interchane the cam caps

[Addy Leung]

I have a spare stock low mile head of GS1100.
Could I use those cam caps on my ported head of a also gs1100?
any idea?

[crag antler]

I have a spare stock low mile head of GS1100.
Could I use those cam caps on my ported head of a also gs1100?
any idea?

What years are the 1100's??

[chiphead]

Those heads are line bored so my answer is no, you cannot IMHO.

[Addy Leung]

They are both 1981 gs1100 - 16V.

My old man also told it is not a good idea to interchange the cam caps.

[Steve]

"Not to interchange the cam caps" also includes within the same engine.

Do not move cap #1 to position #3 or any other, leave it at #1.


.

[rphillips]

It's not a good idea, keep everything as it came apart, "IF POSSIBLE". If not possible, I wouldn't throw it away, I'd try caps from another head, Keeping them in their original locations as they were on their orig. head.

[Hap Call]

Notice that the cam caps are lettered to correspond with a letter cast into the head. That is done so that the caps will not get interchanged. You cannot interchange caps between heads. It would be a very bad idea to do so.

Hap

[rosco15]

I would agree it would be a very bad idea. Don't do it.

I had a KZ head that was ported with ss valves a number of years ago. I had snapped a cam cap on it and didn't want to scrap the head becuase of it. I went ahead and put caps from another head in and it seemed to work just fine. it was kind of a last resort thing.

[tomcat24551]

I would agree it would be a very bad idea. Don't do it.

I had a KZ head that was ported with ss valves a number of years ago. I had snapped a cam cap on it and didn't want to scrap the head becuase of it. I went ahead and put caps from another head in and it seemed to work just fine. it was kind of a last resort thing.

But if it worked just fine, why is it a very bad idea?

If the caps come from an identical head, why isn't it ok to put "A" to "A", etc. so long as the cam-to-bearing clearances are within spec? I know it ceases to be a mated unit when you change to different caps, but nobody seems worry when you put a different cam under the original caps. How come?

Not trying to be difficult here, just trying to learn.

Tomcat

[rphillips]

OK., we all agree it is not a good idea. But now, if the original caps, for a head are damaged or missing, What then???. If the orig caps weren't damaged or missing, You wouldn't be changing them anyway. Would you be better off to throw the head away now, & spend $$$$$ for another, or try it with other caps & take a chance it will work. If it does work, you came out smelling like a rose. If it doesn't work, then the head will be trashed so then throw it away & spend $$$$$$ for another. I agree, never change them just for the fun of mixing them up, but if you have no choice.....

[chef1366]

I think it has something to do with wear patterns.

[49er]

OK., we all agree it is not a good idea. But now, if the original caps, for a head are damaged or missing, What then???. If the orig caps weren't damaged or missing, You wouldn't be changing them anyway. Would you be better off to throw the head away now, & spend $$$$$ for another, or try it with other caps & take a chance it will work. If it does work, you came out smelling like a rose. If it doesn't work, then the head will be trashed so then throw it away & spend $$$$$$ for another. I agree, never change them just for the fun of mixing them up, but if you have no choice.....

It's not a good idea. However, if you are trying to resurrect a highly modified head, do as tomcat mentioned, match the ID numbers between the heads. Depending on how high the mileage is on the replacement head, some of the caps could be "in spec".
With the valves removed, lightly oil and fit up the caps to your cams. Now lightly tighten the bolts. Try to rotate each cam by hand. If they are tight remove all caps and apply bearing blue to the cap surfaces and retighten, one cap at a time. You will now be able to see the areas that are touching. You can then scrape the bearing surfaces intil the desired clearances are achieved.
It is likely that in some cases, natural wear will cause excessive clearance when trying to match the caps. You need to check the clearances with plasti-gauge before deciding on whether to proceed.
The only possible interchange of caps is A & C or B & D. With other combinations, the thrust rings on the camshaft will bind through inadequate clearanace due to a slight offset of the bolt positions on the caps. The hole centres of the locating dowels may also vary from head to head and cap assys.