Quick question about the BX 14 intake settings

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citsncycles
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Quick question about the BX 14 intake settings

Post by citsncycles »

My 14TGE has a manual control on the air intake to pull air from either the exhaust manifold or the front corner of the engine bay. Are there recommended temperatures for switching between settings?

Thanks in advance for any answers :D
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docchevron
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Post by docchevron »

Erm, yes, but I can't rememebr what!
To be honest unless we have a winter like a bad week in Cyberia I wouldn't worry about switching it over.
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Far too many BX's, a bus, an ambulance a few trucks, not enough time and never enough cash...
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Post by citronut »

if its the flap you manualy switch, you switch it over to use warm air from the manifold when the vaparised fuel in the carb freeze's,

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Post by kiwi »

When I had a BX14 the rule of thumb I was advised was switch it when the clocks changed. ie winter of the manifold, summer from the front. Whether or not that works I have no idea but having a carb freeze up once on a BX16 that did not have the warm air flow from the manifold it makes some sense. Less likely in summer to get an icing problem een in the UK.

Only remebered that today with the NZ clock change to summer time 8)
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Post by citsncycles »

if its the flap you manualy switch, you switch it over to use warm air from the manifold when the vaparised fuel in the carb freeze's,
That's the one - I believe that the larger engined models have an automatic system.
Whether or not that works I have no idea but having a carb freeze up once on a BX16 that did not have the warm air flow from the manifold it makes some sense.
I've had a similar experience when I used to run an H van many years ago. That used to need switching to the winter setting at around 12C because the speed the air needed to pass through the comparatively tiny carb used to cause it to ice up. Seeing how small the 14's carb is, I wondered if it was prone to something similar.

I also know that fitting the grill muff on a Dyane (which as well as restricting the air over the cylinders also stops a rush of cold air through the intake pipe) can make a difference of 5mpg in the winter!

I also know that the theory is that you want the air as cold as you can get without causing icing as the cool air is more dense, allowing more fuel/air mix into the combustion chambers.
Mike Sims
BX 19RD Estate Mk1 - Timex!
BX 4X4 Estate - Oh god, I've done it again!
BX 17RD MK1 - it called to me!
BX14 TGE, - SOLD
XM Turbo SD,GS Club Estate,Visa 17D Leader,HY Pickup,Dyane Nomad,Dyane 6,2CV AZL,Falcon S,Trabant P50,3x Land Rovers (88" series 1,109" series 2a FFR,series 2a Marshall ambulance),DKW F7, Lambretta LD150 x 1.5,Mobylette SP93,Ural Cossack,Ural M63,CZ 250 Sport,Honda Varadero 125,lots of bicycles & tricycles including (but not only) Sunbeams,Higgins & Bates!
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electrokid
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Post by electrokid »

I also know that the theory is that you want the air as cold as you can get without causing icing as the cool air is more dense, allowing more fuel/air mix into the combustion chambers.
That's something of an urban myth Mike. Cold dense air does contain slightly more oxygen than warm air so more will get into the combustion chambers - it can only be of use if the carb is already running rich - and it'll only make a difference to the car's performance at full throttle.

Now 'cars running better on wet days' true to a small extent - water vapour turns to steam and therefore expands when the fuel burns providing a very small amount of extra pressure / thrust.

As for the intake flap - difficult at the moment with temperature varying between frosts and 25° but as a general rule run the carb as warm as you can as long as you don't get vapourisation.

The lightest fraction in modern petrol is Pentane which has a boiling point of 36.1°C so getting close to that will cause a small amount of vapourisation to take place. 'When the clocks change' sounds pretty reasonable to me or maybe at the first frost. I'd say run it warm sooner rather than later - poor starting when the engine is hot is easier to deal with than a frozen carb.

On the other hand - if someone has an original owner's manual for the 14 it should tell us.
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citsncycles
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Post by citsncycles »

That's something of an urban myth Mike. Cold dense air does contain slightly more oxygen than warm air so more will get into the combustion chambers - it can only be of use if the carb is already running rich - and it'll only make a difference to the car's performance at full throttle.
That'll explain why I've noticed a difference with the Dyanes and similar stuff I've run in the past :lol: :lol: :lol:
Mike Sims
BX 19RD Estate Mk1 - Timex!
BX 4X4 Estate - Oh god, I've done it again!
BX 17RD MK1 - it called to me!
BX14 TGE, - SOLD
XM Turbo SD,GS Club Estate,Visa 17D Leader,HY Pickup,Dyane Nomad,Dyane 6,2CV AZL,Falcon S,Trabant P50,3x Land Rovers (88" series 1,109" series 2a FFR,series 2a Marshall ambulance),DKW F7, Lambretta LD150 x 1.5,Mobylette SP93,Ural Cossack,Ural M63,CZ 250 Sport,Honda Varadero 125,lots of bicycles & tricycles including (but not only) Sunbeams,Higgins & Bates!
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electrokid
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Post by electrokid »

:lol: :lol:
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scarecrow

Post by scarecrow »

Funnily enough I popped mine over to Hever last week - (I thought I'd do it whilst I it was on my mind). I now realise that I've probably exacerbated my vaporization issues...

Pffffff
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