Last week was rather fun for me and my 1966 Coronet 500 as well, not because I drove it around like Jeff mentioned he did with his Coronet, but because I was actually able to accomplish a few important things on my "to do" list. This past week, the restoration shop next door to my buddy's shop that rebuilt my Holley 750 carb a few weeks ago, did several things on the car to help set it up for street use. This restoration shop specializes in all types of restoration and performance work for vintage hot rods, including sheet metal fabrication and body work, high performance engine and transmission work, high performance tune-ups, high performance brake system work, electrical system work, etc.
This time around, I wanted them to dial in the carb as far as the primary and secondary jetting, power valve and carb settings. I also wanted them to look at the issue that I've been dealing with regarding my Master Power front power disc brake conversion kit which was installed back in 2000. That issue involved poor engine vacuum output at idle due to my Mopar Performance camshaft, which is the original design of the .284 / .484 Purple Shaft hydraulic camshaft, (part #P4120235) which is rated at 68 degrees of valve overlap and a 108 centerline. With this camshaft in place, along with my Edelbrock Torker single plane intake manifold and my Holley 750 carb which has been upgraded with a Holley secondary metering block in place of the stock Holley secondary metering plate, my 440 is only producing a verified 8 inches of vacuum at idle, which is well short of the 18 to 20 inches of engine vacuum recommended by Chrysler to properly assist options such as power brakes and factory air conditioning.
Knowing I had this problem with the brakes back in 2000, along with plans to reinstall my cars factory a/c system, or a variation of that system, with some newer technology aftermarket parts such as a Sanden a/c compressor and maybe a serpentine belt and pulley set-up, I also ordered and installed one of the Master Power Brakes 12 volt electric vacuum pumps (part#AC2724K) and plumbed it to the vacuum booster with a check valve. While this vacuum pump did seem to supply an increased supply of vacuum at idle and low rpm's for the power front disc brakes, the pump also seemed to be running almost continuously, so that problem still needed to be addressed at the time the car was parked in 2005 to avoid wear and tear on the expensive vacuum pump and the drain it was putting on the cars electrical system when it was running.
So fast forwarding to last week, here's what was done.
(1) Used a gas analyzer to see if the carb jetting, power valve and carb settings were correct for best output and drivability on the street. As seen below, they were fairly close, as only minor jet size changes were needed along with a power valve change and a small timing change.
(2) Changed the primary carb jets from the Holley .70's that I had in place, to a set of the slightly larger Holley .73's that I supplied to them from my Mopar Performance (part #P4349307) Holley Main Jet Assortment kit.
(3) Changed the secondary carb jets in my Holley rear jet block from the Holley .80's that I had in place, to a set of the next size larger Holley .81's that I supplied to them from my Mopar Performance (part #P4349307) Holley Main Jet Assortment kit.
(4) Checked and reset the carbs float level and adjusted the idle and mixture settings.
(5) Changed the 6.5 inch hg rated Holley power valve (part #125-65) that I had in place, to a Holley 3.5 inch hg rated power valve (part #125-35) that I supplied to them from my Holley parts supply.
(6) Changed the engine timing from the 36 degrees total that I had it set at for drag racing, to 13 degrees base and 34 degrees total.
(7) Added and plumbed a Summit Racing black metal vacuum canister. (part #SUM-G1464. This canister was mounted underneath the Master Power vacuum pump on a newly fabricated steel mounting bracket, which is located where the factory battery tray and battery were originally mounted in the car. (my Optima Red Top battery has been mounted in the trunk since 1991)
(8) Added a secondary engine vacuum source line with an additional check valve from the carb to the new vacuum canister via a brass tee that will allow me to add the new Summit Racing vacuum gauge (part #SUM-G3125) that I have on order and coming to me in the next couple of days.
(9) Add an electrical relay, 20 amp fuse and the electrical wiring to the vacuum pump to reduce the electrical load on the vacuum pump and the cars electrical system.
The car still isn't home yet, because after paying the bill at the restoration shop, we took the car next door to my buddy's shop so that this coming week we can install all of the new Year One and SMS Restoration parking brake parts from the foot pedal assembly back to the rear brake assemblies. I will also be installing a new B&M "T" style shifter handle that I just purchased from Summit Racing (part #BMM-80643) that does not incorporate a line lock activation button into the shifter handle like my current B&M "T" style handle does. I run one of the B&M Quicksilver shifters, so while having the activation button on the shifter handle was fantastic on the drag strip, it's somewhat of a p.i.t.a. for street driving with a full manually shifted automatic transmission in place. I will relocate the line lock activation button to another location so that it will still be available if needed.
Hey Rich, with me installing all of these parking brake parts out of my storage bins, my status as a Mopar parts hoarder will be in real jeopardy buddy!
I can say however, that when my buddy and me took the car out for a short test drive after getting it back from the restoration shop, it broke the rear B.F.G. Radial T/A tires loose in both the low gear to second gear shift and also during the second gear to drive gear during a couple of "acceleration tests"!
My 8.75 rear differential equipped with 3.91 gears and a Sure-Grip were having a little fun and it also put a pretty big
on both of our faces as well!
Richard