Rubber anti vibration blocks

Hi. Here's two pics of the rubbers in my cooling fins. Any advice on how many and what pattern there should be?

 

You're missing a couple, in the bottom pic you can see where the one just below and to the left of the plug used to be.

I'll take a close look at my 550s and see where they all are; I'm pretty sure I'm no longer missing any, and the placement should be very similar as they're YICS motors also.

They're NOT "critical" they just keep the fins from "singing."

 

I made the mistke of cleaning the head on my XJ11 in solvent durring a rebuild last year. Since then most all of them are missing, I have a definate "buzz" from the engine around 4000 rpm now. Chacal has replacements for all other XJs but not for the 1100. Some engines don't have that problem but some do.

 

Are 1100 fins that special? Considered exposing 2 together, shaving down a little thick and cramming them in just in case epoxy fails?

 

OK, I looked at both of my 550s (YICS motors, the non-YICS 650 barely has any) and although different from what your pics show, it doesn't look like you're missing too many. I make one, maybe two on the left side missing and only the obvious one on the right.

On the 550s, they have them between both fins above and to each side of the plugs, then pretty much every other set on the fins that actually stick out, as yours are.

There are also a couple on each side in the tall fins inside the spark plug gallery behind the inner plugs.

 

I don't think they are special Bob. I know the spacing between the fins is different than the other XJs, the others don't fit quite right. I have not found any material suiatable to make some, though I have not tried real hard. The vibraton is not a terrible problem.

 

Thanks Bigfitz and the others for posting. I may order a few from Chacal when I get my valve cover gasket and donuts. However, now I'm curious about the difference between the left side / right side rubbers (CYLINDER FIN RUBBER INSULATORS as they are called on his parts catalog near the bottom of page 2) because they have different part numbers whether sold by the piece or by the set. Maybe tomorrow afternoon I'll measure some and see if there are different sizes. I'll post the info after I do it.

 

I just picked some up from the dealer here for my 400. Mine had different part numbers for each side. There is a distinct difference in the size and shape (angle of wedge) for where they go for the 400 at least.