Suspension is new. Good alignment. I posted this in another thread. "The reason the Holley is on there is because I was able to bolt it on and go, and they don't break. Trying to get a TV cable to hook up properly to a Q-Jet requires more money, labor, and frustration. I don't know if I mentioned this but I worked for 7 days in a row 9AM- 6PM in 20-30* weather getting this car running again and if I had to piece together all the stuff to use a Q-jet it would not be on the road right now." I also blocked the exhaust crossovers and I am using a Spectre Cold Air Intake. So my intake is ALOT colder. Does this lower mileage?
If you aren't running a stock 4 bl. intake, I have one for sale. Its in great shape, and I'd love to sell it.
the blocked crossovers will make for poor warmup, usually running rich for too long, so yes on that part but once it's up to temp the cold air should be fine. As for bolting on and going...not so much, out of the box Hollys require tons of dialing in. As for never breaking, back fire through it and blow a power valve...bowl leaks from re-jetting, other issues. I've run them in the past and will not again. A well set up Q-Jet will run well for a long time...I rebuilt the one on my 68 Skylark and drove it for 11 years and 100,000 mile without ever having to go in it again. All that being said 850 CFM is flat out too big for your setup, period, I was running an 800 Q jet on my 4800 pound SportWagon with a huge cam, 9.5:1 compression, headers, intake and 3" exhaust, TH400 3.42 posi, points and an MSD 6A and it was running 13.31@102 Your carb is too big, therefore crappy milage
Since you are happy with the trans cable setup on the Holley, I think the perfect solution in your case would be a Holley 600cfm with vacuum secondaries and a dual plane intake, stock or aftermarket. You may lose a few horsepower on the top end but these carburetors are great for most applications not requiring more than 5,000rpm all the time and they're pretty darn good for economy. I know you're on a budget but I would also consider stepping up the gear ratio to a 3.73 or better. Your present combo will net you a 2.29 in OD, whereas a 3.73 would step that up to a 2.50 and a 4.10 in OD will produce a 2.75. For the best fuel mileage you want the engine to run in that 'happy' spot, and in many cases too high of a gear will make it lug and actually have to work harder. Once you find the rpm where the engine seems to work the least, gear it accordingly. Just a few thoughts.
A perfect example of my previous post about gearing is an `83 GMC K1500pickup I had years ago. These were the early years of many manufacturers experimenting with OD. The truck had a 350 4bbl., 700R4 and a 2.73 gear, yielding a 1.91 final drive ratio in OD. It wouldn't even stay in overdrive on the interstate if I hit even the slightest incline. After checking the mileage I eventually found that it was getting 15mpg in OD and 18mpg if I left it in drive. I never used the overdrive again after that.
I think there are linkage kits available to add a TV cable to a Q'jet or you can get parts from a 307 Olds (carbed) with a 200r4. I made my own, took about an hour I think, although final adjustments aren't done. I agree with Bill on the gearing especially with that big carb.
I think I have an 8 or 9 power valve I am going to put in. Holley says you use a power valve equal to half of your idle vacuum. When driving on the interstate I have to give it ALOT of extra throttle to increase the speed just because the current power valve is not engaging until you open the throttle alot more. What makes you think this iron intake stays cold? It will still burn my hand if I touched it with the engine warmed up. I think I would just get a 1st degree burn instead of a 3rd degree if the crossover was working.:Brow:
You don't want the power valve to open if you are concerned with gas mileage. A 6.5 will serve you well You have a double pumper. The secondaries are mechanical so they work all the time. If you block the exhaust crossover, the intake will take a long time to warm up. It will always run cooler than a stock set up. That wastes gas. If you have a choke hooked up, the choke will come on, but never open up fully. The intake will not get hot enough. The stock Buick 350 is going to like to run about 2000 RPM at 60 MPH. That's what they ran with the 2.56 gears. Timing in the 40* range total should give the best gas mileage. Get another more economical Holley or a Q-jet.
20 MPG ..... a couple free bee's Inflate tires to max pressure ..... It will help Install a vacume gauge ...... you might learn something about the ideal cruise range. A 50.00 Qjet & 15.00 kit W/float would be worth a try ,Holley @ one time offered a 450 cfm 4brl Qjet replacement I used one for a summer & got outstanding mileage...... before the main body warped beyond repair & later became a known issue with this carb. A 600 might be a good choise but stay away from the counter clockwise air fuel metering blocks. ick
I grappled with hooking a 200-4R TV cable to a stock Q-jet before.. no biggy, just think "out of the box".. The stock TH350 in that car used a downshift cable.. think about where that hooked up.. on the gas pedal.. There is already a hole in the firewall that will just take a little massaging, and the pedal assembly already has the the bracket to hook the end of the cable to.. just use an aftermarket adjustable cable, and it's a snap.. way easier than trying to hook it to a older Buick Q-jet. Find a late model Q-jet, with an electric choke, get it jetted right, and you will be a long way toward getting your mileage. And the choke will work for good start up and drive away cold.. JW
Cason, this looks like a good guide for setting up the TV, it even mensions the radius that the cable end needs to see to operate properly with throttle position. http://www.cpttransmission.com/tech_tvcable.htm Devon
I wish I had never blocked the exhaust crossovers on the TT project car. I really don't think there is much to be gained HP wise, and it takes forever to get warmed up enough to idle with a stock ( no choke) 750 Q-jet.. If the intake is ever off again the plugs are coming back out.. It actually idles and runs OK when cold with the BG Blow Through carb.. Probably dumping a ton of gas down there..
When no one is looking throw a good q-jet on it... this is a coded message to Cason's girlfriend ... idnit? :TU:
