Lotus Elan

Crankcase breather / airbox

PostPost by: birdthom » Sun Sep 18, 2005 2:37 pm

Dear All

A few questions:

1. I noticed a while ago that my crankcase breather pipe was missing. My car is a standard spec srint running on webers with the original airbox setup. I now have a NOS replacement breather pipe (metal pipe with gauze in one end) but it is shorter than the gap between the head and the airbox. Am I right in thinking that I am going to need a length of flexible piping to connect the breather pipe to the airbox? Apart from vandalising my garden hose, does anyone have any recommendations for this?

2. There is a plastic plug/ring in the head where the breather pipe should fit in. It's proving difficult to get out. What's the best way to remove it? Once it's out, does the breather pipe slot straight in?

3. Are there any setups which are easier/better to use than the standard airbox setup? I know it needs to deal with the fire risk and get cold air in from the front of the engine bay, but the standard setup takes up huge amounts of space and is prone to leaks. The Wilkins book says not not mess around with the standard setup but frankly I think it's junk. Any opinions on this?

Any advice would be much appreciated.

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PostPost by: types26/36 » Sun Sep 18, 2005 3:04 pm

Yes, there is a length of hose to connect the pipe to the airbox, the hole in the head (where the pipe goes in) has a grommet in it, the pipe just pushes into the grommet.
All the grommets I have seen are rubber, they turn hard with heat and age and can be difficult to get out as they break up, the only way is to "dig" them out but part of it can sometimes break off and fall into the breather chamber in the head.
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PostPost by: david.g.chapman » Sun Sep 18, 2005 3:16 pm

I had a missing breather pipe when I got my Stromberg +2. I found that a length of 15mm copper pipe (used in central heating systems) fitted quite well. I had to put two slight bends in it though, and then painted it black to look better.

To stop it moving about in the grommets I added two short lengths of plastic tubing with an OD of 18 mm or so, that was a tight fit over the pipe. this tubing was positioned to start about 10 mm from each end.

This arrangement goes all the way from the head to the airbox. There is no flame trap fitted however. Having never seen the original pipe - should there be?

Dave Chapman.
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PostPost by: SADLOTUS » Sun Sep 18, 2005 6:43 pm

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PostPost by: Foxie » Sun Sep 18, 2005 6:45 pm


I tapped the hole in the cylinder head to take a threaded brass nipple (the head was off at the time). The crankcase breather can then be routed to the airbox or preferably to an oil catch bottle. This cures a major source of oil leakage.

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PostPost by: john-c-elan+2 » Mon Sep 19, 2005 7:43 pm

Tom, heater hose pipe - u know the black stuff that carries the water to & from the heater is the right diameter to fit breather pipe to airbox. Available off the roll from most motor factors, even halfords ! Take yr breather pipe in and make sure its right internal diam to fit. Get 2 jubilee clips and jobs done. jc
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