Head ID

[Aches n Pains]

Picked up a spare head as part of a deal for a 1979 Special. Trying to figure out the vintage of this head.

I have posted several pictures in the following album:

https://picasaweb.google.com/1084313...726/XS1100Head

In the first picture (lower left) there is a stamp that says "1M 83." Would that identify it as the head from a 1983 engine? Any way to be sure it is an XS head vs. an XJ head or something?

Thanks for your help,

Doug

[crazy steve]

That is a XJ head; it can be identified by the YICS passages. In the third pic from the left, top row, there's four drilled bosses on the intake port side even with but separate from the head surface, along with two tapped holes. These are the YICS passages, the 'plenum' that's supposed to connect them is part of the cylinder casting.

Other than that, these are functionally the same as the '80-81 heads (valve sizes, cams, etc) and could be used in place of those by plugging the YICS holes. Those two tapped holes you would just ignore.

[Yahman]

That appears to be an XJ1100 cylinder head, you can see the YICS port passages in the first and third photos. The valve cover is from an XS. I don't know if it's an 83. To use it on an XS engine, you would need to plug those passages by tapping them and installing some plug screws.

Larry

[Aches n Pains]

Thanks very much, guys.

Any idea what XJ's these heads will fit?

Thanks again

[Yahman]

Thanks very much, guys.

Any idea what XJ's these heads will fit?

Thanks again

Only the 82 XJ1100 in the US, 82 to 84 in Canada.

Larry