'66 T120r Bonnie Motor

19Bonnie66 · Jul 11, 2019

I've decided to strip the motor on my '66 Bonnie with a view to rebuilding it with as many performance enhancements as are feasible plus to get that lovely fresh engine look.

I have a few questions for those that are in the know:

• Where do I get the cases/head etc vapour/bead blasted for that factory fresh look?
• What finish should I have on which parts?
• Performance wise what are the 'normal' upgrades I can do?
• Best or preferred supplier of engine parts - been using Monty's classics very happily so far for my Bonnie parts.
• 7 plate clutch conversion - is this the right thing to do to improve the clutch?
• Exhausts - which ones as I am running TT pipes but happy to put Bonnie silencers on if they help performance plus the TT pipes are so loud when you're riding for any length of time.
• Finally whilst I'm happy and capable to do this myself is there a Bonnie engine guru out there who can manage all the above for me and just return me the finished motor to put back in the bike?

Many Thanks folks..

darkman · Jul 14, 2019

There are plenty of places doing vapour blasting these days and you would get the rocker covers head and crank cases done and polish the primary timing and gearbox outer covers. If tuning the engine you would at the minimum have your crank sludge trap cleaned, crack tested and balanced along with new billet rods/shells/bearings and pistons plus a rebore, cam bushes would need checking and replacing if worn along with new cams if req plus checking pushrods, lifters, tappet blocks, timed breather disc, rockers and shafts for wear inc adjusters, cylinder head would need measuring to see if valve seat depth is ok and if not then new seats guides and valves fitted and i would recommend a Morgo oil pump. Also gearbox will need bearings and needle rollers minimum and fully check all gears and shafts along with complete new clutch set up and primary chain. As for cams carburettors and ignition there is plenty of choice Further tuning can be done with special cams and billet cranks along with gas flowing if you are prepared to spend big.