Next, build the crankshaft up and fit the conrods. Wilson mentions measuring them to see how they fare against each other, putting short rods with long pistons and long rods with shorter pistons. We had two which paired up at 86.16mm (using reference points) and two measuring up at 86.04mm using the same references. These got installed at 1 & 3 and 2 & 4 Whilst we was at it, we checked the conrod side clearance, which worked out at three rods having 0.15mm and the fourth at 0.20mm, which was well inside the maximum 0.70mm!
Distributer drive gear and dizzy installed, set the drive gear end float, reads 0.7mm - maximum should be 1.27mm. Check Cylinder head studs installed and pressure relief valve installed Same again with Oil control valve installed Next week, refit the crankshaft!
How did you know where to set the dizzy body? I notice you've marked the side with a blue pen. Was that to mark no 1 position?
Yes, indeed it is! If you take the cap off, there is a line on the seat where the cap sits, that's what corresponds with the blue line we marked so we know its the #1 position! Roughly where the books show it should be
Oh ok....that'll explain it then! Basically all I've done is compare the 2 and rotated the body so it looks like it's in the same position as my old one. Hopefully that'll be near enough to get it running and I can tune from there
In reality the dizzy can sit anywhere so long as: 1. you are 100% sure # 1 piston is at tdc on the compression stroke 2. the rotor arm position corresponds with the respective plug lead position on the cap The above is not the usual convention and may cause confusion later in time..so long as cylinder, rotor arm and plug lead all tie in, jobs a good un
Massive progress this week, well chuffed with how we have progressed! Crankshaft lubed with Torco, located it in the case, checked it turns smoothly and doesn't snag..camshaft timing marks located in the correct position wrt the dots..check Oil pick up tube located back in (new o ring fitted)..check Case vibration dampers in one half, halves located together, long bolts screwed together..check! The flywheel was popped on along with a dial gauge to check the endfloat; we require 3 x 0.38mm shims to get to the minimum (we measured 1.21mm) Whats the best method of cleaning out the breather box? Just rinse out with white spirit or something similar
Time to sort the flywheel out and refit it. It required a new bearing but the only ones available are about three mm longer (Wasserboxer's) so we had to open the hole on the flywheel. Thanks Paul for the explanation why it wouldn't fit Clocking it for running true on the lathe Bore the hole out; sorted! The clutch face was a bit rough so we turned the flywheel round and clocked the other face up New tool tip nice and shiny! Another little job done..tick!
Onto checking the deck height (only one photographed; all four checked using the same method: Bolted down using a couple of sockets and washers shaped to suit the profile of the cylinder rim Using a ground bar to use as a reference, we measured the deck heights all round the piston and took an average of the height measurements #1 = 1.53mm #2 = 1.50mm #3 = 1.53mm #4 = 1.52mm Slap bang in the middle of what Wilson recommends, result! Whilst we where at it, he also mentions checking piston heights versus long and short conrods. We'd sorted this earlier on the fitting of the conrods - so we used reference points on the pistons themselves and found the shortest reference point was 29.51mm, 29.61, 29.71 and 30.2mm. The shortest went on #1 followed by #3, #4 and #2 the longest piston. Next week, refit the p & b's and heads! But first
If you were really picky you'd had skimmed the face the clutch bolts to as well to retain the same clutch pressure.
We attempted to cc the heads (only one pictured). @paulandchez you set a high target with this one Thanks to Paul (paulandchez) for the guidelines, it is a useful thread to follow! We made a little plastic lid to fit the top, with a hole in it filled with fluid from a syringe All in all, we found each combustion chamber to hold 56/57cc which, based on the John Maher Racing link, it gave us a compression ratio of 8.1:1 (56cc) or 8:1 (57cc). Sorted!
