Author |
Message |
Doncasto
| Posted on Sunday, January 07, 2018 - 01:05 pm: |
|
I have found a bit of a conundrum with a set of heads I am selling. The heads were part of a large consignment of extra parts from a friend's shop that arrived without any source or background information. The numbers cast into the heads are 16682-87A, 16684-87A . . .and there are a few search results that indicate they are S2 heads. However, when I look in the Buell S2 Parts book different numbers are listed . . .16450-94Y, 16698-90A I seem to recall some discussion previously about the difference between "casting numbers" and "part numbers" but got no search results. The ongoing question is . . .are these in fact S2 cylinder heads? If some helpful BWBer has a set of heads known to be from an S2 on the bench . . .could ya help a brother out and check to see what the casting numbers are on them? Thanks in advance . . |
Ratbuell
| Posted on Sunday, January 07, 2018 - 09:01 pm: |
|
I've got my original set out in the frozen tundra...er, garage. I can chip them out of the glacier for ya in the morning and check |
Hootowl
| Posted on Sunday, January 07, 2018 - 09:46 pm: |
|
S2 heads are just sportster heads, no? |
651lance
| Posted on Sunday, January 07, 2018 - 09:57 pm: |
|
The casting numbers and the production / part number will not match most of the times. The casting number is the part in its raw state with out and machining. Then each part machined from that casting will have its own part number. If you post pics of the heads we can look into and help you out. We’ll need them of the front mounts of the front head and the combustion chamber. |
Ratbuell
| Posted on Sunday, January 07, 2018 - 11:30 pm: |
|
I believe that yes, S2 heads are simply Sportster heads. I had to change my front mount (in my S2) when I changed to a Thunderstorm top end. IIRC an S2 motor is nothing but a heavy-flywheel Sportster motor, dropped in a trellis Buell frame. |
Buelliedan
| Posted on Monday, January 08, 2018 - 11:18 am: |
|
Yes that is correct. S2 heads ARE JUST stock sportster heads. There is nothing special about them and they are the worst of the EVO XL heads. The later Buells came with what I call lightning heads which are similar to the S2 heads but has extra material added to them to bring the compression up. They still have small valves and poor flowing ports. It wasn't until the thunderstorm heads came out that we really started to see some good flow numbers on XL heads. |
Ratbuell
| Posted on Monday, January 08, 2018 - 11:07 pm: |
|
16682-87A and 16684-87A are the numbers stamped into my original S2 heads. |
Doncasto
| Posted on Tuesday, January 09, 2018 - 12:41 pm: |
|
Thanks, Joe . . .that was the confirmation I needed. |
|