MWFan
Well-Known Member
I have loved "hot rods", muscle cars, performance vehicles since I was in elementary school but I never owned one until last May. I retired and treated myself to my 64 Polara. Its a 440, Pushbutton 727. Dana 60 .354. The previous owner evidently never attempted high performance, he had 6 classic Mopars and was 78 years old, a cruise night guy. It had a Edelbrock 600 sitting on a loose Mopar aluminum intake manifold that was sucking air when I brought it home. I stuck a Holley 750 vacuum secondary on it and replaced the valley pan gaskets. I have hobbied with mechanical stuff, motorcycles, boats and my MGB, and got "a little knowledge ", which as we know is dangerous.
Last few days I decided to get serious about eliminating the bog when I stomped the pedal. Read a lot about it and assumed some stuff that was wrong. Like "bog" was a function of carburetor tuning only. Read here from some wise people who mentioned getting the timing right first. This is one of the best pieces of tuning advise I have heard. Reading here how much initial advance the 440 prefers, I quit paying attention to stock specs and set it at 18 degrees. Lo and behold, the idle adjustment on the Holley 750 actually started improving manifold vacuum. Before, with initial timing at 10, I couldn't see much difference wherever I set the jets, I had very little vacuum. Now I could get much higher vacuum readings, and see the vacuum fall off if I adjusted away from that precise setting. Took the car for a ride and the bog was MUCH less, but still too much. I had read about carb squirters helping, so went and got a 34 to replace the 31 that came in the Holley 750, and WHAT A DIFFERENCE. This is a relatively stock 440, 9.5/1 compression, 354 posi, stock trans with a kit, stock converter, and I can now literally flame the tires just stepping in it. The car just freakin ROCKS!
Thanks to all of you who have been trying to explain this stuff to us newbys (like me) who THOUGHT they knew something about tuning a big block Mopar.
Bernie
Last few days I decided to get serious about eliminating the bog when I stomped the pedal. Read a lot about it and assumed some stuff that was wrong. Like "bog" was a function of carburetor tuning only. Read here from some wise people who mentioned getting the timing right first. This is one of the best pieces of tuning advise I have heard. Reading here how much initial advance the 440 prefers, I quit paying attention to stock specs and set it at 18 degrees. Lo and behold, the idle adjustment on the Holley 750 actually started improving manifold vacuum. Before, with initial timing at 10, I couldn't see much difference wherever I set the jets, I had very little vacuum. Now I could get much higher vacuum readings, and see the vacuum fall off if I adjusted away from that precise setting. Took the car for a ride and the bog was MUCH less, but still too much. I had read about carb squirters helping, so went and got a 34 to replace the 31 that came in the Holley 750, and WHAT A DIFFERENCE. This is a relatively stock 440, 9.5/1 compression, 354 posi, stock trans with a kit, stock converter, and I can now literally flame the tires just stepping in it. The car just freakin ROCKS!
Thanks to all of you who have been trying to explain this stuff to us newbys (like me) who THOUGHT they knew something about tuning a big block Mopar.
Bernie