They didn't run SU's with a single fixed needle to meter fuel....
Sent from my iPhone
On 20/01/2012, at 2:39 PM, Bob Spidell <bspidell at comcast.net> wrote:
> How did the old 'ramcharged' Dodges and Chryslers get away with it?
>
> Bob
>
>
> On 1/19/2012 3:56 AM, Chris Dimmock wrote:
>> Hi Alan,
>> No, you cant pressurise a cold air box.
>> Never set up your cold air box so it rams air in at higher than
>> atmospheric pressure straight into your carbs
>> If you do, the end result will be too much air, not enough fuel, a
>> lean mixture and a destroyed/ melted piston or 4. Probably at high
>> rpm.
>> A cold air box is just that. A cold air box - the ability for cold
>> air to be sucked into a carb on a hot engine. A cold air box
>> generally
>> is not sealed. It is open at one end (or somewhere) so it can't
>> pressurize and force air into the carbs at higher than atmosperic
>> pressure.
>> Think about an old supercharger for a minute. The carb - often an SU
>> on the sort of superchargers found on BMC cars - is on the outside,
>> it
>> mixes the fuel and air which is then compressed and fed to the
>> engine.
>> I.e it is a fuel air mix which is compressed, not compressed air
>> alone.
>> I've seen the results from some homemade "cold air sealed ram
>> boxes" -
>> and trust me, unless your dad owns a piston company, you don't want
>> to
>> go there.
>> So the end issue is the 'flow' into the cold air box is pretty
>> irrelevent, it's just a way to get cooler than underbonnet air in
>> front of the carbs.
>> Whether the volumetric area of a 100m cold air box is enough - no
>> idea.
>> But pressurize or seal a cold air box on SUs at your own peril....
>>
>> Best
>> Chris
>>
>> Sent from my iPhone
>>
>>
>>
>>
>
>
> --
> *******************************************************************
> Bob Spidell San Jose, CA bspidell at comcast.net
>
> *******************************************************************
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