Technical Big Break ???

Running down the tarmac heard a thump pulled over? Gen-set hanging by wires. No belt no water flow towed home. Any ideas!

 

Did you happen to initially install it without spacers to keep it above the fins? Am wondering if it was somehow cracked during initial installation?

Also, how tight was the belt? Maybe you over-tightened the belt and it created a lot of stress/load on the bracket (that would be my best guess). You don't need a lot of tension on these wide belts - many folks tighten them way too much.

You were fortunate that this didn't cause a big/major issue when it happened . . . the Hotrod Gods were on your side that day!

 

Cast aluminum failure.

 

Maybe just too much stress for a cast aluminum bracket, especially after belt tension is factored in. Steel might be a better, but less sexy, option?

 

It was a (speedway) part. It has stand off’s in casting to clear finned head. Belt was tight. Has a long leg to left water pump. Just blew my mind.

 

Pretty simple...metal fatigue, equaling a broken part.
Probably starting with a porous (full of air!) casting.
Could have been exacerbated by a VERY tight belt, and or possibly an out of balance armature .

Mike

 

And now you get to untorque three head bolts to replace that bracket. It is why I used studs, torqued down nuts (rocker stands) and then the bracket and the polished acorns. Just an idea for all of you contemplating the gen mount on the head.

I used the Navarro bracket from H&H and I have not had an issue with it. Call Mike and have him send one out.

 

I'd say, aluminum, heavy generator, engine vibration, road pot holes, stress constantly changing due to engine rpm's and fan belt, equals failure...

And no other support to the rear of the generator.

....

 

Weak cast aluminum bracket. Use steel or fabricated aluminum and it'll be good to go.

 

Speedway sold the bracket, they had nothing to do with the design or manufacturing. It is an Offenhauser product.

 

That I understand.

 

Show photos of the crack faces. That will show if it was a bad casting to one the had been progressing for some time.

 

Can you “glue” it together and fabricate out of steel?

 

If you know someone that can TIG weld aluminum, I would repair it and fab 1/4" aluminum gussets to strengthen it, where it broke sure looks like a weak point. Of course if you contact Offenhauser they will tell you that it's never happened before. Consider yourself lucky that the generator didn't take out your radiator or do any other damage.

 

Looks like a problem with the mold or design - the 1094 passenger side bracket has a clear path with no gusset. The drivers side 1093 shows a gusset that would prevent the break.

 

This is the break area.

 

Just wondering the brand of the 1093? Looks like way better design !

 

They are both listed as Offy one is to mount the generator on the drivers side 1093 and the 1094 mounts it on the right.

 

The design could've have a raised rib edge and longer gussets. Maybe gussets off the bolts.

 

Looks like an alternator in your picture; did that require higher belt tension than the "loose" tension normally used on flatheads. Maybe add a rib to bottom of the new one.

 

Bad design. Maximum force in exactly the worst direction on the weakest part of the bracket.

 

I have the same bracket, granted, I've only got about 500 miles on my setup. Curious on how many miles and time is on that bracket? Years, Months, Days? Did you hit anything large to jolt the car in a big way at that time? It would take bit to make that happen all at one time, so I'm thinking stress cracked before the final break, or a slow progressing crack.

 

Made from 100% pure CHINESIUM.

 

The design is one issue.
And the alloy used, is a question mark.
Was it made in USA ?
Is it a real Offenhauser piece, or a cheapo imported knock off ?
Not all Aluminum is the same.

 

I just finished the car. Been short 20 mile trips and home. About 300 miles on it I’d have to guess max.

 

I kept it snug little play on long leg of belt.

 

Offenhauser, cast and machined in California.

 

Amazing the beef put into the driver side arm. Passenger side is a weak design I see.

 

A new product shouldn't fail like that if installation and operation was correct. Sounds to me like a fault with the bracket. Have you contacted Speedway and/or Offenhauser about the problem? That should maybe have been the first thing done, possibly before throwing it out here on the HAMB. You never know, a company that takes great pride in what they do might just look after the situation in a positive way for you. They should at least have that opportunity.