Click on image for the lowdown. 
====
| | |
1 members (mason86),
60
guests, and
1
robot. | | Key: Admin,
Global Mod,
Mod | | | Forums66 Topics128,050 Posts1,055,671 Members48,426 | | Most Online14,466
Apr 26th, 2026 | | AD Chevy Trucks  Over 6,000 pictures Brad Allen has an awesome collection of Chevrolet factory pictures that he has set up from film strips. Check them out!
Lots of work on Brad's part ... pure enjoyment (and references) for you!
| | THANKS!
For helping keep this great
old truck web site
on the Internet for over 30 years! and not clogged down
with Ads!  Again, thanks!
| | | | Joined: Feb 2000 Posts: 5,200 'Bolter | | 'Bolter Joined: Feb 2000 Posts: 5,200 |
Last edited by Joe H; 07/28/2021 1:04 PM.
| | | | | Joined: Mar 2014 Posts: 4,481 Moderator, Electrical Bay | | Moderator, Electrical Bay Joined: Mar 2014 Posts: 4,481 | Wow! 3 Rochester Bs, pulleys that might or might not line up, a belt tensioner with a different pulley width and a thermostat housing about 20% corroded inside with what looks like a spider's nest in there. This guy is well on the way to creating a very special engine. When he gets it started it will be time to buy stock in Chevron.
~ Jon
1952 1/2 ton with 1959 235 | T5 with 3.07 rear end
| | | | | Joined: Feb 2004 Posts: 29,769 Kettle Custodian (pot stirrer) | | Kettle Custodian (pot stirrer) Joined: Feb 2004 Posts: 29,769 | Now I know what Forrest Gump's Mama was talking about, and I don't mean "a box of chocolates"! At least when Ford did that with the 312 engine, they built a pressure box around the carburetor!
Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!
| | | | | Joined: Dec 2008 Posts: 1,922 'Bolter | | 'Bolter Joined: Dec 2008 Posts: 1,922 | IIRC all of the Paxton (fixed drive ratio) & McCullough (variable ratio) blowers used that method in aftermarket kits, and factory Packard and Studebaker V8.
John Erb (of K-B Silvolite) wrote extensively about these, Google "John Erb supercharger" for a long list. | | | | | Joined: Dec 2018 Posts: 2,450 'Bolter | | 'Bolter Joined: Dec 2018 Posts: 2,450 | JoeH Do you think they are going to hold that with 4 little main bearings and those little skinny rods ??? | | | | | Joined: Jul 2008 Posts: 326 'Bolter | | 'Bolter Joined: Jul 2008 Posts: 326 | The early T-Bird 312 V8s were blow through. I think they even used that weird "tea pot" Holley.
SimS | | | | | Joined: Nov 2002 Posts: 2,763 Carburetion specialist | | Carburetion specialist Joined: Nov 2002 Posts: 2,763 | Ford used two different "Holley type 4000" carburetors on the 312 with the blowers.
Neither were made by Holley, but they were sold by Holley.
Good luck on finding any information on these in the Holley books.
Jon.
Good carburetion is fuelish hot airThe most expensive carburetor is the wrong one you attempt to modify. If you truly believe "one size fits all," try walking a mile in your spouse's shoes!The Carburetor Shop | | | | | Joined: Feb 2000 Posts: 5,200 'Bolter | | 'Bolter Joined: Feb 2000 Posts: 5,200 | I put together a Macho-TA for a local fellow, 1979 Trans Am with a turbo charger (1 of 9 dealer made cars ). The Quadrajet had a special plate under it that provided boost to the outer ends of the throttle blades via small holes drilled in the base plate. This was their way to seal the throttle shafts so pressurized fuel mixtures were not blown into the engine compartment. It also had a special vacuum advance unit which retarded the timing under boost ( Turbo Corvair I believe ). On top of that it had a boost line going into the top of the fuel pump so fuel pressure would rise as the boost went up. I am not sure what was done to the inside of the Quadrajet, it was rebuilt by the guys that designed to turbo system back in the late '70s.
I wouldn't know where to start on the three carburetors, what happens inside them under boost? Where is it likely to leak from? How much boost will the floats take? Lots of questions need to addressed. The Macho-TA didn't have any boost control, it went full boost, as much as the turbo could make, no blow off, or waste gate. I think what kept it alive was the small turbo size didn't make much more then 7 -8 lbs of boost. A modern turbo would blow the crank out of the block!
Last edited by Joe H; 08/01/2021 12:47 PM.
| | | | | Joined: Nov 2002 Posts: 2,763 Carburetion specialist | | Carburetion specialist Joined: Nov 2002 Posts: 2,763 | Where there is a "will", there is generally a "$way$".
Have done a number of "blow-through" genuine Carter AFB carbs, and also a few Holley 4000 carbs.
The Rochester B (opinion) has enough issues without pressure; don't think I would want to be trying these.
Listing modifications REQUIRED for the Carter AFB:
(1) Throttle shaft vacuum seals
(2) Idle mixture control screws pressure seal
(3) Accelerator pump shaft pressure seal
(4) Fabricate aluminum baffles for INSIDE the brass float pontoons (no, Virginia, foam floats do NOT work!)
(5) Boost reference for the fuel pump (depending on boost)
"Pull-through" carbs are MUCH easier!
Jon.
Good carburetion is fuelish hot airThe most expensive carburetor is the wrong one you attempt to modify. If you truly believe "one size fits all," try walking a mile in your spouse's shoes!The Carburetor Shop | | | | | Joined: Dec 2008 Posts: 1,922 'Bolter | | 'Bolter Joined: Dec 2008 Posts: 1,922 | "4 little main bearings"?
#1: 2.684” (front)
#2: 2.715” (2nd)
#3: 2.746” (3rd)
#4: 2.777” (rear)
By comparison:
Chrysler 426 (gen 2) hemi 2.75"
Chrysler 392 (gen 1) hemi 2.6875"
Chevy LS 2.65"
Chevy 427 2.75"
Ford FE 427 2.75"
GMC Atlas 2.756" | | | | | Joined: Dec 2018 Posts: 2,450 'Bolter | | 'Bolter Joined: Dec 2018 Posts: 2,450 | PANIC I suppose your right,makes me feel a little better about doing one of those rear main seals. That million dollar CNC machine looked like over-kill to me.Can do it with a Qwik Way boring bar. | | | | | Joined: Dec 2018 Posts: 2,450 'Bolter | | 'Bolter Joined: Dec 2018 Posts: 2,450 | panic sorry my posts go hide | | | | | Joined: Dec 2018 Posts: 2,450 'Bolter | | 'Bolter Joined: Dec 2018 Posts: 2,450 | | | | | | Joined: Dec 2018 Posts: 2,450 'Bolter | | 'Bolter Joined: Dec 2018 Posts: 2,450 | panic Agree, forged shaft too ! | | | | | Joined: Dec 2018 Posts: 2,450 'Bolter | | 'Bolter Joined: Dec 2018 Posts: 2,450 | | | |
|
|
