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836cc kit choices - do I need a new cam?

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JamesH:
Phil - did you need to machine the upper cases to allow the Cruzinimage pistons to clear m? Trigger advised me not to use the 836 kit as this required additional work to clear the cases?

philward:
No - just got them rebored at a local firm in St Helens - he's a Z1 owner (£50) - my previous research on .net never mentioned re-machining cases

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theshootist:
Well the more I've looked into it the more it seems costs would get out of control for little gain.

I'm having the heads inspected and since I've already had new valve seals if the valve guides are okay I will probably just fit the existing head with the 836cc pistons. Once I added up gas flowing the head, potentially fitting new valve guides, a new cam, stronger valve springs, it starts to add up to silly numbers!
 

Yoshi823:
Because I modified the standard 750F2 frame I could work on the top end easier. So for riding abroad I used a standard cam to go with the fitted Yoshi 823 pistons I bought from Dixon Racing. At the time 812 pistons wern't available hence the reason I got the 823 kit. As far as I remember the 836 kit is 0.5mm up on the kit I had. This was the furthest you could safely go with the standard liners. For a 900 kit new liners needed to be pressed into place.

I polished the ports but didn't remove much metal. I fitted ally/bronze valve guides, S&W valve springs, had the seats recut, had the crank & conrods polished, balanced & lightened, fitted a 750K0 solid cam sprocket & degreed in the reprofiled cam I used for fast road use. The base circle of a standard F2 cam was ground to give slightly more duration & lift. This worked perfectly with the F2 carbs & Andrews high output coils, gold plugs & Boyer-Bransden ignition. The standard exhaust was welded up & a CG exhaust bolted up. Worked a treat  ;)




My bike was in a CB750 feature in Superbike magazine back in 1982

Greebo:

--- Quote from: Yoshi823 on November 20, 2016, 05:59:49 PM ---Because I modified the standard 750F2 frame I could work on the top end easier. So for riding abroad I used a standard cam to go with the fitted Yoshi 823 pistons I bought from Dixon Racing. At the time 812 pistons wern't available hence the reason I got the 823 kit. As far as I remember the 836 kit is 0.5mm up on the kit I had. This was the furthest you could safely go with the standard liners. For a 900 kit new liners needed to be pressed into place.

I polished the ports but didn't remove much metal. I fitted ally/bronze valve guides, S&W valve springs, had the seats recut, had the crank & conrods polished, balanced & lightened, fitted a 750K0 solid cam sprocket & degreed in the reprofiled cam I used for fast road use. The base circle of a standard F2 cam was ground to give slightly more duration & lift. This worked perfectly with the F2 carbs & Andrews high output coils, gold plugs & Boyer-Bransden ignition. The standard exhaust was welded up & a CG exhaust bolted up. Worked a treat  ;)




My bike was in a CB750 feature in Superbike magazine back in 1982

--- End quote ---

Yoshi What do you gain in performance / genuine BHP after all this work ?

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