View Single Post
  #21  
Old 09-14-2022, 09:21 AM
Cliff R's Avatar
Cliff R Cliff R is offline
Ultimate Warrior
 
Join Date: Nov 2000
Location: Mount Vernon, Ohio 43050
Posts: 18,027
Default

+2 on tuning the AFB clones. I had a customer send me two "Marine Q-jets" that turned out to be Webber built AFB Marine clones. Instead of sending them back, which I typically would do if I didn't break them on one of my "hook shots" i decided to dive into them.

Right to start with they had the correct part numbers on them, and original to his twin 454 powered boat. However, when I checked them over closely they were NOT the same for jets, rods, IFR's, air bleeds, etc. So now the quandrum, which one do I copy to make them IDENTICAL units.

Thankfully he had tagged them and noted that his fuel meters showed one fo them using considerably MORE fuel than the other, so I started there. I was able to obtain the same jets and metering rods, and "modify" everything else to make them identical twins. However, on my test engine they didn't run all that great, very rich at idle, and noticable hesitation and overrich condition right off idle thru transition.

So I went into the parts catalog and bought multiple jet sizes and dual tapered metering rods for them and went to work. When I was done they were FLAWLESS, but I had several hundred dollars tied up in tuning components as mentioned above.

The owner got them, and few months later gave me a call telling me that they were also flawless on his end and his fuel economy was a LOT better than it had ever been since he purchased the boat.

Sadly we could have prepared two Marine Q-jets and done better, but his intakes had no provisions for divorced chokes and sourcing out Volvo Penta e-choke Marine Q-jets can be difficult and expensive......

__________________
If you can read this, thank a teacher. If you can read this in English, thank a Veteran!
https://cliffshighperformance.com/
73 Ventura, SOLD 455, 3740lbs, 11.30's at 120mph, 1977 Pontiac Q-jet, HO intake, HEI, 10" converter, 3.42 gears, DOT's, 7.20's at 96mph and still WAY under the roll bar rule. Best ET to date 7.18 at 97MPH (1/8th mile),
The Following User Says Thank You to Cliff R For This Useful Post: