conn rods

[jfpracing]

What type of aluminium conn rods are made of ?

and for the bronze is it sae660 ?

thank' s

-jf

 

[izitbrokeyet?]

Bronze bushings are usually made of SAE660 like you said.

Commonly, connecting rods that are machined are made of 7075-series, sometimes they're made of t-62 or t-651 and they're usually made of Ti-6al-xV if they're titanium.

 

[izitbrokeyet?]

If you're making your own rods...I might suggest trying Fortal aluminum. I use it a good bit because it machines easy and has very similar properties to 7075 AL.

 

[jfpracing]

Yes I want to make my own rods ... I have 2 choices of doing them ...

wire edm or cnc 5 axis ... I have to see wich one of the 2 has less

programing... sounds like a good project.

-jf

 

[jfpracing]

Is the weight of the rod is an important factor ?

 

[izitbrokeyet?]

light weight rods are a must especially if you're reducing the counter-balance weight......The lighter the better ....all the way up to the point where it's too light

Too light and your motor goes KA BOOOM!

 

[Geraghty]

The best material for rod bushings is 510 or 544 bronze.

This is what RPM and the original K&B rod bushings are made of.The SAE660 I have used in the past has proven not to be the best bronze for rod bushings.

The only Titanium that I know for sure that has been used in Ti rods is 6AL-4V.

I think this is what Brad Christy is using also.

I have several K&B Ti rods made out of 6AL-4V by Paul Dassonville in the mid '80s.He made them for the K&B outboard hydros [sundowners]run in NAMBA.

The rods are absolutely bulletproof.

If you are going to make your own rods make the weight as close to stock as possible.This will insure the stock balance will be maintained .

 

[izitbrokeyet?]

In what ways are the alloy grades 510 or 544 Bronze better than SAE-660?

 

[Geraghty]

544 has 2X and 510 has 4X the tensile strength of SAE660 bronze.

I have had problems with 660 bushings,replaced them with 510 and the problems went away. 544 and 510 press with a lot less distortion to the bushing.

544 is also called free-cutting phosphor bronze.What does that mean,who knows.

I do know both 510 and 544 machine great.

Check out www.matweb.com This is a great website.

Maybe they have more info on 510 and 544 that will help your curiosity.

 

[Chris Attebery]

Ahhhh,

Paul Dassonville, AKA Master Paul. Paul is an awesome machinist, especially for a hobbiest. He taught Charles Dandy and I a ton about setup and motors when we were newbies. He's racing a Camaro with a 510" Chevy in it now. Got bored with the boats I guess.

I wish that I could have met him before he got out of boating, I only got to see him race once or twice. He ran a .45 hydro with a K&B .82 in it at one race and it had to have been running 85+ when all the fast guys were running in the low 70s. Made some fast boaters look like they were standing still.

Chris