36 replies to this topic

[satvinder]

Slight unrelate, but the same is true in the aviation industry with jet engines. They work more efficiently when there's drizzle or light rain as the added moisture in the air aids combustion.

the water helps to make the air dencer there fore helping the combustion and increasing power!!!

[Sprocket]

Lol at this thread

[satvinder]

y???????????

[yeti21586]

does this mean that if "we" can find a way of pumping cold water/air through the lil pipe then it will inturn help with combustion????

[Dan]

y???????????

Firstly, please stop typing in TXTSPK.

Why does Sprocket laugh? Because this thread is full of the same old myths being trotted out all over again. How fast do you think the charge flows through your inlet manifold? How dense do you think it is? Do you know that air is a very good thermal insulator? Given all that, how much heat do you think the charge is going to pickup from the manifold at delta-T of about 80 degrees in the fraction of a second it is in there for? How warm do you think it will get, bearing in mind that the charge is refrigerated by the action of the atomisation at the venturi in the first place? What actually does happen in a manifold with cold walls is fuel condensation. Fuel condeses on the manifold walls and flows into the ports as a liquid. Liquid petrol doesn't burn. This is the effect that many people confuse with carb icing but is in fact entirely different. This is why the manifold should be heated, to ensure that the fuel that has been atomised stays atomised and the mixture remains the same whatever the weather. It doesn't aid atomisation so much as maintain it once it's occured. Why did the Cooper S not have a heated manifold? Because it had twin carbs, so it had shorter and straighter manifold tracts. The charge is in the manifold for less time and doesn't flow round as many bends as in a single carb manifold so deosn't make as much contact with cold metal and doesn't tend to condense. An ally manifold will be colder than an iron one in the same circumstances and not simply because the iron manifold is connected to the exhaust manifold. Single carb ally manifolds need heating.

[stormintrooper]

i tend to go with what dan says as i have never found him to be wrong

[satvinder]

first the manifold isnt cold. you go touch ur manifold when the cars be on for a while, hot!!! so howq can the fuel condence on the wall!!! im gonna stick to what i think as ive done aerospace engineer for 2 years so i think i may be slightly correct

[Sprocket]

first the manifold isnt cold. you go touch ur manifold when the cars be on for a while, hot!!! so howq can the fuel condence on the wall!!! im gonna stick to what i think as ive done aerospace engineer for 2 years so i think i may be slightly correct

You will get on in life far better if you drop the superiority complex

Dan is right, and said pretty much what I would have if I could have been bothered. I couldn't be bothered as there is always some one that dissagrees, which I have no problem with. Every one is entitled to an opinion even if its wrong.

As for the manifold being warm. well drive at 60 for 10 minuets, pull over and stop, imediately get out, open the bonnet and then feel the temperature of the manifold.

the heated manifold has nothing to do with carb icing. Its purpose is to keep the fuel film on the inside of the manifold as thin as possible.

[haz]

HA! rich.

This is why I all but stopped using this forum.



Ok so there's a differing of opinions, but at the end of the day, it makes little difference if you plumb it in or not. I ran mine for 2/3 months with it on and not plumbed then about a year with it on, didnt re-tune the carb, didnt drive any differently, didnt notice anything other than a leak under my bonnet with a P-clip came loose on the manifold. If I was to ever use one again, I wouldn't bother plumbing it in. Incidently, when I ran a standard non-heated manifold for around 18 months too - again needed no carb re-tuning for changing weather. I dunno, maybe they're more effective if the wind is blowing southeast on a full moon? mmmm yes, I'm going for that explanation.

In future I will only take notice of the internal porting of the manifold and its gas flow capability.

[chappy]

im gonna stick to what i think as ive done aerospace engineer for 2 years so i think i may be slightly correct

that doesn't quite go with what on your profile does it?

just here to have fun, get to no people and learn as much as humany possiably about engines.

[dave21478]

y???????????

Firstly, please stop typing in TXTSPK.

Why does Sprocket laugh? Because this thread is full of the same old myths being trotted out all over again. How fast do you think the charge flows through your inlet manifold? How dense do you think it is? Do you know that air is a very good thermal insulator? Given all that, how much heat do you think the charge is going to pickup from the manifold at delta-T of about 80 degrees in the fraction of a second it is in there for? How warm do you think it will get, bearing in mind that the charge is refrigerated by the action of the atomisation at the venturi in the first place? What actually does happen in a manifold with cold walls is fuel condensation. Fuel condeses on the manifold walls and flows into the ports as a liquid. Liquid petrol doesn't burn. This is the effect that many people confuse with carb icing but is in fact entirely different. This is why the manifold should be heated, to ensure that the fuel that has been atomised stays atomised and the mixture remains the same whatever the weather. It doesn't aid atomisation so much as maintain it once it's occured. Why did the Cooper S not have a heated manifold? Because it had twin carbs, so it had shorter and straighter manifold tracts. The charge is in the manifold for less time and doesn't flow round as many bends as in a single carb manifold so deosn't make as much contact with cold metal and doesn't tend to condense. An ally manifold will be colder than an iron one in the same circumstances and not simply because the iron manifold is connected to the exhaust manifold. Single carb ally manifolds need heating.

Finally, someone has come good with the facts.
Its amazing how ill-informed a little bit of knowledge can make people, and this highlights the problem with internet, its rumour mill and chinese-whisper effect on any facts.

[mini mark]

i will go with Dan on this and i personaly have mine plumbed up.

[ohsuchislife]

sorry guys for starting this thread ... didnt want to upset anyone ...

good views too

[yeti21586]

so i should plumb mine in then and it will help with combustion


im getting horribly confused

so why do we need to ensure that cold air goes into the carb???

[Frog]

Just want to know your views on water heading a inlet manifold ... is it a good thing or bad thing .. i have fitted a HIF44 with a manifold that has water heading pipes but have not used them .. if i was from where would i take it from ...

love your thoughts

Different people with give different advise, the water heated inlet was originally developed for extremely cold climates to stop the carb icing up. I have run my mini's with both the manifold connected & not connected & I didn't really see much difference in it. All the Mg metro's came out the factory with them connected but that was for economy. I personally don't connect them.