Cruising speed

[STROHMA]

OK I've finally gotten my bug tunned up. I put in a new SVDA dist. I'm running an h30/31 carb., new rebuild on and DP1600( 87mm pistons so thats a 1641?) New clutch, and rebuit oil pump.

I've been building and piecing this thing together for 2 yrs.

It runs good in town 35 -45mph but when I try to run on the hwy top speed seems to be 55mph on a flat road, When I go up an over pass it slows to 50.

Is this normal? should I be running with the pedal to the floor all the time? I've read where others run 65 -70 Any thoughts on why I can only get to 55?

Only part I didn't replace is the torque converter but I did a stall test and that checked out.

[Cobey]

That is not normal.  I had similar issues when my distributor was on the way out.  The advance was sticking, causing me to be unable to get over 60MPH.

Check your timing on the SVDA (make sure it's timed to it's spec, not the spec of the year car you have), and make sure the advance is working correctly.  (Give the rotor a twist in each direction - one way it won't move, the other way it will move a little bit and then snap back into position when you let go.)

[bookwus]

Hiya Stro,

I would echo what Cobey has to say.

My 70 Bug is set up exactly as is yours...........1600 dp, SVDA, and 30/31.  I drive it daily on the freeway and cruise easily at 62 mph.  At that speed I have plenty of pedal left.  I have had this car up past 80 mph and could have gone faster.

The stall test on your torque converter won't really tell you anything about a top speed.  It has more to do with how your torque converter is passing the power along from a standstill.  A torque converter which fails the stall test will pass power along VERY slowly.  So, off the line in Low range feels like off the line in Second Range.

A thought to add to Cobey's advice.  Is your clutch pressure plate in good shape?  If it is not strong enough to hold that clutch disc in place it could be allowing some slippage.  That would especially show up under a load.  That scenario does seem to match your symptoms.  Just a thought.

[Cobey]

Clutch slippage would be evident in all gears, wouldn't it?

[bookwus]

Hiya Cobey,

Yes, it most likely would.

Just trying to think of another situation which might match up with the symptoms given.  Personally, I'd go with distributor advance before I'd ever get into the bellhousing.  But Murphy's Law does apply here.  With the torque converter and the flex plate plus all the usual clutch components, there are more opportunities for things to go south.

[STROHMA]

I can take off in any gear low is a little better than 2 but not a whole lot. As an example from a stop to 35 mph takes almost 3 city blocks.

The pressure plate is new and the clutch has just been relined.

If the vacuum was hooked up on the wrong port ( above or below the butterfly) would that effect the advance?

[Cobey]

Low will be best to take off in, or Range 1.  Range 2 should *NEVER* be used from a start.  Always drive it like a 3 speed or a 2 speed.  Range 2 should only be used when you're above ~30MPH.  (Personally, I drive it like a 3 speed.)

In low, 0-30 should be no problem in 50-100 feet with the pedal to the floor.

Having the control valve plugged into the wrong vac port on the carb would not cause this.  That would cause you to bump into gear instead of having a nice even transition.  Having the vac line from the carb to the dizzy installed wrong...well...that could do some odd things.

[STROHMA]

OK I believe I figured out my top end problem.

It of course was a simple stupid mistake so was over looked. When I changed out my intake and dist. a while back I installed the carb. but never tugged on the pedal cable. I was only getting 1/3 to 1/2 half the travel when I pressed the pedal down. Pulled the cable out and wouldn't you know it the car runs better.  I ran it up to 60 with a little pedal left.