For as long as they've been around I've run 17H 5MB petrols.

I have x 1 on a 17H. Only I see on 2.25 3MB there's 2 x oil-filler/breathers. Certainly looks easier to fill than my 1 x filler set-up. Why two? Is there another reason.

The oil filler is the one on the left in your photo and the breather is on the rocker cover. Doubtless the oil filler could be fitted to a 2.5.The advantage is that the oil goes straight into the crankcase instead of filtering down past the valve gear.
I have the rocker cover from a 2.3 5mb engine on my 2.5. It has a separate oil filler which saves having to undo the breather cap every time.

Quote from: Alan Drover on Feb 25, 2024, 09:26 PM...The advantage is that the oil goes straight into the crankcase instead of filtering down past the valve gear...

Yes, one small advantage, oil is going to get there one way or another. I'm thinking removed later becuase of budget constraints, and emissions to meet. Yet, that fails to explain why there in the first...

I was thinking to cobble one on for convenience.

A peculiarity of Land Rovers? Probably to facilitate oil filling.
You're probably right about budget constraints though.
I think agricultural tractors used to have a similar layout to facilitate oil filling.too.
You'll need the oil filler tube and crankcase plate to fit it to the 2.5.  It would be much easier to find one than cobble one up.

Question for those of you that've got one. Real world, which gets used?

On the 2.25 petrol engine that was previously in my Series 3 I always used the proper filler, the left one in the photo. It was much easier to undo the filler cap than to unscrew the breather.

 Originally land rovers had 2 open breathers (with a fine wire mesh inside which you cleaned and reoiled) if you look at the back side of the breather on the right side of the engine (engine facing forward on an old engine pre 1969) you will notice a 2 inch x1/4 inch slot. That slot is the breather for the crankcase (as well as the oil fill) so blow by pressure that gets past the rings does not blow out of the crank seals.
 On the front of the breather on the valve cover is another similar slot, that slot takes fresh air (the fan helps blow the fresh air into the front breather slot) that fresh air goes through the engine and out the back facing slot. This helps keep sludge from forming in the engine.
 This 2 breather system was land rovers answer to the road draft tube used on many cars in the 50s and 60s.
 The road draft tube system was a breather cap on the valve cover with a long tube hanging down from the crankshaft area which at road speed created a draft to suck the bad fumes out of the engine.
 Now you have a sealed system which incorporates a PCV valve along with lots of other pipes and hoses which reburns any blow by in the engine itself.

  Victor

The engine I've got in the garage is a late 3mb (K suffix) It's got an open cap on the filler tube (Slots underneath) and one sealed top with an elbow on the rocker cover.

The elbow on the rocker is piped to a drilling on the inlet manifold. I will fill with oil through the tube, and presumably the engine will suck its fumes out via the pipe, and fresh air will be drawn in via the filler.

The original (H suffix) engine which is well used, is a pretty smelly unit when hot, and oil fumes get into the cab. It's got open breathers on both.

When used with the non-return valve on the series 3 set up it provides a recirculatory system. It allow an amount of fresh air in , the crankcase emissions are fed into the inlet via the valve and burned.

This is the oil filler/breather set up on my 2.5 petrol. The 2.25 had the troublesome PCV valve on the inlet manifold. I did away with it by connecting the breather on the rocker cover to the air intake elbow and manifold by using a T piece and blanking off the breather outlet on the oil filler tube. It worked perfectly ok.

Ah, now we get the answers. You lot get it dealt with differently. Seems by late -vintage, LR lumps see less. A 17H gets short-changed on convenience. My set-up is not so common-or-garden, hence I've got injection plumbing and all else going on. Less space to fill etc when I need more. Yet I've only got 1 x filler.

11H gets 2 x fillers, you might argue there's 3 x ways to put oil into earlier lumps. See ABC.

11H got supplied as AD has things, seems some 17H got x 2. I got only a breather-cap, and it's a PITA.

Best  I try the dip-stick tube.


Reckon I'll put a wanted ad in the Trading-post.

Just bought this, never seen one, can I assume the matching cap has no vent to breath?

On the original 2.25 in my Series 3 there was an outlet on the filler tube to connect to the breathing set up.  I can't see one in the photo.

Yes I saw two varaints to these, I bought as above in black, there's another with tube outlet - see silver in this post - can't see I need such things on a 17H. There's also a spacer-plate 'tween block and filler pipe. Not sure why I need that, £6, so bought one anyway.

Spacer is a baffle to help mitigate oil being drawn  into the tube .