Billet rods vs. Aluminum

[85boostbox]

I want to run a light short block set up for my build. But want it to be more or less reliable. Anyone run the billet rods in there setup and if so how did they like them. I know aluminum rods are way lighter but the billet is still about 100 grams lighter than a t2 rod. I want to run something strong as well considering this is going to be a high compression build with boost.

[Kryp2nitE]

Billet is not a material but a manufacturing process. It means the part is processed from one chunk of material. You can have Billet Steel or Billet Aluminum.

In my experience Aluminum rods needs to be pulled and checked more often. So I guess it depends how often you want to tear down the bottom end.

[85boostbox]

Dont really want to tear down unless there is a problem lol. But i guess if i had to i could do it every winter. But I really dont want to do that.

[4 l-bodies]

Better decide before you cut crank as aluminum rods require more rod bearing clearance. Also need to do a slight modification to half of bearing too. IIRC, 5.945" aluminum rod from GRP weighs about 441g. That is pretty light!
Todd

[85boostbox]

Could explain more on the modification part. And have you ever had experience with billet steel rods. I see they weigh about 590 grams. Stock t2 rods weight 690 grams. Just want a solid engine. Want it to be able to handle street duty, auto-x and drag.

[turbo2point2]

Todd may be referring to the lower half of the bearing. On the GRP rods, they have a pin on the cap that helps retain the bearing. The bearing itself needs to be drilled to fit over that pin. For a street engine, I would go with a steel rod. I have run both with no noticeable difference. I currently run Oliver billet steel rods in my motor. Been in there since 2009 and have seen a lot of passes, most were with 8500+ rpm shift point. Occasionally it would see 9000+, and with the auto, they are also punished on shutdown.

[85boostbox]

Thanks Brian. That was the info I was looking for. So looks like I will be going with a steel rod then. Sounds better for my application plus I don't think I will be seeing 9000 RPM revs lol. Maybe 6500 to 7000. Thanks again Brian.

[85boostbox]

And one other question. You don't have to set clearances differently for steel. Set them to factory specs correct???

[turbo2point2]

I run larger than stock clearances(.0028-.003) on my race stuff, but the factory spec will do just fine in your application. I try and stay on the larger end of the spec. and always bump the oil pump up with the MP spring.

[85boostbox]

Makes sense in your application cause you want the least amount of friction you can get.

[GLHNSLHT2]

too bad the billet titanium rods aren't being made anymore.

[cordes]

too bad the billet titanium rods aren't being made anymore.

They aren't? I've read in many places that they're a great compromise between Al and steel rods material wise. Is it simply a cost in machining issue? I've also read that Ti is really gummy and difficult to machine.

[Reaper1]

too bad the billet titanium rods aren't being made anymore.

You can have custom ones made, but be prepared to spend around $2k JUST for the rods! IMHO there are other less expensive places to reduce mass that are more effective.


They aren't? I've read in many places that they're a great compromise between Al and steel rods material wise. Is it simply a cost in machining issue? I've also read that Ti is really gummy and difficult to machine.

Yes, machining titanium is difficult and it also requires special prep of the crankshaft as well as titanium galls very easily. This might be mitigated by using a different alloy of titanium, however.

Stick with a good forged steel rod, or if you want to go balls out, forged steel billet rod. The new metallurgy for aluminum pretty much eliminates the horror stories of back in the "old days" when they had a more finite lifespan, however, aluminum STILL has a finite lifespan as it does work harden over time, and eventually *can* fail. If it's an all out race engine that is going to be torn down every year, go for it! The gains to be had are amazing. However, for a street engine you want to seal up and not mess with...steel is still the way to go.

That being said about aluminum, I do know people who have run the living crap out of the same set of aluminum rods in SEVERAL engines over many years of racing and they never gave up. I also know some that run them on the street. I suppose it all depends on how much you trust them.

[GLHNSLHT2]

GRP, or whatever their name is that makes the aluminum rods also made titanium rods, they claimed that the price increase for just the material helped them make the decision not to make them anymore. Glad I have a set :) Not sure when they'll get run though. I also have a set of Oliver's that will hopefully be running this year. Glad to hear Brian is having good luck with them.

[rx2mazda]

I run larger than stock clearances(.0028-.003) on my race stuff, but the factory spec will do just fine in your application. I try and stay on the larger end of the spec. and always bump the oil pump up with the MP spring.

I assume that your running a double ported head too? I'm sure that helps also.

[cordes]

I assume that your running a double ported head too? I'm sure that helps also.

Come on Carroll that was in post one of his build thread. Get with it man. You've been gone for too long.

[rx2mazda]

You've been gone for too long.


True, true!

[Reaper1]

GRP, or whatever their name is that makes the aluminum rods also made titanium rods, they claimed that the price increase for just the material helped them make the decision not to make them anymore. Glad I have a set :) Not sure when they'll get run though. I also have a set of Oliver's that will hopefully be running this year. Glad to hear Brian is having good luck with them.

I heard the same thing about the material cost. It honestly doesn't surprise me. I wanted a set for my build, but before I dump $2k on rods, I'll dump $5k on a custom crank! WAY more benefit to be had there! ;) :thumb:

[turbo2point2]

Double ported head FTMFW!! :)

[85boostbox]

And stickers...

[turboshad]

I've taken my Eagles past 500 wheel at up to 10,000 RPM though not on purpose. I think they are about the lightest rod you can get.

[Lotashelbys]

I have had good luck with BC H-beams. Been to 8500 a few times and past 40 PSI and they are closing in on 20K street driven miles. They are about as ready to run as they come using standard 2.2-2.5 bearings and .901 pins. I have installed 4 sets and they all checked good to go out of the box. I agree with Brians clearances also


Another problem with aluminum rods in a manual is they dont like to be downshifted