I'll be surprised if you have to tip the valves. mine were around 1.9 - 2.15 from memory.
The two box Hot Cams set of 7.48mm shims I have runs from 1.2 to 3.5mm.
Bought off Spannerspinner on here when he offered them cheap....
I'll be surprised if you have to tip the valves. mine were around 1.9 - 2.15 from memory.
The two box Hot Cams set of 7.48mm shims I have runs from 1.2 to 3.5mm.
Bought off Spannerspinner on here when he offered them cheap....
NZ Cylinders have the head. Things are marginal as far as tooling goes for the tiny valves but it sounds like it may be possible. Unfortunately it isn't worth their while to purchase tooling due to me being the only idiot in NZ willing to pay for a proper valve job to be done on a FZR250 cylinder head. It's a shame really because there are definite improvements to be made even on a good head. Old worn heads will show a significant improvement if good work is done and they are setup properly.
I believe there is an optiional very small tool holder for the Serdi head machines. It's rare but there is one in ChCh. But it's in Barry Lynch's collection of machinery - which afaik is now sitting idle.
I'd be surprised if no-one else had one. There are certainly enough Serdi's around now.
Bit of an update on the other twin, my son's Honda CB125T. The engine went "off" at the end of the 2-hour at Tokoroa. A new 150cc cylinder kit was ordered from China and was on the doorstep about 10 days later. The 125cc engine in it was showing lots of blowby so it seemed logical. Once I started measuring everything I found a big end bearing was trashed. Luckily when discussing it with Becks she pointed out the ESE had a CB125T engine which was duly purchased for a very reasonable price. At one point in time there were 3 CB125T engines in pieces in my garage as I chose the best part options for the new engine. The new engine has the cases, crankshaft, and gearbox from one engine. My modified clutch from the Tokoroa engine, the new block, and the head from the original JCR 150cc engine from the original bucket along with the JCR camshaft. I skimmed 1mm off the block and used the JCR head which was also skimmed. This caused a problem with the camchain tensioner running out of travel meaning I had to dismantle the topend to fit the modified tensioner from the JCR engine. Now the intake valve were kissing the piston but only on one cylinder. I backed the cam timing off just enough to leave .6mm valve to piston clearance on overlap. I also replaced the old square-section seals on the intakes with viton o-rings. Strangely the motor isn't so hard to start now and doesn't seem so cold-blooded. It doesn't sound like all that much work but there is a good solid week of work gone into it.
One thing I didn't mention is that the CB125T is a bit harder to turn over now. I managed to bump start it in 2nd down my drive but had to be in 3rd to get it to turn on the dyno today. Rob gave me a hand to give it a few revs to try it out on the dyno before dragging it to a race track only to find it doesn't work. Unfortunately the software/hardware wasn't playing nice so we don't have a number. After a good warmup it seemed to be running well. The revs were built up over a few runs through the gears and the engine was sounding real sweet, very crisp and responsive. Rob and I both suspect it's making more power than before based on how quickly it revs through the gears. We've had it on the dyno a few times so have a good idea how it typically runs on the dyno. Only one slight concern is a puff of smoke at each downshift. The 150 kit came with new valve guide seals which have been fitted but I did have a concern about the spring retainer hitting the seals with the JCR cam. I'm going to try better oil to see if it helps. Maybe it just needs a bit more bedding in as well.
The FZR has been getting love as well. I fitted the cams to the new head but really wasn't happy with how far off-centre the lobes were on the tappets. In the end I have remachined the previously unused recesses in the end of the head where the cam locating discs now run. Even with the recesses widened the cams couldn't be moved over far enough to centralize the lobes. I have machined one cam and have ground the majority of the disc off the other and will hopefully machine the 2nd one tomorrow. The disc on the end of each cam is reasonably hard. Combined with the hole in the disc it made for an interrupted cut of a hard material and the carbide tips weren't lasting long. Once both cams are finished I'll make a new disc for each cam that will be pressed and welded onto the cam which will fit into the new recess and locate the cam correctly.
As this seems to be the most popular bucket thread - are you allowed to use a rotary (Wankel) engine in buckets? I saw today in a second hand shop a lawnmower with a Sachs rotary. No idea what size, whether is goes or anything els but was tempted by the $100 price.
it's not a bad thing till you throw a KLR into the mix.
those cheap ass bitches can do anything with ductape.
(PostalDave on ADVrider)
. . . And there are no provisions for rosaries, dam autocorrect
Don't you look at my accountant.
He's the only one I've got.
chapter 10 of the MNZ rule book applies to all road racing machines
10.11 The Formulae to Calculate Cubic Capacity:
Rotary combustion (Wankel Patent): Capacity of one working chamber
in cubic centimetres, multiplied by number of rotors, multiplied by two
Wankels operate on the foul (four) stroke principle so for F4 class Buckets a capacity of 158cc applies.
I suggest teaming it up with a CV transmission like TZ350 has been playing around with.
Compare Pornography now to 50 years ago.
Then extrapolate 50 years into the future.
. . . That shit's Nasty.
I think the handlebars tell you all you need to know. Waste of an MB100 bottom end.
Don't you look at my accountant.
He's the only one I've got.
I turn my back for a month and look what happens . . . . . .
Anyway, I'm back. I've been slowly getting little bits done here and there and managed to machine the washers for the end of the cams today. The internal holes had to be slightly different sizes but it all worked perfectly as both washers need to be slightly heated to slip on the cam. Now that I have sanded and ground them smooth they are a nice fit in each slot. I do need to take maybe .1mm off each face where it presses up against the cam to get the cam centred just right. I'll clock them up in the 3-jaw tomorrow hopefully and whiz a bit off. Hopefully welding won't cause any problems with movement and I won't have to do any further machining. I'm pretty happy with how this is coming out.
Slowly getting things done. I have now cut the end off the inlet cam and welded in a bung. I'm getting the hang of getting the sizes exactly what I want. The bung is the same size as the hole in the cam on the inside end and .01mm larger on the outer end. A gentle tap was needed to get it in. Both washers are now welded to the ends of the cams. I ran a small stone over the ends to make sure there were no bumps that were going to bind in the aluminium. It's come out reasonably good. I have decided to make a new steel boss to mount the 1-tooth cam trigger onto. The old one is alloy and not ideal. I'll make the new one out of steel and weld it in. I'll need to spin it in the lathe to make dead certain it runs true. The cam end boss was one lobe that I ground down using my high speed grinder in the tool post on my old lathe. I'm pretty sure that Kevin isn't going to be too happy about me grinding anything in his lathe.
The exhaust cam is nearly finished. The new boss is welded on and machined to size. I just need to finish the thread to hold the trigger on
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