Lotus Elan and Lotus Elan Plus 2 Forums

I tried a similar arrangement to ElanDNAs and found that even after welding a deflector plate on engine side of the blanking plate I still had excessive amounts of oil coming out into the catch tank-and yes, the hose went up (vertically) and yes, the jack shaft is short. The solution was the simple "L" shaped plumbing fixture in the front of the valve cover-no leaks now!

A banjo fitting would look the least like a bodge.

Heavier though!

Elan DNA
What motor mounts do you have? Do you like them?

I plan to use a similar breather arrangement with a Tee from the head breather, then to a catch tank.

Hi,
I agree with Davidb.
I already have the breather in the cam cover but decided to fit another one at the drain tube location (I don't use the drain tube) but now get excessive oil in the catch tank. It won't be going back on.

Regards
Steve

I'd expect, if you take breather off at fuel pump or head to block tube you'll need a deflector plate, as oil is thrown up from crank rotation.

If you have std length dissy/oil pump crank, and you remove the fuel pump the meter blinking plates have a deflector plate spot welded to inner side of the fuel pump blinking plate, oil hits it and is deflected back towards the sump. I'd expect with shortened oil pump/dissy cam that the splash from crank would also require a deflector if you wanted to fit a breather in this location.

I've previously used Alfa Guila Sprint 1600/GTA type engine breather outlet, fitted to front of cover facing exhaust so any oil that may enter is flowing uphill before the 90 Deg turn in casting to breather pipe attachment, sadly these are like finding hens teeth now.


Cheers

V

The moulded in compartment on the right-hand rear end of the head is an oil condensing chamber.
This replaces the tin external chamber used on the original Ford engines.

Oil that condenses in there drips back through the conical rubber drain tube back into the sump.
Omitting the chamber and/or drain will result in a lot of oil in your catch tank. The conical tube works both ways; vapour from the sump can go up (as in original breather) condense and run back as liquid, and vapour from the cam chamber can condense in there to return vapourised oil to the sump as liquid.

Excess pressure in that condensing chamber exits out of the side hole and either drips some oil onto the road via a downwards tube or is sucked into the in-box for any oil vapour to be burned by piston 4.

It follows that any extra breather that you fit that doesn't include a condensing chamber will collect quite a lot of oil in its catch-tank.

Hi Bill,

I am sure what you have said is correct but from the last few years with no drain tube I have only got a small amount in the catch tank.
I think it might be common to leave it off in racing but not 100% sure about that.

Regards
Steve

patrics wrote:I already have the breather in the cam cover but decided to fit another one at the drain tube location (I don't use the drain tube) but now get excessive oil in the catch tank. It won't be going back on.

I have been considering a similar breather : did you plug the head above the drain tube ?

patrics wrote:Hi Bill,

I am sure what you have said is correct but from the last few years with no drain tube I have only got a small amount in the catch tank.
I think it might be common to leave it off in racing but not 100% sure about that.

Regards
Steve

I presume this is a catch tank for a forward extra breather? If the original breather hole in the head near the right-hand back is still connected to the inbox, then the oil vapour will go there & get sucked in and burned.

Hi
I will take some pictures - hopefully tomorrow

Regards
Steve

a bit cheaper alternative to the TTR race version, I just came across this steel repro of the Hart breather (no affiliation on my part)

https://www.ebay.com/itm/Lotus-TwinCam- ... T9&vxp=mtr

Thanks! I have ordered one.

That looks great but USA unfortunately otherwise I would have had one

I'm thinking of trying one of these and turning it upwards slightly:

http://www.burtonpower.com/breather-elb ... fp280.html

Or one of these:

http://www.burtonpower.com/breather-elb ... fl847.html

jono wrote:That looks great but USA unfortunately otherwise I would have had one

I'm thinking of trying one of these and turning it upwards slightly:

http://www.burtonpower.com/breather-elb ... fp280.html

I'm considering one of these; it's a Cortina type that replaces the mini tin chamber above the fuel pump (I would plug the head hole above, the one coming from the Lotus specific chamber where the top end of the conical rubber hose goes) - the rubber part is an early elbow that was originally plugged to a steel tube venting to the road towards the rear at an angle, it would fit the rearmost hole where on later Lotus there is a lightly angled tube to feed cyl. #4 with block fumes.

I've seen fuel pump blanking plates that have an oil deflector inside, but I may also adapt an oil condensor of sort before the catch tank (e.g. a piece of alloy tube filled with coarse metal wool and going up).

My objective is to increase venting without punching a hole in the head cover of my street car, I would keep the original vent, and both outlets would be directed to the oil catch.

Yeah, I would like to avoid that too but I am set on having to drill the front of my cam cover as most of the 'wisdom' suggests this is the best way to provide effective additional crank venting to a TC.

I've already fitted one of the rubber elbows in place of the rear head vent to airbox and lead this to atmosphere. I'm going to gather both pipes into a catch tank

Jon