Re: Since Packard had a V-12 in the 30's....

Posted by Rusty O\'Toole On 2009/7/22 15:04:08

Packard had a V12 in 1916.

Why they didn't make a V8 is a long story.

The first gas engines had 1 cylinder, then 2, then the inline 4 was popular. The inline 4 is an excellent layout but in larger sizes, it has problems. Its primary balance is good but it does have a secondary vibration. This is why they put balance shafts in 4 cylinder engines larger than 2 litres or 2.2 litres, to damp out the typical 4 cylinder buzz. In smaller sizes it is not obtrusive or at least, can be damped out by rubber motor mounts.

Six cylinder cars were the ultimate in performance and luxury starting in 1905, 06 and 07. The straight six is an optimum design. It is the smallest number of cylinders giving perfect primary and secondary balance, and overlapping power impulses. For this reason it became the dominant luxury engine for some years, and in Europe was used by the top luxury cars like Rolls Royce, Mercedes and BMW more than any other engine.

The first sixes had what one critic called "long flexible crankshafts and a vibration period to match". This was a controlled by the crankshaft vibration damper, invented by Frederick Lanchester in 1906 and used down to the present day.

So the six cylinder seemed the ultimate power plant until the first V8s hit the market in 1914 and 1915. Between 1914 and 1923, more than 20 makers offered V8 cars in America alone.

But the V8s of that era had some problems. One was a 4 cylinder vibration because they used a 4 cylinder type crankshaft.The crankpins were at 180 degrees to each other, like a 4 cylinder.

Another problem was the difficulty of getting even mixture distribution to all cylinders. This was overcome by making a 2 barrel carb and letting each barrel feed 4 cylinders.

A third problem was the complexity of the engine. It was essentially two 4 cylinder engines on a common crankcase. The crankcase had to be made separately with 2 banks of cylinders bolted on. The foundry and machine shop techniques of the time did not permit making the block in 1 piece.

What is more, the eights of that era had "knife and fork" connecting rods, more complex and expensive to make than regular connecting rods.

Packard accepted all this complexity and expense but would not accept the vibration. So they made 2 straight sixes on a common crankcase and called it the "Twin Six".

This was the ultimate in smoothness silence and power for the times.

Then, in 1923, they shocked the world by bringing out the first mass produced straight eight.

This engine had advantages over the V8, the V12 and the straight 6.

The engine block and crankcase could be cast all in one piece for greater strength and simplicity than the V8 or V12.

They managed to make the engine comparatively short, in spite of having eight cylinders in a row. They did this by using a long stroke small bore design, and by pushing the cylinders as close together as possible. Again this required a single block casting. It would not have been feasible using the old technology of separate cylinders bolted to a crankcase.

The latest technology in pressure oiling to the main bearings was used. This allowed them to use large crankpins. Combined with the shortness of the crankshaft, and a good vibration damper, this allowed sufficient stiffness of the crankshaft.

The final master stroke of design was the 90 degree crankshaft. This featured crankpins at 90 degrees to each other instead of 180 degrees. This banished the secondary vibration problem at once.

The crankshaft was the key to the whole design. They had to keep it short enough and thick enough for strength. Then, they had to have the 90 degree crankpins. Finally a good vibration damper.

Then they had to have the block and crankcase in a single casting to keep it and the crankshaft short enough. This required the best foundry technique to make such a large complicated casting in quantity, without excess scrappage rates.

The straight eight immediately outclassed all other luxury engines. It was the best compromise between power, smoothness, silence and long life at a reasonable cost.

The V8 makers quickly copied the 90 degree crankshaft and most copied the whole straight eight engine once Packard showed them how to make it.

After 1923 no one bothered with the V8 except those who were strongly identified with the V8 and could not abandon it for commercial reasons. Most prominent was Cadillac-LaSalle.And Ford, whose Lincoln featured a V8 and who had spoken against the six cylinder engine many times after his 1907 Model K proved to be a flop. He demanded the V8 for Ford out of sheer pride and stubbornness, and only after it was plain he could no longer sell a 4 cylinder car.

Practically all new designs after 1923 were flathead straight eights or straight sixes. For certain technical reasons the Ricardo flathead design, introduced in 1921 or 22, outclassed all overhead valve designs of the day. But that is another story.

Practically everyone made flathead straight sixes and straight eights. Even low priced makes likePontiac, Dodge and Essex (Terraplane) flirted with the straight eight. But it was the flathead straight six that dominated the market, with straight eights in the upper price brackets.

Then in the thirties came a few V12s and V16s. They pushed the envelope even farther but turned out to be dead end designs. The extra refinement over a good straight eight was negligible compared to the extra cost and running expense.

To make a long story short. The straight 4 is a good workmanlike engine. The straight 6 is the optimum design for smoothness and flexibility. The straight eight offered more power and refinement. The V8 could match the straight eight, but was more costly to make. The V12 and V16 offered a small extra helping of luxury at a cost even millionaires seldom found worthwhile.

In all this it was the flathead straight eight pioneered by Packard that dominated the luxury car field for a generation. From 1923 to 1949 the V8 wasn't in.

Then changing times, and changes in fuels, driving habits and new engineering breakthroughs made the OHV V8 the dominant engine for the next generation.

It became easy to assume the OHV V8 was always better, and everyone made them once they smartened up. This was not true.

The best engineers tried the OHV V8 and rejected it as inferior to the straight eight or straight six.

Consider the Wills Saint Claire. It was gotten up regardless of expense by C.H.Wills, formerly one of Ford's right hand men. His first model had an OHC V8 but he quickly changed to an OHC straight six. The V8 was inferior to the six at that time. This was only a year before Packard brought out the straight eight. If his company survived I'm sure he would have had a straight eight, probably an OHC.