• Vintage pre war Triumph S 5 engine, engine doesn't turn over damage fins on the head, used part please look at pictures.
• Collection only.

I've been given this from someone, good information, trust it's right.

For 1934-36 engine number codes, S is the code for 500cc, (R is 250cc, T is 350cc). The 1 is the mark number (as in 5/1) and the 5 is the year (1935).