Copyright WWW.DBBP.COM | updated 12-April-2004


I sent you an email asking for some info on Harman engine, here a few old pictures of mine.The blue bike is turbo 150cube"(5"x4.4") project while the red one is my 134cube"(4.5"x4.4") daily ride. Regards Roger Trinne Australia

Hi Roger, thanks for the pics. A turbo 150", wow! You have probably already found the Harman pages in the "Coolest Bikes" section of There are 22 pages of Harman info there, and if you don't mind I would love to add the pictures you sent me and any more you might be willing to donate. I would really love to see more of the Turbo Harman, and any tech info and/or specs would also be welcome! Cheers mate, Duckman

I found your articles about John Harman and his engines , I have been searching for information for for many years.and is great to finally find the history of the man and his engines. In 1990 I bought my two engine kits from an Australian company Strickley Custom Motorcycles who had bought the remaining engine kits and parts from Kenny Boyce in 1988.They only ever got one of the kit together before they went broke, but it was disappointing, as it used 4'' flywheels and run a compression ratio of 6:1 (117cubes)and used a B-grind cam with a pair of down draft webber carbies, it smoked badly due to the oil rings going past the internal oil drains.The heads only flowed 134cfm@10" potential power output was poor, but it was a torque monster. Some the parts they bought were junk due to machining faults and they were only able to put together 10 good kits. When I bought mine I tested the heads on my flow bench and ported them straight away bringing the airflow up to a respectable 210cfm@10'' To cure the oil drainage problem ,I cross drilled the heads and ran a single external drain from each head into the cases, blocked the internal drains and reversed the rear head to make an XR engine. I phoned Jim Lienweber (USA) and he made me an XR style cam to match the airflow and the 134cubic inches (.575"/275duration,similar to his L7grind) I used S&S 4.5"flywheels with 8" Carrillo rods, too reduce the excessive piston weight I welded up the combustion chambers to a bathtub shape and had JE custom make an ultra light weight set of 4.4"pistons .I balanced the crank assembly to 62%. Velvatouch lifters with homemade moly pushrods, Manley valves and spring pack complete the valve train. Modified S&S G carbs with thunderjets feed in the petrol and Crane single fire ignition handle the spark. The 134cuic inch package is in a 1995 FXST and it,s quite exciting to ride. Keeping rear tyres on the beast is the only major problem I,ve had so far.My second engine hasn,t fired a shot yet but its not far off finished .It has a 5''stroke & 4.4" bore, flat top JE pistons, Joe Hunt twin magneto and will be feed by a TO4 turbo .I did have mechanical Hilbourn injection for it, but I recently sold it to a drag race as I plan on using electronic injection in an effort to keep it user friendly. Thank you for the information your site has posted it has answered a list of questions I had, very few people in Australia know anything about Harmans . I would be happy to hear from anyone who has a Harman engine and is willing to offer advice or further information. Regards Roger Trinne