Re: Venting outside air over engine

["David Teitelbaum" <jtrealty@xxxx>]

Hot is a relative term. The engine NEEDS to run hot to run
effieciently and all of the internal clearances are set so when the
metal of the motor is at operating temperature everything expands to
just the right size. To really know if you are running hot you need to
measure the temperature. Start off with calibrating the temperature
gauge. If the coolant is 220 then you can guess that the engine is
maybe 10 degrees hotter which would be normal. If it is having
detonation problems the things to look for are:
too lean a fuel mixture
initial timing off
vacuum advance or mechanical advance not working or not working correctly
Too much or too little or the wrong viscosity of oil
Make sure the coolant is a 50/50 mixture of anti-freeze and water
Wrong heat range spark plugs
Loose water pump belt
Bad pressure cap on header bottle
Too low an octane rating of the fuel you use
Finally the cooling system may not be carrying away enough heat from
the engine because of air in the system, blocked hose, bad fan,
plugged up radiater (air OR water side). The motor can live just fine
with the cooling system it has as long as it is working well. The
cooling system needs to be reliable with 15 PSI pressure in it to keep
the coolant from boiling.
David Teitelbaum
vin 10757




--- In dmcnews@xxxxxxxxxxxxxxx, "content22207" <brobertson@xxxx> wrote:
> Would love to route some air over my engine too, but don't think
> passenger side grill is the location. Engine intake really has to be
> connected to outside world. At 95 degrees, on a treeless highway, with
> hot freon in the condensor, and coolant above 220, my fuel mixture
> will predetonate (full throttle) if it's breathing under the hood.
> Guess hot air is last straw. Did clear up at higher octane (suggestion
> for summer driving).
> 
> Even though our engine compartments are brutal, are plenty of DeLo's
> that have been driven 100,000 miles that way. Probably pushed the
> limits of heat endurance, but they made it. Given lack of options
> (other than Q panel vents, where would re-routed air come from?), best
> option may be to keep cooling system at peak maintenance and lubricate
> with heaviest possible oil. Driving on the edge.
> 
> BTW: actual condition after purchase of cooling system in my
> advertised "maintained" car makes me wonder if a future rash of heat
> related failures, akin to recent TAB problems, is waiting.
> 
> Bill Robertson
> #5939
> 
> >--- In dmcnews@xxxxxxxxxxxxxxx, "cruznmd" <racuti1@xxxx> wrote:
> > I hear this a lot, regarding the mixture valve. I haven't driven my D 
> > yet enough to know either way, but I have an idea about another 
> > complaint that I've heard a lot of...
> > 
> > Most people I talk to say the PRV runs hot. Most say they'd like them 
> > to run cooler or have better airflow in the engine compartment.
> > Isn't there a way to turn at least that passenger side breather gill 
> > for the hot/cold air mixture valve into some kind of vent that washes 
> > air over the engine? Perhaps some kind of duct, or maybe even a small 
> > electric fan with a diverter?
> > 
> > I realize the engine doesn't see much air movement being mounted in 
> > the rear, but at least the cover is well ventilated, and it has a lot 
> > of room around it (relatively speaking). I'm suprised to hear folks 
> > say it runs so hot.
> > 
> > Also, for those who are interested, I've finally got all my 
> > transmission brackets, clutch lines and pieces all hooked up. I can 
> > finally get back to the engine/head work (and work standing up, thank 
> > God) I hope to crank it over during the first week of July.
> > 
> > Ever work on a car so hard, when you're done you're afraid to start 
> > it up?
> > 
> > Rich
> > #5335 -MD
> > 
> > 
> > 
> > --- In dmcnews@xxxxxxxxxxxxxxx, Roland Barmettler <roli@xxxx> wrote:
> > > Hi John
> > > 
> > > > Now that I hooked up the stove connection and the remaining hose
> > > > to the filter unit, it feels that the car runs better. Somebody
> > > > had told me earlier that in hot weather, this hot/cold air mixture
> > > > apparatus is useless. Have an opinion?
> > > 
> > > I came to the same conclusion: if you drive mainly in warm weather,
> > > it's not only useless but a performance impact. I also removed the
> > > mixture valve (which decreases air flow diameter by about a third,
> > > if you have a look at it) and I'm very pleased with the result.
> > > Before the change, flooring the pedal didn't do much better than
> > > just-not flooring it (ehm stupid to explain...), but afterwards
> > > there came more out of it when floored.
> > > So my mixture valve became a nice, cosy spot on the shelf in the 
> > garage 
> > > ;-)
> > > 
> > > Cheers, Roland
> > > VIN 11512