The Bubba trail continues!
Thread Starter
Le Mans Master
Joined: Oct 2006
Posts: 6,842
Likes: 285
From: Palmdale CA
The Bubba trail continues!
The 74' runs strong, pulls hard but you could still feel a roughness in the fuel delivery to the engine. Something didn't feel 'clean' as far as how it revved. So I started working on the Holley 4165 spreadbore, investigating what jets it had, power valve sizing and anything else I could see.
This is the bare metering block. Take a close look at the large hole in the bottom center and you can see the tiny fuel transfer holes for the Power Valve:
Now take a look at the gasket I found on the Primary side! The one on the left is the 'Bubba' gasket and the one on the right is the correct Holley gasket. The Holley gasket seals exactly on that raised surface around the PV hole, no bigger, no smaller.
Check out the 'Bubba' gasket as installed! Nearly covers up the holes and it had to disturb the distribution.
After installing the correct gasket and cleaning everything really well, I tested it. Much smoother idle and now it pulls clean and hard through the gears with no 'rough' feel. Just one of those things I expected on this car! Find it, fix it and flog it!
This is the bare metering block. Take a close look at the large hole in the bottom center and you can see the tiny fuel transfer holes for the Power Valve:
Now take a look at the gasket I found on the Primary side! The one on the left is the 'Bubba' gasket and the one on the right is the correct Holley gasket. The Holley gasket seals exactly on that raised surface around the PV hole, no bigger, no smaller.
Check out the 'Bubba' gasket as installed! Nearly covers up the holes and it had to disturb the distribution.
After installing the correct gasket and cleaning everything really well, I tested it. Much smoother idle and now it pulls clean and hard through the gears with no 'rough' feel. Just one of those things I expected on this car! Find it, fix it and flog it!
