Hi all,

The motor I have bought is a 2180 and it has the breather connectors off both rocker covers (although plugged at this point) and one on the oil fill tube. I don't know if I need just a breather box that releases pressure in the crankcase and rocker area or if I need to have something setup that applies vacuum to these areas.

If you have any experience, could you please advise which way is best and please explain why.

P.S. Engine is N/A, not forced induction.

Thanks, Kevin

Come on guys (and Gals) you are all back from Warwick and its probably you racers that will know the answer to this one. Can someone give me any advice in this area.

Cheers, Kevin

Kev

hidden breather box is best bigger tubes are best as well

this will reduce a lot of oil leaks also

screw it up high as you can get to allow most of the venting to take place with less oil in the air

OK, well I won't claim the "qualified" part, but I've read a bit about how the sand guys do things and have also tried a few different setups on the 1916 in my race car.

Basically when I first built the car I used the standard oil filler neck (with the separator in it) and a line running up to a junction and then off to the tops of the air filters. It worked well for street driving, no oil leaks or anything, but found when racing that the engine was "using" oil. At one event one of the filter top lines came loose, and a heap of oil pumped out... basically what I discovered was happening was that at high revs (like 6000+), the case was getting a fair amount of pressure up and so oil was getting pushed/sucked through the carbs.

So the next evolution has been a catch can running just a single line from one of those chrome filler necks... the can has a separator built in and a filter covering the air exit. Works great and no oil leaks, but it isn't self draining so I have to keep an eye on it and occasionally drain the oil. If I don't, oil can come out the filter at the top since the air coming in is causing it bubble and spurt.

Street driving it pumps out hardly any, but again at high revs it can pump a fair amount and I'm in the habit of checking it several times each event. It's not a big capacity can though... maybe half a liter.

I currently don't have lines from the rocker covers, but will be adding them shortly as well as mounting the can higher and setting it up so that it self drains. From what I've seen, the rocker area generates vacuum at high revs... like at 6000+ it can suck in the rocker cover gaskets unless they're glued in... so my thinking is that two vacuum lines (rocker covers) and one pressure line (from the case) and a drain (back to the case) like the sand guys run, it should even out with a nice circulation sort of thing going on.

So yeah - I think for street driving, a standard separator and vacuum would be fine, but for higher revs like when racing you'll want a breather box/catch can.

CT (fullnoise) will likely have some comments as well with his recent breather issues....

Hi

I had Westie knock me one up for Davids 1303, a line from each tappet cover and a self draining tube from the filler stand. Its mounted roughly where the centre carby was.

Steve

Yeah as above. Go the breather from both rocker covers and the oil filler and/or the og fuel pump location. Definately increase the hose diameter to 3/4 if you can as the lager diameter will slow the air speed so the oil will fall out of suspension ealier and not reach the breather box. Also dont have any downward loops in any lines as they will gather oil which will oddly stop the venting, and the lowest hose at the breather box should be routed as the oil return, so what does gather in the breather box will also drain back to the engine.
Dont worry about thinking vac pump unless your aiming in the 250+hp range.

Thanks guys for all the input, you have got me on track in that I only need a breather to relieve pressure.

Matberry - Thanks for tips in relation to low hose points etc, makes good sense.

My engine has large hose points off both rocker covers and one at the oil filler neck, so I will just need now to buy a breather box and connect it all up.

Maybe something like this http://www2.cip1.com/ProductDetails.asp?ProductCode=C26-115-560

Cheers, Kevin

Sort of

I believe the Berg is best

http://www.cbperformance.com/catalog.asp?ProductID=1748 

Reason being that it gives the oil some where to collect when if falls out of mist/suspension

I really like this one
http://www.cbperformance.com/catalog.asp?ProductID=241 

but the palte seals with a BIG gasket/O-ring thing that just leaks

anyway

barry

Jeez how much blow-by do you fellers have?!

Don't waste your money on that breather, you need BIG hoses. Follow matberry's advice exactly, and you won't go wrong! If you intend to run the car on a race track you may need to comply with a rule regarding breathers.

Cheers, Greg

The link I added was only meant to be as an example and I understand what mat is saying about big is better.

Bizarre, Thanks for the links and I have seen the berg one before but there postage to Oz is ridiculous. As to the second link, I cant see how that is a breather unless the hose at the back/top goes to a filter to relieve the pressure.

Might see if Brad can make me something up similar to Bergs

Thanks again, Kev

Go to Brad and do a copy would be really the best, but remember the dash 8 fittings if you can get the hoses to turn to fit your tappet covers, depending on tinware and engine bay details.

^^^ really? I think its my 2nd fav, after the berg... but the berg ones are hard to come by it would seem.

I just have the old rectangleular breather box... im so cheap.

look on the samba for one of clydes
Nothing wrong with the gene berg originals either!

2nd the motion to follow matt bs advice to the letter...very well said!

Sides might find you need certain capacity catch can to meet cams pegs...5l rings a bell

Can I 3rd to go with what Matt B has said ??? That's basically what I'm going to end up with...

Yeah Daimo - you're right that CAMS makes it more complicated again... BIG surprise.

I didn't go there since the general regs change pretty frequently, and of course you have to deal with different scrutineer's "interpretation" of things.... but if anyone's having trouble sleeping at nite, take a read through http://www.camsmanual.com.au/pdf/10_gen_req/GQ03_Schedule_A_B_Q409.pdf