Topic: SOHC4 race car?

[Scott S]

 I don't have any info in this. Saw it in a FB post this morning. Really cool.
 Anyone ever seen anything like this? Looks like it has a '73 CB550K engine with a modified F header.

[MauiK3]

I think Hondaman has some experience with this type of vehicle with a 750

[M 750K6]

Very cool!

Seat looks comfortable 

[Phoenix]

Back in the early 70's, a friend of mine ran a cb750 engine in the D Sports Racer, SCCA class.  He converted the foot shifter to a hand shifter. He used a number of Yoshimura parts.  The body was much more substantial in shape than the one you pictured.  I think it was called a Pegasus.  His big competition was from speced out Suzukis-I think Ron Wood.  He raced Mid-Ohio, Raceway Park and Elkhart Lake.  It was hard on pistons and connecting rods.  Very easy to work on and a lot of fun.

[Phoenix]

Check out:
http://sports.racer.net/chassis/pegasus/page1.htm

This was the guy my friend bought the car from.

[BenelliSEI]

That’s a VIXEN Formula Four, built in England in the late ‘60’s and early ‘70’s. In England these were often powered by a 1 litre Hillman Imp engine (extremely lightweight engine that very much resembled an FWA Coventry Climax unit). Some really brave Europeans raced them quite successfully with three cylinder SAAB two strokes too!

They were also fitted with various motorcycles engines to complete in the British Formula 750 Series. Engines for that class were limited to 750 cc’s and the Honda cb750 Four quickly became the engine of choice. Later it was Kawasakis too……

There was a surprising number of them built. When I started racing in 1970, Sports Cars Unlimited (the Lotus dealer in Toronto) had  a yellow one in their showroom. Less engine and gearbox, it was $1200….. I was  17 and earning $200/week!

[jonda500]

Awesome - a CB550 race car!
What in that picture makes it a K? The 4 into 1 is from a 400-4 - do all the sohc4's use the same diameter headers?
John

[Scott S]

Awesome - a CB550 race car!
What in that picture makes it a K? The 4 into 1 is from a 400-4 - do all the sohc4's use the same diameter headers?
John

 On the original post, he included the engine number and it was decoded as a 550K. The header looks modified  and I assumed it was from a 550F, but could be a 400F I guess.

[HondaMan]

I think Hondaman has some experience with this type of vehicle with a 750

Yeah, but mostly experience with WATCHING them, and occasionally helping their owners get or make parts out of OEM pieces. Their cars were more like little Offenhauser racers, midget size, with the outboard wheels. The CB750 engines, though, were sans their trannies in that bunch: they cut off the tranny and drove a (non-Honda) oil pump off the bolt-end of the camshaft, with its suction line to a port that was drilled into the crankcase underneath cylinder#1 to pick up the oil before it got too deep under the crank (at least one of these had a copper-pipe suction line from the center of the crankcase instead). The alternator rotor was removed and a heavy-duty version of a key milled into the crank's end there so the engine could mate up to a 4-speed manual transmission's input flywheel - some trannies were complete with a starter to its flywheel/pressure plate. Imagine an MG Midget or the little Triumph cars, how those look under their hoods.