Crankcase Pressure=Oil Leaks?

i am having issues with my crankcase joint (vertical - front) as it appears to be leaking from top to bottom. 500miles after rebuild, i was preparing to get up into the 5000 rpm zone, 6000rpm after 750 miles and beyond post 1000miles.
all head and valve clearances have been adjusted repeatedly along with retorquing cylinder. small weep there too at front primary side just above case numbers.
Any ideas?

Also, oil appears to be finely airated to the point wher it looks to have water in the oil. like when you crack a head in a water cooled engine. is this foaming of the oil, and is it normal?
Using Motul Mineral Oil as i cant get Lucas oils here in Brisbane Australia.

Any assistance would be greatly appreciated.

Cheers

DKT

Dkt26 said:

Also, oil appears to be finely airated to the point wher it looks to have water in the oil. like when you crack a head in a water cooled engine. is this foaming of the oil, and is it normal?

Click to expand...

Sounds like the sump is perhaps not being scavenged properly?

I got that in my Combat till first oil change, after 50ish miles. implies oil not hot enough to evaporate water out but could imply some ring moisture blow by which definitely is associated with weeps about everywhere no mater how nipped down.
Should long ago pulled the finger out and let her rip to red line. Timid use is the worse thing for Nortons. Get it good and hot and seen what oil looks like then clean up again and seek solutions to weeps which in my Trixie case turned out to be too much ring gap I over looked , ugh for a while. I was so timid on my 1st Peel rebuild I took 1000 miles before finding out if would blow up. I was so surprised by the power, hehe and so were many surprised to angry hot shots.

hobot said:

I got that in my Combat till first oil change, after 50ish miles. implies oil not hot enough to evaporate water out but could imply some ring moisture blow by which definitely is associated with weeps about everywhere no mater how nipped down.

Click to expand...

Yes, but I think DKT is only comparing the foamed oil to water contamination (or "mayonnaise").

I'm on the N'side of Brissy if you like me to have a look and give you a second opion, did you do the rebuild or by someone else, is the oil returning to the oil tank, not to much oil in the sump??? Would be hapy to have a look.

Ashley

Cheers ash. Will pm after work
Dkt

Hobot,
Are you saying redline it now?
Ride it like its stolen?

I definately don't think it's water just appears that way like mayo as L.A.B says.
Engine was done by a local builder that was highly recommended tho nothing without issues eh?
My turn next time to do the build. Just didn't have workshop space this time.
DKT

Check your feed and return lines are correct. Someone here recently blew the engine with them reversed and 'water in oil'. I'd get it sorted before redline or too many miles.

Dave

You may be "wet sumping" for the more common reason of poor return and the high oil in the crank being whipped up by the mass into a non edible sandwich spread.

I hope for your sake it is a simple routing issue.

Bad things are block oil tunnels (piston and ring bit). Your builder should have cleared all oil ways, removing all grub screws in the cases and validating openness.

"Oil pressure gauges are good!"

I hope it's just a routing thing. Reversed breather valve?

Are you saying redline it now?
Ride it like its stolen?

Click to expand...

Absolutely, or essentially so, but only after the oil supply is verifed. Maybe the greyish texture is assembly lube left overs? Outside oil line, lowest off tank is the feed from straight through the pump to wet sump. Inside line goes to the upward tube at back of tank the has chain oiler leaker take off. Warm oil should be felt on the inner hose in about a minute before taking off next time. Best thing for rings and cam surface is high normal heat and high throttle high-ish, not highest, rpms. After like 5 break ins I've gotten to point I rev 2000-3000 from first spark and blip it staying in that zone till good smoking vapors off everything, then diddle what ever and seal what ever then re-torque as cooled. Oil flow shows up 30 sec instead of most a min., ring seat no smoking in under a min. Next start up goes for 5 min but as nil fuel burning w/o load its not really dramatic hot by shut down. I change oil then and ugh re-torque, question my sense of sanity on surprise prone hobby, til ok with it to head out for normal type riding keeping rpm up 2000-as much as I can, when ever I can feeling like I stole it. About 500 ish miles I'l change oil then all done with the honeymoon good behavior.

Clean all faces with solvent ??

Use ' Pliobond ' glue as sealant ??

Negative C'Case pressure , would suck the oil leaks in .

Gotta the big Breather on it were sane people have magnetos ?? ( Behind the cylinders / rear of timing case ?? )

Soaking Aloomin um in Acetone gets it all sparkly and degreased , shiny even . Gallons of it . Maybe NEXT TIME .

Actually , if its all set up right now , its not a lot off bother to whip it down and reglue it all together .
Rear right barrel / case joint seems to weep eventually , perhaps . So thats a area to pay particular attention .

While PLIOBOND is a excellent heat resistant gasket sealant . Aryldite is not to be recomended . Its a trifle permanent .

Cheers Matt
I just paid $3k(started as a quick head gasket change) so I am not going to strip it unless I have too. When head was removed scoring was noticed so a set of pistons and big ends prescribed.
Cases split only to reveal cam bush was spinning in the case and about 500miles from total explosion so some would say, lucky????
Anyway, I didn't start the job myself and was promised $1600 should cover it. Bike was eventually returned to me 3 1/2 months later and given that it was my daily transport to werk, you can imagine I was ready to fuckin explode myself.
So that bein said, gonna try get my money's worth, promise myself I will only ever do my own dirty washin(work shed or not- I did rebuild a dodge Phoenix in my front yard and an Austin 1800 in a cow paddock in the bush) and write this off to just a bad experience.
All the performance mods I wanted to do, like cam upgrade, HC pistons etc, I was talked out of it by the local expert.

It's quite disappointing but lesson learnt.

That's what beer is for

Hi DKT,

Is your bike a 750? It sounds like the oil is getting aerated, because blow by and internal air movements are not being vented. That could also be compounded because if the crankcase cannot vent the scavenging of the oil by the pump will be reduced, so you end up with whipped cream!
Just throwing some ideas out, cause I imagine you are over seeing your engine guy?
If she is a 750, check the rear crankcase breather, 850's breath through the back of the timing case, and are usually happy in this area! As an aside, I run a XS650 Yamaha reed breather in the line from engine to tank. This I found, made the engine totally oil tight, all the usual suspect oil leaks went. The oil around the crank case front, have you checked the rev counter drive?
Check on line for correct oil plumbing, old brits sight has the drawing.

Hope this helps

Cheers Richard

Thanks Richard
It's a 73 850 mk1 silver barrel so the 750 issue may not be the same. I have not had contact with the rebuilder yet. Am waiting for my temper to calm a bit

Cheers
Dkt

Bike was eventually returned to me 3 1/2 months later and given that it was my daily transport to werk, you can imagine I was ready to fuckin explode myself.

Click to expand...

Aw man you the man DKT I want to be, again, minus the 'ploding state. If the mess seems to be getting worse as time goes by and smoking then suspect ring blow by from bore seal to gap error, more than check valves can keep up with. I 1st got into my 1st Combat only to fix 13 leak sites, but took 5 yr to fix what was found dangerous bad. I had good seal on Ms Peel by using non melting thread in seams, push rod tunnels included, but last time in Trixie to fix rings got talked out of it and now have head drips [2000 miles later] going over 70 on much throttle. If I stay perfectly legal then nuts begin to rust : (
Sometimes I'm in a hurry to get to work in a public viewing area and can't park where I like if drips there. I'm working myself up to take engine out for like 5th time to do it my way, while its too hot to ride much. I like Hylomar best but its not all that much better than the others and in our elastic engines needs fiber back up too often. As nothing broken nor worn out, should take me an afternoon/evening to remove and open, then similar to put back, if I don't take much breaks and can stand the sweat and bugs in face d/t open shed with attractive lights Or mess up something, again.

One thing on Trixie that seems to have occurred, after 3 re-torques, she seemed fine riding to work often and further afield, so I got lax on the oil tightness re-torque routine, to find once the seams open enough to weep, then likely can't re-torque enough to matter till you know what...again...

Definitely verify proper oil line routing, and evidence of oil return to the tank by peering into the open filler cap.

Then, install a reed valve type crankcase vent and forget most of your oil weepage issues.

In most situations, mounted behind the timing cover works as well as down low at the backside of the crankcase sump (and it's easier to install and service thereafter).

I always use a modified car PC valve in the breather pipe from the motor. One out of a Ford Falcon is OK, but I stand the valve in water while I braze on a tail, so the spring doesn't soften. It causes a negative pressure in the crankcase to suck the gaskets/joints. Some of the early Ducatis had a large bore plastic pipe as breather with a rubber flap valve on the end, but on a racer we must use a catch tank.

Cheers grandpaul/acotel
Any pics?
I can verify routing is correct and will check oil return via filler cap.
Dkt

Sorted so pic ain't needed. Mikesxs site has pics.
Cheers