Help identifying very early Harley manifold

[wyomingpanrider]

Just got in a crate of early HX carbs. One is on a manifold faintly marked. Number appears to be 503-10 or 503-16. Still has the original carb on it. What is the application of this manifold ? Anyone help ? Thanks wyomingpanrider

[exeric]

Can you post a picture? That would help.

[wyomingpanrider]

http://www.bigantlers.com/miscphotos.html Here is a link to a couple photos of it. Can post whatever you need. The manifold is 3 3/4" across and is for the small 1" 3 bolt HX carb. 1 3/8" OD on the steel lips. Just can not make out that last number. It is definitely either 503-10 or 503-16

[exeric]

To me, that manifold looks like the early off-set used on 61" motors from mid '16-'21 . In the parts book, the picture that most resembles that manifold states it is for '15-'16 61" motors. From what I've seen, 1915 twins, and early '16 twins used a straight manifold. I think the parts book reflects what Harley Davidson would have sent you if you ordered a manifold for a 1915-'21 twin. I guess that's about as clear as mud. Let's see what Tommo, and Mark Massa say.

[Tommo]

1916 on 61 cu inch manifold
1915 was a T shaped manifold and if it was an electric model had a take-off point for the vaccuum operated light switch.
1914 was the last year of the screw on carb.

[Tommo]

Eric
Looks like we both hit the reply thing at about the same time and yes you're right.
The 1916 parts book shows both styles and nobody I know has come up with a definative answer as to when the change-over occurred.
You could probably get away with either T or Y on a 16 but definately a Y by 1917

[jurassic]

i use to have one of these intakes. and i also have a 16 intake which is made out of brass. if you look close at this intake it is a bit larger than the standard 16 intake. the OD is bigger all the way around. and i believe the ID is bigger as well. my uncle also has a 1916 M racing motor in an as raced chassis that has this intake.

[wyomingpanrider]

Carb "appears" to be an HX95 which would put it on a 1916 Harley twin ( got to clean it up some more ). This would also fit with the other carbs as the latest is a mid 20's Harley police and then a few early Harley threaded carbs and some HX160's etc. Kind of fits in with what info we were given with them. Several have manifolds I have not run into before.

[MMasa]

That's a 1916 intake manifold. It was also used on FAST and/or E motors for certain years. Sorry, but I don't have my notes or parts books here where I'm typing. This manifold as you can see is Y shaped in only the vertical axis. the 1917 and up manifolds are Y shaped in both the vertical and horizontal axis.
However, as most of us know, calling something 1915 ONLY or 1916 ONLY is a bit ridiculous. The factory used up the parts that were on hand in many cases and often used more than one style of part while assembling two bikes side by side. There is a VERY interesting picture in an older coffee table book called "The Big Book of Harley Davidson" It shows the factory assembly line in the mid teens. The guys are assembling what appear to be very late 1916's or very early 1917's. One bike has the manifold in question and the one right next to it has a "1915 ONLY" manifold. Also, all of the bikes in the picture have a mixture of parts that some would say are 1915 only or 1916 only or 1917 and up. Going from memory here, but on one bike there is a 1915 manifold, the frames are 1916 as are the transmission cases and kicker pedals, but the bike has the 1917 and up footboard side bars with the optional front stand brackets riveted on as well as the front stand (1917 part) attached. I wish there was a calender hanging on the wall in the picture. I'd love to know exactly what month and year that pic was taken. You really can't get evidence more solid than a dated assembly line picture to say what is or is not possible or correct.
Mark Masa

[wyomingpanrider]

Guys, thank you. I appreciate all of you taking the time to answer me. Mike