8/S - 8/SN Top 3.5 cc suitable for 1:8 scale cars 3 ports chromed cylinder.
	PT 21 P1 Top 3.5 cc 7 ports chromed cylinder suitable for 1:8 scale cars on/road and GT.
	PT 21 SP1 Top 3.5 cc 7 ports chromed cylinder suitable for 1:8 scale racing cars on/road and GT.
	PT 21 R1 Top 3.5 cc 7 ports chromed cylinder suitable for 1:8 scale racing cars on/road and GT. Balanced crankshaft and booster exhaust port.

	PT 21 CLB Top 3.5 cc suitable for 1/8 scale buggy competition cars. Long stroke 4 ports chromed cylinder.
	BT 21 B / BK Top 3.5 cc suitable for 1/8 scale buggy competition cars. Short stroke 3 ports chromed cylinder. Available with intake chamber.
	BT 21 SB / SBK Top 3.5 cc suitable for 1/8 scale buggy competition cars. Short stroke 5 ports chromed cylinder. Available with intake chamber.