Ariel Square Four cool engine cutaway drawing.

Saw this over at Scooter McRad’s along with some other cool ones. Check him out..

10 comments

  3. I have often wondered where these kinds of brilliant and excellent drawings are available. Surely you all remember the posters of the Triumph and BSA engines, gearboxes, etc that were on the walls of the old shops. Help? Thanks
    Ted
    First bike was a 1965 T100SC (Jack Pine) 500cc. The Bill Baird model.

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  4. Does anyone know if these air cooled, square four engines have trouble cooling the two rear cylinders?

    Chuck

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    1. I enjoy reading stories about the old SQ4, I think Im the most qualified to reply to your question. Ive owned a 1937 4G for 20 years and in 1999 when I left England, I took it with me to Miami. At traffic lights I shut off the engine but theres never been any overheating. Believe me, in summer I suffer more than the rear cilinders.
      Patrick

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    3. No Chuck they were very low stressed engines with a massive amount of cooling fins. The same heat range plug was used front and back. I ran mine in the 75/85 mph range for hours at a time. Wonderfully smooth engine and pretty exhaust note. Very reliable engine. the flimsy Burman
      gear box not so much. Rode many miles without second gear several times.

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  6. back in 1962 I lived in Canoga Park, Cal. one of my neighbors had about 3 1/2 Areials and a couple of BSA’s . his 3 rear cylinders used to warm up. He bought a couple of cheap small chrome scoop type carberator covers I trimmed away some of the bottom of the cover and made a couple of brackets in metal shop in school. mounted one on each side of the motor and the over heating was done. the worst thing about a square 4 over heating is they will blow the head gasket between the rear cylinders.

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