Smiths Emission Control Valve (ECV)

[philthehill]

After examining original specification Smiths ECVs and later specification Smiths ECVs it was found that there are differences to the internal body fitments of the Smiths ECV and which may cause engine running/performance difficulties when or after replacing the diaphragm.

The early valves had the plunger/washer vulcanised to the diaphragm which then kept the plunger central over the vent hole to the inlet manifold.
The four plunger guide fingers were only incorporated into later emission valves.

The later valves had the diaphragm separate to the plunger/washer but had the four plunger guide fingers to keep the plunger central over the vent hole to the inlet manifold.

The problem arises in that I have been unable to find original valve diaphragms with the washer/plunger vulcanised to it.
Fitting the later diaphragm, plunger/washer and spring to an early valve body does not guarantee that the plunger will be kept central over the vent hole to the inlet manifold which may lead to poor engine running and performance.

So the moral of this thread is if you have an early valve body without the plunger guide fingers and want to replace the diaphragm it may be prudent to replace the valve body with one incorporating the four plunger guide fingers.

https://www.ebay.co.uk/itm/CLASSIC-MINI ... :rk:9:pf:0

[Declan_Burns]

Good to know Phil, I wasn't aware of that.
Here's a photo of the one I installed on the MG where you can see the four plunger guide fingers. Dated 1966.
Regards

Declan

[philthehill]

Declan
Many thanks for the photos.
Whilst I have fitted several diaphragms over the years the difference in the internal valve furniture had not fully registered until answering Southerly95's request for a complete ECV valve or parts.
The ECV body offered and which had the plunger/washer vulcanised to each other came off a MG Midget inlet manifold (engine size and year unknown) but the valve is marked FVP2001/03.
The plunger/washer and spring were very badly rusted and unfit for further use
The NOS Smiths ECV I have and which has the four plunger guide fingers is marked FVP2003/10.
Phil

[ampwhu]

funny this as I bought a manifold a couple of years ago and there was one of these on it. I removed it as I didn't know what it was and its been in my parts cabinet since. I didn't know they sold for so much!

[les]

That's a coincidence, I also bought a manifold at the National a couple of years back, mainly for the valve, which was still attached. I thought it was worth the fiver!

[philthehill]

Les
Unfortunately it may be worth less than that if the type of ECV valve is one without the 4 plunger guide fingers (as per Declans photo above) and for which the vulcanised diaphragm washer/plunger does not appear to be available.

If anyone knows of a supplier of the vulcanised diaphragm washer/plunger and could post a link on here it would be appreciated.
Phil

[southerly95]

I’m sure Declan is aware that his pic doesn’t show the plunger referred to in this discussion. FYI I attach a pic of an earlier Emission Control Valve (with some rusty internals) and missing the later ‘fingers’. Regards, John

[philthehill]

The washer sat on the rim of the lid as shown in the above picture is normally fitted to the center bottom of the valve body and retained by a spring clip? or pressing?. The taper tip of the plunger valve seats into the hole in the centre of the washer.
The flame trap valve which fits into the counter bored center below the washer is missing.
The plunger/washer which is normally vulcanised to the diaphragm has rusted away which is what happened to my early valve.
The return spring is also missing presumed rusted away which again was the same as the spring in my early valve.
The diaphragm is also missing. The diaphragm in my early valve is still extent but is not useable. The pimples where the vulcanising process held the plunger/washer through a series of holes in the plunger/washer can be clearly seen. What was left of the plunger washer was still attached to the diaphragm by that method.

PCV valve 1.JPG (1.38 MiB) Viewed 3998 times

PCV valve 2.JPG (1.32 MiB) Viewed 3996 times

[Telpet]

Hello Phil, am attaching photos of my control valve setup, It is the later type 4 plunger guide cruciform with separate diaphragm. The diaphragm is new. Telpet.

P1000869.JPG (2.41 MiB) Viewed 3944 times

[ampwhu]

checked mine and it has the 4 things in the middle. I may look into fitting it if it is going to work? its in vgc.

[southerly95]

I started this thread as I wanted to use a combination of an HS4, 1275 mini cast manifold and the flat round air cleaner plus an ECV. All of the latter (excepting the ECV) came from our old 1275 GT and would like to use them again. There isn’t enough room for the emission control valve so have used a wider spacer block from an MGB HS4 (30mm) see pics attached. Note the manifold to valve hose is missing. There is enough space for the valve now and hope the set up will work ok?

[Declan_Burns]

Can you not just use a slightly longer interconnecting hose for clearance?
Regards
Declan

[philthehill]

The top of the ECV does not have to be horizontal - it will work in any orientation/plane/alignment.

See attached link for alternative orientations.

http://www.somerfordmini.co.uk/eshop/in ... age&id=174

[southerly95]

Thanks Phil this is the pic of the sideways located ECV you sent me, cheers, John

[Declan_Burns]

Here is the ECV valve at a good price £ 50.82 (inc VAT).
https://www.plminishop.com//UNCATEGORIS ... thing.html
Regards
Declan

[RobThomas]

Is there anywhere with a write-up on exactly how the valve is designed to function?
Thanks,
Rob

[southerly95]

Try this link, cheers, John

https://mgaguru.com/mgtech/engine/cv103.htm

[southerly95]

I failed to include a pic of the 1 and 1/2” carb and ECV upon installation but I’ve shown a pic of a similar installation. (Bottom pic) On mine there was insufficient space for the air inlet pipe and the fuel pump had to be moved.
Since then I’ve moved the air inlet facing the front of the car but yet to put the fuel pump back to its original position. See pic of that, cheers, John