breathers

Post by **les** » Fri Mar 20, 2009 9:55 pm

I am trying to establish the correct combination of breather components, in other words what goes with what. At the moment I have got a tube attached to the front engine side cover venting to ground, a simple oil filler cap, no outlet in the rocker cover and a carb with a brass outlet tube that exits from the side of the carb body. I think I have got various parts from different breather systems. Can someone tell me the combinations of each system used on the late 1098 engines?
I think Willie was clued up on all this, has anyone heard from him lately?

Post by **bmcecosse** » Fri Mar 20, 2009 11:04 pm

You should use a rocker cover with a vent pipe - and connect that directly to the carb pipe. Keep the side cover with vent - I add a bit of pipe to that so it vents well down in the under-car airstream - but that's probably not necessary - although it does eliminate any oil mist/mess in the engine bay. That should contain the fumes nicely, and minimise nasty smells - and oil leaks!

Post by **les** » Sat Mar 21, 2009 9:19 pm

Thanks for that, looks like I need another rocker cover then, but I thought if the cover has a pipe fitted it should go to the air filter housing rather than the carb. At least according to the stuff I've read. Does anyone know what system is used when the rocker cover has the gauze filled cap fitted?

Post by **aupickup** » Sat Mar 21, 2009 9:30 pm

the oil filler vented cap is usaed with the tappet cover tube going to the air filter housing, and no breather on the rocker cover

Post by **PSL184** » Sat Mar 21, 2009 10:28 pm

It was only changed to get round emission regs. Fit rocker cover with breather pipe and attach to carb for best performance or air filter if you don't mind clogging the filters up prematurely... If your rocker has a breather there is no need for a vented cap.

Post by **les** » Sun Mar 22, 2009 8:30 pm

Thanks for replies, the rocker cover I have has no pipe fitted or long neck to accept breather cap, so seems designed to have neither method of venting. However I will go for a vented cover and link it to the carb.

Post by **bmcecosse** » Sun Mar 22, 2009 10:18 pm

I really don't know or understand why BMC eliminated the breather pipe from the later rocker covers. Cost reduction exercise ??

Post by **PSL184** » Sun Mar 22, 2009 11:15 pm

PSL184 wrote:It was only changed to get round emission regs.

^^^

Post by **bmcecosse** » Sun Mar 22, 2009 11:36 pm

Don't see how it helped with that ? I thought that remark referred to the leaky oil cap - which allowed fumes to spill out all over the engine - and into the cabin!