fuel mileage question

[billythefish]

The question that I am about to ask might to some seem strange or even stupid , but then again I'm not a mechanic.
For instance, if were to cover the exhaust around the engine area, manifold pipe and the box under the wing with exhaust manifold heat fibreglass to contain the heat around these areas, would this then produce better fuel consumption because the engine area had become more cooler or would it reduce the consumption.
I have always been puzzled by people saying cold air and petrol produces a better mix in the carb, also would it in another way reduce the noise level as well inside the car?
answers on a post card to the Fool on the hill.
billy
:shock:
PS. Angel I have not been able to measure the trim tabs because of the bad weather, I have not forgotten.

 

[reggie]

chris bonnington

billy
no - no - a little bit same as an intercooler works and noise wise you wudnt no in a renault 4 - ha.

 

[billythefish]

thanks Reggie
billy

 

[reidalpine]

Hi billy! I tried wrapping exhaust-pipe with fibreglass-bandage ie exhaust-bandage, but upon having to remove it after only a few months for some needed work, I discovered that the pipe itself was disintegrating in big chunks or flakes due to the temp inside the pipe getting Too high...
The effect exhaust-bandage gives is maintaining higher speed of exhaust fumes out of exhaust system which in theory leaves pistons to produce more power to the wheels as motor "breathes out" more easily......
On a highly tweaked and tuned motor wher you're looking for the last % of power it might work On our 4's I doubt if you would feel ANY difference at all.
Personally I will not use this bandage-stuff on a mild steel exhaust again

-Cool and moist air usually gives a better degree of filling in the cylinders-Hot air/fuel mixture gives you a lower amount of air/fuel in the cylinder simply because the air expands as it get hot so leaves less room for petrol..hence the car goes slower (same as if you're not putting your led-foot on the pedal) this is why you gain effect if you mount a intercooler on a turbo-charged car.
Theoretical optimal petrol/air-mixture is around 14:1 14 parts air to 1 part petrol... -R.

 

[Steve Hennessey]

Hello Billy, the ideal ratio of air to petrol is approx 14.7:1. Cooler air is preferable to hot air and this is also affected by how far up you are from sea level. Your proposed mod would not make a difference to petrol consumption!! In the cold weather it is more ideal to have warm air enter the carb rather than keeping the choke on so that's why on the R4 (and other cars) there is a winter setting on the air filter. This saves the carb icing up in cold weather. Many carbs will have heated manifolds as well.

If you live in the mountains where the oxygen level is lower then the carb main jet needs to have a larger drilling. Some cars even had a setting for low and high altitudes. Carburation is very scientific and you can have lots of fun trying to get that setting perfect!!

 

[reggie]

billy
i bet tou wished you never asked - mmm
Reg

 

[bison]

Hi Billy,
I have the exhaust bandageing fitted, I did this to see if it would reduce some of the noise level, and the reduction is hardly noticeable, I don't see any change in fuel consumption either, I don't think it's worth the effort to be honest.
Alan.

 

[billythefish]

Reg,
if I didn't ask the question I wouldn't have known to buy the stuff or not, or what the results were.
Now I shall go down to my lab and analyse all the answers very carefully, before deciding to buy or not to buy, that is the question....and the answer is ...not to buy, and by doing so I have saved my self not only time but money, so Reg dear boy always think positive......unless they are about to hang you for stealing sheep.
Thanks again guys
billy getting older but wiser and always willing to learn.