Ducati Sporting Club UK > DesmoDue Race Series > DesmoDue - General Questions and Chat > Fuel and Oil breathers?

[Rattler]

Further to today's other "breather" post, I've sent a message off to the relevant DesmoDue authorities to answer the following questions, as I'm a bit fik when it comes to all this rules milarkey.

If anyone knows on here any or all of the answers, please feel free to respond. But I will post the official response in case it helps someone who's as dumb as I am when it comes to ACU rules.

My question refers to the relevant DD rules;

[i]Hi
I'm looking for clarification of what is required for the catch tanks
for both the oil breather and tank breather on my 620ie.

I assume that the rulings refer to oil breather tube as the tube
fitted to the bottom left hand side (as you sit on the bike) of the
air box. And the fuel tank breather as the tube that is fitted to the
bottom back right hand side (again as you sit on the bike) of the
tank.

Some questions please;

- As noted above, are these both the breather tubes that are refered
to in the rules?
- Does my Monster 620ie have both of these fitted?
- What is typically used as a catch tank?
- Can one catch tank be used for both purposes?
- Where are non-return valves available from?
- Where and how are the catch tanks mounted?

Any other relevant info you can provide would be much appreciated.

Thanks in advance
Tim
[/i}

Tim:ninja;

[skidlids]

Tim I think the Monnies breath through the fuel filler cap where as the SS models and the subject of the previous post have a pipe coming out of the bulge at the front of the tank and come fitted with a non return valve which in turn goes to a pipe that feeds through the centre of the headstock and exits below the engine. With out the valve petrol would exit the tank via the pipe every time you braked hard with a decent fuel load.
As such us SS runners have to have a one-way valve that in the event of failure has to go to a catch bottle.

[Rattler]

Kev - thanks for the info.
I'm easily confused as you know - so just looking for clarification really.

So what can I use as a catch tank?

Tim

[skidlids]

I'm considering either a coke bottle (500ml) or a old rad header tank I have off a jap bike, as I think my other one is a bit flash for the 600SS and if I put a proper value on it would be out of budget (see pic)

[Rattler]

Its probably worth more than the SS !!!

OK - so I can make do with a brake fluid bottle or similar, drill a hole in the cap, fit a grommit and we're sorted - yeh??? Do I need to do this for both the fuel and oil breather though??

Tim

[skidlids]

Tim
I will be routing all hoses to catch tanks/bottles, that includes the fuel over fill pipe that runs from my tank cap surround through the tank and out of the bottom, this will join the Carb floatbowl vents and the fuel tank breather.
The oil breather pipes will be routed to there own catch tank/bottle

From the Desmo Due Spec/rules

1.7.10 The Following Items MUST BE Altered

All motorcycles must have a closed breather system. The oil breather line must be connected and discharge into a catch tank.

Where an oil breather pipe is fitted, the outlet must discharge into a catch tank located in an easily accessible position and which must be emptied before the start of a race.
The minimum size of a catch tank shall be 500 cc.

1.6.15 Air Box

The air box can be removed.
The air filter element may be modified or replaced.
The oil breather line must be connected and discharge into a separate tank.

1.6.11 Fuel Tank
Fuel tanks with tank breather pipes must be fitted with non-return valves that discharge into a catch tank with a minimum volume of 250cc made of a suitable material.

[antonye]

I saw these - they'd be ideal for the fuel catch bottle:
http://www.redracingparts.com/englis...****erfuel.htm

Don't know about the oil breather - the SS has a closed breather system already that goes into a tank (under the seat) but I don't think it'll hold 500ml, so I guess you'd have to replace it.

[Paul James]

Originally posted by antonye
I saw these - they'd be ideal for the fuel catch bottle:
http://www.redracingparts.com/englis...****erfuel.htm

Don't know about the oil breather - the SS has a closed breather system already that goes into a tank (under the seat) but I don't think it'll hold 500ml, so I guess you'd have to replace it.

Watch the volumes and materials you use. Remember that in the case of the oil catch tank it's likely to end up with very hot oil in it if something goes seriously wrong. I used to get good quality Polypropylene bottles with screw lids from a chemical supplies company, they were strong and impervious to oil and petrol. Don't cost that much either.

If enough people are interested I'll see if I can find some, plenty of places that do them, check out chemical suppliers or suppliers of laboratory equipment.