Advice on skimming head please!

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blueflag
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Advice on skimming head please!

Post by blueflag »

Hi all,
I'm thinking of lightly skimming the head on my triarm, I've already removed the quietening gears on the cams.
I know I need to displace slightly the gear train that transmits rotation from the crankshaft to the top end to allow me to drop the head without too tight a mesh on the cam gears. I was wondering if it's possible to remove the quietening gear on the gear that meshes with the crank as well? (I think the answer is probably no BTW :grin: )
Thanks again!
Mike
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Re: Advice on skimming head please!

Post by racesupplies »

Unless you know what you are doing,dont,its tricky.Why do you want to skim the head?
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Re: Advice on skimming head please!

Post by blueflag »

It's a race bike (my first 400 though).
I'm lucky enough to be a toolmaker, so the machining shouldn't be a problem (don't tell the boss though!). My concern is if I introduce even a small amount of backlash into the train it'll mean a valve calamity!
If it's not worth the hassle i.e. limited gains, then I'll probably leave it.
Mike
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Re: Advice on skimming head please!

Post by racesupplies »

Cor blimey,where do you start? Its beyond me to tell you what to do really,but for what its worth. You need some backlash,otherwise as it warms up the gears will bind and transfer the load into the shells or the head.Dont give up,just ask someone that has done it.Get some sort of drawings from them if youre going to do it yourself.Dont guess it.
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Cammo
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Re: Advice on skimming head please!

Post by Cammo »

Whatever you skim off the head you'll need to add to raise the cam carriers via a shim plate etc.
"It's just a ride" Bill Hicks
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Re: Advice on skimming head please!

Post by racesupplies »

Can you do that on ome of those?
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Re: Advice on skimming head please!

Post by blueflag »

The cam carriers are part of the head casting, otherwise it'd be easy! If it wasn't for the quietening gears (they call them scissor gears on Suzuki V twins) it would be simple if a bit time consuming to replicate the backlash. You're right though Racesupplies, unless I'm sure it's probably best not to bother.... :?
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Re: Advice on skimming head please!

Post by racesupplies »

I took a light skim off the head,and the bulk off the block.Then had undersize gears made for the cams.We were fitting one off slotted hubs at the time so the geras were going to be made anyhow.Ive got a 29 motor here with an offset idler gear,but my mate makes gears so we went down that route.
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Re: Advice on skimming head please!

Post by blueflag »

That's a nice sounding solution. I like it........ :grin:
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Cammo
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Re: Advice on skimming head please!

Post by Cammo »

DataRacer wrote:Whatever you skim off the head you'll need to add to raise the cam carriers via a shim plate etc.
racesupplies wrote:Can you do that on ome of those?
I guess not! I presumed it was the same as the vfr's. :sshh:
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