Cam cover difference

[doctorgonzo]

I hope I am not about to get some bad Christmas news. I went out to finish pulling the head off my bike to get ready for the swap and noticed something weird. The Cam cover off my existing head fits on the salvage head I got, EXCEPT that the salvage head (i.e. the one I'm going to put on) has SIX holes per side for attaching the cover to the head, so 12 total. My current head only has 4 per side for a total of 8. That means I was lied to and it's NOT off a 1981 GS1000G. Anybody have any ideas for identification? It's the same size, looks the same. I haven't tried to mount the carbs up to check the spacing on the salvage head yet.

[bwringer]

Got any pics?

The GSR Hive Mind is powerful, not omniscient... yet.


Looks like we need to clarify:

Perusing the microfiches, it looks like the 1980 and 1981 GS1000G uses 16 bolts to attach the valve cover. (6 40mm long and 10 35mm long). The earlier chain-drive GS1000 engine through 1979 are the same.

The 1982-83 GS1100G engine uses 19 bolts total -- 1 45mm, 8 40mm, and 10 35mm.

The 8-valve GS750 (76-79) and the 1979-mid1982 GS850G engine uses 16 bolts, all 40mm long.

The 1982-83 GS850 engine uses 19 bolts, all 40mm long.

Any of these sound familiar?

[doctorgonzo]

Gonna try and post some tomorrow. I know they would help. The mating surfaces of the current cam cover mate against the head everywhere except where the additional bolt holes are. I'm also gonna try and put the carb rack on the salavage head and check the spacing.

[doctorgonzo]

Photo coming tonight, gonna bite the bullet and buy myself a digital camera today since none was among my christmas presents (argh!)

I wandered around and looked at the schematics on on Bike Bandit and found some heads with what looks like the Cam Cover bolt pattern I have on my salvage head. It looks like it might be an 8V 1100. The 82/83 1100GZ for example has the extra bolts for the Cam cover, looks just like it. If that is the case, then we are all good. I will update later.

Another question:
With the Cams removed are there measurements other than the lobe height I should check? Also, is there a trick on the lobe height because the slightest rotation of the caliper will change the measurement enough to throw it in and out of spec. Is there a method to make sure you are measuring at exactly the vetical?

[SqDancerLynn1]

Follow the directions in the service manual as to cam position for adjustment

[doctorgonzo]

And here they are...

My Cam Cover



The new Cam cover



The new head





My head (still on the bike, had to buy a rubber mallet)



I'm going to do some research, I looked at the Cams and they are identical, EXCEPT the currrent Exhaust Cam is marked EX G at one spot and the new one is marked EX B. Was there a B model.....

Ok, I looked again, and it seems pretty certain it's from one of the 8 valve 1100's. Next step I guess is to make sure the carbs will bolt up and go from there.

[anthonygs1000]

heads or tails

does the new head have D exhaust ports ? if so you got the better of the two heads with the new head

[doctorgonzo]

does the new head have D exhaust ports ? if so you got the better of the two heads with the new head

How can I tell.....

I checked and the carbs bolt up, so looks like we're in the clear. I just had so much trouble out of the people I got this head from I got scared for a minute.

[anthonygs1000]

if you look at the exhaust opening, the bottom of the port will have a hump

[doctorgonzo]

Just a bump to say if you've never had to get the head gasket off a cylinder block that hasn't been removed since it left the factory in Japan almost 30 years ago, you don't know what you're missing.

[doctorgonzo]

if you look at the exhaust opening, the bottom of the port will have a hump

Indeed new head does. I see what you mean now by "D" exhaust ports. I haven't looked at my old head's exhaust ports to know if they are "D", but the new ones are for sure.


Edit:
I had to go look, and no, my current head I just pulled off does NOT have the D exhaust ports but my new head does, so bonus.

[anthonygs1000]

can you take a pick of the exhaust opening

[doctorgonzo]

can you take a pick of the exhaust opening

I'll post one tonight.

[doctorgonzo]

I'll post one tonight.

Original Head.. Not much hump.




New Head... with the humpty hump




These are gonna need some cleaning....










Still trying to sort out the new head (what model) for purposes of a Cam Cover gasket (I have two made for my old head... DOH!). Z1 says there is a 20 hole version and a 24 hole version, but neither one looks like it will fit correctly. The 24 looks closer, but a couple holes seem out of place.

[doctorgonzo]

Mystery solved by finding a good scan of the schematics (flatout) and finding the correct bolt pattern.

The head is from....
a 1983 GS1100GD