The V8 Owners Forum -

what i'm thinking is get an carb manifold and cutting the top off , the bit that holds the carbs ?
having looked at one i see there what looks like a core plug on the top
is there water up in there ?
what i'm planning is to put a single downdraft throttle body of some sort on there to make it even more simple for LPG only running

somthing along these lines ( missed this one )
http://cgi.ebay.co.uk/special-rover-3-5 ... dZViewItem
even maybe the front off a efi plenum just welded in place ??
or what ever is able to feed enough air
not looking for power just smooth running

ideas please ?
thankyou ......keith

Personally I would say you already have the best setup for what your doing. The Efi inlet system is built around providing torque, going back to a carb manifold like you linked to is a step backwards. Possibly not a bad upgrade on the standard SU system but that's about it and many would argue against that as well. I don't have a lot of experience on LPG but the mixer rings for downdraught carbs look like a horrible arrangement and nothing like as good as the single perfectly round system you can put on the EFI manifold.

thankyou Marki
the only problem i have at the moment is that is still can't get rid of the "extra air valve"
because there is no electrical connection to it now it has to reley on manifold heat to move it and it's being a pain , is there anyway to get rid of it ???
i asume it controls the air flow to the airbleed/tickover screw on the throttle body
also is there another way to control the tick over the manual says the 0.05 mm gap under the butterfly and yet this site... http://www.mez.co.uk/TuningTheRoverV8-pt11.html .. says closed completly ??

This is flapper right? If it is then that valve only control's fast idle on cold starts. Quite a good idea to keep that really and if you went over to a carb you would still have to rig up a cable to get fast idle. Its not a must have but its certainly a good thing to have and makes life easier when cold starting. Just rig a 12v supply to it and your done, there isn't anything fancy about it.
As for normal idle control I cant remember if the flapper has it or not but there might be a bypass on the throttle body with a sunken screw going to it. Basically just a screw going into a bypass port, screwing out increases idle speed.

Just had a look at one of your other posts and the pic here http://www.v8forum.co.uk/forum/viewtopi ... ght=#26594 shows it all. If you look at where your vac line connects to the top of the throttle body. Behind that you can see a hole, this is where the idle adjust screw is. Stick a screwdriver down the whole and wind it in or out to suit. You don't adjust the throttle itself on these systems for idle.

I think that if you check the circuit for the thermotime switch & extra air valve, it doesn't actually need the ECU to operate. I believe that the ECU just sticks 12V on the thermotime switch which then feeds the extra air valve (or the other way around).

So you may be able to keep the extra air valve & thermotime switch and feed them from the igntion +ve supply, and it will all work.

I could of course be speaking rubbish!

Chris.

no chris you are right , thats basiclly all that is involved , the trouble is i have had the holes welded up ... the injector ones and the 2 temp sensor ones ...not the temp gauge one though
but the extra air valve is also controlled by manifold heat as it's done by a bimetal strip inside that has a hating wire wrapped round it as well sensing the heat from the water

its very tidy under there now and i can remove the complete manifold in one piece as there is loads of room now to get to the bolts

do you know any thing about the butterfly setting Chris ( see my first post)
?

The butterfly should be as good as closed when idling. I think the factory recommend having it fractionally open to prevent it getting jammed.

And as Marki says, idle speed is controlled by a bypass, which is next to the butterfly and recessed.

Chris.