Re-profile of cams

[seb421]

Is it possible to get the standard cam lobes re profiled to say Yoshi / Moriwaki / HRC specks

Where would you get this done in the uk?

what sort or money are we talking for the work?

[VTRDark]

There's some links on the superhawk site somewhere where people have done that. You would need to go to an engineering firm to get it done. I would have thought one that specialises in engines would be best. The type of place where you can get discs skimmed etc.

I have been toying with the same idea myself as I have an engineering firm close by who could do that. Just buy some cams on ebay to play with.

(:-})

[Kev L]

I think Tony has had a go at this

[lloydie]

I think Tony has had a go at this

he did it should be in his engine rebuild thread
http://www.vtr1000.org/phpBB3/viewtopic ... ne+rebuild

[tony.mon]

You can't regrind the cams to anywhere near Yoshi or Mori spec simply by regrinding; I ended up with about 10 degrees more dwell and 1mm more lift. You can't reduce the base circle by more than 1mm or so and still get the rocker arms to work at reasonable angles.
Bear in mind that you need much larger shims, so add the cost of eight of those.

I used a local firm, they were ok, but I had to chase them like mad, took weeks.


To achieve similar profiles to Mori or Yoshi the cams need to be built up, reprofiled, then re-hardened.
Not cheap, and you might find that Yoshi and Mori cams are not as dear as they look, once you have the bill for the welding, regrinding and re-hardening.

But give it a go...

Kent Cams also list some.

I'd suggest building the heads up with just the inner springs fitted and measuring piston to valve clearances from -10 to +10 degrees of tdc, by manually pushing the valve down until it touches the piston or coil binds.
You can measure the clearance with a dial gauge.
Use the old head gaskets to test build it, no point wasting new ones for this.
Up to you as to how much clearance you are happy with, especially if you've fitted high compression pistons or decked the barrels or heads. You don't need huge amounts as the engine doesn't rev very high, so there's no/little chance of valve bounce. But try not to miss gears or over-downshift....

As a halfway house, simply replace the inlet cams with exhaust cams. So you end up with four exhaust cams fitted. Never dyno'd this mod, though, so can't confirm the actual difference in power. Won't be huge, though, but it's only a couple of hours work to try it.
Ideally you degree them in, but most people don't bother.

[benny hedges]

i have a spare set of exhaust cams if youd like to try them seb.


i was very lucky with the cams i got for mine.... brand new billet jobbies off a hrc test guy from belgium... he never got to fit them to his storm as it got stolen.
i got them for £75 delivered lol

dyno andy suggested dialling them in proper... i just set them up default with std cam gears but ideally need to slot some and leave it to him...

regarding the shims.... get a hotcam shim set 9.84mm (iirc) then youll have all the shims you could possibly need, including the larger sizes.

[AMCQ46]

regarding the shims.... get a hotcam shim set 9.84mm (iirc) then youll have all the shims you could possibly need, including the larger sizes.

which reminds me, I now have your shim kit following the workshop day..........didnt use any!

will I send it back to you or back to Tony?

[benny hedges]

nice one... isnt there another coming up shortly?

[VTRDark]

Yep, Purfleet Essex. Don't think anyone is doing any valve clearance checks though. And considering at the last two workshop days where valve clearances have been done, and there has been no need for shims. Is there any need for them.

It just goes to show really that valve clearances don't go out of spec very easily, unless there is some serious high mileage or tinkering with cams. or is it users playing on the safe side and just checking for the sake of it and peace of mind.

(:-})

[benny hedges]

agree, which is why i dont recommend you take a bike for 'the big service' at 16k then pay 300 notes for them to tell you your shims didnt need doing.

i have just told u they dont need doing lol so paypal me the £ instead.

most ive ever done is 2 out of 8 and even then they were only 0.05mm out!

chances are if youve had the heads off lapped the valves in / reseated /replaced valves they'll need doing.

[VTRDark]

agree, which is why i dont recommend you take a bike for 'the big service' at 16k then pay 300 notes for them to tell you your shims didnt need doing.

I have not checked mine yet and I'm not going to, my bike IIRC is under 10,000. And I wouldn't dream of taking it to a garage. I am the garage I have always done my own cars and bikes since I was 17 with my first bike, an early RD125 twin.

£300 for a valve clearance check, is that an average price fookin hell I dread to think what they would charge to do a VTECH

Rip off b8stard

(:-})

[8541Hawk]

Two things,

First, this company (yeah I know it's in the US) makes a interesting re-grind http://www.webcamshafts.com

The second has to do with using a "Hot Cams" kit to set your clearences.
If your kits are the same as our, the issue I have with them is they only include the .05mm steps Whaere as the shims from Honda are in .025 steps.

With the +\- on the valves as tight as it is, if I'm in there I want to put them dead center or why bother. They last stay pretty consistant on these bikes so it is worth it, to me to take the extra time to get them dead on.

As for how offten they need to be adjusted? On my bike the first time I had a valve move was @ 60K mikes or 96,000K or there abouts.
Even then it was 1 exhaust vale out by .001" or .025mm.

With 90K miles (144,000K) on it now I have had to adjust them twice more with a total of 2 the first time and 1 the second time, with all of them being .001" tight.

So IMHO you have a 50% chance of having the actual shim you need when you buy or rely on one of those kits.

[8541Hawk]

agree, which is why i dont recommend you take a bike for 'the big service' at 16k then pay 300 notes for them to tell you your shims didnt need doing.

I have not checked mine yet and I'm not going to, my bike IIRC is under 10,000. And I wouldn't dream of taking it to a garage. I am the garage I have always done my own cars and bikes since I was 17 with my first bike, an early RD125 twin.

£300 for a valve clearance check, is that an average price fookin hell I dread to think what they would charge to do a VTECH

Rip off b8stard

(:-})

The big part of the cost is stripping the bike down far enough to get the front valve cover off. You have to drop a rad. and the oil cooler along with the fairing and carbs. Yeah you might be able to leave the carbs on if you have little girl arms to reach in to take off the rear valve cover bolts on the front cover but I could never do that.

That is why it really is a good job to do yourself. It really isn't that hard. Just take your time follow the service manual. The real benifit of doing it yourself is you get to inspect all the bits you have to remove and clean stops you can never reach when it's all together, plus give all the hoses and fittings a good looking over.

[VTRDark]

It really isn't that hard. Just take your time follow the service manual.

I have no worries doing it myself, I have already had the front cover off when I done the CCT's. I just don't feel the need to do clearances as my bike is such low mileage. And yes carbs came off and the plastic cowl below them. I just undone the bolts on the oil cooler and pulled it forward slightly.

I do have nimble hands (or mechanics hands as I call them) as I can just get my fingers in between the frame to start off the thread on the front vacuum take off. That was fun when I was putting a nipple and hose on there.

(:-})

[tony.mon]

It's all about whether you can have the bike off the road for a few days while shims ordered over t'interweb or through the local dealer arrive.

If you're using it for work, or ride it to a mechanic but need to ride it home again afterwards, you'll just have to fit a shim which gets it into the range of acceptable clearances.
If, however, you can strip, measure, order and then wait for shims you'll have the engine in spec more accurately.

But.....

Is a clearance in the centre of the range better than one at either end of the range?

A tight end clearance will mean bigger actual cam openings, but would go out of range quicker.......

Answers on a postcard, please