Aluminum brake drum fins

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Brett Johnson
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Aluminum brake drum fins

#1 Post by Brett Johnson »

As usual, I'm looking for beginnings and ends. Can anybody give me something definite before June 1951 or after January 1952? These just don't show up in period photos, but also don't get changed unless the car is updated. We should be able to figure this one out, yes? This is my current text:

In MARCH??? 1951 in an effort to improve braking ability Porsche made finned aluminum sleeves, which were the same front & rear, and pressed them onto the VW drums. These likely had negligible cooling effect, but continued to be used until WHEN 1/30/52 at least??? Some cars had these on all four brakes, some just in front.

Thanks in advance!
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Martin Benade
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Re: Aluminum brake drum fins

#2 Post by Martin Benade »

Years ago I got some parts off a bent-window 1500S Cab that I think was a 1953. It had split case trans and the aluminum fins on the drums. I am sure of all those details except year.
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Brett Johnson
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Re: Aluminum brake drum fins

#3 Post by Brett Johnson »

It certainly could have been a bent window car, but not a 1953 model year car, because that one would have had aluminum drums like on 356As (okay, if at the change time maybe not). However, in this exercise I do need chassis numbers to determine things.
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Jeroen van der Velden
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Re: Aluminum brake drum fins

#4 Post by Jeroen van der Velden »

I have vin 11412 24-5-1952 and has 4 steel brake drums with aluminium fins on it
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Brett Johnson
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Re: Aluminum brake drum fins

#5 Post by Brett Johnson »

Most recent information on fin use is through at least July 1952 -- possibly through the end of Model 52s in October/November 1952.
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Re: Aluminum brake drum fins

#6 Post by mats carlsson »

I had 11723, body bumper car, crash box, alu fins on drums.
I think it was Nov -52
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Re: Aluminum brake drum fins

#7 Post by Peter Trill »

not sure if this helps, but I contacted Vic Skirmants to help identify an early complete gear box that I've had for years - and had been stored for many years before that. Vic said:
'Early 1951 would have had a VW crashbox, and the small VW brake drums, probably with aluminum fins pressed on. You have the large Porsche drums, as expected for a later 1952 car. You also have the early axle tubes that take a bolt-on shock mount. The rear hoop is also unique to mounting either a VW crashbox or early 519 into a 356.'
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Mark Todorovich
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Re: Aluminum brake drum fins

#8 Post by Mark Todorovich »

Hey Brett, Our 52 Coupe 11438 has aluminum fins on the front but not on the back. It's had a VW trans( non synchro in first) in it since before my wife bought it 1972 (I think). I always thought that when they switched out the tranny that they just left on the VW drums. it's sitting in my home garage without the rear drums now. Some years ago I bought the aluminum fins from Stepan Gencev EU and have the drums and the fins at a shop to be pressed on. I am not sure how it came.
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James Davies
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Re: Aluminum brake drum fins

#9 Post by James Davies »

Hi Mark,

You car would have originally come with a non-synchro VW transaxle, which is what that 1952 cars were shipped with from Porsche. Porsche even recorded the VW transmission number that went into each car in their production log. That said, you can determine if yours is likely original to the car by looking at the casting date on each half up by the nose cone.

On the 1952 cars, all those were VW parts except for the 19mm wheel cylinders, the pads (I think) and of course the aluminum finned sleeves as discussed in this thread.

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Re: Aluminum brake drum fins

#10 Post by jonathan devereux »

Hi, l have cab 15003 that has Porsche drums front and rear that l am sure are original to the car. My December 50 coupe has finned VW drums that are the originals. Lots of debate to be had with this one . Cheers Jon

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Brett Johnson
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Re: Aluminum brake drum fins

#11 Post by Brett Johnson »

Information I have is that the fins were first used in March 1951 -- though they could have been installed on earlier cars, since they are the same drum. The rings are illustrated in the 1953 parts book as separate items. See page 199 in Authenticity IV (www.tpr-inc.com). They were used from that point until the 1953 model year cars came out in October 1952 when the 11" aluminum drums were introduced. There are cars in this range that don't have them or have them on the front only, but I suspect they were probably on all cars once they were introduced and were replaced with convenient parts over the years. As with all "assembly parts" they were not started or stopped at a specific chassis number, but closer to the same completion date.
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Jules Dielen
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Re: Aluminum brake drum fins

#12 Post by Jules Dielen »

Hey Brett - mine was the opposite way Mark T's was. 11816 had vw drums with aluminum fins in front and the early Porsche 280mm drums in the back - September 52.

side note - worst braking car i have every owned. I took off the fronts and installed 280mm drums. much better now.

original non-crash box.
Jules

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Re: Aluminum brake drum fins

#13 Post by Martin Benade »

James, I think those 1952 cars had not just 19 mm cylinders, but double cylinders and the dual leading shoe arrangement.
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Re: Aluminum brake drum fins

#14 Post by Brett Johnson »

Dual leading shoes October 1951. All Porsches had 19 mm wheel cylinders. Aluminum drums August 1952, before the 1953 model year.
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Re: Aluminum brake drum fins

#15 Post by Vic Skirmants »

Brett Johnson wrote: Wed Aug 12, 2020 8:07 pm Dual leading shoes October 1951. All Porsches had 19 mm wheel cylinders. Aluminum drums August 1952, before the 1953 model year.
356A had 20mm rears.

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