Pointy cams in a Curvey...

[G - renamed]

Ok, providing I don't have to spend too much more time fixing my toilet (!), hopefully I'll be sticking my pointy cams in my curvey minitwin tonight.

I've got a factory workshop manual sitting around, which I still haven't got around to having a look at.

Anyone done this before (or generally played with the cams) and can offer any tips?


I'm not doing the 'buckets' as I'm rather limited in time and haven't played around with valves before - though suspect they probably could do with some attetion.

[Blue_SV650S]

If you are putting new cams in you will HAVE to do the shims dude (I presume that is what you mean by 'buckets'?), the clearances will be all over the shot!!

You would be a fool to at least not check them!

[SV650Racer]

G i cant personally advise but if your not sure give steve a call prior to 6pm today...he should be able to point you in the right direction.

[northwind]

Yeah, you need to check them. There's a very good chance they'll be fine, but you can't assume that.

It's a pretty simple job, as these things go- you'll want a decent mid-value torque wrench. The cam chain tensioners are a bit fiddly, you need to either back them out in situ or, my way, remove them entirely, then back them out, wedge them with the cunningly custom built tool (which I made out of a biscuit tin) then refit- ideally with new tensioner gaskets. Accessing the front one is awkward, Maplin and Homebase sell wee side-armed screwdrivers which you can slip in.

You can sometimes do the front cams without draining the coolant- mine had enough leeway in teh hoses to just drop the radiator, had to remove the fan. It's maybe easier just to drain it, mind.

[G - renamed]

OOO, errr.

The bucket is something along the lines of...
http://www.planetklx.com/images/valves-6.jpg
(The bigger bit of metal :) )

I've got four new ones, would need to get another four for the other cylinder.

I've just read up a guide on doing SV shims (http://www.blueproof.com/motorcycles/howto/svs_valves/), doesn't look as bad as I was worrying. Done tappet style ones, but for some reason presumed shims were a lot more complicated.

If I'm having new buckets, will it meam more hassle doing the shims? - presumably I'll at least need the other 4 buckets before I check the shims.

Cheers for the thoughts so far.

[johnnyrod]

I took the rad off, and how can you say the front tensioner is hard to get at when you've sen the back one? James Herriott. I couldn't get the back one out or lock it, so when it came to refitting the chain I got a screwdriver onto the adjuster, wound it back, and had my beautiful assitant hold it for me while I refitted the chain. Perhaps not best practice but worked.

If it's low miles then no real need to change the buckets too, but do check the valve clearances. Take all the shims out and notes their numbers before you do the reassambly, or you'll be doing that job a few more times if any need replacing. Mine were spot on with the new cams, have also heard the same from other people, so you may be lucky.

There is a thread on svrider.org forums about this with photos, look under 99-02 tech section. Otherwise it's easy, I figured out the exhaust timing by looking at the cams and counting the teeth, which matched the photos so I was happy. Make sure you turn the engine over with a spanner several times before firing it, and make sure you put moly slip grease on the new camshafts and fill the oil reservoirs in the heads before you put the covers back on, so they don't grind themselves when you press the button beofer oil pressure rises.

Also didn't find I needed and fuelling mods, which was odd. And you need a real low range torque wrench, check the manual for this.

[northwind]

He's doing a complete set of K3 cams, so the timing marks will be normal, no monkeying around like you have to do with the dual intake mods (minitwins rules don't allow the dual intakes)

Rear one's easy peasy, it only took me about 5 minutes start to finish to change out my rear tensioner... It's easier with the right hand controls off, though.

And personally, I agree, don't bother with the buckets unless it's a really old engine (Which I'm sure it's not, if you're going to race it!) It's good practice, but in the real world I didn't consider the benefits matched the cost. I always supplied the buickets with the cams when I was selling the bits, but then I had no use for them once I broke the engines.

[johnnyrod]

Good job I was paying attention...

[Robw#70]

One little note:-
PUT K3> TENSIONERS IN NOW :wink:

Save the aggro of changing them later and they are alot more consistant than the earlier ones

[northwind]

Yeah, that's a good idea :)

[NedSVS]

Don't really agree with Blue_SV650S's comment
If you are putting new cams in you will HAVE to do the shims dude (I presume that is what you mean by 'buckets'?), the clearances will be all over the shot!!
When I did the K3 inlets and moved the original inlets to the exhaust side there was no measurable difference before and after on valve clearance. The cams are ground to such fine tolerances that this is not an issue at all. Also you are measuring the clearance at a point on the cam that gets no wear (as it doesn't run on the bucket because of the clearance). If the clearances are good before they will be good after. Just take special care to keep the buckets and shims in the original places, i.e. don't mix them up :!:

[northwind]

You won't be nmoving the shims and buckets at all if the clearances are OK, no risk at all of them getting mixed up. There's a chance that it will need new shims, don't rule it out, but you're right that it might not be neccesary.

[Robw#70]

Also you are measuring the clearance at a point on the cam that gets no wear (as it doesn't run on the bucket because of the clearance). If the clearances are good before they will be good after. Just take special care to keep the buckets and shims in the original places, i.e. don't mix them up :!:

This is why the clearences are measured at this point as it is a constant, Its the valve seats that wear/bed in thus effecting clearences :roll:

And if swopping cams then why the need to remove the buckets at all :?