Bigger Valves for the RH 10 Head?

The whole package is pretty close to the limit with the 850, isn't it?
I guess that is why a market has developed for aftermarket stronger than stock cases , gearbox etc.

Glen
 
baz said:
It'll be interesting to see what you come up with
Just wondering why you'd ask about tuning on here?
Keep us posted
Cheers
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I'm looking pretty hard at the Web 312A using flat tappets for a bit more duration, 10:1 static compression ratio and 1.56" intakes valves with mild port work. (if they will clear the exhaust valves)

It has been suggested that the exhaust valves can be set into the seats if needed for clearance.
 
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Dan1950 said:
I'm looking pretty hard at the Web 312A using flat tappets for a bit more duration, 10:1 static compression ratio and 1.56" intakes valves with mild port work. (if they will clear the exhaust valves)

It has been suggested that the exhaust valves can be set into the seats if needed for clearance.
Click to expand...
That cam new pistons and so on would give you a little more scoot. Head work gurus may push your next ride out to 2024. Choose wisely.
 
Would it not be better to do major port work in the head than putting in larger valves, I built my 850 for the Featherbed frame back in the early 80s, crank balanced, stock cam built up and grind to combat specs, and head done up by a so call head expert (not) and he had to redo it, but later in life I worked at a TAFE college (Tec College) and 2 teachers were experts on British motorcycles, one a Kiwi who work on a Norton race team back in NZ the other a old Triumph old school mechanic but knew his stuff, so major head porting for my motor and working as a T/A to the maintenance fitters I shaved the head for more bang, I am still running the original valves, why replace when they are sealed great, guide have been replaced a few times and running 40 over sized Heplite pistons on very tight clearance between final hone to bore and ran in on a very cold night.
With the work to the head and cam and carbs jetted to the work and balanced bottom end my Norton is very torquey and gets up there pretty quick, the hot 850, light weight bike and of course that big spark from the Joe Hunt and open exhaust, everything works together in a big way and surprises a lot of modern bike riders, its very quick on the pick up with the stock gearing, to me the stock valves work just fine with other work done to the head, the bike is very reliable and has been this way since 1982 with a few minor rebuilds (replace original crank cases and a few little upgrades) inside, this motor has done a lot of miles and still puts a smile on my dial in the way it gets up and go, the motor runs pretty freely with what's been done to it.
So bigger valves????

Ashley
 
worntorn said:
The whole package is pretty close to the limit with the 850, isn't it?
I guess that is why a market has developed for aftermarket stronger than stock cases , gearbox etc.

Glen
Click to expand...
I looked at a T.T.I box, but the price put a big stopper on that idea!
So I went for a different approach to ease the stress on the gearbox,
Maney belt drive and a close ratio gear cluster,
This mod killed 3 bird's with one cartridge!
 
joinerjohn said:
I looked at a T.T.I box, but the price put a big stopper on that idea!
So I went for a different approach to ease the stress on the gearbox,
Maney belt drive and a close ratio gear cluster,
This mod killed 3 bird's with one cartridge!
Click to expand...
Having done lots of mods to bolster the mid range a Commando was born with i still remain sympathetic to the capabilities this engine has...even with a close ratio belt drive that i also run...my 2 cents...
 
Dan1950 said:
I'm looking pretty hard at the Web 312A using flat tappets for a bit more duration, 10:1 static compression ratio and 1.56" intakes valves with mild port work. (if they will clear the exhaust valves)

It has been suggested that the exhaust valves can be set into the seats if needed for clearance.
Click to expand...
I would be wary of it with the flat tappets. With the 312a and 4" radius lifters, it really comes on stronger at 4-4500 RPM and i wouldn't really want it to come on any higher for regular road use.. I have to be careful not to spin past redline (but i I have a Ducati Desmo Testastretta that spins at higher, so I forget at times... )

I spend a lot of time on twisty roads that have 50-65mph speed limits and rarely get out of third gear with 21 sprocket.
 
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gortnipper said:
I would be wary of it with the flat tappets. With the 312a and 4" radius lifters, it really comes on stronger at 4-4500 RPM and i wouldn't really want it to come on any higher for regular road use.. I have to be careful not to spin past redline (but i I have a Ducati Desmo Testastretta that spins at higher, so I forget at times... )

I spend a lot of time on twisty roads that have 50-65mph speed limits and rarely get out of third gear with 21 sprocket.
Click to expand...
Are you running the 313A with radius tappets?
 
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