'Bout time I updated things.
Thu Aug 18, 2011
Thought a good deal about the intake system for this. The supplied manifolds on the engine were lifted straight from the 500 singles. The front one was at a silly angle especially for the carburation that the engine would have been expected to have.
Even with injection, the throttle body would have been going thru my chest! Not ideal.
So something more appropriate was in order. Originally I envisaged using TL1000 throttle bodies, but they're huge and incorporate the injectors, whereas I wanted the injectors downstream of the TBs and pointing in a straight shot at the valves.
Then another idea occured. Why not have a single throttle body feeding a plenum, which would then feed a manifold/ injector housing which would extend the 2 ports to each valve back several inches? A long ram effect with a smooth flow.
Now individual throttle bodys are well known to give a snappier throttle response compared with a plenum, but thinking about it, on a long straight run on the salt snappy throttle response isn't needed or wanted - I imagine you could quite easily induce wheelspin on each gearchange.
So a more damped response is a good thing in this application.
Of course, its easy to forget that airflow needs to be considered holistically (!) Its no good having a perfect port layout if the atmosphere its drawing upon is going the other way at 150mph!
Laminarity of flow is what I'm after. And if its easily convertable to turbocharging, so much the better.
Heres the pics. You can see that the throttle body (off a volvo) will point forwards and the plenum is a curved tube affair to keep it all moving in the right direction. Ducting is deliberately kept on the large side to provide the plenum area right up to the manifolds.
Gas tank. This is the dumpiest tank I ever made! Function before form here.
It needed to be tall enough to house the fuel pump:
But short so I can hunker down behind it out of the airstream. Took a day & a half sandbagging & wheeling - my arm hurts! but its done:
Sat Sep 10, 2011
Got loads more done now. Almost ready to blow it all apart & look inside the engine.
Mostly brackets etc of course.
Exhausts, according to Julian Cranfield, should be 54" long. Thats why they have to snake up the inside of the footpegs. I know the rules say the exhausts cant point at either the salt or the rider!:
RH footpeg setup:
LH footpeg & shift linkage:
HD boxes were never made to have rearsets!
Wed Oct 05, 2011
With the fabrication done, the frame etc off for paint and some customer stuff done, I'm tearing into the engine.
In order to get the cam timing right on reassembly, I fished out my old Hagon 'dural' timing disc. Probably a collectors item now!
I have to figure it all out myself with this - no manuals. Dismantling the cam drive was a puzzle, but got there in the end.
Dealing with a lot of 25 year old silicone seal doesn't help. All stuck fast. Being a low production lump, some things weren't well sorted - like how do you get a socket on this bolt? A bit of machining needed here.
Finally got the head & barrel off. Dished pistons and small volume chambers. Tomorrow I'm going to have to take a burette to it all to measure the compression.
Relieved that the cylinder bore looks in good condition (dont know about the front one yet) I had fears of rust from all those years in storage.