Morris Minor Owners Club

Seb

Look at this other post, it shows what the setup should look like and is identical to my own.

viewtopic.php?f=4&t=72576&p=658485#p658485

Your problems will probably be caused by the fact you are taking the vacuum from the manifold, if you take it from the brass port on the carb body then it will be behind the throttle butterfly and not in front of it like it is now.

Phil

Thanks Phil,

As well as moving the intake to the carb body, would it be worthwhile fitting a PCV valve in place of the plumbing valve? Or are you suggesting I just take a hose straight from the tappet chest breather port to the brass intake on the carb with no valve in between?

Best wishes,
Seb

Apologies, I've looked at the photos in that thread again more carefully and spotted that the hose goes straight from the can type tappet chest breather to the brass inlet on the carb. Would still be interested in in fitting a PCV valve if possible, having read this explanation of how they work, anything that decreases leaks and fumes is OK by me: https://mgaguru.com/mgtech/engine/cv103.htm

Best wishes,
Seb

As long as it is not a forced induction engine the pcv valve off of a modern car should do the job, try to mount it in the orientation it was installed on the modern car as well.

kevin s wrote: ↑Wed Aug 26, 2020 9:15 pm As long as it is not a forced induction engine the pcv valve off of a modern car should do the job, try to mount it in the orientation it was installed on the modern car as well.

Thanks Kevin, I've got hold of a secondhand BMC PCV valve and ordered a replacement diaphram for it, from what I've read here https://mgaguru.com/mgtech/engine/cv103.htm it looks like it'll do the job perfectly. Will attach it to the brass inlet port on the carb and get rid of the unnecessary plumbing. Will report back.

Seb

Make sure that you have obtained the later type of PCV valve as the early type with the diaphragm vulcanized to the valve pin is no longer available.
The early and late valves both look the same from the outside so until they are stripped you will not know as to early or late.
The diaphragms are not interchangeable. The centering of the valve pin is controlled by the diaphragm in the early valve and by guides which are part of the body casting in the later valves.

The PCV valve is connected into the inlet manifold (as described in the link above) and not the carb.

This is the valve you do not want.

Thanks Phil,

It's a later one - 1970 - fingers crossed should be fine. It's the same part number as this one, which looks correct in the stripped down photo:

https://www.ebay.co.uk/itm/Mini-PCV-Man ... 3581087855

I didn't pay £84 for mine though!

Seb

Seb
You make no reference regarding my comment that the PCV valve should be fitted to the manifold and not the carb.
This is the set up required to fit the PCV valve to the inlet manifold plus a piece of 1/2" hose to connect the PCV valve to the manifold take off adapter. To fit the valve to the manifold you will need a manifold with at least the take off boss but preferably the threaded hole already installed.

Thanks Phil,

Apologies for missing that. I'm hoping I can use the existing connection to the manifold, where the current breather arrangement is attached - obviously I'll need to keep it upright as the diaphram needs to be horizontal. I'll leave the inlet on the carb blocked up as it is presently.

Best wishes,
Seb

Could you not use something like an MX5 one, in the mx5 it sits close to vertical with one end pushed into a grommit in the cam cover and the other end a hose to the inlet manifold, you could easily use it in line with a hose each side.

If you want measurements I can measure the one on our 96 mx5.

Thanks Kevin,

I've got the BMC style one arriving in the post tomorrow so I'll try that first, but yep, I'll try an MX5 type if that doesn't work, they seem to be relatively cheap and readily available. Thanks for the offer, I'll let you know if I go that route!

Seb

I'll keep trying to find one, will try asking Bryan as well.

Spotted this on eBay, states for Morris Minor, however I can't be sure it was from one, though I thought the Mini one was at a different angle?
If not I'll keep on looking, could become an obsession!........
Best wishes,
Mike.
https://www.ebay.co.uk/itm/A-SERIES-ENG ... Swt55fS-7y

You can buy a NEW pcv valve made by Smith's from Moss for around £65. I bought one last week.

part no. 13H5191.

jagnut66 wrote: ↑Tue Sep 01, 2020 8:20 pm

I'll keep trying to find one, will try asking Bryan as well.

Spotted this on eBay, states for Morris Minor, however I can't be sure it was from one, though I thought the Mini one was at a different angle?
If not I'll keep on looking, could become an obsession!........
Best wishes,
Mike.
https://www.ebay.co.uk/itm/A-SERIES-ENG ... Swt55fS-7y

Mike
That is certainly a Morris Minor one.
Phil P

jagnut66 wrote: ↑Tue Sep 01, 2020 8:20 pm Spotted this on eBay, states for Morris Minor, however I can't be sure it was from one, though I thought the Mini one was at a different angle?
If not I'll keep on looking, could become an obsession!........
Best wishes,
Mike.
https://www.ebay.co.uk/itm/A-SERIES-ENG ... Swt55fS-7y

Agh bother! I've not logged in this past week as I'm back at work full time and been rushed off my feet. The item has finished now - I don't think it sold but the owner is away until the 13th. I'll drop him a line and see if he'll sell it to me.

ampwhu wrote: ↑Tue Sep 01, 2020 8:39 pm You can buy a NEW pcv valve made by Smith's from Moss for around £65. I bought one last week.

Thanks - I'm a bit of a cheapskate and I found one on eBay for under £30. Cleaned it up and fitted a new diaphram and it looks good to me. The old diaphram was still in OK condition but for a few quid it's not worth chancing it. The spring and poppet valve are in perfect order so I don't see why it won't work - there's not much to these valves it seems!

Seb

I wanted to report back to conclude this thread, for the benefit of anyone who has similar problems in the future!

While doing some other work, Steve from this forum kindly added a can type breather to the tappet chest cover: At first the hose just went to a catch can, and the oil leak from the back of the scroll seal became a torrent (though nothing ended up in the catch can). However after fitting this hose http://www.minispares.com/product/Classic/12A1735.aspx between the breather and the inlet on the HS2 carb, the oil leak has disappeared entirely! I can't get over it - there has always been an oil leak of some sort, ever since I bought the car. I keep looking underneath when I park to see where the puddle is!
One complication is that as my car has been converted to automatic, the hose got in the way of the kickdown pulley. Luckily, the previous owner had blocked up the breather intake on the carb with exactly the female to male elbow fitting I needed, so I plugged the hose into that and everything works perfectly: I had to adjust the fuel mixture after connecting the hose to the carb, and this was a bit of trial and error. I had to turn the fuel jet adjustment nut one complete turn clockwise to enrichen the mixture, as there was now twice as much air being drawn into the carb than before. I then fine tuned the nut and the idle screw with the engine warmed up, until the engine was running at a reasonable speed (about 700-800 rpm idle) , not stalling when the lifting pin is raised, and not covering the spark plugs with soot! The car seems happier than before, and I'm going to keep an eye on the mpg and the colour of the plugs over the next week to see if it can be improved at all.

Sounds like you got there in the end.
I dont know why people keep messing around with other Heath Robinson breather set-ups when this type works perfectly well.

Phil P

Bump..

John ;-)

pgp001 wrote: ↑Thu Apr 29, 2021 8:52 am Sounds like you got there in the end.
I dont know why people keep messing around with other Heath Robinson breather set-ups when this type works perfectly well.

Phil P

Indeed - never let any 'mad professors' near your cars!