Oil Catch Tanks And Breathers (Szr660 Dry Sump Engine)

[monkeystew0]

I need a second opinon and some advice on breather hoses and oil catch tanks for my Supermono project.

The engine is a tuned, bored, stroked and tweaked SZR660 . Dry sump with a seprate oil tank. Currently there are 3 hoses on the crankcase acting as breathers but I need to route them into something....The question is what and how.

As you can see in the pics below. The two original breather hoses route vertically and would have connected to the airbox (which is no longer there), The third is a big 18mm bore outlet on the Tigcraft side plate.

1. Can I get away with blanking off the smaller pipes and just running the large pipe to a catch tank under the seat?
   
2. Should the breather on the top of the oil tank also be routed to the catch tank?
   
3. How big should the catch tank be volume wise?
   

I wouldn't expect a dry sump engine to breath heavily as the scavenge pump should return most of the oil to the tank and the space availabe under the seat will take something about 500cc give or take.

Any advice or alternative suggestions greatly accepted...

[Superdunc]

One of the standard breaters is for the gearbox, this needs to go to the catch tank. The other 2 can go straight to the catch tank. though I'd be tempted to run the smaller to the oil tank for neatness.

You will definatly need a breather from the oil tank to the catch tank.

The catch tank should be as big as you get, and should have a decent size breather, at least 13mm,to atmosphere.

[monkeystew0]

Wow. That was a quick response.

Just to clarify

All the 4 hoses need to route back into an oil catch tank.

Is it acceptable to join the hoses via T pieces to reduce the number of inlet spigots required on the catch tank? (The three smaller bore pipes could be combined in to one inlet and then a second larger input spigot for the 18mm one.)

It looks like I will have to get a custom tank fabricated so it might save a few pennies.

For the Catch tank vent to atmsophere I need a min. 13mm spigot with a small filter mounted on the end? Something like this but make the tank as big as space allows:

[Superdunc]

The filter can be remotly mounted to give more space, or left off completely.

I wouldn't T the gearbox breather into the others, as you'll end up pumping engine oil into the gearbox and vice versa.

[4tgp]

SuperD, I agree with everything you say except the last bit about the T! The engine and gearbox share the same oil and the same space so it makes no odds?

Monkey, if you need someone to fab the tank, give us a shout.

[Superdunc]

SuperD, I agree with everything you say except the last bit about the T! The engine and gearbox share the same oil and the same space so it makes no odds?

Monkey, if you need someone to fab the tank, give us a shout.

Fair enough, I assumed being a drysump engine it had separate gear oil.

[kanerdog1x1]

i would be tempted to plumb all three hoses from the engine into the dry sump tank to scavenge as much oil as possible, then have a single hose to the breather tank, then a single hose to atmosphere. and definately have a filter attached, i see so many cars and bikes without and it makes i cringe. all that dust being potentially sucked into the oil.....

[monkeystew0]

I'll have to get busy with the cardboard and tape and make a mock up to see what fits the space and where inlets, outlets and mounting brackets etc could be positioned. Should help me decide how it will all fit in the space avaialabe. I amy have to modify the oil tank so the smaller hoses route to there frst

Then i'll sketch it up, create some type of drawing and get it made.........