Oil From the Exhaust Ports?

Hahnda · Post by **Hahnda** » Sat Sep 29, 2012 9:58 am

If the bearings are flush I would say that is your problem. They need to be recessed a bit. If you take a look at your cam covers they have a lip on them. That lip should seat the bearings in a bit. Tapping on the end of the cam probably won't move the bearing. A couple of light taps on the cover itself with a rubber or plastic mallet might do it.

houseowax · Post by **houseowax** » Sat Sep 29, 2012 10:08 am

Thanks, Kevin- I'll see what I can do.

So after the bearings are properly seated that puny packing and the screwed-down side cover should be enough to stop the oil from seeping out of the hole in the rocker pin? Seems like not enough to me. Then again, I assume the guys that designed this engine had slightly more engineering experience that I do, which is exactly none.

Hahnda · Post by **Hahnda** » Sat Sep 29, 2012 10:18 am

Yep that should be enough to keep it from spewing oil. Its not under a very high pressure.

houseowax · Post by **houseowax** » Sat Sep 29, 2012 10:27 am

Thanks. I should clarify that when I said I was careful to install the bearings 'flush' I should have said ...I dunno...'plumb'? Meaning that I was careful not to allow the bearings to cant and lodge in the holes and maybe warp the casting. I feel pretty confident that the holes cast into the head are round and the fit is sufficiently tight.

Anyhow, I'll have a look at my earliest convenience and let you all know.

houseowax · Post by **houseowax** » Mon Oct 01, 2012 9:15 pm

Here's the latest:
I got behind the valve head side cover and gave the bearing set a nice persuasive whack with a chromoly bike seat post and a deadblow mallet. It snugged down significantly. I was sure that would be the answer so I replaced the cover and fired it up and no leak! For about 6 seconds, then it started again although far less alarmingly.
I tried to repeat the process but the camshaft started pushing out the points side and I knew I'd reached the end of the line.

My guess is that I'll need to get back into the camshaft- maybe I somehow didn't get the two halves of the camshaft together tight enough(?)

Here's a question, though: When my left-hand valve head sidecover is on the fins on the cover sit about 1/8" or so proud of the fins cast into the head. That seems like an unlikely design which makes me think that my side cover ISN't sitting flush even though I feel like I pushed the bearing in enough to give it ample clearance.

See attached pic- does your side cover sit proud of the head like this?

Thanks as always to those who have taken the time to help.

LOUD MOUSE · Post by **LOUD MOUSE** » Tue Oct 02, 2012 2:28 am

Remove the top cover and you will be able to see if the end cover is flush.
I suspect you are correct that you need to get the middle of the cams tighter to the cam sprocket. ...........lm

houseowax wrote:Here's the latest:
I got behind the valve head side cover and gave the bearing set a nice persuasive whack with a chromoly bike seat post and a deadblow mallet. It snugged down significantly. I was sure that would be the answer so I replaced the cover and fired it up and no leak! For about 6 seconds, then it started again although far less alarmingly.
I tried to repeat the process but the camshaft started pushing out the points side and I knew I'd reached the end of the line.

My guess is that I'll need to get back into the camshaft- maybe I somehow didn't get the two halves of the camshaft together tight enough(?)

Here's a question, though: When my left-hand valve head sidecover is on the fins on the cover sit about 1/8" or so proud of the fins cast into the head. That seems like an unlikely design which makes me think that my side cover ISN't sitting flush even though I feel like I pushed the bearing in enough to give it ample clearance.

See attached pic- does your side cover sit proud of the head like this?

Thanks as always to those who have taken the time to help.

houseowax · Post by **houseowax** » Tue Oct 02, 2012 8:48 pm

What a day.

Dropped engine yet again. Got the cams all snugged up tight and liked the recess in the head casting; was pretty convinced that the side covers were going to seal up tight. The left side cover STILL didn't sit right to my eye, though- the fins were stiil visibly proud of the fins on the head, especially toward the exhaust side.
Just on a whim I dug through my spares and found another side cover. It was identical, but a slightly thinner and less weighty casting. I tried it in place of the one i'd been using and it fit perfectly: it practically formed a vacuum when I pushed it in place. I opted to go with it, so I put in the packing and tightened it down.
So feeling like I'd got this issue conquered I go to seal the head up for what feels like the millionth time. Previously I'd torqued the head nuts down to LM's spec: 22 ft lbs. Last timr the outside/oil travel stud on the left side made me a bit nervous- it took forever to reach 22 lbs. THIS time i was probably a quarter turn away when
POP
the stud snapped in two and shot out through the top of the acorn nut!
Fortunately I have a donor engine and my friend managed to extract a replacement stud from it. What seemed like a disaster only took about an hour to remedy.
Alas, I ran out of time and wasn't able to get the engine back in the bike. Im hoping that once I do I don't have to drop it again anytime soon!