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cb350 engine build

Bike preparation, class eligibility, technical questions.

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cb350 engine build

Postby Jim o » Wed Jan 15, 2020 10:44 am

I am new to VRRA and am preparing a cb350 what pistons should I use will the ones sold by sirius.ca hold up? I see I should use the KN slipper cam chain tensioner.what chain should I purchase? What valves guides and springs should I use?I cant seem to find suitable race tires can I use the stock rims?I live in Mississauga is anyone living here who can give me some advice and maybe let me check out their equipment.I am signed up for the Shannonville school anybody have some race tires to sell with enough life left for the school and first race. Thanks Jim
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Re: cb350 engine build

Postby TimV » Wed Jan 15, 2020 4:20 pm

Welcome Jim,

my answers below are assuming you're building a P1 CB350(basically stock engine with drum front brake). Read the latest VRRA rule book as there are restriction on what you can and can't modify on these engines!

Pistons: Those Sirius pistons should be fine, although I had an issue with one(possibly an assembly error...) We're allowed to run the Wiseco pistons up to 65.5mm. Old stock Honda pistons work just fine too.

The KA tensioner is a good idea.

Cam chain: I was advised to use the Tsubaki Cam Chain with that tensioner, although it seems they are no longer available. THR was selling the KA tensioner and a DID gold cam chain.

Valve guides: need to use stock steel units.

Valve springs: better aftermarket springs can be used - RD, Kibblewhite, etc

Tires: I run Heidenau K44 90/90-18 on a 2.15" front wheel, K65 110/80-18 on a 2.5" rear wheel. Avon makes tires too, and there's a chance we'll be able to use Radials this year if the rule passes.

I'm way up North, but hopefully you can hook up with someone locally to help.

Hopefully I'll see you at the first round!

Tim

Jim o wrote:I am new to VRRA and am preparing a cb350 what pistons should I use will the ones sold by sirius.ca hold up? I see I should use the KN slipper cam chain tensioner.what chain should I purchase? What valves guides and springs should I use?I cant seem to find suitable race tires can I use the stock rims?I live in Mississauga is anyone living here who can give me some advice and maybe let me check out their equipment.I am signed up for the Shannonville school anybody have some race tires to sell with enough life left for the school and first race. Thanks Jim
Tim Voyer #840

CMR Suzuki TR750 Replica
CMR-Seeley 350 Replica

Whatever you do, always give 100%. Unless you're donating blood.
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Re: cb350 engine build

Postby Jim o » Wed Jan 15, 2020 8:04 pm

Who is THR? Thanks JIm
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Re: cb350 engine build

Postby TimV » Wed Jan 15, 2020 8:51 pm

Jim o wrote:Who is THR? Thanks JIm


Todd Henning Racing. Buff Harsh is the guy you'd be dealing with. Here's a link to one of his ebay items. You can contact through ebay for info on the chain. https://tinyurl.com/suwlk92
Tim Voyer #840

CMR Suzuki TR750 Replica
CMR-Seeley 350 Replica

Whatever you do, always give 100%. Unless you're donating blood.
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Re: cb350 engine build

Postby The Flying Fossil » Thu Jan 16, 2020 9:07 am

Welcome to VRRA and the CB350 club!

I think the reason to use the Tsubaki chain with the KA tensioner was the fact that, apart from better quality, the Tsubaki chain has full width link plates and not the "peanut" link plates of the standard chain. If so, any full link plate chain should work. I use the DID chains in my modified motors but have found the standard chain and tensioner works fine in my standard motor.

Les.
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