Boring the case: you install thecam chain tensioner bracket
(shoe upside down) with speciallyprovided allen screws,
but the boring bar will still nipthem a bit, also the inner
diameter of the bracket. Clampwell, go slow for this.
840 liners installed. Halco kithas special two-piece dowels to get around the interference.
Larger lungs:
completed cylinder and 840 pistonvs. stock liner.
277 crank in place, Carrillo rods.These or European 552 rods required.
If you'd rather not pay the priceto have the lobes re-positioned professionally, here's
an alternative. Stock D cam wasparted, larger I.D.s turned into ends, button made to exactly
replace removed metal. Retainsaxial alignment when re-indexing. With the whole shaft
and button held together by a longbolt (engine stud and washers, head nuts work great),
you can locate the offset indexesexactly. Grind into the button flange, burn in a good bead
across all three pieces, rotate180, repeat, rotate 90, repeat, rotate 180, repeat, etc. This way
you don't warp the axial alignmentwith welding heat.
Recommend indexing the offset marks
in the engine with the same setupyou would use to degree-in the cam. I've done this twice
and found slight differences inthe amount of offset from one engine to the next, possibly
due to any number of variablesinvolving crank wheels, cam chain or sprockets, actual
cam grind, wear, or just plainpilot error. Best to take the time, do the work of set-up with
the actual parts you will be using,be accurate, double-check before welding.
Removal of ridges around valvepockets is recommended by vintage racers to improve flow.
Ports are opened to 38mm, polished.R&D valve springs keep 'em honest.
Lower point set can be moved withouttoo much improvising:
Can be done in either direction
Cooling the beast:
Oil flow is tapped out from theprimary case, fed to Summit thermostat, which bypasses
the cooler until temp reaches 180;this unit also eliminates air traps in system. Oil returns through
10 micron spin-on filter. Cooleris 10 feet of 3/8 copper tubing coiled into one-inch space below
crankcase, shielded by stainlessfloor plate. Relocated exhaust mounts make perfect
brackets for this, plate also scoopsair, may help stiffen frame. Because bulk of extra oil is
stored/circulated below, nominalcrankcase level is not much affected.
Extra guage is for oil pressurepeace-of-mind. Likewise for small unit above turn signal
indicator lights: (it's a Dynaunit that monitors charging system status.)
Extra lever under clutch is compressionrelease.
Monster Thanks to:
Bob Bertaut of Sports, Inc.
Mike Lalonde of Mike's XS
Ted Cole of Cole Tool, Inc.
Tony Hall and Halco, U.K.
Dave Rayner Down Under
Mike 'Mercury' Morse of VintageBrake
XS 650 Society Intl.
Summit Racing
E Mail Info Request.............AboutEarthcom
Residential BuildingTrades.....The Fifty-Minute House
Pricing
Film Festival Documentaries:
The Last Real Circus..................Mr. Jefferson's Rotunda
Patrick Henry,Virginia Patriot
Patrick Henry'sFight for Individual Rights
The Brews Brothers
Copyright 2002 Earth Communications Corporation