MTFCA Forum

I keep hearing the Model T Ford loves to cruise at 35 mph, and 45 is "abusing the engine." Most people recommend only going up to 35, but WHY? Don't give me "it's unsafe," I already know about that. But internally, engine-wise, what happens? What get damaged, worn faster?

This is discussed from time to time. My opinion. Ford built the Model T to be capable of going 45 mph. That doesn’t mean that is the cruising speed. You wouldn’t go out and drive your modern car wide open all the time. Most tours I’ve been on run 25 to 35, and we plan about 25 when we are setting up a tour. I do drive mine wide open sometimes, but I build engines, so if I wear it out Or break it, I can fix it. It just makes sense that the easier you are on the car, the longer it will last. Me, I have racing in my blood and like to go fast. I have other things to go fast in, so I tend to baby my T’s.

At 50 mph you out run out the std. ignition and you feel like your on a ten speed bike at 40mph, they float in the front end and the brakes are shit, a mag drive or distributer will get you faster but the steering is not there or brakes???? Been there done this!

Do some research on "torque vs. HP" for the Model T and then come back with the results. The question will answer itself.

They run best around 35 to 40 top speed, however, there is one place between San Diego and Escondido where the most direct route is to take rte 15 across a river. Any other route is many miles longer. There is a place where I take the 15 across Lake Hodges bridge. It is level and I get on at the last entrance before the bridge and off at the first exit after the bridge. I stay to the right and go as fast as it will go. About one half mile. I haven't had a problem with the engine from doing that, but I wouldn't recommend going that fast all the time.
Norm

The Model T engine was designed in 1908 when there were no paved road and cars ran on mud trails. The engine power curve peaks at about 1100 rpm and terminates at 1600 rpm. This equates to about 25 mph and 36 mph and this seems to equate to the normal and maximum speed that is normally associated with Model Ts. I believe that over 2000 rpm, the valves will “float” due to weak valve springs. Also I think the valves will start to embed into the block due to the high speed hammering when closing. Now the engine was quite well balanced but the pistons are heavy, over two pounds and ride on quite small bearing surfaces. While fine at 1000 rpm you can expect a shortened life at higher speeds. To some extent this us born out by the Montana 500 races, their engine don’t seem to last more than one race before a rebuild. This is certainly true in modern engines which will last many thousands of miles at low speeds (up to 4000 rpm) but Less than 100 miles when racing at 7000 rpm.
Now we can add hardened valve seats, stronger springs, stouter camshafts, lighter pistons and so on and so on but it’s no longer an as designed Model T.
JMHO

Joe Bell nailed it

Watching this thread with interest. Still waiting for pictures of over revving carnage....

(yes, I'm comfy cruising at 35)

If speed is all-important then a T isn't the car. There are too many reasons to list.

What get damaged, worn faster?

Moving parts.

If you want to go fast in a stock car get a Packard.

I have just submitted an article for our club magazine on the joy of slow driving. Throughout the T era, 1903 to 1930, the national speed limit in Britain was 20mph.

Yes...Joe and Tony nailed it. In my point of view; driving a Model T on a bucolic country road is sheer joy. The faster you drive, the shorter time span of “sheer joy”.

When I had the Chevrolet over head and Bosch front plate distributor on mine, I got to over 50 (that was with a VW a 28 carb no less) on the flat and straight road with not not much traffic. Did I feel safe, no I did not. Between the steering (which is in good shape), brakes (RM's) and those narrow 3-1/2" tires! It was fun to try. When conditions allow, maybe in the 40-45 range in overdrive, but as said above; that's getting outside the power/torque curve so mostly keep under 40. I do a lot of around town driving and have upgraded to 21" tires to have a little more stopping power at least. (some may not call putting a little extra rubber on the ground an upgrade, but if I am going to drive a T I want to live a little longer )

I am so glad someone has addressed this topic!

I myself am a speed freak, but old age and common sense has to kick in. Public safety, modern tires are not as good as older USA Made ones (my opinion), etc are key.

My cars really get up and go, but the older I get, my response time lags a bit. Time to calm down and enjoy!

Dad said it best.., “Hill climbing competitions, drive it like you stole it”.., “Normally driving..., take it easy, idiots are on the road and you are driving a car that was made about 100 years ago. You are putting a lot of faith old metal. Things fatigue”!

Thanks Dad! Point taken!

Humbled Hank in Tin-A-See

Steve Jelf wrote: ↑

Wed Jul 15, 2020 11:36 pm

. . . If you want to go fast in a stock car get a Packard.

Yup. Truth is, while a 1922 Packard “Single Six” is capable of an honest 70mph, in spite of pressure oiling and advanced engineering, long stroke, high torque engines running babbitt bearings will beat themselves to death if the top speed is sustained for any length of time.

Jem, how very sensible in those bygone days ! We moderns are over-velocitized, and that can ruin one’s Model T experience if you let it. It’s a question of habit and perception. In the horse-drawn world, everything moved at 5mph on average. Fast coaches might roll at 20-25 for ten mile stretches. 30mph is a high lope on a good horse, John Wayne movies not withstanding, you can’t travel like that for very long. 80 miles is an incredibly long day horseback.

Consider how liberating it would have seemed, to have been able to travel farther, freely ? At 20mph, one’s time/distance reach was improved four-fold. High speed roads have desecrated the countryside. Has no one through the past century considered how ineffably ugly the landscape has become as we constructed an automobile-based environment ?

If your engine sounds happy at 45 or more go for it. Mine seem happy at 33. I drove 50 or more in the Speedster for years but had a lot more problems than I have now at 33 with the same engine. Balancing the engine and transmission will help a lot.
It took several years for me to enjoy going slower. I don't travel with the fast crowd any more.
Rich

TonyB wrote: ↑

Wed Jul 15, 2020 9:27 pm

The Model T engine was designed in 1908 when there were no paved road and cars ran on mud trails. The engine power curve peaks at about 1100 rpm and terminates at 1600 rpm. This equates to about 25 mph and 36 mph and this seems to equate to the normal and maximum speed that is normally associated with Model Ts. ....Now we can add hardened valve seats, stronger springs, stouter camshafts, lighter pistons and so on and so on but it’s no longer an as designed Model T. JMHO

How fast your Model T can go depends on several factors. But just like all cars, your RPM red line is the limiting factor. Stock engine? see above. Modified crank etc ask the person that built it. Then you would need to factor in your drive line - ring/pinion ratio, Ruckstell/Warford ? Without knowing any of these the best answer is to revert to the intended design 25 - 36 mph as TonyB has described.

Roz wrote: ↑

Wed Jul 15, 2020 9:14 pm

.....Me, I have racing in my blood and like to go fast. I have other things to go fast in, so I tend to baby my T’s.

We're birds of a feather.

My dad's main hobby was drag racing, which he did from the late 50's through the early 80's. I came along in '69 and tagged along and got that high octane in my blood.

I'm about to undertake another rebuild on my high school car ('54 Ford tudor sedan) with a stroker small block Ford...looking for around 500 hp. With my Model T, the goal is to slow down and enjoy the scenery.

Tony's explanation of the engine internals is one of the best explanations I've seen of why the little engine shouldn't be revved too often. I baby mine....probably too much.
.
.

I will add that I have gone as fast in a Model T as I ever wanted to and lived to tell about it. That helped me learn to enjoy going slower.
I hope those who like to go fast enjoy it as much as I did. It's a great thing.
Rich

I'm past the two-million miles driven mark and I think that I have a pretty good feel for my T. Most cars have a "sweet spot" where they run the absolute best; for my 2005 Dodge Magnum RT that speed is 79 mph. Unfortunately, there are certain individuals - usually dressed in blue, who do not approve of my driving the Magnum in it's sweet spot. My '27 T on the other hand, likes 34.8 mph (GPS readout). It just runs, handles, and feels smoothest at that speed. I had a friend's distributor-equipped '24 to 44 mph and it felt pretty good. I will not subject the 93 year-old reciprocating parts in the T's engine to that kind of stress. I do like to go fast, and have two street vehicles that will satisfy my speed yearnings. I'm happy at 34.8 MPH in my T. BTW: the '24 had a recent well-rebuilt engine in it.

My wife's T likes to run at between 30-35. Anything faster or slower it has issues with hills.
The motor just hums. I had it up to 41 and the motor was not happy and very vocal about it.
Settled down to about 35 and everything gets quite and smooth.

The main reason to driving the T is to slow down and enjoy the scenery.
Or smell the roses if you're going slow enough.

I will start by say, I neither recommend nor condone ANYTHING I've ever done in my lifetime !!

My touring with a Ruckstel and 3:1 gears, along with a distributor and HC head will easily do 55....
That being said, I have not tried to do so for anymore that a few miles on a smooth road w/no traffic.
My car is pretty happy around 40-45mph and pulls hills in direct gearing at those speeds the best (50 if it's a big hill)
I have a decent front end, but high speeds are a handful and one little oversteer and the rubber side could likely be up.
We won't even talk about stopping....

The 26 RPU likes 28-30 mph. I find myself going slower on the way home as I know when I get there the drive is over.

The TT with high speed gears likes about 22 mph.
I have a Chicago in the TT and have held on at 42 just seeing what she would do.
The roadster hit 47mph with the Muncie in O.D.
I drive them both in straight drive 99% of the time. The aux trans in both are more for the underdrive than overdrive.
I have a go fast car and motor cycle if I feel the need for speed which is less all the time.

Joe Bell wrote: ↑

Wed Jul 15, 2020 9:15 pm

At 50 mph you out run out the std. ignition and you feel like your on a ten speed bike at 40mph, they float in the front end and the brakes are shit, a mag drive or distributer will get you faster but the steering is not there or brakes???? Been there done this!

I like that explanation, and have experienced it... My car will do 45-50 just fine. But at 60+, it just ain't got the oomph at those speeds, like I'm at the end of it's rope, and that front end on a single semi-elliptical spring is somewhat "floatey"...

I tell people that the T was built to run.
Breaks are a suggestion.

John, So Far you didn't get very many real answers to your question but instead most guys just telling you why they like to go slow close to the 25 to 35 mark. That's a nice speed for in town but I find it too slow if there is any hill coming up. I hate to lug my engine down.

Except driving on tours with many other T's away from home most of my driving here in SoCal is on the freeways. My '12 Torpedo is light and is happy at 50 to 55 with the Warford Overdrive. I have also driven the Montana 500 several times for the Green Team in a 26 Roadster.

Here's what I can tell you from what I've seen relating to your query. As the RPM's and the Load increases the weakest link or worn out part will show up sooner than at a lesser load. Excessive speed or rpm will require better lubrication. An outside oil line that flows oil to the front of the engine especially for any hills is good. Babbitt will take a lot of stress if properly fitted, lubed and not overheated. Overheating happens as the speed increases this can lead to rod or main bearing failures and seized parts if not properly sized and fitted. Long distance high speed can result in failure of the original valve spring retainers or the pins or both. There was a run of improperly hardened parts from the vendors that have failed in several cars. The early crankshafts were much smaller and weaker than the later ones. The crank is subject to lots of flexing which can lead to a broken crank. As speed increases so does the vibration of the car over the road which may loosen bolts that are not properly secured or tightened. This has often happened to starter cars where a loss of oil may result and damage the bearings. Seized pistons can also result if the rods are not straight and as heat builds up from low oil or poor cooling systems. Few people are running the original two piece valves that might be tempted to drive faster so I haven't heard of any valve failures at speeds. It is also a concern at high RPM's the possibility of a magnet coming loose on the flywheel resulting in a major failure. I guess I should say that a flat tire may be more prone to failure as speed increases because of heat build up and more stress such as during a turn.

I'm not sure I agree with the post about the limit of the mag and coils. Montana cars operate with coils and timer Averaging speeds every year over 50 mph for the 500 miles. That system can be very reliable when properly adjusted and maintained.

My experience has been that a Model T can be driven at speeds of 50 MPH continuously for many many miles IF it has been properly assembled, maintained and serviced. The great late Ralph Ricks always used to say "A fast car can always drive slow" Enjoy driving your T and find that Sweet spot that YOU and Your car both likes!!

SurfCityGene wrote: ↑

Thu Jul 16, 2020 6:34 pm

John, So Far you didn't get very many real answers to your question but instead most guys just telling you why they like to go slow close to the 25 to 35 mark. That's a nice speed for in town but I find it too slow if there is any hill coming up. I hate to lug my engine down.

Thanks, Gene. That really helps me! You may notice that I continuously keep posting questions on the Model T Ford. Rather than just reading things online, I decided to get answers straight from real Model T users, and then write them down into my many journals.

Neither one of our T's have a speedometer, so my driving speed was an educated guess. I know how fast I'm going now since I installed a free GPS speedometer for the Android phone made by COOL NIKS. It has a nice screen showing your speed in large font, and is handy for getting a quick look at how fast you're going.

SurfCityGene wrote: ↑

Thu Jul 16, 2020 6:34 pm

. . . 25 to 35 . . . a nice speed for in town but I find it too slow if there is any hill coming up. I hate to lug my engine down . . .

Time to time, charts have appeared on these boards showing the Model T’s peak delivered horsepower occurs at 25-30 mph. Is there a real advantage to “getting a run at a hill” ? Old timers seemed to agree there is, but what, exactly is in play here ? Certainly it depends on the grade and it’s length, but what’s a good rule of thumb strategy for taking a hill ?

OK, here is my two cents. I have aluminum pistons, a distributor, a high lift cam, a shaved low head (high compression), and a fresh but broken in engine. I also have 5:1 steering gears and true 5 degree caster. Oh, and also 3:1 gearing in the rear end. My car is a 1915 touring car. Mechanically it is in good shape. Steering is tight, new spokes for the wheels, etc. I also have disk brakes on the rear end. I have a straight through NH carb.

I can go an honest 50 mph going up a slight grade with the top up. It doesn't strain the engine. The rpm is about 20% less than a car with stock gearing in the rear end. Do I drive at 50 mph all the time? Hell no. The condition of the road has a lot to do with how fast I drive. A 4 lane road with a speed limit of 50 or 55 mph that has good paving and the lanes are wide, I will drive at 45. The two lane roads in the back country with some not so good paving I will drive at 35 or maybe 40. It is just more fun and far less stressful. That is what driving a Model T is all about, right?

Neil

Lots of thoughts here. I'll add mine. Most of my T's are really happy up to 35 mph. At 37-38 mph the engine goes through a vibration node that it seems to dislike, (and so do I), sneaking past that, up to 40 mph, everything smooths out like silk. The mirrors calm down so you can actually use them! If I'm just travelling to & from, I like the 40 setting. For touring, anything 35 & under will do.

As to what wears at higher speeds? Babbitt bearings first & foremost, in my opinion.

As for what speed is best for engine wear & tear, I can only quote my departed father, who left me with this kernel of wisdom, "A horse that shits fast don't shit long". I've never owned a horse, but I have found this to be true of many other things!

I enjoy driving at speeds of up to 25 with an occasional run up to 30 when approaching a hill. Easy on me and the car. It's not high tech but everything that moves can only move so much before it wears our. Higher speeds mean more rpm's. It's just plain old common sense. I don't drive my T's because I'm in a hurry to get someplace so why rush!

Russ T Fender - Your post reminds me of something that has sort of "stuck" with me since I read it in this forum several years ago:

Royce Petersons father (R.I.P.) who had forgotten more than I'll ever know about Model T Fords, said that if one were to drive a Model T Ford consistently at 28 mph, it would last for the lifetime of the owner and several of his offspring, or words to that effect.

Can't say that I drive my Model T's at that speed all the time, however, whenever possible, my favorite way to drive is just about that speed, just "puttering" around this little town that I live in. To me, a Model T just sounds, acts, and feels like it really could just comfortably run like that forever. My Dad used to tell me that my grandfather (his Dad) wouldn't let him drive the family Model T over 25 mph because he said that any faster than that just wasn't safe. Well, many, many years later when I started owning and driving Model T's, I think of that, and I firmly believe that my grandfathers "rule" about "not over 25 mph had more to do with how the car felt "comfortable" at that speed than even his inner thoughts he might have had about "safety". Just my "thoughts" FWIW,.....harold

I don't have a speedometer on my Model T's. I just drive at a speed at which it doesn't seem to be straining, and at which I can stop comfortably if I need to stop. I have passed speed indicators which post my speed. I am usually under 40.
Norm

One of the problems with these discussions is the meaning of “minor” modifications.

My comment relate to unmodified Ford Model T engines and drive chains. As built the power curve peaked at 22HP and 25mph and stopped at 16HP and 36mph. When run like this it was probably the most reliable inexpensive cars of the era.
Does anyone disagree with this statement???

Now with “minor” mods you can generate a fire breathing monster easily capable of 75mph. Indeed I was involved with such project using a T block and side valves that ran at 5000rpm and 218mph at Bonneville Salt Flats. See it all depends on the meaning of “minor”.

I know many of the guys who are in this discussion and none of the boys claiming 50mph run Ts as Ford built them. They have all “minor” mods which is fine but I’m concerned on the effect of the newbies who could get very discouraged when the plod along at 30-35mph and other club members pass them at over 50, claiming “it’s standard old boy, you just need to fettle it”.
What BS.

Many upgrade to Model A intake and exhaust systems. This adds at least 10-15HP and allows cruising at 40-50mph, similar to a Model A.

Adding a distributor will considerable smooth out the engine running, due to better timing control. Alternatively an electronic firing of the T coils will also smooth out the engine but not necessarily increase the speed due to limitations of the coils.

Any of these changes increase the loads on the bearings and they will fail quicker than standard One old time member tuned his T to the “nth” degree with every little trick in the book. He found that the end play of the crank increased by 0.001” for every 1000 miles and after less than 15,000 miles had to rebuild the third main bearing.

Adding aluminum pistons will increase bearing life but the idle and slow speed performance deteriorate.

An easy way to improve acceleration is to remove the magnets. But it’s no longer a standard T with its buzzing coils.

Have you really looked at a Montana 500 car. One I closely inspected had sensors in each exhaust port to measure the gas temperature. Have you looked at the camshaft? Please don’t insult my intelligence by saying standard. The only limit is you are not allowed to remove any block material to install it, everything else on the camshaft design is open.....

The 218mph engine used a T block and camshaft gear cover. That was it. The crankshaft was custom five bearing design, custom aluminum cylinder head and an enormous turbo charger. The throttle lag was about 10 seconds and made a Porsche 930 appear docile.

Still a T. Ahhhh

This was a pressure fed crank with less than 10 hours but 6500rpm
Reliability is in the eye of the beholder.
(Picture from Erik Barrett)

With 3:1 gearing I calculate that at 1000 rpm my car is going 30 mph. So at 10,000 rpm my car would be going 300 mph.

From memory the final drive on the 218mph car was 1.8:1 with about 43mph per 1000rpm. The crown wheel and pinion were custom made. I’m sure the whole rear end was very special.
The first runs were made with a two speed transmission. On the second attempt a five (or four) gearbox was used. A major problem which needed a unique solution was space to move the lever. Maybe they needed paddle shifters from a Ferrari

I may have missed the memo, but this discussion on going fast mentioned engine and drive train. And brakes. But would wheel, rims, and tyres be important? Certainly the use of wood spokes need to be tight and solid. They are safe up to at least 60mph, and at 30 mph should be no problem. And speeds approaching 100 mph solid disk and wires would be preferred. And the tyres, rated to at lease 120 for modern highways?

Dallas, that bare chassis TT with that TIRED engine did 42.7 MPH with me and my Buddy on a LONG straight stretch of road with his GPS, just to see what it would do. Only did that once, I was surprised, not bad for a TT. For you to get to 42 MPH full dress is very impressive. Back then, it would cruise very nicely at 30 MPH with no cab or bed, did it many times. Dave

It also would climb a very steep slope. He had a creek behind his house with a pretty tall levy, it climbed right up it with no problem. That heavy rearend made a lot of difference. Dave

It had to be part goat just to get up to your house Dave!

Been Here Before wrote: ↑

Sat Jul 18, 2020 6:46 pm

I may have missed the memo, but this discussion on going fast mentioned engine and drive train. And brakes. But would wheel, rims, and tyres be important? Certainly the use of wood spokes need to be tight and solid. They are safe up to at least 60mph, and at 30 mph should be no problem. And speeds approaching 100 mph solid disk and wires would be preferred. And the tyres, rated to at lease 120 for modern highways?

No you haven't missed the memo! It would appear that the second part of the question "is Too Fast" has been overlooked. "Too Fast" is about what is required to ensure the survivibility of both car and passengers.

This question comes up fairly often. Beyond the general suggestions guys have already given, the best thing I can say is to drive your car for a while and let it tell you where it's happy. Every T is a little different, and if you're mechanically inclined, you just get a sense after a while. I wish I could say "38mph on level asphalt" but there too many variables.

My 1923 roadster (SurfCityGene should know the car) had a dead stock motor when I bought it: cast iron pistons, .009 taper from stock bores, 7 valves still have the snakebite holes for a forked valve grinder. Stock ignition, NH carburetor. It could do 35mph all day, 40 with a bit of throttle to go, and maybe 45mph if you pushed it and didn't have a passenger. Steering was ok, but 2 wheel brakes are not going to stop in time if you have an emergency. It would also pull hills pretty darn well. An old, tired, original motor should not run that well. My Dad was mystified, and he joked that my worn out valves and recessed seats were unintended valve porting.