58 Domi crank case breather question

I don't ride my Domi every day or every week for that matter but I get it out at least once a month and do a bit of a ride. The problem is that the bike wet sumps! On wide line there isn't a froth tower on the oil tank and I can't put a later oil tank due to the took box and upper frame rail being in the way. So when I start the bike a great deal of oil gets dumped out. I don't trust the anti drain check valves so that leave me a problem. Been thinking of welding in a return high on the side of the oil tank but below the vent. Do you think this would work and do you see any issues I might have?

John in Texas

When my Dommi has stood for any length of time I do one of two things. I first check the oil level in the tank and if it isn't too low I just start up the engine and leave it ticking over until all the oil has returned to the tank - I don't rev it during this time as high revs and deep oil don't go well together. If the oil level is very low in the tank - meaning the oil is all in the sump - I then drain the sump and manually return it to the tank. I do though use the newer type sump plug with the small central drain http://www.norvilmotorcycle.co.uk/techtalk18.htm

I would be dubious about modifying the oil tank to take a larger return as it could end up starving the top end oiling.

I am not very familiar with the early Dommie oil tank, but there should be plenty of room below the vent, and above normal oil level. My Atlas, for example, has the breather tube enter the froth tower just above the tank roof level, then turn 90 degrees down toward the oil level. The exit of the breather tube ends up just below oil tank roof level.

The link below has a pic of the Atlas froth tower and the location of the breather inlet tube. You might consider welding in a 1 inch Dia. Tube and fabricate your own froth tower.

https://www.accessnorton.com/NortonCommando/atlas-dommie-oil-mist-scrubber.16411/

Slick

That is a good modification, trouble is it won't work on my wide line featherbed, for this reason. The tool tray is full width and there is no space for a froth tower. Yes I could remover the tool tray but that has the anchor for the gas tank strap. I acquired an Atlas oil tank had it cleaned and painted before realizing it wouldn't fit because of the problems I just described. I will take the seat off and take a few pictures so you understand.
I guess the easiest fix wound be to install a manual valve to shut off the oil and make a flag that I attach to the bars that says remove before flight.
John in Texas

Early oil tanks were not fitted with froth towers. This came later on the slimline bikes.

Your only option I can see is to obtain another oil pump and if used check it is not worn and get it reconditioned, also paying attention to the cast iron cover is not standing proud of the pump where it bolts up against the crankcase, allowing the oil to drain unrestricted when stationary. The thick rubber “o” ring from pump to timing cover should always be renewed.

N0rt0nelectr@ said:

I guess the easiest fix would be to install a manual valve to shut off the oil and make a flag that I attach to the bars that says remove before flight.
John in Texas

Click to expand...

What happened to your idea of welding in a breather return in the side of the oil tank? Have you seen a flaw in that scheme?

If you decide to go with a manual valve, have a look at what I used before turning to the AMR modification. See reply #47.

https://www.accessnorton.com/Norton...-wet-sumping-that-is.16671/page-3#post-243254

Slick

Here is a picture of the oil tank and tool tray, gives you a better idea of what I am dealing with.
If I go with welding a tube into the oil tank I just have make sure I have the clearance needed for the hose.
I will take the tool box out and look at the clearance. Also the original oil tank had a cover welded to it to mask the Volkes air cleaner so even if I could use an Atlas style oil tank I would wind up with a gap between the battery box and the oil tank. A manual valve with a "flag" on the bars to remind me to turn it on might be the simplest way to go.
Always something!
John in Texas

AMR modification for your oil pump and timing cover

I will contact Mike at AMR and see what he has to say on the subject.
John in Texas