I have a set of cylinder heads listed on ebay that I thought were 45 heads. After some messages and a little checking they appear to be --maybe rare-- VL heads. The have a casting number "PAT`D 11-13-23" on the top and "high compression" cast on the bottom. I am told that these are RICARD PATENTED HEADS. Check them out soon as the listing is up tomorrow or if you have any comments, let me know. Thanks
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1930-1935 VL "HIGH COMPRESSION" Heads
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Englishman Sir Harry Ricardo earned his Knighthood developing more-efficient internal-combustion engines for the Brits in the Teens and Twenties, including their First World War aviation engines. He's the one who found that sidevalve (flathead) engines ran much stronger with the exhaust valve much farther from the cylinder center than the intake valve, by "offsetting" the valves beside the cylinder bore. Anyone who built such engines were using the Ricardo patent, and paid Sir Harry for the privilege. That's why you didn't see American Clinton and Briggs & Stratton lawn mower engines ever change. They didn't buy the privilege. The symmetrical valve train was a "good enough" powerplant for mid-century American lawn mowing.
1929 was when Harley-Davidson adopted the Ricardo improvements and side-valve technology, with the D-model 45s, followed in 1930 by the V Big Twins.
You get eight headbolts on a 45", and the head is much smaller than a 7-bolt 74" head.
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Note that the width of the transfer area narrows as it reaches the bore edge. In his auto-bio he describes experiments to modify this ratio, but that a restriction is necessary to provide proper turbulence.
Placing the largest chamber volume at the exhaust valve is still good practice today.
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Originally posted by Sargehere View PostEnglishman Sir Harry Ricardo earned his Knighthood .. .. Anyone who built such engines were using the Ricardo patent, and paid Sir Harry for the privilege. That's why you didn't see American Clinton and Briggs & Stratton lawn mower engines ever change. They didn't buy the privilege...
When did Indian first produce a similar design?
Did Indian pay the patent?
Thanks in advance as always...
....CottenAMCA #776
Dumpster Diver's Motto: Seek,... and Ye Shall Find!
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I guarantee you Indian paid Ricardo patent royalties. Just look at their heads. They used the features of Ricardo sidevalves right up until they died in 1953. Now, the Franklin Indians predated all this, and were "old fashioned" symmetrical sidevalves.
Just look at the valve and piston locations through the Twenties and you can see when Indian got on the band wagon. And Ricardo's lawyers doggedly collected from every firm that used their improvements. The Ricardo Patents were credited with giving sidevalves a whole second life in the Nineteen-thirties. Figured in the design of the Harley KR into the 1970s.Last edited by Sargehere; 12-26-2018, 10:21 PM.
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There wasn't much finning on a 7-bolt VL head. The VL, 74, hadda almost 3 1/2-inch piston, a 45, about 2 1/2-inches. You should be able to tell which ones you have from that.
I just ran a ruler over a 9-bolt iron head: it's about 9 by 9 inches and meatier than a VL head.Last edited by Sargehere; 12-26-2018, 11:03 PM.
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Yes they look like VL 7 bolt heads, but unusual in that they have small stiffening ribs on the top running at right angles to the regular finning, and high compression cast in the bottom. I'm guessing they were made either as aftermarket or Harley replacement heads in the 1940s/50s. On the Ricardo patent, Harley had just been hit for an alleged one million dollar settlement of the Eclipse clutch patent suit in 1929 and I'm thinking once bitten twice shy. William Harley would have had numerous patents in his own name by then, so no doubt also developing some respect for intellectual property.
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