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Cam housing sealant

Posted: Sun Mar 31, 2024 10:28 pm
by wolf_walker78
Not a lot of discussion about his online and only a vague suggestion in the shop manual, but what with/where are we sealing the cam housing to the head? At a glance I think Loctite 510 should do it, and I don't think there was anything on there when I pulled them off today anyway. I assume it needs sealing around the bolt holes? Or maybe just the center upper one where the feed from the head is?

Re: Cam housing sealant

Posted: Sun Mar 31, 2024 11:53 pm
by gltriker
Scroll down just a little bit to Similar Topic.

Re: Cam housing sealant

Posted: Mon Apr 01, 2024 9:19 am
by robin1731
I've never used anything. Several engines. No issues.

Re: Cam housing sealant

Posted: Mon Apr 01, 2024 11:11 am
by wolf_walker78
gltriker wrote: Sun Mar 31, 2024 11:53 pm Scroll down just a little bit to Similar Topic.
I always forget to scroll down lol.. Thank you

Re: Cam housing sealant

Posted: Mon Apr 01, 2024 11:20 am
by Lucien Harpress
I can get a specific picture later, but I was one of those guys who had to seal mine. I spent a month tearing my hair out chasing a minor oil leak out my points cover, and it turned out to be the cam holders.

You don't need much. There's about 1/4 inch on all four "corners" that isn't covered by the valve cover gasket or cam seals. Usually there's enough schmutz left over when the holders get taken off that they seal up well enough when they get put back together, but sometimes they need a bit of help.
FuelPump.jpg
This is what I'm talking about. This is a close-up of the fuel pump side, but these exist on all four ends of the cam- they end up inside the points cover, and inside the timing belt housings up front. You can see there is a tiny bit of metal-on-metal with no sealer. 90% of the time you don't need any, but if you do, a tiny dab in those eight spots (4 per cam holder, on each corner) is all you need. Hondabond/Yamabond/Threebond is my go-to.

Re: Cam housing sealant

Posted: Mon Apr 01, 2024 2:44 pm
by wolf_walker78
For my next brilliant feat, watch as I become unsure which cam holder is the left side and which is the right side between last night when I stopped working and today.

I don't usually like mixing and matching machined parts like these. Hmm...

Edit, are the cast in arrows pointing forward?

Re: Cam housing sealant

Posted: Tue Apr 02, 2024 6:20 am
by redglbx
You cannot mix the cam holders, it’s a very bad idea. Leaks, binding and excessive bearing wear are the end result as the cam holders are “line” bored & honed with the head,, you cannot mix these up, they must remain paired up

Re: Cam housing sealant

Posted: Tue Apr 02, 2024 9:43 am
by wolf_walker78
redglbx wrote: Tue Apr 02, 2024 6:20 am You cannot mix the cam holders, it’s a very bad idea. Leaks, binding and excessive bearing wear are the end result as the cam holders are “line” bored & honed with the head,, you cannot mix these up, they must remain paired up

That's usually the way with engines. There really isn't any way to tell one from the other with these after looking at them.
I *think* I remembered which was which, they aren't binding. It'd be a good idea to put an ID mark on these if they are both coming off.

Re: Cam housing sealant

Posted: Tue Apr 02, 2024 10:17 am
by robin1731
wolf_walker78 wrote: Tue Apr 02, 2024 9:43 am It'd be a good idea to put an ID mark on these if they are both coming off.
I always do that. Even worse than mixing just the towers is the rocker arms.

Re: Cam housing sealant

Posted: Tue Apr 02, 2024 10:20 am
by wolf_walker78
Only other thing I can think to do is check the valve lash and see if they are grossly off, I set them not too long ago. I'd think if there was much dimensional difference or contact pad wear on the rockers or such it'd show up if I have them flip-flopped.

Don't drink and wrench late at night boys...

Re: Cam housing sealant

Posted: Wed Apr 03, 2024 9:26 am
by wolf_walker78
If anyone else happens to screw this up by flip flopping the cam carriers, the way I found to figure it out was the valve lash.
As it turns out I had not got them wrong, but when I tried one on the other side the valve lash was hugely off, and I know it wasn't prior. So, mystery solved. I was wrong once, it was that time I thought I was wrong. :)

Re: Cam housing sealant

Posted: Wed Apr 03, 2024 11:42 am
by redglbx
I have found that if you mount the cam holders on their locating dowels and then run your finger over the joint they should feel perfectly smooth if they are correct, you will feel a slight bump/step if they are not the right ones. This condition will side load the cams causing slight binding and wear on the bearing and cams.

Marking them before disassembly is a very good idea !
They must be matched !

Re: Cam housing sealant

Posted: Sat Apr 06, 2024 5:07 am
by Track T 2411
Like Robin, I've never used a sealant. IIRC, there's an oil passage involved, and too much sealant runs the risk of fouling it. My 2 cents...
I mark mine AND keep all the unassembled parts in separate containers. I also bag and tag each valve/ spring/ keeper, and make a cardboard 'bolt holder' so I know exactly which bolt went where. A LONG time ago I used to rely on memory; now I can't remember what I ate for lunch (or if I even had lunch, lol!).

Re: Cam housing sealant

Posted: Sat Apr 06, 2024 9:21 pm
by wolf_walker78
Yeah I generally use egg crates or baggies or something, I was lazy.
Seems like I lucked up at any rate.

The loctite I used you can smear on just about invisible so I feel like I made a safe effort.
It hasn't exploded at any rate. I did torque one side and remove just out of curiosity and it didn't migrate at all, and
there near the cam oil seals it looks like it'd be a good idea to have something between the mating surfaces.
No leaks so far.

Naturally the thing still smokes on cold start but I've only warmed it up twice so it's vaguely possible it will go away.
Otherwise I've done my part, at 44 years old I reckon it can smoke a little till it's warmed up if it wants to.

In the course of things I checked the ignition timing and read over the "split-timing" thing and I can't see any deviation of my test light coming on at all with the dyna pickups. Maaaaaybe 1mm but I wouldn't swear that since you can't look at the timing mark dead on (duh). I fashioned a pointer, used a mirror, etc, etc. Timing didn't seem to need to be adjusted from where it was. Carb sync was about where it was before as well. Starts instantly and seems to run alright, but it always has.

Re: Cam housing sealant

Posted: Sun Apr 07, 2024 10:32 pm
by Sidecar Bob
They all smoke to some degree. It is worse when you use the side stand (oil pools in the downhill cylinders and works its way past the rings) but the sidecar holds mine upright all the time and it still smokes on occasion.
There was even a Service Bulletin about that
https://ngwclub.com/forum/viewtopic.php ... in#p731782