General Category > Quadrajet Carb Talk and Tips
Looking for best MPG on 454
akdale:
Just finished reading Cliffs book. Nice!
Not sure if the specs for the ford carb will be the same for the chevy.
So, It looks like the recipe 1 is the one for my engine and application?
and since my carb uses the hot air choke, no Idle bypass?
Anyone have a choke plate and screws kicking around? Someone removed the one from my carb before I got it. Choke is a good thing in Alaska.
Thanks,
Dale
akdale:
Cliff--
Is recipe 1 the one that I need to use? Do I need to change anything?
I have a 1984 31' class A Pace Arrow Motorhome.
I estimate that the weight is about 14,000 lbs.
It is on a P30 chevy truck frame.
The engine is a 454 that appears to be untouched although I am not sure if the factory put in a light cam for the motorhome application.
Timing is at 6 BTDC Supposed to be at 4 BTDC. (Vacuum disconnected and plugged from Dist.)
Mechanical and Ported vacuum Dist.
13-14hg Vacuum at 800rpm idle
Smog still hooked up.
Carb number= 17084502 2373HNX
Jets=73
Primary rods=49M
Secondary rods=DH
I do not have the Bleed and passage info.
My bits should be here tomorrow.
The tranny is a 3 speed turbo 400 which I would like to change to a 4 speed. (That is not in the cards yet until I can find a reasonably priced stand alone computer to manage it.)
Thanks in advance
Dale
akdale:
I can't edit the above post to insert the following info.
I destroyed an Idle tube removing it and will need a pair.
Not sure about the jets and primary rod sizes. They were working great.
Will reducing the size of the primary metering rods overly richen the mix and use more fuel, or will it make the engine use the fuel more efficiently?
Carb number= 17084502 2373HNX
Idle tube=.042
Idle down channel=.042
Upper Idle Bleed=.067
Lower Idle Bleed=.060
Idle Screw Holes .090
Jets=73
Primary rods=49M
Secondary rods=DH
Cliff Ruggles:
The best course of action for a stock carburetor on a stock application is to completely and correctly rebuild it with good parts using stock settings. Then test the carburetor and go back and address any areas of concern.
Leave the plug out over the APT screw, or tap the castings for a screw in plug, so you can raise and lower the primary metering rods without taking the top off of the carburetor.
Set the idle mixture screwsd for the best idle quality at the leanest settings, and APT screw back to the stock setting. If the stock setting is not known, or tapering is suspected, set it at 3.5 turns up for seated for initial testing. Using our "tip-in" procedure from the book to fine tune the APT will also get you very close to where it needs to be.
I would also inspect the distributor to make sure the mechanical and vacuum advance is working correctly. Timing is equally as important as fuel in the search for best engine efficiency and fuel consumption.....Cliff
akdale:
Thanks for the reply Cliff.
Does the above configuration look like it may be the stock configuration for the application?
The carb had been opened before I bought the motorhome.
Dale
Navigation
[0] Message Index
[#] Next page
[*] Previous page
Go to full version