VCCA Home Forums TECHNICAL - 1945 AND NEWER 1949-1954 highway speed or overdrive ?

I have a 51 convertible with an original 235 powerglide. I have never driven the car as it is under restoration. I was wondering what I could expect out of highway speed cruising. my wife nad I would like to tour the country with the car and I understand that with the dipper motor and the Babbitt rods you have to be a little careful of sustained highway speeds. does anyone have one or has had one and can advise me on what to expect. also if the safe sustained speeds are only around 60 or so has anyone had any experience putting an overdrive in line with this kind of setup

Your '51 is a cruiser and you should have no problem maintaining highway speeds. I drive my '51 Chevy on the highways and/or freeways at speeds between 60 to 70 MPH and I have been doing that for years.

Being a Power Glide it will have a 3.55 axle ratio. I have driven my present 1950 P.G. at 70 MPH on interstates for long distances.
I would not just take any engine and do this. It is important to have the rods adjusted correctly, oil pump screen clean, and make sure the oil pipes for the roughs are not plugged-up.

I have '51 Styleline Deluxe 235 powerglide and it seems to be happiest at around 50 to 60 mph. I have run it at 70 mph and above, but man that ole' stovebolt sounds like it's workin'!

Good advice and opinions so far, although I think the sustained 65-70 for long distances with a 51 235 is a bit far-fetched. Not to say it isn't so but still... If you are going to run that fast you need to make sure you follow Gene's advice about the condition of the engine.

Owing to the engine noise, the wind noise which will be acerbated by the convertible top (either up or down), I think you will find a compromise speed that will be tolerable. If you run above 55 with the top down the wind will beat you to death.

In any case, that speed arrived at as tolerable (nor any other will that you can maintain), will be above that to avoid most other more modern traffic from passing you (especially VW bugs and Canadians ). For most other cars on the road, if it's a 65 MPH zone will cruise at 74, if 70 MPH zone then they will whip along at 79 or so.

I think you will find a speed of 55 as your top speed. That is above most state minimums. it will be as fast as you can stand on a sustained basis. Anything more will drive you crazy. Use interstate roads. Others will merely pass you. If you create a "parking lot" pull over for until it clears.

If you get behind a "chicken truck", forget the condition of the engine, step on it and pass as soon as you can. Especially on highway 65.

Charlie

BTW: If you can stand the engine and wind noise and and buffeting and still want to run with the "big boys" then drop in a 265. With the 3:55 you will have the umph to do it. It may stretch your top.

BTW2: Make sure your cooling system is in good condition, also. You don't know when you will come up on a "parking lot" created by a 38.

At 70 mph with he 3.55 ratio the engine is turning over at about 3000 RPM wich is toralable for an engine in good shape. 65 is a very comfortable crusing spped also and if you are going 65 or 70 the modern cars are still whipping by you.

I would have to add that your engine must work harder...A lot harder...The wind resistance is almost double at 75 MPH than what it is at 55, that means your fuel mileage could decrease by as much as 40 percent...Not only that, it takes a tole on your tires...Studies show it can decrease the life of tires by 10 to 15 percent...So, go ahead and drive like a "bat out of hell"...The oil and tire companies need your money...

In addition to the above comments, my ongoing concern has been for the possibility of metal fatigue on suspension parts, frame parts on vehicles 60 + years old.

I think that the parts you described will hold up just fine. You may consider them overbuilt, even.

Gene, your description of "very comfortable" is probably a lot different than mine.

Correction: In earlier post I meant to say drop in a 261 nor a 265. Mercy! No V/8, please,

Charlie

All good comments and prudent.

IMHO, why not ditch the Interstate and take the secondary roads?? After all, we drive our classic Chevys to enjoy the ride. You'll see more of America and its people that way too.

It's not a trip, it's a journey. Enjoy the ride.

Personally, driving the remaining paved sections of the Mother Road (US-66) is on my "bucket list." Maybe we should start a new thread on the Mother Road. Anyone out there drive it in an old Chevy??
Cheers

Rick,

The surest way to create a "parking lot" is to drive the back roads or the state roads. Especially if you are in a touring group.

Stick to the interstates as much as you can, if you have somewhere to get to. If you just want to view the countryside, there is no good time to do that. Well, not here in NC, anyway. Too much traffic and too many curves and too many drivers that are afraid to pass you even if they have a clear and safe shot at it. The reluctant drivers are the actual ones who create the" parking lot" but it is still a "parking lot."

Charlie

BTW: No matter the speedometer's top speed (90, 100 etc), I think the Chevrolets before 1955 were built to run no more than 40 MPH. That seems to be their "sweet spot." You know, where everything is humming along just fine and you can still hear the radio without it being turned wide open.

Charlie,
I fully agree about some roads in NC being curvy. On our recently completed "Road Trip" we drove the Blue Ridge Parkway, Hell Bender and Tail of the Dragon. Scenery was spectacular, what you could see by grabbing a quick glance before you got to the next curve. Had a couple of motorcycles pull over to let one of our people in a '70 Impala past on the "dragon". Learned to drive in WVa and apparently reliving his youth. Lost a front hubcap in the process. Guess he flexed the wheel a bit too much.

In truth saw more "parking lots" on the interstates due to accidents and construction than the back roads. It may be the not so back roads that you are thinking about.

There are two "ways" my old cars were used. For traveling to meets and tours often several hundred miles from home. Then they were driven faster and on interstates if possible. Often coverd 500 to 600 miles in one day. Then used for general touring at much lower speeds.

Charlie,
It's different depending on where you drive in the USA.

Fortunately, here in Vermont (we have lots of curvy roads)people are courteous almost to a fault. Even so, I make it a point to watch my rear view and when I see a collection piling up behind me, I pull over and let em by. It's really enjoyable driving our back roads (paved ones that is) here. Guess that's one good thing considering we only have limited months we can drive here with our weather. One does get the rubber neckers and I've had to watch for tailgaters trying to get a better look at my car. Driving defensively and courteously has a new meaning when driving old cars.

By disclosure, I might add we only have half a million people in the entire state, so not many people compared to NC and other places.

All I can remember about Vermont is from a 6 Cylinder Tour we had there a few years back. Some of the "Back roads" are best driven with a 4 wheel drive vehicle.

Pretty chopped up or non existent and abandoned in New Mexico. I drive a 5 mile stretch on my way to work just east of Albuquerque.
Get your kicks on rt 66!

Gene, now come on, Rick wrote a very nice piece and you had to go and disrespect his state with the comment about 4-wheel drive roads. Mercy!

What in the world could Rick have to say about Wisconsin with its methane producing, ozone killing cows a-s--ting everywhere and the Grain Belt beer much less the roadsides covered in continues ten (10) snow plow piles most of the year. Where is one going to pull off the road then?

Dads51,

One of my bucket list things to do is drive route 66 (some of it at least) in the 41 project car. I've been on a stretch of old 66 between Tulsa and OK City, which goes through Stroud, back in the 70s. I want to see them "Caddies" a-sticking up out of the ground. Not sure where they are.

Gene, 500-600 miles in a day (24 hours) is just about right, I suppose, but I think that even I could surpass that. I don't stop to read every roadside sign. May be missing a lot there.

Back in the sixties, I used to drive my 41 SD Town Sedan (long gone now) at a steady 47 mph on the interstate back when the speed limit was 55. That was a bit more than the "sweet spot" but it did okay between Ft Rucker, AL and Fayetteville, NC. Did that trip with the 41 several times.

Charlie

BTW: I think that back in the 70s, Big Richie drove a 41 cross country and wrote an article for the G&D about it. Interesting article and well done, too.

Charlie,
Thanks for coming to my defense! I was not referring to back roads but rather the divided highways in Vermont. And yes, we certainly have our share of dirt roads which during mud season(Spring) are unpassable without all wheel/four wheel drive.

BTW--the Cadillac Ranch ("Carhenge") is located on RT 66 in Amarillo. I hear OK and AZ have some of the best remaining pavement of RT66.

It's not just a ride, it's a journey!! Stop and smell the roses!