The International CBX Owners Association

Hi!

Yesterday I started the teardown of my 1982 engine, mostly because I want to send the cam chain tensioners out for repair. Also because my engine comes with some questionable history :

- Not original cylinder head ,possibly a -80 model head
- 3 spark plugs are cross treaded
- loose bolts and missing gaskets

Compression test was OK , also leakdown somewhat ok (some leaking pass piston rings).

And boy did my night of fun wrenching turn into nightmares fast. After removing 15 camshaft caps that looked OK it was time for number 16 (marked 8, right front corner), it looked like this :
I drank some more beer, and decided to continue with the cylinders and found Cylinder 1 to be pitted about halfway up. I then drank more beer.

I know this is bad, but I need someone to give me the bad news gently.

Kind Regards, Robin

I would love to give you good news but I don’t think there is any. You need a different head. You better check your bottom end as well. That grit went somewhere. Find another motor might be the best bet.

For sure this motor is coming apart completely, I will call Bert from SixCenterMotoren tomorrow and check if he has any heads. Not so keen on an completely new engine, but I am willing to sink money into a new head and cylinders. Do you think the grit would have done much damage in the bottom end?

Thanks for your fast reply and news delivery

Inside the camshaft ends are rubber coated rings to prevent oil flow out of this holes.
If they are pushed too much inwards they block the lubrication hole of the camshaft bearing.

aahrens1 wrote: ↑

Sun Sep 08, 2024 5:40 pm

Inside the camshaft ends are rubber coated rings to prevent oil flow out of this holes.
If they are pushed too much inwards they block the lubrication hole of the camshaft bearing.

Thanks for the info, I will have a look tonight!

You were completely right aahrens1, the only rubber piece that was pushed too far in was the one on my damaged corner. The knowledge on this site always amazes me!

Have not heard from Bert yet, but I see a new head and oversized pistons in my future...

Update :
Unfortunately Bert did not have a good used head in stock at the moment, always nice to talk to him on the phone.

Louis Mintrone hooked me up with a cylinder head and right exhaust cam ( + right and left leg guards for my pro-link ), for a very good price.

The right exhaust cam showed some signs of wear, of course where the bad cam cap was. Does anybody know if all years of camshafts are the same? Just want to be 101% sure.

Read some where that the 80 vs 79/81/82 exhaust lift is different.

Since your engine seems to be a mix-and-match assemblage, you need to measure your good cam lobes to see what cams you do have before Louis sends it out. There is a chart here that gives lobe dimensions and what years they are. The FSM also has lobe dimensions. Both '79 cams have the highest lift, both '80 cams were different, then the Pro-Link intake cams are different yet. Exhaust cam is the same as the '79. Is Louis supplying you a Pro-Link head? If not, the early ones will work, but you must drill out the center four stud holes for the 10mm Pro-Link studs.



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Dave

Thanks Dave

To be honest our deal went so fast, I didn't really ask precisely what head he had. He just said that it will fit and work fine with some refurbishing . The earlier heads had smaller studs in the center right? So its just a matter of enlarging existing holes?

For the cams I understood that all exhausts are the same, but that could be my mistake. So the cam I bought is not checked, same with the ones I have. But I figure my chances are good then 3 to 1 , I will check as soon as i get it!

Well, not exactly. The '80 cams are both completely different spec than the other years. But not likely you have '80 cams. but who knows? With any project, and particularly this one, you have to check EVERYTHING.

Dave