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Bypass hose clamps

Discussion in 'Factory Original Alpines & Tigers' started by hartmandm, Jun 5, 2019.

  1. hartmandm

    hartmandm Moderator Platinum Level Sponsor

    Did the series V come with the double-wire clamps on the bypass hose?


    I am replacing my bypass hose and have the clamps above. They even have the #2 BA screws. If the car originally came with these clamps, I am wondering if it is a bad idea to use them, given how hard it is to change out the clamps if there is an issue.

    So really two topics here - what was originally on the car and thoughts on longevity of the double wire clamps.

  2. Barry

    Barry Platinum Level Sponsor


    Regarding originality, WSM-145 shows "double wire screw clamps" for the by-pass hose and shows both (???) double wire screw clamps (in the cooling section) and simple "band screw clamps" (in the heater section) for the heater hoses.

    All types of screw clamps on hoses suffer from a loss of clamping force as the rubber in the hose goes through "compression set." Not really a problem if the screw clamps are re-tightened after the first few heat cycles and periodically for the life of the hose. I don't like wire screw clamps because of the highly localized compression loading on the hose, but there are examples that have been in use for a very long time.

    They are not period correct, but band style clamps such as "screwbands" (aka, Jubilee clips) and "tower" clamps (aka, Wittek clamps) are much easier on the hose because the compression load is spread over a wider area. Like all screw clamps, they need to be re-tightened after the first few heat cycles and periodically for the life of the hose.

    Modern cars use a lot of "wide band spring clamps" which are quick to install and continue to squeeze the hose against the internal fitting during / after compression set. Again, they are not period correct. IMO, they are the best type of clamp in terms of short / long term sealing and hose life for low / medium pressure applications. Properly sized spring clamps are pretty close to "install and forget".

    For a very clean / modern look (again, not period correct), there are "heat shrink hose clamps" that work very well for medium pressure coolant hoses. Like spring clamps, they continue to squeeze the hose against the internal fitting during / after compression set. The downsides include cost, limited "adjustment" range and not being reusable.

    Let the nit-picking begin.
  3. 65beam

    65beam Platinum Level Sponsor

    Doug Jennings has told me many times that I tighten things too tight. Leaks show that you still have oil or coolant in the system. Regardless of what you use p 110_0590.JPG osition the clamps in a way that you can get to them if they need tightened. This photo shows what I used on the bypass hose of the Harrington engine . Of course they're very hard to see with the over flow tank.
  4. hartmandm

    hartmandm Moderator Platinum Level Sponsor

    Thanks for the reply.

    I've noticed the discrepancy in the series V manuals before regarding the hose clamps and that is why I am asking if anyone recalls (has first hand knowledge of) what is original.

  5. 65beam

    65beam Platinum Level Sponsor

    The books show the wire clamps on the bypass hose and the band clamps on the heater hoses. Our series 5 is set up in that manner using original restored clamps. This signal red 100_0549.JPG 110_0793.JPG 16K mileage series 5 has some of the original clamps still being used. Note the clamp on the heater valve.
  6. hartmandm

    hartmandm Moderator Platinum Level Sponsor

    Do I see different width band clamps on the heater control valve connections? Maybe it is just the photo perspective. The parts manual shows 6 clamps with the same part # for the heater hoses.



    WSM 145 cooling section has a diagram with a wire clamp for a heater hose. They probably were sloppy and didn't update the diagram. It looks like the earlier series diagram, as the bypass hose is straight instead of curved. Also, the alternator bracket has a bend, which is the earlier series generator bracket.


    Last edited: Jun 6, 2019
  7. 65beam

    65beam Platinum Level Sponsor

    I would suggest that those of you that see problems in the manual take the time to go to the TE/AE site and read thru the tech tips, service bulletins, etc. This would give you better insight as to changes made and the reasons behind these changes. You might want to consider buying the book "Sunbeam Survivor". I'm not meaning to upset anyone but think about the cost involved for limited personnel to update and change the drawings in manuals as changes were made. It wasn't as easy 50 years ago as it is today. They probably didn't take into consideration that 50 years later some would question the manual. Due to my age and owning these cars since the 60's I've found that if I went to a dealer back then and wanted a generator bracket( a common break) they sold you the most current updated item being sold. Not what was original. Some mods might have been suggested based on the bulletin. The service bulletins verify this. I drove the series 4 into two trees back in 70 and had to have a new wheel. What came in was the later wheel for the fastbacks which have a different center section. The frustration of finding parts and being able to afford the cost in my younger days led to me buying tremendous quantities of parts as the years went on. Those are the facts.

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