Fuel Pump Arm Mod

[jlmccuan]

I'm in the process of modifying a Carter small block Mopar fuel pump to use on my R2. When I bent the pump arm cracks appeared on the surface. The arms appear to be chromed and the chrome just couldn't move with the base metal. Under magnification, one can see the base material which has no cracks. So now the questions. Are these arms in fact plated? Can the arm from the Stude pump be moved to the Carter? I did take plenty of pics of the process of sealing the vent and porting the boost reference for anyone wanting a look.

Jim

_________1966 Avanti II RQA 0088______________Rabid Snail Racing

[StudeRich]

Jim; the arm has to be heated and it would also help a lot to be notched (V'd) on the inside of the bend (sides of the "U" channel). Doesn't it look more like Cad plate? I can't imagine it being chromed! You could have stress cracked the base metal if you did it cold it's probably toast! Hmmm cold toast!

Probably not funny though at $65.00 to $80.00 a copy!

StudeRich
Studebakers Northwest
Ferndale, WA

[jlmccuan]

It's not bad if you never add all the mistakes up. lol It is a silver color. All the cad plating I've messed with was yellow. I thought maybe it was hard plated for the wear. The cracks are open on the stretched side of the arm, but it looks like an M&M shell. I'll try to chip off some of the material and see if it's magnetic. At least I didn't think chrome was magnetic - but it's so late now I don't remember for sure.

Jim

_________1966 Avanti II RQA 0088______________Rabid Snail Racing

[sweetolbob]

Jim, If they are indeed cracks in the coating, I would not trust the arm under stress. Theory would say the if the cracks are evident in the outer shell and,Importantly, the coating is well adhered to the substrate then shear cracking is highly likely. In a previous life, This is exactly the technology we used in plastics to promote shear fracture in structures and, I know, from another previous life that this is also true in metals. If you remember years ago, Companies were trying to chrome plate solid axles and experiencing failure do to Hydrogen Enbrittlement enducing shear fracture.. It is possible to do it now do to improved technology but, it illustrates the potential issue with cracked chrome in high stress areas.

Your Avanti is way to nice and the parts to valuable to bet on this horse. If it were mine, I'd try to find a pump with no "chrome" plate on the arm. JMHO. Bob

[64Avanti]

Hydrogen enbrittlement is only a problem with higher strength steels.

David L

[Kdancy]

The arms do look like chrome but I don't see any reason for them to chrome the arm being as it's unseen once installed. I have done two of these by cutting a notch with a cut off wheel, bending to shape and welding the notch up. So far so good, both seem to perform well.

[jlmccuan]

We hard chrome parts all the time. Sometimes it's a sanitation thing, sometimes it's parts rubbing together that don't warrant a bearing. Shotgun bores are another example.

Jim

_________1966 Avanti II RQA 0088______________Rabid Snail Racing