but I don't know anything about them.....I was wonderin if anyone has used these.....let me know and tell me how well they worked for you.....or if anyone else has a better suggestion

 

[Big Woo]

What is your planned primary use for this project? Street/strip or only street, or only strip.

 

[DeadlyEclipse95]

Street and Strip.....I want to build a car that I can drive around and still get on it whenever I want and for it to hold up....I know DSM's are known for breaking but I want to try and build an almost bullet proof setup.....so that I can autocross, drag race, and drive on the road.....Thank god I have another car to drive

 

[SBstar]

Obviously Shep uses them, but aluminum rods do have the longetivity of steel which is what most OEM rods are made of. There are many benefits to Aluminum rods take for example this little article I found on them.

"So why are aluminum connecting rods the preferred choice for those running high RPMs, lots of boost, or making huge horsepower? Well, the answer is quite simple. Think of the connecting rod as a spring. The aluminum connecting rod is your spring. It cushions the inherently rough nature of combustion and acts like a buffer between your more expensive pistons and crankshaft. In these applications, a steel rod is too rigid and rather than performing its job like a spring, it's more like a sledge-hammer, often leading to damage to the crank and the rest of your engine due to failure of the rod itself or a part connected to it. Some manufacturers claim their rods are street-able and can outlive a steel rod. We'd be lying if we made the same claim. An aluminum connecting rod is a spring and there is only an X number of times a spring will compress and return to it's rest state without deformation. Deformation in our case is a rod failure, as with any connecting rod. Aluminum has a fixed fatigue life. Well, what's that you might ask? Every material can be deformed to a certain extent and only a certain number of times before it breaks. Think of a crushed soda can. You can bend it forwards and backwards in the middle a few times before it will split open or tear in half. It's the same thing with a connecting rod. Depending on the material and the application, a connecting rod might last 500,000 miles or it might last just a single pass. It's hard to say with an aluminum rod what is the useable life. Controlled deformation and its performance as a spring and shock absorber is the reason people seek an aluminum connecting rod. If its weight reduction that is needed with the strength and longevity of steel, say longevity of an OEM part, it's a titanium connecting rod you need. But the price you pay is its extreme cost. The old axiom pick two holds true: price, strength, reliability- you can't have all three. Some guys change their aluminum connecting rods religiously every few runs or every season, since typically the cost of a set of rods is less than the cost of the rest of the parts in a race engine. Import racers whose cars double both as daily drivers and weekend warriors typically use their rods for 10 to 15 thousand miles and again, change them just as a precautionary measure depending on how hard they run their engines. We've even seen customers put hundreds upon hundreds of passes on their connecting rods without failures. Like we already said, we can't guarantee how long a connecting rod will last but we do take the time and make the effort to build the best connecting rod possible, and do it affordably."

This article is found here and there is more too it explaining titanium and steel rods, forging, etc...
http://www.rrconnectingrods.com/choosing.htm

So in the end if this is a street car, I would say no, don't use the Groden aluminum rods, a pure track car where you can afford to replace rods every so often (supposedly Shep has used his for an entire season, although I can't prove that) the aluminum rods are a tremendous upgrade.

Hope I've been of help.

 

[topstreet]

SBstar- That article was a good find. Please keep in mind though, that many of the people who have experience with the alum. rods are V8 guys. The piston size and weight, and even anlge of the engine all play a factor in "stretching rods".

I have talked with different people about this on numberus occations and I have never personally seen a set of stretched rods on a 4cyl.. One of the bigger parts that people need to read in the quote you found is more simply put... Aluminum rods absorb knock! (To a point) Dont go out there and try to find it. But it may save you on something like, MINOR ignition tune goofs.

The weight of the rods is one of the other big big factors. When you are having a rev war with a crotch rocket, and make HIM feal dumb... Yeah, you know where thats going!

I do not daily drive my car. I do however bomb around on the street as much as I can. I have been using, the same set of Aluminum rods since december of 05. I am not really even thinking of pulling the engine apart to look at them.

IMO: Greater then 90% street car... Prabably not. Weekend driver / Track car! Sure...

Jake H

 

[SBstar]

Thanks topstreet, I do realize most of that info is from V8 guys. However, it still remains true for the most part. As I posted I've read/heard that Shep has used his for an entire season, being that he has seen rpms as high as 13000 on some passes means they can handle quite a bit if they've lasted that long. Great to know you've been running them for so long as well. I've been considering the Groden Rods when I finally get my motor rebuilt. I guess what I truly mean is don't expect them to last more then 200,000 miles like many stock steel ones do. I would in the very least inspect them once a year, but maybe I'm a little overcautious.

 

[topstreet]

I guess what I truly mean is don't expect them to last more then 200,000 miles like many stock steel ones do. I would in the very least inspect them once a year, but maybe I'm a little overcautious.

I would completely agree with this. I will say, that I have not put as much use on the car this year as I have wanted to. But it could have been a lot less too.

Jake

 

[wishihadatalon]

What about heating them up? A guy I talk to was telling me that he broke 2 sets because they were not in the ideal hear range. He said he let his motor heat up for over 10 minutes and when he hammered on it snap wen the rod.

 

[1gcrazy]

Letting them warm up is probably the best thing you can do... If you womp on them cold...they're brittle just like every other metal on that oh so large table we call periodic...
He may have had something wrong and just blamed it on the most obvious scapegoat...who knows.
I think you should stick with steel, i'd go forged. if you're really looking for something lightweight and strong try an A beam rod instead of an H beam. They'll last you alot longer since they're more durable. I've yet to read someone snapping an A beam....H beam is another story.

 

[DeadlyEclipse95]

I guess I should be going more towards forged pistons........