Stinking rich..not in a good way
10-12-2009, 12:05 AM
#1
Member
Thread Starter
iTrader: (5)
Join Date: Jun 2006
Location: Montreal, Canada
Posts: 276
Likes: 0
Received 0 Likes
on
0 Posts
Car: '83 Berlinetta
Engine: 383 CI
Transmission: T56
Axle/Gears: 3.73, Eibachs, Tokiko Illuminas,
Stinking rich..not in a good way
Hi all. I've been trying for months to tune my Quick Fuel SS650 DP to run leaner at idle without any success at all.
First off, with cam specs at: 222°/230° @ .050", .509"/.528" lift, 113 centers is there any reason that I'm just wasting my time?
OK, assuming no...the carb came with .71 idle air bleeds, .31 idle feed restrictions and a 6.5 power valve. Timming is at 16* of advance before vaccume. I've tried incrementally increasing air bleeds all the way up to .90. The bigger bleeds need just a little more in the mixture screws to maintain the 14-15" of vaccume that car needs to keep from stalling after deceleration. But regardless, it doesn't clean up the smell.
Next I set it back up to stock and changed the idle feed restrictions from .31 down to .29. Apart from some part throttle drivability issues, no difference. Tried different air bleed sizes - no difference.
I changed out the power valve last night, just in case, but that didn't help. I haven't tried a power valve lower that 6.5 because with 15" of vaccume it should be closed at idle.
I'm out of ideas. Between my two engines (previous engine was bone a stock 350 from a TBI truck) I've had two Holley's, an Edelbrock 750AVS and now this one. I was sure that the adjustablility with this carb would be the answer but it's always the same. The best I can make it is to not make you're eyes tear while standing near the car. But it stinks.
Thanks,
Jon
First off, with cam specs at: 222°/230° @ .050", .509"/.528" lift, 113 centers is there any reason that I'm just wasting my time?
OK, assuming no...the carb came with .71 idle air bleeds, .31 idle feed restrictions and a 6.5 power valve. Timming is at 16* of advance before vaccume. I've tried incrementally increasing air bleeds all the way up to .90. The bigger bleeds need just a little more in the mixture screws to maintain the 14-15" of vaccume that car needs to keep from stalling after deceleration. But regardless, it doesn't clean up the smell.
Next I set it back up to stock and changed the idle feed restrictions from .31 down to .29. Apart from some part throttle drivability issues, no difference. Tried different air bleed sizes - no difference.
I changed out the power valve last night, just in case, but that didn't help. I haven't tried a power valve lower that 6.5 because with 15" of vaccume it should be closed at idle.
I'm out of ideas. Between my two engines (previous engine was bone a stock 350 from a TBI truck) I've had two Holley's, an Edelbrock 750AVS and now this one. I was sure that the adjustablility with this carb would be the answer but it's always the same. The best I can make it is to not make you're eyes tear while standing near the car. But it stinks.
Thanks,
Jon
10-12-2009, 08:00 AM
#2
Supreme Member
Re: Stinking rich..not in a good way
How far are the butterflies open on the pri and sec ? If there open to much then you will be rich at idle. Where is your float level at also ?
10-12-2009, 09:20 PM
#3
Member
Thread Starter
iTrader: (5)
Join Date: Jun 2006
Location: Montreal, Canada
Posts: 276
Likes: 0
Received 0 Likes
on
0 Posts
Car: '83 Berlinetta
Engine: 383 CI
Transmission: T56
Axle/Gears: 3.73, Eibachs, Tokiko Illuminas,
Re: Stinking rich..not in a good way
Floats are good - just a hair under QFT's reference mark by the sight glass.
I've experimented with having the rear butterflies a touch open. Right now they are closed. With smaller bleeds I can have the front side all the way closed. With the bigger bleeds I have them open but just a bit - so that with the carb flipped over the transfer slot is exposed as much tall as it is wide (looks like a square).
Thanks,
Jon
I've experimented with having the rear butterflies a touch open. Right now they are closed. With smaller bleeds I can have the front side all the way closed. With the bigger bleeds I have them open but just a bit - so that with the carb flipped over the transfer slot is exposed as much tall as it is wide (looks like a square).
Thanks,
Jon
Thread
Thread Starter
Forum
Replies
Last Post
Ghettobird52
Tech / General Engine
15
12-29-2023 08:23 AM
