i cant drive 55

[michael.warshaw]

well in my bmw i cant drive 55 but in my p15 i can, but with the new od tranny i might be able to keep up with the ne cars.

[1942cowdodge]

When these cars were manufactured the average hwy speed was about 50 or so. So if your doing 55 thats pretty fast for those 230 engines. I cruse at about 45 to 50 even if my engine is brand new almost I still know there is a limit to how much strane one can put on these old cars.

[insaneradio]

That brings up a good question. How fast do you drive your Plymouth?? I do not go above 60 mph. Is this too fast???

Dave

[michael.warshaw]

with the od tranny i hope to get to 70 and cruise at 65.

[55 Fargo]

In mY 47 Chrysler coupe, with 3spd trans dry clutch, 3.73 rear end, P205 75 15 tires, I cruise at 55 mph.

My engine is not rebuilt, but is a decent engine with good oil pressure and uniform compression.

I knwo guys that run these engines without OD trans at 70 mph, some guys on here cruise at 60 to 65 mph without Overdrive.

These engines even witha 4.11 rear end can handle 50 to 55 mph, probably all day long.

Here use this calculator to determine your engine RPM, at highway speeds, I would venture to guess a flat head 6 in good condition could run 2500 to 2600 rpm all day long.

http://www.4lo.com/4LoCalc.htm

Edited May 24, 2010 by Rockwood

[Young Ed]

Funny I drive 65 and have hit as high as 80 without OD in my p15

[55 Fargo]

Hi Ed, I think as long as the engine is in good shape as yours is, they can handle 60 to 65 mph cruising, and probably as you mentions bursts to 75- 80 mph.

I once had mine up to 70 mph, it would have gone higher, and from 50 to 70 mph, it was fairly easy to get there............

[daddyo23]

I've taken my '48 on a number of decent runs (240-350 miles at a time) running 60-65 with bursts to 70 and it's always handled it. They may not be geared to run real high speeds like guys with od or a t-5 can run but these motors are tough.

[JoelOkie]

I cruised my 48 4 door with several other folks and their cars, and never had any trouble staying with them at 65. I suppose the law of motion has something to do with it, as once you get rolling good, especially out here on straight flat roads), you can roll along pretty easy. Joel

[David Strieb]

All depends on final gearing/tire size. My 36 chrysler with a 251/od/21575r15 tires will do 70 all day. My 38 dodge pu with a 230/std 3 spd/23575r15 will cruise at 55. Not sure of the chrysler diff ratio, the dodge is a 3:78 (if i remember w/out looking). I go by engine response and noise before speed. At 60 mph my chrysler is at 2200 rpm in od, at 70 mph it's 2600. My '40 ply with a 350/700r4/10bolt/2:81/21575R15's will do 75 mph all day. My Chrysler is first choice for a road trip, others are daily drivers. Gotta show it off.......

[TodFitch]

Didn't we just do this thread under a slightly different title? Maybe on the truck side rather than the car side and topic title about RPM...

Anyway, when I am on the freeway (not my favorite place with the old car) I run 55 to 60. This is with a stock 1933 drive train: 190 cu.in. L-6 engine, 4.375:1 rear end and narrow 17 inch tires with a mounted diameter of about 28.1 inches. Works out to about 3000 RPM. And this is not just for sprints, I've done it for 300 mile runs.

If you have a P15 with a 4.11:1 rear end and 16 inch tires that same RPM should be about 65 MPH.

[Cpt.Fred]

this is great, i was wondering about the exact same thing out on the autobahn yesterday.

the '40 has 201cui/ 3speed dry clutch and, if i measured correctly, a 4.22:1 rear end. wheels are 16" with 6.00x16" silvertowns.

i'm going 65 without a problem, cruise speed is 55-60 miles.

there's more to come above the 65mph mark, but i want to install a tachometer first and change to SAE 50 oil,

since the oil pressure is dropping when the engine tempgets past 180F.

then i'll know where i am and can try to go faster.

i was really impressed how well these cars handle, the ifs and telescope shocks work great,

so does the 3speed, and with the 6.00 bias plys the steering powers are really low and the car is very agile in city traffic.

back to topic:)

i couldn't open the link, it says "video not available in your country",

so i guess it's some kind of music video?

[Joe Flanagan]

One of those cheesy 80s music videos.

[Merle Coggins]

Funny I drive 65 and have hit as high as 80 without OD in my p15

Just keep 'er under 100, aye Ed?

[Cpt.Fred]

One of those cheesy 80s music videos.

good. so i didn't miss a thing:rolleyes:

[blueskies]

with the od tranny i hope to get to 70 and cruise at 65.

No sweat with the OD. My '50 will run 70 mph at 2500 rpms all day long. On my Tulsa trip a few years ago, I did ten hour days at 70-75 on the freeway.

http://www.youtube.com/user/idahoblueskies#p/u/12/PwexHHm5O2U

Pete

[55 Fargo]

well in my bmw i cant drive 55 but in my p15 i can, but with the new od tranny i might be able to keep up with the ne cars.

http://www430.pair.com/p15d24/mopar_forum/showthread.php?t=17114

Here is another thread you started Mike, on this topic, I just love these type of threads, I always enjoy discussion on how fast we drive our flat head Mopars, or how hot an engine runs in summer etc. I just thought I would add this info to your new thread on how fast we should and can drive our old flatheads..........

[DLK]

Funny I drive 65 and have hit as high as 80 without OD in my p15

Ed the scary part is how far would it take that car with stock drum brakes to go from 80-0...

[TodFitch]

Ed the scary part is how far would it take that car with stock drum brakes to go from 80-0...

Yep. That is part of the question about how fast one should drive an older car.

I guess if you really want to drive it like a new car with fast acceleration, high cruising speed, good handling and good stopping then you need to replace all the running gear with new stuff. Basically a new car styled like an old car.

But I actually like driving within the limitations of the older designs. Yes, drive it 60 or maybe 65 to get out of the city. But then look for the older routes where 45 to 55 MPH is just fine and the scenery is better. And I like thinking that it takes a bit more skill to drive too: You need to anticipate situations better to allow for the slower response. And if you are a total automotive Luddite, you can smile smugly to yourself when you pull off a proper hand signal, a smooth double clutched down shift and tight turn into the correct lane at the same time.

On the other hand when I just need to get someplace 400 or more miles away without taking forever, the new car has power steering, cruise control, AC, and a good sound system. Also gets about 3 times as many miles on the same amount of fuel. Different cars for different purposes.

[55 Fargo]

Yep. That is part of the question about how fast one should drive an older car.

I guess if you really want to drive it like a new car with fast acceleration, high cruising speed, good handling and good stopping then you need to replace all the running gear with new stuff. Basically a new car styled like an old car.

But I actually like driving within the limitations of the older designs. Yes, drive it 60 or maybe 65 to get out of the city. But then look for the older routes where 45 to 55 MPH is just fine and the scenery is better. And I like thinking that it takes a bit more skill to drive too: You need to anticipate situations better to allow for the slower response. And if you are a total automotive Luddite, you can smile smugly to yourself when you pull off a proper hand signal, a smooth double clutched down shift and tight turn into the correct lane at the same time.

On the other hand when I just need to get someplace 400 or more miles away without taking forever, the new car has power steering, cruise control, AC, and a good sound system. Also gets about 3 times as many miles on the same amount of fuel. Different cars for different purposes.

Tod, I am with you on this one......Fred

[Cpt.Fred]

pull off a proper hand signal, a smooth double clutched down shift and tight turn into the correct lane at the same time.

i'm trying hard, and some day i'll handle it:) but the car is really patient with me

and it's fun to drive anyway, even when the car shakes because of my poor beginner skills in pre-war car operation. always fun to learn stuff!

[michael.warshaw]

well these cars are about 60+ years old and look how far weve come in 50 years from now how much better will they be? i dont see how it an get any better? i mean beside having someone else drive the car by pc or something? my bmw does 0-60 in a blink of any eye, can they get faster and better?

[Cpt.Fred]

i dont see how it an get any better? i mean beside having someone else drive the car by pc or something? my bmw does 0-60 in a blink of any eye, can they get faster and better?

that's not better at all...

[55 Fargo]

i'm trying hard, and some day i'll handle it:) but the car is really patient with me

and it's fun to drive anyway, even when the car shakes because of my poor beginner skills in pre-war car operation. always fun to learn stuff!

From 1 Fred to another Fred, enjoy your car, drive it often, make upgrades to allow you to be safe in your particular driving environment.

These cars are a blast, whether we are crusing at 55 mph, or 70 mph. I just would not want a collision at higher speeds in these cars, that is why we drive 100% more vigilant, than the average driver.

You get more used to how these old Girls handle, the more often we drive them........

[Cpt.Fred]

I just would not want a collision at higher speeds in these cars

TRUE!