Warming up an Engine
03-03-2008, 06:13 PM
#1
2nd Gear Member
Thread Starter
Join Date: Jul 2007
Location: INDY
Posts: 297
Warming up an Engine
I have a 68 302 v8, and usually when its cold, I have to wait several minutes to have the engine warm up to drive it.
Just a basic stupid question. What is the difference between newer cars, where you can turn them on instantly and drive them, but with the older ones, we have to wait and warm them up.
Is there something you can add to my mustang to instantly driveably like the newers ones?
Again, I know its a stupid question, I just do not know the answer.
Just a basic stupid question. What is the difference between newer cars, where you can turn them on instantly and drive them, but with the older ones, we have to wait and warm them up.
Is there something you can add to my mustang to instantly driveably like the newers ones?
Again, I know its a stupid question, I just do not know the answer.
03-03-2008, 09:27 PM
#8
Join Date: Jan 2008
Location:
Posts: 25
RE: Warming up an Engine
I don't know where you're at, but on my chokeless '68, I never had to warm it for more than 15 seconds before I could drive. Then again, it ran a metering rod size or two too rich and it was in a California "winter", after all. Really, out of all the carb'd cars we've had, I've never had a problem starting + runningwithout choke. It may be that yours is running too lean (too little fuel)?
03-04-2008, 01:21 AM
#9
6th Gear Member
Join Date: Apr 2007
Location: California
Posts: 10,468
RE: Warming up an Engine
+1 to a good choke and running a bit lean. And EFI will compenstate for the cold air/engine provided all the sensors are within range. Still though, whether it's EFI or carb it's a good idea to always let the engine warm up before you drive, get the oil and internals up to operating temp. Just because you CAN drive right away with EFI doen't mean you SHOULD.
03-04-2008, 04:14 AM
#10
6th Gear Member
Join Date: Oct 2006
Location: Cork, Ireland
Posts: 6,417
RE: Warming up an Engine
the tech side of that:
a carb basically works in such a way that it sprays fuel into the airstream your engine is sucking in.
more air->more fuel
now when it's cold outside and your carb and intake manifold are freezing then the carb will accurately spray fuel, but most of that fuel is condensating on the carbs and intake manifolds cold walls. less fuel but same air arrives in cylinder->lean mixture
for this the mixture has to be richer when starting cold.
Now a FI car will measure the air/fuel ratio constantly and thus no problems running cold.
The carb uses a choke to regulate that. No choke->horrible cold start
a carb basically works in such a way that it sprays fuel into the airstream your engine is sucking in.
more air->more fuel
now when it's cold outside and your carb and intake manifold are freezing then the carb will accurately spray fuel, but most of that fuel is condensating on the carbs and intake manifolds cold walls. less fuel but same air arrives in cylinder->lean mixture
for this the mixture has to be richer when starting cold.
Now a FI car will measure the air/fuel ratio constantly and thus no problems running cold.
The carb uses a choke to regulate that. No choke->horrible cold start