It does Cammo. I've just edited my last post to ask about tappet shims.
Quite a bit of work in doing this so I'm wondering what the gains are. I'd love to dyno the bike at each stage but it's a long way to the nearest reputable tester and far from cheap!
I've decided to leave the backlash gears in to keep the engine sound and I can't get a solid answer on whether it gains much other than the loss of weight. Looking at other graphs the engine picks up a tiny amount quicker but I'm thinking that I'd achieve this more easily (though at greater expense) by putting on a GSXR generator.
That's something I'll have to research though. Can't find much info on here. I know Rick does the cover but he's not answered emails for a couple of weeks.
As for other tuning I'm not sure. Most gains are made inside the combustion chamber but such things tend to be closely guarded secrets.
Thanks again Cam.

Thought I'd post a few photos:
Removing collets with home made tool and magnetic tip of a screwdriver.

Everything out and placed in order.

Before and after exhaust valve. Lower stem is not machined which is why it's dull.
Battery was going so no flash either which doesn't help.

I'll have these finished today.
The lapping stick hasn't worked well. It's only a tiny bit smaller than the valve face, especially the exhaust valves, and a tiny bit of grinding paste means it wont stick. Instead I've got a piece of plastic tube (off a garden weed sprayer) which is a good fit over the valve stem. I then put the other end in a variable speed cordless drill and used that. The tube means you don't have to use the chuck jaws direct onto the stem and you don't have to worry about being dead in-line. Works well. Anything more than light pressure and the tube slips on the stem so stops you going too hard.
Duncan

Mananon wrote:That's great Malc. Thanks very much.
Is the 2mm both inlet and outlet valves mate? I've ordered a Haynes from Aussie but it's not here yet, They're usually a bit different. Visually the inlet valves do appear to have a narrower mating surface.
I'll get those shims made up at work this week.
Any idea what that does to the compression ratio, power output and if there are any adverse knock-on effects?
Last thing, and I'm assuming you've done this, I'll need thicker tappet shims. Are they hard to get? Davis Silvers site says they can get them but doesn't say if they can size to order. Nowhere in NZ stocks these and they charge a mint (admin charges they call it) to order any parts.
Thanks again Malc.
Duncan

Yes, me and one other bloke who visits here sometimes done it together. I cannot confirm power outputs yet cos the engine was only run for the first time recently and I haven't had chance to dyno it yet, but it definitely felt stronger after 2 x 20 minute sessions to run it in, even on a very hot (comparative) day with higher than normal engine temps.

I do have calculations somewhere about increase in compression ratio, but I'll need to dig them out - from memory it goes up around 1.0 (e.g. 12.0:1 increase to 13.0:1) but again would need to confirm.

You do need extra thick shims, mine was about 0.25mm extra all round (0.2mm skim and invariably regrinding valves will cost you a little bit too), I got them from eBay UK based user called motorcycle-tuning-direct, at 2GBP each, he would probably post them to you.

Sorry about the vague 2.0mm but I see Cammo was more specific for you, thanks Cammo!

Cheers Malc,
I've sent the drawing you posted to a couple of profiling places I regularly use for work so I should be able to get them laser cut for not bad money. I wouldn't think the material needs to be anything fancy so I've asked for prices in 316 stainless
I'll let you know how I get on.
Thanks again,
Duncan

Anybody know why the valve spring have red paint on them, i thought it was just mine but obviously not!???
I've used a bit of fuel injection pipe with a bolt in one end to clamp in a battery drill and a cable tie on other to keep it on the valve stem to grind valves for ages, got sore hands playing with a wood lapper!
Good stuff hope it goes well.
Cheers.
Ian

Just part of the assembly process I’d guess Ian.
Lots of black pen marks, white paint pen marks here and there. We do the same at work to indicate that something’s been torque up or is ready for next phase of assembly.
Paint might be used to make things like washers stay put while work is done, a sort of temporary glue.
Sounds like yours needed a lot of work to get them lapped. Mine took 5 mins each once I had a decent system working. A fiddle to keep checking the tolerances without fully removing the valve. I was paranoid about getting grinding paste into the valve stem though.
If anything I’ve gone a bit under tolerance. High performance engines seem to have a smaller/narrower tolerance so I erred on the side of caution.
My next fun job is the ports so I’m storing up patience as I’m guessing that’ll be another tedious job that I need to be cautious of.

Cheers,

MexicanGringo wrote:Polish the exhaust ports but not the intakes, the slight extra turbulence of the casting helps with fuel atomisation.. If you take the heads off, may as well put new rings in and replace the valve stem seals. I got a full gasket set including them.. Youl also have to rehone the bores for the rings, get this done professionally... You could also check all bearings and clearances while its open

Just going back to this, 've had some more advice and you were right there Mexican.
Apparently a very smooth surface causes fuel to bead or condense on it. A slightly rougher surface prevents this. Same principal as golf ball dimples I guess. Nice one amigo.
Not taking the cylinders off so leaving the rings and bores alone. Got a price for stem seals and nearly fell over. $400 plus for a set! I'll keep them super clean and cross my fingers.

I think theres pros & cons to a smooth/rough intake, and since youv heard it from experienced racers there has to be some truth, but its prob better to leave it as is, unless you wudnt mind buying another set of heads and experimenting for all of us?...

And thats ridiculous for stem seals, i bought a gasket set for what equates to round $150US, that included head gaskets, stem seals, exhaust gaskets, sump & crankcase cover gaskets and tappet cover seals.Im trying to remember the brand, think it started with a v

Thats $400 NZ, not US but if you remember who you got the set off please let me know! I've seen full gasket kits on ebay uk (about NZ$200) but I worry about quality and not sure it they include stem seals. I'll mail them and ask.
Honda dealers in NZ should all wear ski masks!
They stock nothing so it takes them ages to get the bits and then they want and arm and a leg for the hastle.
I can usually get parts from David Silvers in the UK (on the other side of the planet!) faster and for less than half what I can get them locally. Mad!

I am being very carful with what I'm doing and have just had some advice from a race proven tuner. I've asked permission to reproduce the info here so stay tuned for good solid info if he agrees.

Rebuilt the top-end of my ZXR last weekend, didn't replace the stem-seals though, they wern't leaking before hand and arn't leaking now.

If you went with the 24 head you'd need the NC30 cams so you'd have to make sure journal clearances were within spec.

An easier option might be to use the NC24 valve gear.. (rocker-arm etc and put them in the 30 head)