idle adjustment
08-30-2011, 12:33 PM
#1
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idle adjustment
i was watching the holley carb DVD
and when viewing the idle section
they stated to use the recommended idle settings from the vehicle
simple if i new were the engine came from
is it that important
what can idle have an affect on besides hoe much gas its sipping at the stop light?
what idle speed would you recomend
i have 440 posibly a early 1976. attached to 727 trans
holley 750 cfm, manual choke not set up yet
edlebrock 440 performer intake
with a spacer between carb and intake
the distributor looks stock and has a vacuum advance thats piped to the carb
its all in a 59 f-250 cant remember the tare weight at the moment if it matters
and when viewing the idle section
they stated to use the recommended idle settings from the vehicle
simple if i new were the engine came from
is it that important
what can idle have an affect on besides hoe much gas its sipping at the stop light?
what idle speed would you recomend
i have 440 posibly a early 1976. attached to 727 trans
holley 750 cfm, manual choke not set up yet
edlebrock 440 performer intake
with a spacer between carb and intake
the distributor looks stock and has a vacuum advance thats piped to the carb
its all in a 59 f-250 cant remember the tare weight at the moment if it matters
08-30-2011, 03:31 PM
#2
Hell no, put them where you want. A '76 engine would orginally been "horribly smogged" with a very lean carb and calling for reduced (retarded timing) settings and very lean idle. Many original engines in this era had serious drivability problems
One caveat is your distributor. If you have the original, it would pay to do some research on the advance curve. Some of these distributors had very long very slow advance curves, not what you want for performance.
I'd suggest "trying" 10 BTC or so, set your idle screws for highest RPM/ best/ smoothest idle, and then just touch them "lean" maybe a quarter turn. It is important to set mixture when the engine is good and hot
Set in this order:
1 Point gap/ dwell (if you have points)
2 timing
3 rough in idle speed if necessary
4 adjust idle mixture
5 set in gear and check curb idle LAST
One caveat is your distributor. If you have the original, it would pay to do some research on the advance curve. Some of these distributors had very long very slow advance curves, not what you want for performance.
I'd suggest "trying" 10 BTC or so, set your idle screws for highest RPM/ best/ smoothest idle, and then just touch them "lean" maybe a quarter turn. It is important to set mixture when the engine is good and hot
Set in this order:
1 Point gap/ dwell (if you have points)
2 timing
3 rough in idle speed if necessary
4 adjust idle mixture
5 set in gear and check curb idle LAST
09-05-2011, 11:49 AM
#3
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i havnt thought of doing research on my distributor yet
thanks for the advice.
with the engine revved the engine sounds fine
at idle its just ta bit rough ( 500) i think its abut 6-700 now still rough
could this be because my spark plug wires are not in the air
can they arc through the wire??
i dont have mounts on my valve covers im still looking for some wire
mounts
one last one hopefully not too far off base with the question.
-is it better to cut and crimp my own wires the ones i got from the shop were wrong sizes one caught on fire (exhaust manifold) i relocated it
but than i shocked me so i know i need to replace.. maybe there some flame resistant out there
thx in advance---
thanks for the advice.
with the engine revved the engine sounds fine
at idle its just ta bit rough ( 500) i think its abut 6-700 now still rough
could this be because my spark plug wires are not in the air
can they arc through the wire??
i dont have mounts on my valve covers im still looking for some wire
mounts
one last one hopefully not too far off base with the question.
-is it better to cut and crimp my own wires the ones i got from the shop were wrong sizes one caught on fire (exhaust manifold) i relocated it
but than i shocked me so i know i need to replace.. maybe there some flame resistant out there
thx in advance---
09-05-2011, 12:10 PM
#4
Mopar Lover
a -
Is the cam stock? That can make the biggest difference. Most stock 440s will be happy around 700 - 800 in neutral, dropping to about 650 in gear. If there's a bigger cam, then it might be higher.
You can check the advance on the dist with a timing light. 10o intial to about 32o total should work. Again, that's dependent on the cam.
If it's a stock motor with stock exhaust manifolds you can use stock wires, if you route them the way the factory intended. With headers and if you want to get creative, you will almost have to cut your own from a universal set.
Good wires should not arc, even if lying on the engine. If the wires were poorly assembled or heat damaged (like too close to the exhaust manifold), they can arc no mater where they are.
Archer
Is the cam stock? That can make the biggest difference. Most stock 440s will be happy around 700 - 800 in neutral, dropping to about 650 in gear. If there's a bigger cam, then it might be higher.
You can check the advance on the dist with a timing light. 10o intial to about 32o total should work. Again, that's dependent on the cam.
If it's a stock motor with stock exhaust manifolds you can use stock wires, if you route them the way the factory intended. With headers and if you want to get creative, you will almost have to cut your own from a universal set.
Good wires should not arc, even if lying on the engine. If the wires were poorly assembled or heat damaged (like too close to the exhaust manifold), they can arc no mater where they are.
Archer
09-08-2011, 09:29 AM
#5
Mopar Lover
[QUOTE=auerdoan;73980]i was watching the holley carb DVD
and when viewing the idle section
they stated to use the recommended idle settings from the vehicle
simple if i new were the engine came from
is it that important
what can idle have an affect on besides hoe much gas its sipping at the stop light?
what idle speed would you recomend?
As far as speed I would go with what works best for your engine.
To set the mixture screws
first get the engine up to temp,
then kill it,
then screw the screws all the way in
and back them out 1 1/2 full turns
restart the engine,
with it up to temp and @ idle
turn one in 1/4 turn then the other one in 1/4 turn
go from one to the other 1/4 turn at a time
until you hear a RPM drop
then back both out 1/8 turn
Or if you have a vacuum gauge keep all mixture screws the same amount of turns to get the highest vacuum reading
you can
If it has a performance cam you might need to change the power valve
For the power valve size you will need to
check your engine vacuum @ idle ( in gear if auto trans )
then cut your reading in 1/2 for a power valve size ( with a performance cam this needs to be done )
and when viewing the idle section
they stated to use the recommended idle settings from the vehicle
simple if i new were the engine came from
is it that important
what can idle have an affect on besides hoe much gas its sipping at the stop light?
what idle speed would you recomend?
As far as speed I would go with what works best for your engine.
To set the mixture screws
first get the engine up to temp,
then kill it,
then screw the screws all the way in
and back them out 1 1/2 full turns
restart the engine,
with it up to temp and @ idle
turn one in 1/4 turn then the other one in 1/4 turn
go from one to the other 1/4 turn at a time
until you hear a RPM drop
then back both out 1/8 turn
Or if you have a vacuum gauge keep all mixture screws the same amount of turns to get the highest vacuum reading
you can
If it has a performance cam you might need to change the power valve
For the power valve size you will need to
check your engine vacuum @ idle ( in gear if auto trans )
then cut your reading in 1/2 for a power valve size ( with a performance cam this needs to be done )
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