Aluminum Push Rods

[davidd]

These push rods are made by Smith Brothers and are aluminum with steel ends. They fit through the adjuster hole in the rocker arm. The part number is NA56-AA and the overall length has to be specified. Unfortunately, Smith Brothers does not do international shipping, so you need to be in North America or have a friend there.





http://www.pushrods.net/

David

 

[davidd]

I should have mentioned that the push rods cost $11 and change each without postage.

David

 

[bmetcalf]

Do you use them? How about on a Rap in std tune?

 

[mercurycrest]

I should have mentioned that the push rods cost $11 and change each without postage.

David

Postage? Bend, Oregon is a nice Saturday Ride from here.

 

[A_HRD]

David,

Should I be worried that there is no apparent 'waisting' of the ball?
I've had followers and rockers that seem to indicate this would be necessary…


Peter B
Bristol, UK.

 

[vibrac]

can you get the ends out and shorten the tubes if required? Are the ends held in by interference fit or chemical locking?
I remember someone in the UK VOC suggesting this years ago but he was using alloy arrow shafts and hardened tips, Truly there are few new ideas but it takes the US to make it into a business

 

[davidd]

I just received these, so I have not run them. Carleton Palmer ordered them and used them for years in his racer. There is no problem with the ends according to Carleton. I don't know if the ends can be removed to shorten the rod. I ordered a few in different sizes to save me the work. Smith Brothers will copy the original in steel or aluminum if you wish. I always had a machinist make mine out of aluminum with no steel ends and never had an issue, but I like the idea of the steel ends as well as ordering the size I want. I have also never had a problem with the material growing in length for tappet adjustment. I checked clearances when hot and there was no problem, so I assumed the short length of the rod was the key.

I think these rods have no restrictions and you could run them in your street bike, but I am not sure that there is a problem to solve, unless you want a specific length that is not easily available from the Club. Carleton and I have gone to 8500 RPM a few times so, valve train weight can be important. Tim is right that it is nice to have a business dedicated to this. They have a lot of experience and they generally will stop you from doing something stupid like using the wrong materials.

David

 

[Robert Watson]

I have been running them for many years in the Woolly Mammoth Rapide (9.4:1 ported heads MK11 cams Harley sparks 34mm flatslide Mikunis etc) and here is what I know.

The ends are a press-ish fit and can be removed to shorten the tube

The straight ends DO foul SOME adjusters and break out little bits -- this can be cured by chucking them in a lathe and giving a bit of relief behind the ball end. They didn't (to my HIGHLY trained ear) make a db bit of difference to the noise level!!

 

[davidd]

Robert,

Thanks! I spoke to Carleton about the fit prior to posting, but apparently, he has been lucky!

David

 

[Vincent Brake]

they expand, must do as alu gets longers as steel when hot. so we need to adjust for it. how to do so?
Why cant we make them just from hard anodized alu all in one piece? and even spare the steel ends??

I see a great advantage using them in standard set up and then make higher valve spring caps ,so to relief the whole system., (who goes faster in normal traffic than 150km/h?)

I will dive into it, and look about the the tribology in the joint: hard anodized against hardend steel. anybody got a clue?

Vincent brake S