Crank-case breather

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Wally2
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Crank-case breather

Post by Wally2 »

Hi, On my English 1966 Moke there is a breather pipe from the rear tappet cover up to the breather control valve which sits on top of the inlet manifold.
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The tappet cove has a curiously bent steel pipe brazed to it which the flexible pipe from the control valve connects to. When I first got the Moke the rubber diaphram was missing but I managed to obtain one and fit it. When I came to remove the cylinder head due to the gasket blowing, I had great difficulty removing the exhaust pipe from the manifold as the pipe from the tappect cover was hard up against the exhaust clamp also the flexible pipe had been so close to the exhaust manifold that it was partially melted. On reassembly I assumed that the tappet cover was perhaps on the wrong way round as the pipe 'u' bend went down from the cover, was full of oil and interfered with the exhaust. So I tried fitting it the other way round, only to find that it then collided with the exhaust manifold preventing the cover from seating properly, so in the end I cut the steel pipe so that I could at least assembly the exhaust and prevent the flexible pipe from melting.
After asking a few people the suggestion was made that I obtain another blank tappet cover, fit it and block up the hole in the inlet manifold. to that end I managed to get a pair of covers from e-bay for 99p plus postage.
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These covers are from a later mini and I'm thinking that the one with the breather on may well fit and miss the exhaust manifold.
So do I fit this one or fit the blank and chuck the control valve etc. away? ( I'm usually of the opinion that if something has been designed, manufactured and fitted its usually for a good reason and so I am usually reluctant to delete said item).
Chris
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Dean
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Re: Crank-case breather

Post by Dean »

When I was fitting my Maniflow system, I read (somewhere) that as the back breather pipe would not fit with the freeflow manifold in place, fitting a blank tappet cover and using only the rocker cover breather pipe was OK. However, when I came to fit the exhaust, I found that the back breather did just fit so I left it in place. I'll see if I can find the original article I got that from.
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Re: Crank-case breather

Post by Wally2 »

Hi Dean, Thanks for that, it would be useful if you could find the article, As I say I am reluctant to do away with it unless someone can confirm that all works well without it.
I should also just like to say that not having the Moke that long, that this forum is great for getting advice, where else could I keep posting my little problems on for someone to give good advice about?
Thanks alot to everyone helping me out, its great to know that you are there, and that a smile is not far away with some of the posts/responses!!
Thanks guys
Chris
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Re: Crank-case breather

Post by Wally2 »

Hi, I've been looking at engine pics of English Mokes and I've not seen any with the crankcase breather control valve, so is it normal for it to be removed and a blank tappet cover fitted?
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Re: Crank-case breather

Post by Bodge »

I have not seen any Mokes with closed circuit breathing either, but details about it are included in the mechanical parts list.

What is interesting is that cars with closed circuit breathing may have had the engine prefic "8AN" rather than "8AC" and it may have been a requirement for the North American market as there are other Mokes on the North American Register with 8AN engine numbers. It appears that a tappet chest cover with an oil separator pipe similar to yours would have been used on these engines.

I am not sure about the benefits of a closed circuit breathing system but you may simply be able to replace the tappet chest cover with a conventional U shaped pipe and remove the valve on top of the manifold and simply run the engine without. Roger
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Re: Crank-case breather

Post by Wally2 »

Hi Roger, The tappet cover I have on at the moment was the conventional 'U' shaped pipe (until I cut it so it fit better), the one in the photo above is one I'm thinking of replacing it with (from a later mini) as I think it may well fit better. Either that or I fit the blank one and blank off the tapped hole in the inlet manifold.
Chris
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Re: Crank-case breather

Post by Wally2 »

Janz, What has your 'Minty' got? i.e. has it got two plain tappet covers?
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Re: Crank-case breather

Post by Bodge »

The tappet cover in your photo (with the oil separator) is the correct one for an engine with closed circuit breathing. You would then connect a length of pipe from this to the side of the breather control valve on the manifold.

If an engine is designed to have a breather pipe, then personally I would not replace it with a blank tappet chest cover. Roger
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Re: Crank-case breather

Post by Wally2 »

Hi Roger, think I'm going to fit the cover with the oil separator on and see how it goes.
Chris
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Re: Crank-case breather

Post by clm »

Hello Chris,

My moke which has the engine numbered very close to yours (8AC-U-H3100) has the swan neck open style breather with no gulp valve.


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Chris
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1961 Morris Traveller - Bent but repairable
1960 Morris saloon.. err wagon.. err Pickup, yeah that's it! - My first car
1980 Mini 95 Van shell - pickup load floor donor
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Re: Crank-case breather

Post by Nigel(no top)Sykes »

Did you sneak out in the dead of night to take those pics ?
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Re: Crank-case breather

Post by clm »

Well not if you go by your time of day.... Granted it was kind of late here :)

Chris
1965 Austin Moke - Rust was not free, I paid dearly for it
1961 Morris Traveller - Bent but repairable
1960 Morris saloon.. err wagon.. err Pickup, yeah that's it! - My first car
1980 Mini 95 Van shell - pickup load floor donor
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Re: Crank-case breather

Post by Wally2 »

Hi Chris, Thats what mine had but fitted the other way round! i.e. with the 'U' bend downwards and over towards the exhaust clamp. It just filled with oil (as it would!) and quite alot of it got sucked up into the inlet manifold. When I had the head off to replace the head gasket, I tried fitting it the same as in your picture but it then collided with the exhaust mainifold. I've managed to fit the new one with the oil separator tube and it just fits (does just touch the radiator bottom hose though), figers crossed it seems to be performing ok. I'm pleased that it fits ok as like Roger I am reluctant to delete something which has obviously been designed and manufactured to do a job, otherwise they wouldnt have gone to all that trouble.
I will take some pics and put them on here later.
Cheers
Chris
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Re: Crank-case breather

Post by Wally2 »

Hi Chris, piccies as promised.
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Image
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Re: Crank-case breather

Post by janz »

Wally2 wrote:Janz, What has your 'Minty' got? i.e. has it got two plain tappet covers?
Chris
Hi Chris, thgis post completely escaped me - sorry :shock: Yes, you guessed right, no cranck case breather valve and 2 plain tappet covers. 8AC engine number too.

Picture not from best angle. Will take one from rear of engine later.

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