Page 1 of 2 12 LastLast
Results 1 to 10 of 11

Thread: Inlet manifold 1941 knucklehead

  1. #1
    Join Date
    Jul 2017
    Location
    Netherlands
    Posts
    32

    Default Inlet manifold 1941 knucklehead

    Would it be safe to say that all (late?)1941 knuckleheads had a brass inlet manifold?
    According " Palmers" the change into cast iron ones was introduced in '42..:
    "The brass inlet pipe was soon replaced by a cast iron one for 1942-1947 models, but until the new pipe was available,all future 1941 models were assembled with the brass pipe and bushing well oiled"

    The manifold on my late ( Vin 41EL61xx ) is cast iron but should it be brass?

    thx Rein

  2. #2
    Join Date
    Jan 2006
    Location
    Menomonie, WI
    Posts
    1,243

    Default

    I do not think any of the 41's came with a brass intake. The only original bikes I have seen with a brass intake are 1947's.

    Jerry

    Quote Originally Posted by nukkel View Post
    Would it be safe to say that all (late?)1941 knuckleheads had a brass inlet manifold?
    According " Palmers" the change into cast iron ones was introduced in '42..:
    "The brass inlet pipe was soon replaced by a cast iron one for 1942-1947 models, but until the new pipe was available,all future 1941 models were assembled with the brass pipe and bushing well oiled"

    The manifold on my late ( Vin 41EL61xx ) is cast iron but should it be brass?

    thx Rein

  3. #3
    Join Date
    Jun 2001
    Location
    Central Illinois, USA
    Posts
    4,073

    Default

    I agree with Jerry!

    Invariably the OHV brass manifolds that crossed my benches were '47s, and I have encountered U and Servi manifolds that were from late '46 and '47 machines.

    And thanks to a forum member, here's a WL cast -43.

    They are cheesy post-War ordinance scrap. Wasting a strategic material at the beginning of a war would have been treasonous.

    ....Cotten
    Attached Images Attached Images
    AMCA #776
    Dumpster Diver's Motto: Seek,... and Ye Shall Find!

  4. #4
    Join Date
    Jul 2017
    Location
    Netherlands
    Posts
    32

    Default

    thanks both Jerry and Cotten!

    Quite a different story..!


    So no point in buying a brass one for a 41 knuckle !

    Rein

  5. #5
    Join Date
    Jun 2001
    Location
    Central Illinois, USA
    Posts
    4,073

    Default

    Once its "cad", Rein,..

    Nobody can tell the difference anyway!

    The last brass that came through didn't have porosities, but there were obvious inclusions when the spigots were cut.

    Here's some more leakers...

    ....Cotten
    PS: Late edit: Found my photograph of the inclusions still on the camera. It hadn't been developed yet.
    Attached Images Attached Images
    Last edited by T. Cotten; 02-19-2019 at 02:24 PM.
    AMCA #776
    Dumpster Diver's Motto: Seek,... and Ye Shall Find!

  6. #6
    Join Date
    Jul 2017
    Location
    Netherlands
    Posts
    32

    Default

    There seems to be a lot of contradicting info regarding these brass manifolds being either 41 or 47..( also on other fora).

    I checked my own manifold that turns out to be an extended steel one, which can be seen in the picture.Never had problems with it though but the more I look at it I want to replace it!

    I was able to buy a 74 brass one and am going to use that one instead on my 41.

    As Cotten already stated, as soon as it is cad plated (steel or brass) no difference can be seen..
    A giveaway could be being not magnetic or the spot where the choke rod rubs along.
    Also at its bottom near the flange it has kind of an X mark where the steel ones have a drop form mark.

    The brass ones are much rarer and the moment they turn out being "definitely 41"(?) I already have one..

    91C2CB5D-103C-49D3-8492-9F354FFD7CB8.jpg
    present extended manifold
    80F8CE14-F45F-4FEE-9DF4-352E68F0083F.jpg
    brass 74 manifold with x mark
    CB895D45-BAFD-4F49-B6FB-2500F5636C4D.jpg
    Steel manifold with "drop" mark

    On closer inspection the rear manifold nut is the wrong type for 41 so that will be taken care off as well.

    Rein
    Last edited by nukkel; 02-27-2019 at 04:37 AM.

  7. #7
    Join Date
    Jun 2001
    Location
    Central Illinois, USA
    Posts
    4,073

    Default

    Rein!

    Notice how your brass manifold has squished spigots.
    That's not unusual for steel manifolds as well.

    You will want to swage the spigots back out before re-cuttng and fitting with seals.

    ....Cotten
    PS: If they were really made in '41, why aren't they bronze?
    Attached Images Attached Images
    Last edited by T. Cotten; 02-27-2019 at 12:10 PM.
    AMCA #776
    Dumpster Diver's Motto: Seek,... and Ye Shall Find!

  8. #8
    Join Date
    Jul 2002
    Location
    North Hills, CA and Pine Grove, CA
    Posts
    5,417

    Default

    Long time H-D Dealer Andy Verrone told me that the brass were indeed 1941. However most got changed out because the packing galled on them and they leaked. Wartime restrictions on brass were not in effect yet in 1941.

    Here is a 503-39 WL intake made of brass.
    Be sure to visit;
    http://www.vintageamericanmotorcycles.com/main.php
    Be sure to register at the site so you can see large images.
    Also be sure to visit http://www.caimag.com/forum/

  9. #9
    Join Date
    Jun 2001
    Location
    Central Illinois, USA
    Posts
    4,073

    Default

    Quote Originally Posted by Chris Haynes View Post
    Long time H-D Dealer Andy Verrone told me that the brass were indeed 1941. However most got changed out because the packing galled on them and they leaked. Wartime restrictions on brass were not in effect yet in 1941.

    Here is a 503-39 WL intake made of brass.
    So why did they go back to brass after the war, Chris?

    ....Cotten
    AMCA #776
    Dumpster Diver's Motto: Seek,... and Ye Shall Find!

  10. #10
    Join Date
    Jan 2006
    Location
    Menomonie, WI
    Posts
    1,243

    Default

    Chris

    In 40 years of looking I have never seen any even remotely original 41 with a brass intake. I can point you to 10 original paint 47 with brass intakes. Even your buddy Todd when pressed to go put a magnet to an original paint 47 had to admit that it did not pull it.

    Jerry


    Quote Originally Posted by T. Cotten View Post
    Rein!

    Notice how your brass manifold has squished spigots.
    That's not unusual for steel manifolds as well.

    You will want to swage the spigots back out before re-cuttng and fitting with seals.

    ....Cotten
    PS: If they were really made in '41, why aren't they bronze?

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •