highway horror

I just got back from my second time ever taking the 62 falcon out of town on a 2 hour trip. I'm running a 200 out of a 70 maverick, that I believe now has about 20,000 after a rebuild from previous owner. a 2 speed trans and stock rear-end. Car does fine if you run 60 mph....doesnt do to well above that. Is this the limit for these drive trains or do I have aproblem somewhere?

What was the actual issue with the car - too slow, revving too high, unstable?

60 was about the top speed for 2nd in my C4, not sure what the 2-spd gears are like though
what's with the root beer can?

the car is stable...I've run it up to 80 for a short distance with no problems, It just doesnt seem to like to cruise at 65 plus. If I run it a 70 plus it blows oil out the breathers. Ive upgrade to the pertronix ignition, and am running dual exhaust and 15X7 wheels w/ 195 50 15's. I need to get my tach hooked up and see what I'm turning


the root beer can is just a fuel pump cover up..its a 60's company named Custom. which i thought was pretty cool being My car is done as a 60's custom

mine cruises at 75 no problem, and I've had it over 90 once or twice. however, that's with big wheels and 3.25 gears. Before, when I had 3.50 gears, it revved pretty high on the freeway.

Besides the tach try hooking up a vac gauge just to see what its doing at those speeds. Have you messed with the curves (both mech and vac) in the dizzy?

My 60' has 3.90 gears in it. it turns 3k @ 52mph. and it has a 200. I think I got it up to 72mph one time. it was about 35 degrees outside so it was getting some good air.

My 63 falcon had a 2 speed , 3.50 gears , and short tires like yours and it could'nt do sustained driving for long distances above 65 mph.At sustained speeds of more than that after 3-8 miles it began to overheating,blowing out water, and also oil .If kept below this speed,the motor ran perfect. We drove several hundred miles to cruising events.I later Installed a wide ratio(292 1st gear)c4 and 3.00 gears. You could drive it 75mph as far as you wanted.I never tried faster because of the old slow steering.Hope this helps.Berry

My 66 stang with a 3.0 rear and the C4 will do 70 easily unless there is a lot of wind or a long steep hill. Flat ground and no wind it will get over 80. 55 is never a problem.

fordconvert--I'm running a pertronix in the dizzy

I have the 3.90 rearend as well.

was told going to a c4 wouldnt do anything since it has a 1 to 1 final ratio

so I guess i need to locate a new rear.

Check your ignition system before doing anything else. Make sure the plugs, wires, cap, and rotor are up to snuff. Gap the plugs at no more than .035". Set timing at 12 degrees BTDC.

Also, where is the vacuum line to the distributor connected? It should be running directly to a vacuum source on the carb. Without it, you may not be getting enough ignition advance to run at higher speeds. Do not time the car with the vacuum advance hooked up.

If all that checks out, then take a look at fuel. Check the filters and check the strainer on the fuel pickup. A blockage on either will cause poor running at high speed. Then look at the float level.

El Pajarito":1pwec3x8 said:

I have the 3.90 rearend as well.
<snip>
so I guess i need to locate a new rear.

Click to expand...

You have answered your own question.

As a reference point, my 200 has Pertronix II and matching Blaster coil, it and the C4 are otherwise stock, I've got 2.83 gears in the 7 1/4 rear end, and it will run at 75-80mph all day knocking down 23-25mpg.

8) all my sixes always liked to be running at around 65-70 on the freeway.

I'm going to echo 69Falcon and robhm's thoughts. I don't think you can get a 'smooth' cruise at 70+ without a highway gear rearend or an overdrive transmission (especially with any kind of built set up). Chasis stability then becomes an issue above 80mph, IIRC.

There's other versions out there but this page may help you backout your rpm, till you get your tach.
http://www.bgsoflex.com/auto.html

El Pajarito":7jgog6nx said:

I have the 3.90 rearend as well. .

Click to expand...

YOW! With those tires (22.7" diameter), your engine is turning just over 4K rpm at 70 mph.

I'd look at taller tires while you're hunting a replacement rear. 195-70/15 at almost 26" tall will reduce the rpm at 70mph to about 3500. Still high, but a lot easier on the engine.

As I read I hoped someone was going to metion the tire size throwing the speedometer off not shure which way.. So you may be going faster than you think.
Check your pcv valve make sure its clear and working good.
good luck
Tim

I plugged in your tire and rear axle ratio into a spreadsheet I have. I don't know what the gear ratio of the 2 speed transmission is, but if it is a 1:1 ratio like the 3 spd trannies, then at 4000 rpm you would be travelling 69 mph. The tire size you have is small and the rear axle ratio contribute to high revs. I know my old engine kind of runs out of air at 4000 rpm.

If the 2 sp tranny has a ratio other than 1:1, then that may make it rev even higher at highway speeds.
Doug

Thanks for all the input.

You need to take one of the breathers OFF and put in a PCV valve.

If you do not draw a vacuum in your valve cover you'll blow out oil at higher speeds.

My 61 falcon LOVES 75 MPH and about 210 degrees and pisses out about 1/2 quart more coolant than normal driving, but levels off and does not over heat.

Taller rear gears is what you need...

It's that root beer can sitting on top of the fuel pump. Remove that and you should be fine!