TR4/4A Closed Circuit Breather

[Fireman049]

A Register member has a TR3A fitted with a TR4/4A engine with the closed circuit breather system.

If we removed the system and blocked off the inlet manifold intake could we let the engine

ventilate through the rocker cover vent pipe?

 

Tom.

[ctc77965o]

I would imagine you'd get quite a bit of oil spraying out there as the crankcase fumes blow thru the pushrod tubes to atmosphere.

must be better to vent the crankcase direct if you're gonna go to open breather

[Robin Powell]

Yes you certainly can. My 4A does exactly that via a catch tank and a rubber pipe down to just below the chassis.

[Fireman049]

Thank you Dave and Robin ~

Tom.

[Rob Salisbury]

Yes you certainly can. My 4A does exactly that via a catch tank and a rubber pipe down to just below the chassis.

Ditto, and the stuff you get in the catch tank you really don't want going through your engine, it's all oily,gooey,watery,slightly acidic gunge, though where your supposed to put the contents of an emptied catch tank I'm not really sure, mine goes in with old oil from an oil change and to the local re-cycling centre.

Cheers Rob

[Geko]

As Dave says - the TR4 crankcase vent pipe located on the block is much better. You'll find out if oil starts leaking from the gaskets as 80% of the crankcase pressure remains below the cylinder head. You can test that by removing the dipstick with engine idling and see if oil splashes on the inner wing (and your shirt). If it does then you may think about further relieving the crankcase pressure with something like this:

 

[peejay4A]

... or remove the plug from the blanked off hole where the snorkel crankcase breather goes on early engines and install a snorkel. Not easy with the engine in situ as posts passim have described.

[ianc]

A crude, cheap but effective ploy is to attach a length of rubber hose to the tube coming out of the rocker cover, loop it over the top of the cover and then run it down the left side of the engine, past the petrol pump until it is alongside and level with the end of the crankcase breather.

Like this, you won't trap water vapour in the rocker cover, yet oil won't splash out because the hose rises over the top of the cover.

I have used this arrangement since I fitted an alloy rocker cover in 1998.

Ian Cornish

[monty]

Racetorations breather kit for me. Not cheap but appears to do the job efficiently & just has to be better than putting all that muck that is accumulated in the catch tank back into the engine.

Regards.

[Bulatovic]

Hi Guys! Sorry to open an old question - but I'm just getting to know my newly acquired TR4A and it's one leaky thing! The oil seems to come mostly from the fuel pump area and the tubes on the head where the pushrods go through, and it's also a bit moist around the engine/gearbox lower area - not sure if that's actually leaking from there or is just dirty from other oil spils.

 

Now i've read that it'd be a good idea to add a breather pipe to the crankcase, but am reluctant to try and open the existing plug - as i don't intend to take the engine out just yet, nor am i ready to ditch the mechanical fuel pump and use its place for breather as seen here.

Now, how big a tube would i need to properly vent the crankcase? I've got a spare fuel pump and something got me thinking if it's possible to make a threaded hole on the side of the pump where the lever sits (some 1/2" hole) and add an adapter and a hose to go from there.

 

Would that be even remotely a wise idea or should i live with the moist engine block until i decide to take it out and do the venting the proper way - by removing the plug below the pump?

 

Cheers!

 

Luka