Performance Air filter and Crankcase breather

[fishlegs]

-Air Filter:
I want to mount a performance air filter on my 435 Greaves Enfield, and was wondering if anyone can recommend one? I imagine I'll have to lose the aesthetic appeal of the stock oil bath air filter for something like an open-sided K&N filter. Will I need to adjust my fuel settings to maintain the proper air:fuel ratio?

-Crankcase Breather:
Also up to this point, I've run without any hose or duckbill off the crankcase breather. I'd like to put a hose on it at least pointing at the ground if not to the chain for a bit of oiling. Assuming I need to throw on some form of check valve, duckbill, etc., what "cracking pressure" should I look for in valve? Seems like it should be pretty low (some fraction of a psi).

I understand that ideally the plumbing for the breather would be routed on a continuous climb to the output. However, with the breather hole on top of the engine, the hose would not be climbing if I route it down to oil the chain. Will this be problematic?

I've also wondered about just putting on a K&N "crankcase vent filter" to clean up the emissions a bit. Has anyone here used one of those instead?

Thanks,
erik

[IgorVigor]

I would just fit a tube to the breather, and as you said, route the end near the chain for some oiling

tbh, I doubt you would get much out of it though.

as for a performance filter, I personally wouldnt bother...
at the end of the day, you havent got a performance engine, and the oil bath filter will be very good at filtering...

if you still want to fit one, I would recommend a foam filter (motorbike UNI POD filter?) over a K&N (Cotton gauze)

the cotton gauze allow a lot of air, at the cost of filtering ability
the foam is better, but not perfect...

and please dont start an argument people about how good a K&N or foam filter is, an oil bath is the most effective filter available.

the size of your filter connection would decide what filter you would have...

car filter are usually at least 60mm
bike filters (MX Bikes) range from around an 1" (25mm)

good luck either way...

[Sphere]

I'm not sure that it is a good idea to run a diesel without a paper filter. Well, at least it won't be restricted

About oiling your chain, I dislike the idea of oiling the chain at 60mph. It means the oil won't actuallly just go onto the chain, but everywhere. Instead, I would prefer a system you can trigger when you are about to dismount. Something like http://www.osco.nl although it is a bit expensive.

[IgorVigor]

I know what you mean sphere...

I would stick with the oil bath myself...
they are basic, reliable, effective, cheap and look good

K&N or foam will offer a little more performance (easier to rev more than anything) but sacrifice filtering...

a paper is ok but only slightly better than the foam which itself is only a little better than the K&N (cotton gauze)

the paper does offer a little more flow than the oil bath though...

so basically here is a list ranging from best filtering/worst flow to worst filtering/best flow
- Oil bath
- Paper
- Foam (UNI, Pipercross)
- Cotton Gauze (K&N)
- Wire Gauze (Ripspeed from halfords)
- No Filter

One other thing I want to mention.
These so called 'Performance Filters' dont really offer that much more...

On a Land Rover 2.25 petrol engine, fitted with a Oil bath filter as standard you are looking at around 70~75hp
Fitted with a 'Performance Filter' you might be VERY lucky and see 80hp, but not likely...

It will feel faster, as they offer less resistance for the air (less filtering) so the engine can rev a bit quicker...

A high performance tuned engine can make use of the extra air flow, and sometimes they do need a high flow filter, but not for more power as such, its so the engine can get enough air.

No matter how you look at it, your Greaves diesel is NOT a performance engine...sorry

At the end of the day though, its your bike, you choose what you want and then go from there...

The only thing I would say is sit down and think it through in your head, and ask your self a few questions...
Do you live in a dusty area?
Do you want the induction noise?
Do the benefits of a high flow filter out way the lower filtration rate?

[coachgeo]

Oil breather:

Feed it up to a canister with with a kitchen scrubby in it. The very open weave type so air can pass thru. Design it so that the air does pass thru to atmosphere while the oil condenses on the scrubby falls away and be caught for dripping onto the chain.

[fishlegs]

Thanks for the tips. I'll probably stick with the oil bath air filter and make a gravity feed chain oiler with a toggle switch..

I know the greaves is no performance engine, I've just been weighing some options for boosting the speed any fraction that I can.

[TimppaX]

I´m about to go that foam"power"filter, olied, path. Must anyway either manufacture new intake or rip whole yanclone intakehose system away and it looked better without it.

Definetly I won´t gain anything else than the looks by using those "power"filters. Still wondering where to lead breather. Exhaustpipes?

[IgorVigor]

chain oilers are always a nice thing.

however, I wouldn't have a gravity feed one again...

I made one from half a big syringe, (did away with plunger and had a push fit lid with small breather hole)
connected some pipe to the bottom and then used 2 metal air line taps to adjust flow.

the first one adjusted the actual flow rate and the second was for an on/off tap.

that was the idea...the problem was I ended up having to use both for the flow rate as the oil didnt want to flow unless the hole was a certain size..
I tried changing oil grade from chainsaw chain oil to EP90 and it made no real difference...

everytime I stopped and turned it off, it left a puddle of oil where the rest of the fluid drained from the second tap (tube was 6mm bore and from the tap to the nozzle it was around 10cms (4 inches)

it changed the flow rate according to temperature, humidity level, moon phase, orbiting characteristics of jupiters moons, etc...

I would recommend if you want a chain oiler, to buy either an electronic one or a vacuum one.
they are tried and tested and work well...

either that or stick to a spray can...

I recently changed to Muc Off's Dry PTFE chain lube...

it makes your chain a matt grey (at least it does mine) but my chain is so smooth and doesnt attract dirt like it used to (using spray wax or oil)
and since I lubed my chain with it, I have done probably 200 miles without needing to relube it...

[Diesel Dave]

Either bin the oil bath or run it with just a light covering of oil over the gauze inside.

It takes quite a lot of energy to suck air through the oil bath.

Better yet use the std enfield air cleaner and a flexi vacuum cleaner hose for much improved breathing.

Your Greaves should have a valved breather on the rocker cover with a pipe connection - run this to the gearbox sprocket. There is no need for a duckbill as the valve is in the rocker cover.

If your not getting enough oil mist to the chain to keep it lubed then you must have a very good motor In this case but a Loobman system for 20 quid and fill it with chainsaw oil as this is cheap and has anti-fling properties.

Chains last about 35,000 miles on mine with the Loobman. (about the same as a Avon rear tyre )