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Quote:

The 1915 Dodge Brothers was 12v.

Prince, B&S started ohv about 10 years ago on 5 hp and up. Maybe earlier. I have several around here. They still make the flat heads too. Electronic ingition too.

I'm sure there was most likely some isolated examples of 12v systems world wide prior to '55. But to make the statement that The US was slow in converting to 12v sounds like something out of HotRod Magazine. I mean hell, we could include military issue that was 12 and 24 volt WWII production as well as 6v.

6v was most widely used world wide prior to 55.

G'day all, I shall dig up the article about the 1930 match race. I shall also dig up a very interesting article about 6V versus 12 volt systems, BTW, I wasn't intending to imply that the US was slow in going to 12V. I have always defended 6V systems and kept all but one of my Packards on 6V. I did also try my 38 six on 8 V for five years but changed it back to 6V two years ago. Best regards Peter Toet

G'day all, I consider that I should explain where I am coming from with my comments on the side vale and 6 V issues. On the side valve issue it was simply a public perception here in Australia at least that OHV or OHC must be better engines because they were more complex and breathed more freely. Similarly, on the 6V issue, In Australia in the Twenties, Thirties and Forties we had very severe tarrifs on vehicles which did not come from Commonwealth countries, such as Canada and England. Most of the vehicles in Australia were English and 12V. Our first Holden cars were 6V between 1948 and 1956. There was again a public perception that the average 6V vehicle was subject to very slow engine cranking and poor lighting. Hence the ads to convince people to fit 8V systems to VW's and older 6V cars. I would like to start a new forum on the topic of the reasons why manufacturers ( Packard especially) went for 6V initially and the reasons for going to 12V systems. Best regards, Peter Toet

When looking up overdrive solenoids the other day, I notice Packard had 6 & 12v versions for 17-19th series. What were these cars.

It is a serious mistake to assume that OHV engines are better than flatheads. For almost 30 years, the flathead was better in every way.

In the early days of making engines, they tried every possible arrangement of valves. By 1920 or so, most could be classified as either OHV (overhead valve) or L head(flathead).

Then, English inventor Harry Ricardo invented the Ricardo head. This immediately made all other designs obsolete, at least for regular road going vehicles.

The secret of the Ricardo head, an improved flathead design, was to bring the head down tight to the top of the piston. This did 2 things: reduced the effective size of the combustion chamber, and caused the piston to squish or squirt the mixture into the valve chamber. This swirling turbulence made the mixture burn very fast and evenly, when the spark plug fired.

Flathead engines already had advantages of simplicity, low cost, silence, and reliability. The Ricardo head made them as powerful and economical as an OHV.

After 1921 nobody made a new OHV engine for almost 30 years. The only exceptions were companies that had pinned their faith the OHV engine years earlier and stuck with them out of tradition. This included Chevrolet, Buick, and Nash in the US. All had made OHV engines for years and all stuck with them, even though they had no advantage over the new flatheads in power economy or anything else.

Every other new car engine from 1921 on was a flathead.

The only exceptions to this rule, were racing engines and semi racing engines. By semi racing I mean expensive cars like Stutz, Mercedes Duesenberg and Bentley. For racing it made sense to spend a lot of money to get a small increase in power. These were not ordinary OHV pushrod engines. They were overhead cam, and in some cases hemi head engines. If they had any advantage in performance, it was small and it was bought at a high price.

In most cases they were no faster or better than comparable luxury cars with flathead engines.

So why don't we buy new flatheads today? The answer is in gas quality or octane.

It was only when heavily leaded, high octane gas became available in the early 50s that the flathead became obsolete.

The typical flathead engine is limited to a compression ratio of 7 to 1 or 7 1/2 to one.

It's hard to believe today how little advantage the OHV engines had at these compression ratios.

For example, in 1949 both Cadillac and Lincoln introduced new V8s. Both were similar in size, 331 cubic inches and 337 cubic inches respectively, and both were designed to power luxury cars.

The new modern OHV Cadillac made 160HP. The obsolete, old fashioned Lincoln made 154HP. Both had compression ratios of 7:1.


More sophisticated designs like the Hudson and Packard had higher compression and a power output nearly equal to their OHV competitors. The highest compression flathead ever made was the 1954 Packard at 8.7:1. It was a 359 cu in 212 HP straight eight,standard equipment in the Packard Patrician.

The most powerful engine made that year was the 235HP 331 cu in Chrysler Hemi V8, optional in New Yorkers. Their standard engine was the same engine with 195HP. Cadillac's standard engine was also 195HP.

So you see, up to that point the power advantage of the OHV design was small or non existent.

Hudson and Packard both made excellent flatheads but they overlooked one thing. The public wouldn't buy them.

When they finally switch to OHV V8s it was too late.

In the meantime oil companies increased their octane to the point where 9:1 and 10:1 compression ratios became feasible. By this time, the flathead was relegated to utility duty and all performance engines were high compression OHV designs.

Incidentally if you compared the Buick and Packard engines head to head I doubt you would have asked this question.

Let's take the 1948s as typical models:

Buick Special Eight, 248 cu in 110HP @ 3600RPM .44HP/cu in

Packard Standard Eight, 288 cu in 130HP @ 3600RPM .45HP/cu in

Buick Roadmaster Eight, 320 cu in 144HP @ 3600RPM .45HP/cu in

Packard Super Eight 327 cu in 150HP @ 3600RPM .46HP/cu in

On top of that, Packard had a 356 cu in 160HP Custom Eight but we won't go into that because Buick had nothing to compare.

When you look at a fair comparison it makes you wonder why Buick didn't make a flathead engine like Packard.

Great replies, everyone. I learned something new from reading this thread! I think Rusty O\'Toole explained it the best. Also, I didn't mean Buick was a lesser car in general, only compared to a Packard. I am a Buick man, but Packards are on the level of Cadillac. I knew the straight 8 Buicks were pretty gutless by 60's muscle car standards, but I didn't know the Packards were equally as, er, made similar power as OHV engines.

I would assume of the many reasons given that Packard chose to stay with it mainly because it was quieter and tried and true. Also, similar hp meant it was not worth the investment for a struggling company. I saw a guy with a 55 Packard at a crusie in recently. I stared at his V8 for a long time, although it wasn't sexy, it is probably the rarest of any V8 made in the 50s. I bet chevy made more 348's than Packard made V8s. And if I am wrong on that I would love to pick your brain on which is the rarest.