Fitting a divers helmet dizzy to an 8BA.....

G

gavinnz

Senior Member
I have been having fun and games fitting a 1932/36 divers helmet to my 1952ish 8BA.....

So I got the three bolt front cover.... And I got a rebuildable early divers helmet dizzy. Turns out none of the 8BA crank pulleys will clear the bottom of the dizzy... So I am looking for an earlier pulley now. Then I will get water pumps to match the pulley spacing...

Then I got a cam that was a short nose with the slot for driving the dizzy. Then the fun began.....

The early cam had a valve lift of 7.13mm and the 8BA cam has a lift of 8mm..... ( both of my 8BA cams are the same and have EAB on them).
The late cam is in very good condition and with the higher lift and the cam angle being right I decided to try and use it.

So stared at the cams for a while and came up with a plan.....
 
That's the back of the dizzy with the drive....
 

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I cut the cam drive gear off the BA cam and set it up in the lathe and machined the end smaller and round.
 

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Then I put the cut off end in the lathe and machined it to size and cut a hole in the back to match the knob left on the other cam....
 

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Here are the two parts ready for final fitting which took a bit fine tuning to get a perfect fit....
 

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Bit fitted. Note the four punch marks I did before cutting so I got it the right way around!
 

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Next the bits were very well cleaned with brake clean and tinned with silver solder.... The solder was applied inside the cap, and the top, then it was sat on top and heated with a torch until the solder melted and it dropped into place....

Then I left it to cool slowly with a hot light pointing right at it to keep the temp up for a while.
 

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After it had completely cooled I cleaned up the solder and it now looks like this....
 

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And here is the new cam beside my other 8BA cam so you can see the start and finish.....
 

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Not a bad days work. Just goes to show what can be done with a bit of outside the box thinking and a home machine shop!.
 
Before someone asks.... I am fitting the old dizzy because I like the look of them and they suit the age of the boat I am putting the engine in......
 
Well, I for one am impressed with your ingenuity and skills even though I 'll probably never benefit from your experience. I too, have done some things that, at first blush, didn't make sense because I wanted to and I could.
 
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