Essex vacuum plumbing

[oldgeebee]

I'm slowly getting the engine back together (1979 3000S with standard V6 Essex) and have got to the stage where I'm looking to replace the various hoses. Looking at the vacuum pipes from inlet manifold to carb and dizzy there is a double connector on the inlet manifold take-off and one tube has a yellow stripe along it.



There's also a stripe on the short branch going off to the carb but no stripe on any of the others.
The vacuum circuit also seems to have 2 parallel connections to the dizzy, interrupted in one path by some sort of circular device.
Is there any significance in the yellow stripe? And what is that device in the tube feeding the dizzy?

GB

[pridaux]

Hi GB
I have e mailed you pictures of mine hope they help
A

[Terminator]

The vacuum hose goes from the carb to the PVS (the valve on the inlet manifold) and also from the carb to the distributor through a 1 way valve then to the distributor vacuum capsule. The idea is for the PVS to be closed when the engine temp is under 71ºC and the vacuum is fed through the 1 way valve, locking the distributor advance on max to prevent misfiring.

When above this temp, the PVS opens and allows the normal carb to distributor vacuum operation, therefore allowing it to advance/retard the distributor.

I've no idea regarding the significance of the yellow stripe.

Information shamelessly taken from the M-Fix site

[oldgeebee]

Thanks for that - I think I've got it now (but it took a few minutes with a pen and paper till the penny dropped). I hadn't realised that the "double take-off" on the manifold was a valve although I did wonder why it seemed to be mounted on the water jacket!

Maybe the stripe is to make sure that the carb feed to the valve is connected to the right port (assuming that the valve has an in and an out)?

If I'm renewing the vacuum hose, I take it that the double connector is just a convenience - in other words I can just connect 2 hoses separately to the 2 tubes on the valve?

Thanks again,

GB

[Terminator]

You can see from the above diagram as to how Ford designed the system.

I wouldn't advise plumbing it your way, as by-passing the one-way valve may cause issues.

[oldgeebee]

Thanks - I like diagrams!

Terminator said:

I wouldn't advise plumbing it your way, as by-passing the one-way valve may cause issues.

er ... this matches "my way" (i.e. as I found it) or am I missing something?

The only difference is that in my system the air filter is fed from a separate tube on the carb but the dizzy circuit in your diagram is as per my photograph.

GB

Edited by oldgeebee on Friday 2nd November 22:41

[Terminator]

oldgeebee said:

er ... this matches "my way"

Then it should work fine

[whitewolf]

When I got my Taimar it had the original pipes setup with one way valve etc.
Then when I had to change the inlet manifold (stripped the threads to the thermostat housing) the new fuel I fitted only had two pipes.


The connector into the rear of the inlet has a threaded in plug, which I haven't never and the engine seems to run fine, even managed to make 30mpg on a 130+ miles run.


I'm not saying this is perfect but seems ok.

[oldgeebee]

With the PVS cutting in at 71C then the original plumbing is, apparently, making sure the dizzy is at max advance until the engine warms up. After that, it's the same as a single pipe. The pictures that Andrew sent me of his 3000S also showed just the single pipe from carb to dizzy and he has no problems with a cold engine. Since this only compensates with the engine cold then mpg on a long run would not be affected by either type of plumbing.
Maybe it needs to be brass monkey weather until a difference is noticed.

GB

[bluezeeland]

Graham,

Can I suggest you rebuild as found ? (the yellow line has no significance other then to distinguish) The system however does has a significance (when hot...) allowing for advance /retardation (try without(next year, lol)) Get some 4 mm i/d fuel line, and plastic T or Y pieces, this will do the job, think you want to check the correct action of the vacuum system within the dizzy as well.
I know pridaux runs without, but I am sure the engine runs better with all this plumbing, obviously with pre-ignition properly set.
The line from the air-filter (if you are still running it)operates a 'flappy' thing, which i've all binned, running a KN filter..


Please report findings !

best regards

Frank

[oldgeebee]

Frank,
it's all going back as original - I just want to make sure I learn as much as possible in the process. Once it's up and running then I can think about any mods that might improve things.

Next thing I need to understand is the cooling system and why there appears to be no bypass for the heater matrix so that the auto choke still gets its supply when the heater is set to cold!

GB

[phillpot]

oldgeebee said:

Next thing I need to understand is the cooling system and why there appears to be no bypass for the heater matrix so that the auto choke still gets its supply when the heater is set to cold!GB

The 3000S may be completely different but on the Taimar the heater control only moves a flap, water always flows through the heater matrix.

[oldgeebee]

phillpot said:

The 3000S may be completely different but on the Taimar the heater control only moves a flap, water always flows through the heater matrix.

Y'know, when I was typing I thought that maybe it's air-flow controlled but then I remembered a diagram I'd seen at some time showing a bypass. I need to check out the matrix box tomorrow - thanks for the pointer!

GB

[whitewolf]

phillpot said:

The 3000S may be completely different but on the Taimar the heater control only moves a flap, water always flows through the heater matrix.

Although mine isn't fitted to the car, mine would be the same as Phillpots. However at Papplewick I did see a few with (what's he proper work) diverters? Anyway it blocks water flow to the matrix, which I'm looking at utilising

[bluezeeland]

re the vacuum plumbing; you will find on checking (with a strobe light) what the hoses are doing (trial and error case, here)
re the coolant system, it is important to understand the flow direction, water goes from at the thermostat to the auto-choke, to the heater matrix and back via a hose and pipe to the pump. Indeed the the heater is air flow controlled, by another flappy in the box, wire-driven from the control on the instrument panel. Both can be surpassed (putting on a manual choke if so desired) and loosing the heating altogheter(which is not advisable)in which case a bypass-hose from the thermostat to the pump is required.

More items to discuss at NEC in a forthnight, looking forward to that a lot !

Frank

[bluezeeland]

btw; getting 'the system' as was, and then trying to improve is not only logical but also sensible. You will find that changing for instance airfilter or jets or whatever has and effect on all the rest (not to mention performance, i personnally do not care about mpg at all..........)
Obviously the above is called tuning, and not in the sense of yobo' in their vauxhall astra' !

[pridaux]

Hi Graham
Dont use mine as an example for the 3000s as at some point in time it has been set up like a 3000m set up which is different to ours i believe but not 100% sure i will probably change it back but will wait till i get her up to Adrian next year as i believe he does a good heater upgrade which sounds Hot??? which at present mine is just warmish.
Andrew

[oldgeebee]

OK - it didn't take long to confirm that the heating is air-flow controlled - I should have looked at the heater box before posting!
Still, one more "problem" out of the way - thanks for all your help.
There'll be plenty more to talk about at the NEC though, Frank!

GB

[tunepipe911]

Graham

there will lots off stuff to talk about at the NEC,

Rudy

[bluezeeland]

Yes,like his new purchase ! Congrats, mate !