When did belled holes spread from aircraft to race car construction?

Look again. To me, it looks like the edges of the holes in the frame rails as well as the holes in the pedals have been rolled. Keep in mind, the amount of flare will vary, depending on the diameter of the tool used relative to the size of the hole, and also, the modern application of this technique is generally alot more about looks than function, and it is therefore exaggerated, to say "Hey, look it me! I'm a hot-**** tin bender! I belled these holes!"

 

Thanks! And thats more in line with what I would have expected. Whats the consesus, do those holes look belled, or is it just me?

 

Yeah, the Europeans were pretty far ahead, in race car construction, back then. Here's a shot of a Kieft formula 500 car from around 1951 and though it's hard to say for sure, it appears that the front bulkhead and lower a-frame were built that way.

 

Also Marston Mats, I believe.

 

Yea, THATS what I was thinking of!

 

For sure, its clearly visible on the rear trailing arms. Whats your take on the two Kurtis photos, the one I posted and the one Relic Stew posted?

 

Thanks for keeping me honest. Maybe I'm seeing what I want to see.

 

FWIW-the MG EX179 Bonneville streamliner from 1954.

 

I'm going to dig some more. Hard to believe that after seeing this on aircraft and race cars from overseas that American race car builders could't/didnt pick this up till 15 years later.

 

oh, about 2008-2009....

 

I believe your refering to marsden mat. My car trailer has it as a floor. My grandfather was a Sea Bee in Korea and said they laid miles of it down on soft ground for runways and parking lots for equiptment.

 

I believe Colin Chapman was an aeronautical engineer. The photo of the Hemi powered Indy roadster ****pit, why is the fuel valve safety wired open?
I know you don't want to bump it with your elbow.What was it used for then?


Ago

 

Whos got a pic of the inside structure of a 27 T coupe trunk lid? I did but be damned if I can find it.

 

I have a 26 door with factory speed holes, but they aren't flared. I also have a 23(?) firewall that has a couple holes with rolled edges. I'd guess that was to protect a cable or wiring, not a structural thing.

 

Inner structure on my 30 Es*** deck lid.



Roy Chapin (Hudson) had his finger on the aviation pulse. In 1932 he would hire
Amelia Earhart and the Es*** would become the Terraplane...

 

Trivia.......they're known as flanged lightening holes in aircraft (note the spelling)

 

Also known as "Dimpled" holes made with Dimple Dies

Ive done a few for my OT truck



I made the dies as well

 

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That's what I was thinking-

From what I've seen, or remember seeing:

*Lightening holes in drag cars and hot rods, yes.

*Belled lightening holes... pretty fancy, more manufacturer-ish.

(and "lightning" is another phenomenon altogether... hasta do with clouds and such.)

 

If the question was "when did they spread to hot rods" I'd probably
agree with that.

 

I am surprised to not find them in post-war American race car construction. Anyone with a lathe and a reasonable level of machining capability could turn out a pair of dies in a couple hours. Add to that that post-war, any hot rodder that had spent time servicing aircraft would have seen them, and lots of guys would have even seen and used the dies. Considering the obsessive use of lightening holes post-war, you would think that at least guys like Kurtis and Kuzma would have been all over this. The potential weight savings throughout an entire car, as compared to thicker material with simple holes drilled in it was considerable, and small european race car builders were all over this at the same time.

 

A new twist on flanged or belled lightening holes. I guess I'll call these "balled" lightening holes, since the flanges are from ball jars. I've actually considered doing this..all they'd need would be a dab of some adhesive to hold them in place. Opinions?

 

#19,...that was also made from aluminum...aka P.A.P. "Pierced Aluminum Planking". Definitely preferred, by the folks who had to manhandle it ! We were still using both in V.N., circa 1967.

4TTRUK

 

Colin Chapman employed many ex- DeHavilland engineers,so this was old hat to them. Chapman also went too far in lightning racecars and killed several drivers in the process .

 

So is there an actual correct name for this type hole? ... I go by flared hole but have heard "cupped", "belled", etc ... just wondering what the correct name is.

 

I could be wrong, but I seem to remember some of the big holes in my 37 Ford sedan's K member were belled, some were even ovals, as part of the stamping process. Gary

 

Element of truth in that last statement...

 

I was using the term "belled" as the tools used are commonly called "belling dies". Not sure if that is actually the correct terminology for the holes themselves...

 

it looks to me like those were just deburred with a countersink tool, not dimpled.