New breather for 4.5

[cerb45]

If anybody out there running a 4.5 is fed up with the cheap fibreglass breather leaking due to the heat of the exhaust making it crack, I have found a comapny called Radtech who make nice shiny alloy ones that does'nt, Price is £185 and it is a direct replacement Radtech's no is 01543 502525.

Edited by cerb45 on Monday 21st January 15:44

Edited by cerb45 on Monday 21st January 15:47

[paulj]

Which part are you refering too ?

[_Neal_]

The fibreglass "collector" pot from the oil breather on the o/s front of the block, I think

[cerb45]

Sorry Guys for the confusion, just to clarify this is the fibreglass collector bowl that it is under the drivers side air box and is connected to the front cover breather, I have had issues with mine leaking due to the exhausts cracking the fibreglass.

[volospian]

Can you just replace this setup with an alloy catch tank and block off the hole in the airbox?

[_Neal_]

I understand it's a common issue - often solved by re-glassing the collector pot I think - this metal pot will sort it for sure.

Radtech's stuff looks v.good quality, but that ain't cheap!

[_Neal_]

volospian said:

Can you just replace this setup with an alloy catch tank and block off the hole in the airbox?

Would have thought so - it's the same arrangement (i.e. hose going to a small tank). From your reference to the hole in the airbox I'm presuming the standard tank vents into the airbox? This would mean relocating the catch tank elsewhere if you weren't using the hole - sure that could be done though

Quick internet search indicates that an alloy catch-tank arrangement would come in well under £100 - just a matter of getting the correct diameter hose to fit the breather pipe on the block I guess. Anyone done this?

[Nefarious]

volospian said:

Can you just replace this setup with an alloy catch tank and block off the hole in the airbox?

If you do that, you might as well just have a vent-to-atmosphere effort, which would work, but just not as well. The pipe to the airbox is there to provide active "suck" for the crank-case gases. I previously made one for an old Saab using a fat cigar tube filled with steel wool, and a couple of lengths of windscreen washer hose. Worked a treat too, but the wool needed replacing/cleaning every few months.

[_Neal_]

Ah right, now I understand - Cheers

[julian64]

The reason it leaks is cos the only thing that connects it to the airbox is sealant.

I think I did a whole thread on this (could be losing me marbles though)

I took mine off which was done by looking sideways at it. Put four rivnuts through the fiberglass and four bolts now make it the strongest, least likely part of the engine to leak.

[longbow]

Guys, this was discussed before Xmas and this is the way I went;



The tank has an internal baffle and I stuffed stainless scouring pads into it as well - its working very well, with no traces of oil in the pipes feeding the airboxes. Standard setup is crap.

Edited by longbow on Friday 4th April 20:37

[volospian]

Nefarious said:

If you do that, you might as well just have a vent-to-atmosphere effort, which would work, but just not as well. The pipe to the airbox is there to provide active "suck" for the crank-case gases. I previously made one for an old Saab using a fat cigar tube filled with steel wool, and a couple of lengths of windscreen washer hose. Worked a treat too, but the wool needed replacing/cleaning every few months.

True, but mine seems to get contaminated with a lot of oil, hence the idea of some kind of catch tank. I suppose you could connect the catch tank vent to the airbox to provide the suck, but to still stop the metal scouring pad filter thing becoming clogged with oil and causing smoke to billow from the right bank exhaust?

[Nefarious]

volospian said:

True, but mine seems to get contaminated with a lot of oil, hence the idea of some kind of catch tank. I suppose you could connect the catch tank vent to the airbox to provide the suck, but to still stop the metal scouring pad filter thing becoming clogged with oil and causing smoke to billow from the right bank exhaust?

Not sure I quite follow (of even if I'm meant to), but the catch-tank is effectively acting as a Liebic condenser (remember those from school!) to precipitate out the oil vapours - the pipe from the crank case goes right to the bottom of the recepticle, so the vapours have to travel through all the steel wool before reaching the pipe to the airbox. The cigar-tube version worked particularly well because both pipes went in through the screw-on cap, so you could just unscrew the long part every couple of months to pour out any liquid oil goop that had gathered in the bottom.
Perhaps on a larger engine a larger recpticle might be more appropriate, but you get the idea.

[volospian]

Nefarious said:

Not sure I quite follow (of even if I'm meant to), but the catch-tank is effectively acting as a Liebic condenser (remember those from school!) to precipitate out the oil vapours - the pipe from the crank case goes right to the bottom of the recepticle, so the vapours have to travel through all the steel wool before reaching the pipe to the airbox. The cigar-tube version worked particularly well because both pipes went in through the screw-on cap, so you could just unscrew the long part every couple of months to pour out any liquid oil goop that had gathered in the bottom.
Perhaps on a larger engine a larger recpticle might be more appropriate, but you get the idea.

lol, I think you've lost me now

My issue is that, on the standard set up, it seems to throw a lot of oil into the pipe, which gets sucked up the pipe and into the existing pot (for want of a better description). After a while that oil gets sucked up through the mesh and finds its way into the airbox itself, and then gets sucked into the intake and burnt, resulting in little puffs of blue smoke from the irght bank.

Now, I'm not sure how much gunk it actually does throw as it may have been 10 years of crap in the pipe when I examined it, but it was pretty full at the time. Took bloody hours to clean up and the wife wasn't impressed at the eye watering hot water and oil fumes in the kitchen for a while

Anyway, after I put it back together, I checked it again and already it had started to get oil back into the pipe.

My reasoning for the catch tank is that it would make the oil easier to keep out of the intakes, and drainable if it gets any real amount of oil in there.

Obviously it would lose the suction of the intake, but I wondered if connecting the catch tank vent to the original airbox hole would help or if that would reduce the effectiveness of the catch tank and result in the same problems.

Ummm.... if you see what I mean

[Nefarious]

I think the source of the confusion is that the pipe isn't actually sucking up oil, but rather what you're seeing is either condensed oil vapour, or settled oil mist. You can't do anything about that, you can only vent it to atmosphere, blow it back into the intake (via the airbox), or collect it in a catch tank as described.

[julian64]

Apart from the fact that doesn't 'seem' the case.

If you look inside the airbox when the engine is running (my engine) you will see that the catch tack is brimming with oil (must be at least two to three cup fulls) from about 2 minutes after you start the engine.

When you think about the weight of oil with nothing but the crankcase pressure behind it I couldn't understand (still can't) how oil vapour does that.

[volospian]

Nefarious said:

I think the source of the confusion is that the pipe isn't actually sucking up oil, but rather what you're seeing is either condensed oil vapour, or settled oil mist. You can't do anything about that, you can only vent it to atmosphere, blow it back into the intake (via the airbox), or collect it in a catch tank as described.

Oh yeah, I know that, but there seems to be, as julian64 says, quite a lot of oil in that system. It may well be oil vapour or mist, but once it is in the pipe it condenses back into oil and there seems to be so much that it gets sucked into the airbox from the pot.

Maybe a more freeflowing air filter would drop the internal suction of the airbox and draw less from the pot?

[trackcar]

The oil is actively blown out of the breather .. if you rev the engine with the breather pipe disconnected off the front of the engine watch how quickly the radiator and fans get a nice coating of engine oil .. it gets everywhere!

[volospian]

Hmm, in which case a catch tank venting to atmosphere would be adequate... unless the tank causes a restriction, causing a build up of pressure in the crank case?