'36 Terraplane weight distribution musings

terraplane8

I weighed my car today (Model 61 4 door sedan with one sidemount) at the local landfill station and this is what the numbers said:



Total weight with driver 1460kg = 3,212 lbs



Front wheels weight with driver 680kg = 1,496 lbs



Front weight = 46.57%

Rear weight = 53.43%



The total vehicle weight seems a little heavy on these numbers. Taking off allowances for the driver, petrol and tools etc gives a weight of 2,932 lbs still some way above Hudson's weight of around 2,700lbs. Perhaps Hudson weighed them without the spare tyre, oil or water, ie a dry weight? That would peel another 150lbs or so off. The scales may be inaccurate of course.



The key point though is that the weight distribution of the car is surprisingly lighter at the front than the rear. That would help explain the light steering and the nice balance of the car when cornering quickly. It does have an anti-roll bar on the rear as standard which would reduce understeer. Ultimately near the limit I have found it will oversteer. I think the '37 model had anti-roll bars front and rear or was it just the front? Anyone know?



I asked a friend of mine who knows much more about vintage cars than I will ever know what he thought the weight distribution would be. He thought there would be quite a bit more on the front than the back. He was very surprised when I told him it was the opposite. I do recall reading somewhere that Hudson was aware of the importance of an even weight distribution even in the 1930's.



It's still going like a rocket too, the 20-40mph increment in second comes up in 4.85 seconds. The clutch was slipping a bit too at the start so that time may be closer to 4.5 seconds. That is much quicker than any new Terraplane 6 and most of the H8's too going on the Brooklands road test data I have. And that is stock apart from higher compression and a good valve job using the later thinner stemmed valves. A new tuned length header over the top exhaust system is next. To be continued.........

Park_W

Way back when, I remember being really surprised when I weighed my '35 Terraplane coach on some commercial scales in my home town. Even with a non-stock eight-cylinder engine squeezed into it up front, the rear axle still had over 100 lbs. more weight than the front. Amazing, and very rare for an American car at that time. I also note the spec's for my present '47 C8 sedan show a hundred pounds or so heavier at the rear.

terraplane8

Park W wrote:

Way back when, I remember being really surprised when I weighed my '35 Terraplane coach on some commercial scales in my home town. Even with a non-stock eight-cylinder engine squeezed into it up front, the rear axle still had over 100 lbs. more weight than the front. Amazing, and very rare for an American car at that time. I also note the spec's for my present '47 C8 sedan show a hundred pounds or so heavier at the rear.

Given the H8 engine is around 7" longer than the 6, did you fit it in without re-working the centre crossmember? I wouldn't have thought there was enough space between the gearbox and the cross-member? As there is no scope to mount the engine further forward given that the front pulley is not far back from the front cross-member, in fact there's just enough clearance to lever off the pulley to get the timing case off with the engine in situ. Also the firewall would have had to have been recessed?

Park_W

terraplane8 wrote:

Given the H8 engine is around 7" longer than the 6, did you fit it in without re-working the centre crossmember?

I mounted the engine at the rear in the normal place and manner. All the needed mod's were at the front. Took a bit out of the front crossmember to clear the crank pulley. Had to find a shorter and narrower radiator that would fit further forward and down a bit in the grille shell. Ended up with one from a '36 Chevy, I think. Only problem was the top hose spout of the radiator was so much lower than original that there was virtually no room under the upper radiator hose for fan blades. No electric fans on the market back then, so I just ran it without one. Was fine unless I got stuck in totally stopped traffic ... the least bit of forward movement and it was OK. Oh, and I had to use a funnel and a length of heater hose to fill the radiator. But if you're seventeen and all that hassle lets you do burnouts and "smoke" new '56 'vettes from a traffic light, the tradeoff is a no-brainer!

Uncle Josh

One of the best fambly cars we ever had ( a 72 Chrysler Wagon ) recommended tire pressure of 22 Front and 32 Rear, which kinda shows where the weight was. Absolutely unstickable in the winter.

hudsontech

From a factory issued weight sheet that is in the Weight Sheets section of my General Information Handbook........ the following figures are given for the 1936 Terraplane Sedan:



Shipping Weight - 2845

License Weight - 2770

Total Weight - 2920

Front Weight - 1330

Rear Weight - 1590



You will note the difference between front and rear weight - which supports what your car weighed out at. The ratio's are about 45.56% front - 54.45% rear (in rounded out figures.)



Later sheets indicate License weight to be with 1 gallon of gas, oil and water.





Hudsonly,

Alex Burr

Memphis, TN

terraplane8

Alex, that's interesting info. The front weight of my car as weighed with driver etc is 46.57%, compared to the factory's 45.54% which would be sans driver. That would indicate that the weight of the driver puts more weight on the front which stands to reason.



The factory total weight figure is almost the same as mine at 2,920 vs. 2,932 lbs. So what exactly was the shipping weight then since it is 75lbs less?

RL Chilton

terraplane8 wrote:

Alex, that's interesting info. The front weight of my car as weighed with driver etc is 46.57%, compared to the factory's 45.54% which would be sans driver. That would indicate that the weight of the driver puts more weight on the front which stands to reason.

The factory total weight figure is almost the same as mine at 2,920 vs. 2,932 lbs. So what exactly was the shipping weight then since it is 75lbs less?

terraplane8-

You are actually quite close. You won't get exactly advertised weights for various reasons, one of which, was factory fibbing, which was done in all specs, some lower and some, like horsepower, much lower than actual. I assume your car has been restored. Done any chrome-plating? Modern triple plating is much heavier than what was original to your car. Added any stainless steel fasteners? Believe it or not, these can add up to a gain of a little to as much as 20lbs. or so, depending on how many fasteners were used. Original upholstery? I'm not talking about the outside, what's on the inside? Any dealer or factory options? Any options were not included in advertised weight sheets and often were listed under a seperate Service Bulletin which listed weights for various options. Granted, all of the items listed are minimal, but add up a whole bunch of little things, and the difference becomes apparent.

Interesting post, though!:)

terraplane8

Actually the car is a time-warp somewhat dilapidated original complete with aged original upholstery, very worn running board rubbers, paint weather-worn down to the primer in places, surface rust in places where the paint has worn away completely. Everyone tells me not to restore it as cars in this sort of patinated condition are quite rare now, ie it's got the patina of age and the interior has that original old car smell too which is quite nice and part of the character and which of course is lost with new upholstery. You'd see cars like this in NZ on the roads in the 1960's every day as new cars were not allowed to be imported unless you had foreign funds, therefore scarce so old cars were kept in service by necessity. So I don't think there's any extra weight from modern chrome or stainless fasteners, good point though. The only extra as such is the side-mount spare.

hudsontech

RL Chilton wrote:

terraplane8-



Any options were not included in advertised weight sheets and often were listed under a seperate Service Bulletin which listed weights for various options.

I have some of those service bulletins giving accessory weights, up-dated factory weights, etc, - but they are in the step-down era.

Doesn't mean there weren't any for earlier years - just means I havn't found those early sheets yet - or found somebody who has these early bulletins and would like to loan them to me for scanning and inclusion on my web site.

By the way - FEI I am in the process of, with Aaron's help, moving the web site to the HET web site, along with the manuals on the On-Line Hudson Web Site. Should finish the transfer soon, I hope.



Hudsonly,

Alex Burr

Memphis, TN

terraplane8

Some interesting weight-distribution info from the 1937 "What, How Why" Hudson Terraplane book that is available on Alex's site.



This amazingly detailed 213 page book also says that the '37 models had an anti-roll bar only on the front, due to the 1 1/2" lower centre of gravity compared to '36 models through using the new double-drop chassis. They said that a rear bar was available if required for exceptionally rough roads.



29 - Is the motor in Hudson-built cars moved forward to

balance the weight over the front and rear axles?



No, the motor is mounted to the rear of the axle, and there

is more weight on the rear axle than on the front.



30 - Does an equal distribution of weight on the axles give

smoother driving?



While this may appear true in theory, it is untrue in prac-

tice. Certain manufacturers were compelled to move the

engine forward in order to get sufficient body room. Hudsons

and Terraplanes do not have to resort to this expedient.

Cars with the engine moved forward are notoriously hard

and uncomfortable to steer and their practical top speed is

reduced several miles an hour. The principal reason is: The

heavier weight on the front axle puts a greater burden on

the steering mechanism and the driver has to "carry the

added weight." This heavier weight also causes much

greater front tire wear. As an example - shortly before the

Hudson Eight set its records at Muroc Dry Lake, California,

another manufacturer tested his car, which has a forward-

mounted engine, at the same testing ground.

Many new tires were required on the other car during a

24-hour run, but the Hudson, running at higher speeds,

went 24 hours without a single tire change.