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Engine goes quiet over Tiger Country


Tecsar

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Mightn't be a pension when you get there, LS.. SV means sidevalves ot " flathead" in the american idiom where they stuck to them for a long time. The valves are not in the head but in the block alongside the cylinders, They (The americans) weren't alone. Morriss had them till about 1953 and Hillman/ Humber also. They are an inefficient (but compact) design that has been revived in "trials" motorcycles of late . ( I don't quite know why). But there you are. The flat four aeroplane engines were SV, in the early years also when they delivered about 45 HP. from a 200 cu in motor. ( which only had two main bearings0... Nev

 

 

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Henry Ford allegedly invented the V8 and his first V8 was a side valve.

 

Typically no push rods in a side valve engine. Most engines prior to 1950 were side valve. The valves are in the cylinder deck beside the piston, not in the head (hence the term to day 'overhead valves as in over head camshaft). The valves are driven directly off the cam via a cam follower. Simple operation but the limitation is compression ratio because the combustion chamber in the head has to be large enough to include the piston diameter and the valves which are beside the piston and operating in the same plane as the piston. Also the depth of the combustion chamber has to be deep enough to allow for the opening valve, whereas in an overhead valve engine the valves open down into the path of the piston and the timing of the valves with the piston determines piston to valve clearance. Phew ... that was a mouth full, but hope it helps you understand the difference.

 

I see Nev beat me to it, BTW I am no where near a pensioner yet ... or am I???

 

 

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Pretty good summary David . Just to add a few more facts:-

 

JAP had an aero engine in V8 Form about 1910. ( air cooled based on their motorcycle engines) At that time Henry Ford engines were flat twins and the later straight sixes and fours ( the deservedly famous model "T").

 

What Ford achieved and cemented his claim to be associated with the V8 configuration was to produce the first one piece V8 block which went into production as the famous "double B" in 1932.. A silky smooth engine (which evolved through the "T" to the "A" model and the "B" about 1931) and good value for money car. This was a masterpiece of patternmaking and moulding technique for the time. Other makes , Cadillac ( GM) made V8's but they were 3 piece blocks and quite expensive.. Nev

 

 

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And there is nothing on earth - car, bike, boat or aircraft that sounds as good as a worked 1948 flat head Mercury with an open exhaust.

LOL

 

I have heard plenty of engines sound better- euro ones.

 

So all you guys had to say was Side Valve V8 and all would be understood.

 

Briggs and Stratton still use this ancient design.

 

I would never give ford credit for the V8- even for cars. He just produced the cheapest in big numbers, by clever manufacturing and casting.

 

By the time the flat head came out, DOHC, superchargers and 4 valves per cylinder were around and often in one engine. They just weren't cheap.

 

Given the low compression and poor power- I would expect it to be smooth with 8 weak power pulses.

 

Some brave soul has designed and marketing a flat four aero engine with side valves and hoping the narrow width will overcome the compromised performance. I am underwhelmed.

 

 

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.....By the time the flat head came out, DOHC, superchargers and 4 valves per cylinder were around and often in one engine. They just weren't cheap.

Yep Singer had an overhead cam and valve engine in 1932, I had one as a kid. Classic it was.

 

Some brave soul has designed and marketing a flat four aero engine with side valves and hoping the narrow width will overcome the compromised performance. I am underwhelmed.

Oh yes, it was also displayed at Oshkosh I believe, I was also underwhelmed.
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You can't apply the requirements of todays world to the technology that fitted in with something 80 years ago. At that time most engines operated with the valve gear out in the open. The Ford was completely enclosed. The epicyclic gearbox employed all the principles that are incorporated in to most modern automatic transmissions.

 

Delage had a desmo four valve overhead cam racer in 1913. They built 3. This was as far removed from what would work for the average driver ( who would have to be wealthy in any case) as you could conceive.. It wasn't practical. It's dead easy to judge something as just a marketing thing. It was also a design hallmark and brought motoring closer to the aspirations of the average worker. The "T" model Ford was cheaper than a motorcycle at the time,and used the latest metallurgy. Vanadium steel alloys.. Nev

 

 

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What a bloody crack up you guys. Talk about thread drift ... from engine failure from fuel selection to flat head V8s ... brim hats ... thrupenny bits ... circlips and Christmas puddings. I love it ... you can really get us old blokes going.

 

 

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Alan your family must have been loaded, uncle Nev told me his family was so poor they had to make do with 3/8" spring washers wrapped in foil one decade

Loaded you say....we tried it one year (spring loaded) but it practically destroyed the oven. You see the spring washers expanded so rapidly with the heat that they sprung out of the pudding mixture and hit the top of the oven inside. It sounded like a world war one fighter aircraft gun going off. (Thats the best I could do to keep this aviation related) 099_off_topic.gif.20188a5321221476a2fad1197804b380.gif

Alan.

 

 

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