Inlet manifold 1941 knucklehead

[nukkel]

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

[Jerry Wieland]

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

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

[T. Cotten]

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

[nukkel]

thanks both Jerry and Cotten!

Quite a different story..!


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

Rein

[T. Cotten]

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.

[nukkel]

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

[T. Cotten]

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?

[Chris Haynes]

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.

[T. Cotten]

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

[Jerry Wieland]

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

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?

[T. Cotten]

This doesn't prove anything, Folks,...

But here's a brass WR manifold.

....Cotten
PS: I appreciate the pic of the 503-39 for my collection, Chris!
But its an unfriendly format that can only be saved with a screenshot.
External photohosting sux.