Decorative Spark Plug Cooling Jacket

[BigLakeBob]

I know you can buy these from Tedd's relatively cheap, but I was fortunate enough to have a friend loan me an original, so I decided to make two for a '48 45" bobber I'm working on. Just thought I would share a simple lathe project you could also do yourself.

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If you're still out the Len, thanks again for the plugs!

[Rubone]

Nice Bob! What does the rest of the 45 look like?

[BigLakeBob]

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Here is a rough mock up.

[exeric]

I've seen Bob's 45 and it's going to be a first class job when he can find the time to finish it; which I hope is this Winter About those spark plug coolers; did they actually work, or do they just look cool ?

[T. Cotten]

.... About those spark plug coolers; did they actually work, or do they just look cool ?

If they worked, Eric,...

Plugs would foul, and nobody would run them.

Maybe they do.

....Cotten

[kitabel]

Plugs transfer heat to the cylinder head when riding through conduction at the thread. When stopped, a tiny fraction of this loss occurs thought radiation and convection (air current).
In theory adding surface area will increase both of these last 2, but I would guess too small to detect.
I suspect that the fins are too close together. The loss of area (fewer fins) is more than compensated by much higher air flow though the fins. Julius Mackerle wrote about this 60 years ago.
Many decades ago some engine's cylinders, heads and top end bits were made with the fins horizontal (rather than parallel to the deck surface), very pretty but did they work? IDK.

[kitabel]

wl-camcover-02.jpgThe very pretty cam cover is not original but a work of love. Begin with a common 1937-* finned cover, and grind all (or some) fins down to follow the casting curvature. Made a few back in the 1980s (all sold long ago).

[exeric]

Thanks for the information, Tom, and Kitabel. The plug coolers do look good and really fitting on a bike with custom features. Bob also de-finned his gear cover and did a very nice job. He started with a busted cove so he has nothing to go to confessional about I had an Alcoa cover welded by a talented welder, but despite his skill, you can still see the different alloy color of aluminum filler rod. Again, thanks for the information.

[Rubone]

I like the early fork but not sure about the spring covers. A nice update would be a BSA front hub with 8" brake and the cooling holes in the drum. Some of the AHRMA guys run them. I am thinking of one on my 42WLD bob job.

[BigLakeBob]

I like the early fork but not sure about the spring covers. A nice update would be a BSA front hub with 8" brake and the cooling holes in the drum. Some of the AHRMA guys run them. I am thinking of one on my 42WLD bob job.

Not spring covers, just aluminum tubing used to simulate the spring length for mock up. I have the ride control all rebuilt to be added also. The front leg was already chromed when I got it and the holes were 1/2", so instead of making a bushing I made new studs with a 1/2" diameter instead of 7/16 and a little longer to suit my needs. Here is a picture before heat treat. DSC06642.JPGDSC06643.JPG