I was in Detroit last week, and since my wife was along we had to stop at one of those antique malls. I normally resist these kinds of excursions, but since it was drizzling and ugly outside I decided to go in and sniff around a bit. I scored one interesting piece. I found a booklet for one of the presentations at the 1961 SAE International Congress and Exposition of Automotive Engineering about the new Buick aluminum engine, in nearly perfect condition. It is amazingly detailed, with great drawings and specifications. But the neatest thing about it was something that preceded the presentation by a decade. It had a couple paragraphs about the Experimental XP-300 powerplant from 1951. That engine was also 215 cubic inches like the ones in the early 60's, and also all aluminum. The similarities end there. Supercharged, hemi, a pair of sidedraft carbs, and 335 horsepower at 5500 RPM. In 1951. Damn, I wish one of those would parachute out of the sky and land in my yard. Check out the orientation of the exhaust valve rocker arms in the drawings.
The intake manifold also holds the cam and lifters. But it could just be part of the block? since the crosshatch pattern is continuous with the block
Super cool! Engine[edit] The XP-300 was powered by a supercharged V8 engine made of aluminum that weighed just 550 pounds (250 kg) yet produced 335 horsepower (250 kW).[1][11] This engine is 250 pounds (110 kg) lighter than the engine used in the contemporary production Buick Roadmaster, but is twice as powerful.[7] The XP-300's engine could run on either gasoline or methanol, and the car featured two separate fuel fillers and fuel tanks, one for each fuel.[12] The engine was fitted with a Bendix-Eclipse two-barrel carburetor,[12] with one using gasoline and the other methanol.[7] The methanol carburetor automatically cut in once the gasoline carburetor reached 40% throttle,[7] in order to prevent engine knocking during rapid acceleration.[6] With a displacement of just 215.7 cubic inches (3.535 l), the engine, which also powered the Le Sabre, had an impressive power-to-size ratio for the era.[13] It also boasted a chain-driven camshaft and hemispherical combustion chambers,[13] the latter of which allowed it to achieve an air-to-fuel-mixture ratio of 10.0:1, also considerable for 1951.[14] The engine features rocker arms that were mounted transversely on its intake valves but in a fore/aft position for the exhaust valves, which made it more compact and allowed easier installation into the car.[12] It is mated to a custom Dynaflow automatic transmission.[6] https://en.wikipedia.org/wiki/Buick_XP-300
According to this article, Navarro was the first hot rodder to put a roots blower on a car engine in the 1950s, so this was pretty new stuff. https://vintagedieseldesign.wordpre...nd-why-does-he-have-a-blower-named-after-him/
No. They are in line with the intakes and the pushrods pass the valve stems to connect with the rockers.
I don't understand. Is the photo above of a "concept car" with the 215 Hemi or did that engine actually go to some level of production? I had never heard of it before (which isn't surprising) and my guess it was a "what if" engine idea that never made it to the production floor. Maybe Speedway Motors has one in their extensive engine museum?? Lynn
@lake_harley , yes, it was just another one of the many experimental engines GM produced over the years.
Well that looks like it would work great for the intake charge, not so much for the exhaust..... And I guess pistons need quite a pop up to make good compression, eh?
It's not very clear in all the illustrations, but in these two cut-a-way views it looks like they pretty well stuffed the combustion chambers with the domes.
Sorry, I was talking about the nailhead, there should've been that cutaway picture of the nailhead V8 in my post, I don't know why it's not showing up
The Jalopy Journal
