450 Desmo heads

[Gboblebeef]

So I have been told that the 450 Desmo heads from the RT and the D road bike are different castings. Especially in the intake and exhaust ports. Can anyone shed some factual light on this?

[DewCatTea-Bob]

" So I have been told that the 450 Desmo heads from the RT and the D road bike are different castings. "

____ I've had both types, and while the two different 450D-heads are clearly MACHINED differently, I don't recall any clues indicating that they're different "castings" as well.


" Especially in the intake and exhaust ports. "

____ I think that those two cyl.heads' intake-port/manifold-mouth mounting may look slightly different, but I don't recall ever noticing anything significantly different about their ex.ports, which could indicate differing castings.


" Can anyone shed some factual light on this? "

____ If there is indeed any such claimed differences, then I'd bet that fellow-member Eldert can confirm so.


Hopeful-Cheers,
-Bob

[PhilA]

The R/T has the decompressor, the road bikes don't. I suspect the R/T head is a modified normal Desmo item rather than a different casting.

[wcorey]

I had been told that the R/T had a 38mm intake valve and the road model a 40mm, can't confirm that from my own experience though.

[Gboblebeef]

Yes the RT has a decompression device, not a lever like on the springer, but that is down to machining. I suspect the 38mm vs 40mm valve is machining too, but thus the original question.

[DewCatTea-Bob]

By: wcorey...
" I had been told that the R/T had a 38mm intake valve and the road model a 40mm, "

____ All std.production DESMOs have the same 40 (& 36mm) intake (& exhaust) valve sizes.
I've never seen a 38mm DESMO-valve !


Dukaddy-DUKEs,
-Bob

[Eldert]

the Mark III 450 Desmo head and the 450 RT Desmo head look the same to me .
they have the same 40 / 36 mm valves to

the compession release is the only thing that sets them apart

Eldert