Page 2 of 2
Re: skim head? how do you move cam gears?
Posted: Thu Nov 20, 2008 3:45 am
by duh_ave
RVF wrote:As stated, if its done right there will be minimal extra noise.
Each cam gear needs to be shimmed individually to get it right.
If you, for example take off 0.1mm off the head face and remove the backlash gears you do not simply add 0.1mm of shim under the cam carrier.
You need to set up a dial gauge and turn the motor over and measure the backlash clearance ever 90 deg of the cam wheel on each cam shaft.
Average this figure out and then work out the size of shim (or the amount you need to remove from the cam carrier... it has been known!)
Of course you have to know what sort of clearance you need to run in the backlash gears but that comes with experience.
Engines that rattle because the backlash gears have been removed just proves who ever did it was lazy or didn't know how to set up gear driven engine.
I take it you've never done this? You're information couldn't be much more off.
If you remove the quieting gears, it does get louder. Much louder. It sounds like it's going to send bits of shrapnel about the universe at any second. This is perhaps why they are often referred to as quieting gears, no?
The cam towers are to be shimmed the same amount that is removed from the head. This does not need to be done on the individual parts of the carriers unless you skimmed the head with a hand held grinder. Do it properly and all will be perfectly even and parallel to the original surface, so no need for the fancy shimming.
The drive gear clearances are in the service manual. It only takes the experiences of reading to learn that bit of information.
Re: skim head? how do you move cam gears?
Posted: Thu Nov 20, 2008 3:49 am
by duh_ave
brooky wrote:without getting really technical and measuring chamber volumes to work out exact cr what is the guide amount to remove from the heads without causing problems, assuming all standard at present
mine are skimmed .5mm. I have been told that .75mm can be done safely, by someone who builds these engines (specifically) for racing.
you'll need these thicker valve shims (Along with the need to shim the cam towers, you'll need to use thicker valve shims);
I had a hard time getting them in the graduations I wanted here.
Re: skim head? how do you move cam gears?
Posted: Thu Nov 20, 2008 3:51 am
by duh_ave
another way I read on is to modify the upper gear position on the gear drive unit itself.
I dont know any one who has actually done this, but saw it linked from this site a long time ago.
This modification would eliminate the needs to both shim the cam towers and to use thicker clearance shims.
Re: skim head? how do you move cam gears?
Posted: Thu Nov 20, 2008 8:08 am
by royster81
duh_ave wrote:RVF wrote:As stated, if its done right there will be minimal extra noise.
Each cam gear needs to be shimmed individually to get it right.
If you, for example take off 0.1mm off the head face and remove the backlash gears you do not simply add 0.1mm of shim under the cam carrier.
You need to set up a dial gauge and turn the motor over and measure the backlash clearance ever 90 deg of the cam wheel on each cam shaft.
Average this figure out and then work out the size of shim (or the amount you need to remove from the cam carrier... it has been known!)
Of course you have to know what sort of clearance you need to run in the backlash gears but that comes with experience.
Engines that rattle because the backlash gears have been removed just proves who ever did it was lazy or didn't know how to set up gear driven engine.
I take it you've never done this? You're information couldn't be much more off.
If you remove the quieting gears, it does get louder. Much louder. It sounds like it's going to send bits of shrapnel about the universe at any second. This is perhaps why they are often referred to as quieting gears, no?
The cam towers are to be shimmed the same amount that is removed from the head. This does not need to be done on the individual parts of the carriers unless you skimmed the head with a hand held grinder. Do it properly and all will be perfectly even and parallel to the original surface, so no need for the fancy shimming.
The drive gear clearances are in the service manual. It only takes the experiences of reading to learn that bit of information.
mmm how do i put this nicely without trying to offend,when the guy who works on RC/NC V4's and has set up more HRC hondas than i have had warm meals comes onto this forum and tell's you how something is done ,i wouldn't question it.....
you only have to look at stephens last two bikes that graced these forums pages to know he isn't talking out of where he's sitting on ,unlike alot of forum members on here (unforturately).
forgive me if i have came across harsh duh-ave but stephen has helped me out on more than one occasion and i have alot of time for him and his years of V4 racing experience.
Re: skim head? how do you move cam gears?
Posted: Thu Nov 20, 2008 8:24 am
by RVF
duh_ave wrote:RVF wrote:As stated, if its done right there will be minimal extra noise.
Each cam gear needs to be shimmed individually to get it right.
If you, for example take off 0.1mm off the head face and remove the backlash gears you do not simply add 0.1mm of shim under the cam carrier.
You need to set up a dial gauge and turn the motor over and measure the backlash clearance ever 90 deg of the cam wheel on each cam shaft.
Average this figure out and then work out the size of shim (or the amount you need to remove from the cam carrier... it has been known!)
Of course you have to know what sort of clearance you need to run in the backlash gears but that comes with experience.
Engines that rattle because the backlash gears have been removed just proves who ever did it was lazy or didn't know how to set up gear driven engine.
I take it you've never done this? You're information couldn't be much more off.
If you remove the quieting gears, it does get louder. Much louder. It sounds like it's going to send bits of shrapnel about the universe at any second. This is perhaps why they are often referred to as quieting gears, no?
The cam towers are to be shimmed the same amount that is removed from the head. This does not need to be done on the individual parts of the carriers unless you skimmed the head with a hand held grinder. Do it properly and all will be perfectly even and parallel to the original surface, so no need for the fancy shimming.
The drive gear clearances are in the service manual. It only takes the experiences of reading to learn that bit of information.
Only on HRC RC30's, Factory HRC RVF's, HRC RC45's and F3 NC30's. Apart from them never touch them
Does yours still rattle?... point proved
Re: skim head? how do you move cam gears?
Posted: Thu Nov 20, 2008 7:22 pm
by royster81
i hope my "mate" is reading this as he just wouldn't listen when i told him his shouldn't rattle and should sound like a louder standard bike....but what do i know ,i'm not a racer ....
Re: skim head? how do you move cam gears?
Posted: Thu Nov 20, 2008 8:37 pm
by Cammo
Mine rattles like a bag of marbles.
Because the builder was lazy.
Re: skim head? how do you move cam gears?
Posted: Thu Nov 20, 2008 9:22 pm
by leon
duh_ave wrote:another way I read on is to modify the upper gear position on the gear drive unit itself.
I dont know any one who has actually done this, but saw it linked from this site a long time ago.
This modification would eliminate the needs to both shim the cam towers and to use thicker clearance shims.
this is what i am on about. does anyone know how or where on the net this is. its a lot better on the engine to not have to shim them up and add heavier shims on the springs?
Re: skim head? how do you move cam gears?
Posted: Thu Nov 20, 2008 11:07 pm
by sa.racing
Leon the gut your after is David Simon - 07766525812 he modifies the cam gears for the CBR and RVF's Give him a call hes a top bloke he will sort you out.
Re: skim head? how do you move cam gears?
Posted: Mon Nov 24, 2008 8:39 pm
by slapead
just cbrs at the moment mate, but give it time. :)
The back lash measurement is without doubt very relavent when skimming the heads and shimming or moving the gear. That may be the one draw back with moving the gear wheel.