[Vwdiesel] Gasser's 'n' diesels'n' threads

LBaird119 at aol.com LBaird119 at aol.com
Wed Jul 21 21:41:17 EDT 2004

In a message dated 7/21/2004 5:14:09 PM Pacific Standard Time, 
mark at shepher.fsnet.co.uk writes:

> Loren your point about 'head' in a carb is interesting; but I think 
> wrong... at a guess most carbs operate on a suction process; so raising float level 
> has little or no effect until you reach the point where  overfilling results 
> in spillage into the throat that then means that idle screw adjustable 
> leanness begins to disappear; ranging from an intermittant dribbling causing 
> 'yellow flareups' on idle or fast idle; up to a permanent yellow flame. But I agree 
> too low a float exposes the jets either at idle or under load. Just grab one 
> of those transparent spark plugs [ I wish there was one for the diesel :o( 
> ..] .

  I wasn't thiking that "head" made any big difference but conceivably could 
make a small difference.  Most likey the real difference is in how much 
"splash" or starvation you get on corners or acceleration.

> As for our VE heating connundrum.. the only simple way to find out if 
> friction effect is greater than cooling effect is to insert a thermometer in a 
> 'tee' on the return line a few cm from the banjo..If using a short run to a 
> pickle jar then a thermometer on i/p (in pickle jar for ease) will give our i/p 
> temp.  lag an area of the puimp near to the outlets and up stream of the 'lift 
> pump' and a thermometer tucked underneath will give an estimate of  temp of 
> post  lift pump but pre piston.
> Come to think of it 'ow about the oil squirters peeing on the piston walls; 
> isnt this similar?

  Technically I s'pose the oil is warmer at the exit than after or before the 

squirters.  The pressure is about  1/100 of what it is inside the injector 
pump.  I still see the heat as mostly being from the bypass "squirt" 
friction.  Get a flat plate, oil up your hand and rub it on that plate.  
get HOT if you push hard.  Pressure and friction.  The lubrication 
keeps wear down but there's still friction.  I've read somewhere some 
comment on how much of the heat in engine oil comes from the bearings.
There's no contact so it's oil, pressure, friction.  The flow keeps it from 
getting too hot.  Not quite the same example but the same elements.

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