I am trying to replace a couple of tubes in engine frames. I am having trouble finding the appropriate sizes. There are two cross-sections, 1.0x1.25 and 1.25x1.50. I simply want to replace them with an ANSI 4130 chrome moly steel which is not the problem. The problem is the unusual cross-sections.

Someone is building them, Martin Robey for one so the material is coming from somewhere. Any ideas?

Best,

 

Have you called "Metals Supermarket" ? Check for them on Google.
Edward

 

They say those tubes can't be welded because they are some funky Reynolds alloy. More info...

https://newhillgarage.com/2011/09/14...-frame-repair/

Frame Rail Repair? ? You bet! | Monocoque Metalworks

Hope that helps.

Jim

 

Thanks for the reply. They do have the 1x1.25 in a cold rolled steel. Not the ANSI 4130 I am looking for but it may suffice as it has a thicker wall. I have been pretty extensive in my search calling many resources both local and abroad. The hard one is the 1.25x1.5 cross-section. That is the big one on top. It might as well be unicorn horn at this point.
I will keep looking.

 

I have visited those sites and called Chuck at monocoque. He stopped building the engine frames because he was cannibalizing old frames to get his tubes and it stopped being worth the trouble. People with money can just buy new.
I intend to braze the repair. Newhill did a patch job with a wrap-around section brazed over the original. It is an option but I am trying the full repair first.
Again, thanks for your help.

 

reynolds 531 tubing was used to build original frames, an alloy that needs to be heated and cooled specifically to retain its strength. Replacemments do not use thuis exotic metal (bicycles do) but only really adds weight. Replacing entire tubes and using end plates might work but repairing tubes not so much

 

The original frames were made from Reynolds 531 steel alloy, but this isn't available anymore. The tubes were bronze-welded together which is not classed as brazing, but is similar in that there is no actual fusing of metal, it being a bit like a metal "glueing" process.

Weldcare Bronze Welding

If slotting in tubes of a later steel alloy, it will be important that the original joining process is followed. However, if the whole frame is copied in one of the newer alloys, then that can be TIG welded.

https://en.wikipedia.org/wiki/Reynolds_531

 

Since this frame is so critical, I would source new. There is too much riding on their dependability.