Carb problems again

[P3Steve]

OK chaps bit of a problem that just doesn’t seem to want to go away, about three years ago the accelerator pump on the Solex carb on my P3 75 started to leak fuel and as suspected the fine rubber diaphragms inside had perished. A kit was obtained and fitted but the carb was found to have a cracked/broken emulsion tube and the only replacements I could get were from a Ford V8 pilot carb in which the internal holes were slightly larger than the original Rover ones but as they say beggars cant be choosers. Any way it ran ok if a little rich but I was getting 20+ to the gallon so was content to live with it.
After a year the leak returned and again the carb was stripped and cleaned nothing was found but a few gaskets were replaced and once back on the car seemed to run ok but this kept happening about once a year and for the last year the MPG figure has dropped through the floor. So question is dose any one know where one could get a new carb or two is there an alternative carb say a Webber that can be made to fit or has any one fitted the twin SU’s from a P4 with any success, can they fit on the original P3 head by just changing the manifold or do you have to change the head and if it works dose any one know where one could get hold of this assembly. Any help would be appreciated on this as its turning out to be the Achilles heal for this car.

[lakesrally]

Hi Steve,
I believe the usual conversion is to fit the complete head and twin carbs from an early P4 75 to the P3 engine. I've not done this myself though, I have been quite happy with the P3 carb and have done may thousands of miles with it. It suffered from a sticking needle valve when I first put the car on the road but otherwise it has been fine.

Best of luck,

[Paul Gregory]

Hi Steve,
Sorry that you are still having trouble with the carb. Like Stewart I still run the original carb on my P3 and have had little trouble, but that of course doesn't help you. As Stewart has mentioned a twin carb conversion can be achieved by fitting an early P4 75 head and carbs. It needs to be from a Cyclops or a very early post cyclops car (before the '54 model year I think, but I'd need to check to be 100% certain on when the change occured) as the later 75's had a spread bore and single carb arrangement. On the P4 the inlet manifold is cast as part of the head (except for the late Weslake head which was on the 110) so it is not possible to take just the manifold and carbs across onto a P3 engine. I suppose another option would be to fit a P4 engine, but that seems a bit extreme.
Not too easy to suggest where to get a head from though as the early cars are quite thin on the ground now - might be worth giving Richard Hedger from Lincolshire a call as he deals in second hand parts for P4's. I'll PM you his phone number.
Regards
Paul

[neil.henderson]

Hi steve,
I've just recently bought two P3's and have one running (though not well enough for a roadworthy test yet). The emulsion tubes were damaged on both cars.
I've put one carburettor in for rebuild with a carb expert here in Murrumbateman - I managed to get replacement emulsion tubes from Gower & Lee in the UK - Jeff is very helpful there. They get new emulsion tubes made from brass because they know the old ones tend to break.
Only thing you have to watch is the external diameter of the emulsion tubes where they slot into the base of the carburettor - make sure you send Gower & Lee the diameter at the emulsion tube base - I had to get them to make up a collar for mine because the original was too narrow.............
Their email address is sales@gowerandlee.co.uk.

Good Luck Neil

[marnol74]

Hello folks,

I haven't managed to get along to the forum for some time and I wonder if I am too late to help here with the carburettor problem. However, I thought that I would add that I had the carb on my 75 refurbished by the Carburettor Exchange in Leighton Buzzard (01525 371369) who were extremely helpful and appear to have done a super job. My carb looked positively modern compared to some of the other examples on the bench so they are used to dealing with obscure or obsolete parts.

I hope that this can be of some help.

Best

Matthew

[P3Steve]

No not to late, the problems still on going so any help is appreciated

[neil.henderson]

Hi P3steve,
My P3 is also running very rich, and the carb has been completely rebuilt with new needles & emulsion tubes, + gaskets.
I am becoming very suspicious of the air filter, so took it off & this made a major difference, though I am still to check the colour of the plugs after running with no filter, will do this tonight.
Question now is - how best to clean the air filter - does the paraffin soaking technique mentioned elsewhere work well? Should I try to take the filter apart?
Any tips from on cleaning the air filter?

Thanks Neil Henderson
p.s. its 26 degrees here today

[P3Steve]

A good question Neil there seems no easy way of taking it apart to give it a proper clean and like you I wonder if washing it out with paraffin would just loosen up 60 years of muck with out really cleaning it, I guessed that worked back in the day but even Rover didn’t expect the cars to be around 60 years later. I might look at if I can sympathetically take it apart at some point and wonder if any of the other forum members have been down this road if so how did they do it?

[Paul Gregory]

I haven't tried to clean my filter at all. I know using paraffin was the usual way to clean an oil bath filter but I have no idea about the one on the P3. Sorry can't be of any help on this one.
Regards
Paul

[lakesrally]

I was going to try to break open my original air filter to clean it properly because I was also worried about it being choked up. I had tried cleaning it out with petrol and paraffin over the years but it never seemed to do much. Then I found someone selling a virtually new complete filter so that went on the car and the old one went to the back of the garage to be forgotten about.

Best of luck with trying to get it open.