Does your bus seem to run better in winter or when weathers colder

Someone will probably tell me ??, mine runs fine in summer too, but always seems just a tad more lively when the weather gets colder. Just been for a 40 mile tare up the Motorway n back and it just seemed to want to fly,no flooring it either ,overtaking ,uphill,all seemidly more ease, praps its just me enjoying it more :-

 

don't all cars run better when the air is denser and cooler......?

 

Colder air is more dense, more dense air has more oxygen in, more oxygen in the air means more oxygen in the combustion chamber which means bigger better stronger bang.... which means engine seems to go better.

 

denser and cooler air means more oxygen to make the spark go bang more efficiently is my understanding? hence powerful cars having intercoolers and suchlike? i'm sure a brain box will make me look dumb but thats the gist of it according to me, if you take a car up a mountain road for example it has less power due to thinner air innit?

 

see?

 

Yes better I reckon. If it makes your bus go better then thats a good thing Won't make it go bang if that's what you mean.

Nick

 

up mountain it's colder but thinner air so i guess it don't work there.... i suppose flat road on a cold wet day by the sea is the ultimate..... so all our busses should be F1 speed in this country! as for doing harm or not? wouldn't think so? the ultimate for anything that runs by producing explosions has got to be as much oxygen as you can give it

 

I Wondered why holmsens buses were quicker than ours ;D

 

A normal modern injection car should feel a little bit more responsive in colder weather due to the denser air containing more oxygen for combustion and the computer feeding in more petrol to maintain the correct air-fuel ratio. However, I don't think it'll make much difference on our buses with carbs on ???

 

carbs? not me guv.

 

Think RR used water vapour injection at one stage as a way of getting a short power boost on the Merlin engine. Once through the throttle "gate" I believe there was about a 15% increase for literaly a few minutes, enough to get you out of the poo in theory, before it wrecked the engine. So yes water vapour in the combustion air can make a difference. My old BSA used to run very sweet on a damp autumnal day.

 

I know 2 stroke is slightly different but the theory is the same. I have found that I can re-jett my two stroke carbs depending on humidity and altitude to get it to run at its maximum power.

I don't think it is the reserve of FI....

Nick

 

Well apart from nitrous oxide i have non of these so maybe theyve changed the hills round here.So no one else is experiencing this G then ???

 

'tis true. Old school carbed engines do run much better in cooler weather due - as above - to a nice dense, cool fuel/air charge which improves the volumetric efficiency of the engine. It's not your imagination.

Hot, expanding air into the engine reduces the efficiency, rather like trying to breath with your nose blocked up. A good reason to get the thermo-flap on your air filter fixed .

I wouldn't think you'd notice any difference on a modern engine - everything's engine-managed out.

 

Im not mad then :crossed