Tucker engine history

[gavin@farmer3645.fsnet.co]

Dear Tucker enthusiasts,

My name is Gavin Farmer, I'm a motoring writer and historian. I have begun researching cars powered by so-called "boxer" engines--horizontally opposed if you like. The Tucker had a flat-6 engine.

I'm looking for details information on who designed and tooled it for production, photos of it as well as technical line drawings. Can anybody out there help me please?

Please respond to my e-mail address shown above as my user name.

Thank you.

Kind regrads,

Gavin

[Guest]

Don't know why you haven't got an answer yet but maybe I can shed a little light.

Tucker was first going to use an engine of their own design, when this proved impractical they bought the Franklin engine company.

This company made an air cooled, six cylinder aircraft engine that was used in Bell helicopters and possibly other aircraft. Tucker engineers adapted it for car use.

This was quite a job. For a start the engine stood upright in the helicopter with the crankshaft pointing straight up. They had to lay the engine down, convert it from air cooled to water cooled, devise new carburetor and intake system, exhaust system, oil pan and oiling system, generator and coil ignition instead of magneto and so on.

The result was a 335 cubic inch overhead valve, 166 HP engine in 1948. Compare this to the sensational new Cadillac OHV V8 that debuted in 1949 at 331 cu in and 160 HP and the even more sensational Chrysler Hemi V8 that debuted in 1951 at 331 cu in and 180 HP.

In 1948 the typical luxury car engine was a flathead straight 8 of about 135 HP. There was also the Cadillac flathead V8 of about 150 HP and the Buick OHV straight eight of 135 HP.

In other words the Tucker engine was similar in size and power to the best luxury car engines of the early 50s. It represented a considerable advance on the state of the art of 1948.

Its performance was sensational by 1948 standards. And in typical auto industry fashion, there was more horsepower potential that could be unlocked with a few simple improvements as time went on.

[Tatra Man]

I'm curious about the stated horsepower ratings on the Tucker motor. The Tucker Corp. said a lot of things in its advertisements that were false or misleading, which makes me skeptical about the stated ratings. Has anyone with a Tucker motor actually tested one to verify what was stated in promotions?

By the way Gavin, if you're looking into boxer engines, don't forget the rear-engine flat 4 cylinder Tatra T97 (introduced in 1936) that Porsche copied to design of the Kdf-wagen (VW Beetle) from. Check out www.tatra.demon.nl

Tatra also had many flat engines starting in I think 1923 with the T11.

[Guest]

Don't know what you mean by false or misleading claims. Auto writer Tom McCahill tested the Tucker in 1948 and said it made every other car in America "look like Harrigan's hack with the wheels off". Its performance figures of 0 - 60 in 10 seconds and top speed over 100 MPH were nitroglycerine stuff for that day.

He was roundly criticised for this writeup and it cost him a lucrative contract with another magazine that was busy running the Tucker into the ground at the time. But he stood by it and time proved him right.

The horsepower and performance figures were in line with other cars of similar size and horsepower, in fact if anything the power was understated not exaggerated.

[Tatra Man]

I'm have no doubt that it was a fairly fast automobile. But I am going to open up a can of worms here by saying that all the miscellaneous inaccuracies published by the Tucker Corporation itself would be a pretty thick book.

I’ll start with the January 1946 PIC article as example. This was not the first article to announce the Tucker, but it was one of the first major articles to appear. Here are the publicized features, none of which happened on the “production” models:

Capable of 130 mph and 65 mpg; 150 HP; Sell for around $1,000.00; Designed to cruise at 100 mph continuously; Central driving position (like McLaren F1); Front fenders that turn with the wheels; Sealed cooling system will require no attention, summer or winter; Vehicle will weigh approximately 2,000 lbs.; 126 inch wheelbase; Overall height of 58 inches; Body construction of Plastic or Aluminum; Optional two, four, and six cylinder engines; Engine should run thousands of miles before it begins to pump oil; Half the number of engine revolutions as compared to other automotive makes; Welded steel tubing chassis; Disk brakes; Fuel injection; Hydraulic torque converter drives on each wheel.

Another favorite article of mine (and the SEC investigation) is from March 2, 1947, which reads, “Not it can be told… How 15 Years of Testing Produced the Surprise Car of the Year.” The article continues by stating, “Already pilot models that will be the inspiration of years to come are now being completed in the Tucker plant….” Yet, the Lippincott design team had not even arrived yet to finish the design of the car. It continues by discussing the “smooth surge of FLOWING POWER”, the hydraulic torque converter drive that never happened.

In the March 1, 1948 article in Automotive News entitled “On Progress of the Tucker Car”, Preston Tucker discusses his hydraulic torque converter drive again. According to the article, “Tucker says, however, that engineers sympathetic to his cause but working for established auto concerns, have called him up to say that their companies are working hell-bent to steal his torque-converter drive from him, and they think it’s a dirty shame.” The article spends much time discussing what was said in 1945 as compared to the present (ca. Feb. 1948). Of all of the 1945 features discussed, the article states, “The packaged motor, torsion bar suspension, single disk airplane-type brakes, and torque converter drive still go”. Neither the disk brakes, nor the torque converter drive appeared. And this interview took place after “production” of the Tucker ‘48’s began.

One of my favorite more modern quotes is in regards to the Tucker’s coefficient of drag (cd). It has been stated quite often that the Tucker has a cd somewhere between 0.28 and 0.30. As far as I am aware, no Tucker has ever been close to a wind tunnel. About a year ago I talked with a retired General Motors aerodynamicist while standing in front of a Tucker at a car show. He basically stated that these figures were impossible, and he would love the opportunity to test it. Does anyone out there know of any such test having been performed?

[130rapid]

One of my favorite more modern quotes is in regards to the Tucker’s coefficient of drag (cd). It has been stated quite often that the Tucker has a cd somewhere between 0.28 and 0.30. (...) He basically stated that these figures were impossible, and he would love the opportunity to test it. Does anyone out there know of any such test having been performed?

I think Tucker’s coefficient drag Cd 0.30 is possible.

Here you are another car with non-aerodynamic look.

French Hotchkiss-Gregoire (they made 274 copies since 1951 to 1954, mostly sedans and few convertibles).

It was modern, spectacularly constructed car with monocoque body, all wheels suspended independently, front-wheel drive and water-cooled flat four (133 cu in, 70 PS / 4000 rpm).

Typical European car in early 50s which had comparable frontal area (59.8” height, 66.9” width) and similar power was able to keep top speed 80-85 mph. Hotchkiss reached 97 mph!

How was it possible? The secret revealed in last 80s. Collector’s Hotchkiss-Gregoire 4-door sedan was put on wind tunnel. Can you imagine the amazement when computers calculated coefficent drag? Cd = 0.26!

* * *
I discover strange things about Tucker's (Franklin) engine thanks to automobile acceleration simulation program.

Declared power and torque ratios don’t correspond correctly. Torque / power curves show clearly that torque ratio is too high, or power ratio is too low. (One figure even suggests higher Tucker's power – compression ratio 7.0:1, high in 40's.)

I tried many combinations and “puzzles” matched perfect with 200 hp / 3200 rpm and 372 lb ft / 2000 rpm.

Why these figures? Power / torque curves looks ideal and complete. And only with these hp / lb ft ratios, with Tucker’s frontal area, coefficient drag Cd 0.30, tires 7.00-15 (2,3 bar pressure hot), my virtual car reach top speed 119 mph (at 4200 rpm) and can accelerate 0-60 mph in 10 s.

Anyone know real Tucker’s gear / final drive ratios?
Sources declare 4th gear ratio 0.64 and final drive 4.70.

Original Cord gearbox had 2.34 / 1.51 / 1.00 / 0.71 and final drive 3.88.

(I use combination with 2.34 / 1.51 / 1.00 / 0.64 - 4.70 for simulation but Cord’s original ratios fit better).