8 valve head conversion

Well duh, I remember your 'engine development' quip but no head mod details. I remember the down sides of Truimph head disscussed but not how that was over come.

I don't believe your blanket statement that just faster flow will make more power, if it can't flow as much as another head, much as it may lag getting to top end flow rates. You left the evidence for this with the head graphs and even the posts on Fullauto head mention not much if any top end help. Anywho I was there and me and everyone else watching had slack jaws and wide eyes at how out powered Tim left the rest behind. I remember Tim's teasing on this forum before the event and the verbal jabs in the pits area during Barbers, and how it made my innate Norton power pride drop a few points, unless power adder cheating which could be applied to Tim's as well for more shame maybe.

Unfortunatly maximum flow doesn't have much to do with how much power is made. If that was the case then ports could easily be made huge and give big flow numbers easily. Look at the old boss Ford small block engines and what they ended up doing to make them competitive.
An engine will only draw so much air and air flow is determined by the bore size and piston speed at the moment. Remember the piston only draws mixture through the port for less than 180 degrees but the valve is open for 300 plus degrees. Air speed is needed to keep air moving into the cylinder long after the piston quits pulling it in.
And yes, If you gave me Kenny's bike for a year with the incentive to make it as fast as possible [and pay my bills] then I am sure that motorcycle development [note I did not say cylinder head development] would create a Norton every bit as fast as Tim's Turnip.

One more thing. Developing Kenny's Norton would likely mean going to larger valves and slighly larger ports to keep the air speed in the correct range along with cam tuning ,exhaust tuning and intake tuning to get everything working together. The head on Kenny's bike was designed for a street bike not a race engine and most of the rest of his engine is made of very streetable pieces. But the potential is there for something very fast.
Jim

comnoz said:

Unfortunatly maximum flow doesn't have much to do with how much power is made.

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Wise words.

Its maybe worth quoting some much earlier tuning secrets, from days gone by. ?

Jack Williams, Development Engineer for AMC ( and father of Peter Williams, rider of JPS Nortons) did some work on the 1950s 7R racers ( ohc 350cc single). He found that spraying ink into the airstream while working on airflow into the inlet port resulted in a 10% power gain if the flow was arranged so the ink didn't inpinge on the port walls whilst swirling it into the cylinder.
3 or 4 hp may not sound much, but for an existing race engine design, its a winner...

Developing Kenny's Norton would likely mean going to larger valves and slighly larger ports to keep the air speed in the correct range along with cam tuning ,exhaust tuning and intake tuning to get everything working together. The head on Kenny's bike was designed for a street bike not a race engine and most of the rest of his engine is made of very streetable pieces. But the potential is there for something very fast.

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See, there ya go creeping up on port/valve size to catch up to Tim. Tim's bike out sprinted the pack at start but lost some ground to let off the wheelie. But
don't misconscrew me, I'm a propagandizing missionary believer in smallish ports for higher velocity as the way to go for more power - up to point it becomes a restriction to further flow. About ALL my Ms Peel tall tails occured with the 28 mm ports and fell off that responsive power with bigger port Combat head, all else same. It was so good, I intend to reproduce it as its 'inexpensive' simple but oh so wrist straining delightful, so bad it may be too much to put to use in an unlinked Cdo as too easy to accelerate in sweepers into hinged hell.

For real life I'd pick the Fullauto head in a heart beat, but for Daytona, Manney size ports and valves. Tricky compromise with the points you listed is part of the fun of the '$cience'.

I'm still tingling from the Texas Mile extremists, where I intend to put some my own flow ingestion theory to the test, with and w/o power adders.

As long as you realize that if you installed the tested Maney stage 3 head on a long-stroke 750 like Kenny's it would make a lot less power at any rpm in comparison to the Fullauto head. I can say that because I have tried it. A 750 longstroke motor wil not create enough airspeed to make the port work. Jim

Ok JIm, that's educational for me. I thought Kenny ran a 920 regular stroke. Impressive as hell 750. So Manney stage 3 ports are too big to fill 750 long stroke.
That I can believe.

I've studied the principle of stroke on the suction action as tie into cam selection too. I've got detonation dangers on Ms Peel 10.5 CR 920 on 91 octane. Part of her anti-detonation design is to use small ports and valves for the size of displacement. Faster intake makes better turbulence and smaller valves get rid of heat better. Compression ratio enters equation too.

Over the years, if I live that long, I'd like to try some top speed events, I wonder how the Full auto head would work on Peel with boost to over come any port restriction. But I want Peel to work good w/o boost so Fullauto head is extra tempting me. What works best in natural inspired engine works even better on mild boost below one Bar but blow up on much higher boost.

hi all,you can bet your last dollar tims not running flat topped pistons and i bet comp ratio is up in the 11s and i bet hes on avgas

chris plant said:

hi all,you can bet your last dollar tims not running flat topped pistons and i bet comp ratio is up in the 11s and i bet hes on avgas

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Actually I am sure he is running leaded race gas. Av gas make poor race fuel. 11-1 is probably a conservative estimate. 12-1 wouldn't be a surprise. Jim

hi jim,i agree i should have said 11 plus,but when you get into 12s thats methanol teritory,i would have thought avgas was the best leaded fuel,as a side note i dont think kenny will see any more power gains until he goes short stroke,which im sure hes thought about

chris plant said:

hi jim,i agree i should have said 11 plus,but when you get into 12s thats methanol teritory,i would have thought avgas was the best leaded fuel,as a side note i dont think kenny will see any more power gains until he goes short stroke,which im sure hes thought about

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I agree on the short stroke. We talked about doing a short stroke but that requires a lot more time and money.
I always found about 5% more power with B32 race fuel over av gas. Av gas is specifically designed for a slow turning aircraft engine and not really good race gas. If you want to spend real money on fuel there are some oxygenated race fuels around that will make even more power. Tolulene is used and can be pretty nasty if you get it on you. Jim

The most popular fuel at Texas Mile for bikes and cars was Q16. They had to change ignition curves from regular road fuel to get its advantage. Some cars were betting on E85 and proved their point by respectable runs.

Here's site with scope of fuels, Q16 included.
http://www.vpracingfuels.com/vp-drag-racing.html

Q16™
Q16 will work well in any drag racing application -- naturally aspirated, nitrous or blowers. Q16 is highly oxygenated, requiring a 4-6% increase in fuel flow, which will make 3-5% more power than competitive 116 octane fuels. Q16's oxygenation will significantly expand the range of air/fuel ratio acceptability, so performance will be more consistent and won't vary as dramatically with altitude or density changes. For bracket racers, variations in ET from run to run will be substantially reduced. This added fuel flow also effectively increases its octane by 6-8 numbers above its standard ASTM octane rating.

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Hi

Just to add a few words. I have a stage 2 Maney head on my 750 Commando & I really enjoy riding it.
However my Jim Lee framed, T120 engine with original Rickman 8 valve top end is just a joy to ride.
32mm mk1 carbs, 10.25 to 1 compression, 5 speed box. it pulls from anywhere, revs for fun. Pure pleasure.
This season I will be running a Maney 920!!! Back to grunt! Plus a 5 speed Triumph\Nourish box, & I cant wait!!!!!!!!
Chris

Yes I still have a 55 gallon drum of Q16 that was left over from racing days. It was in the storeroom at the shop when I had the fire. It was buried under burned timbers but had not ruptured. When the fire department saw it they about shit. Seems they did not know I had a permit for fuel storage. Wonder how well it keeps in a sealed drum for 10 years. Jim

Chris said:

Hi

Just to add a few words. I have a stage 2 Maney head on my 750 Commando & I really enjoy riding it.
However my Jim Lee framed, T120 engine with original Rickman 8 valve top end is just a joy to ride.
32mm mk1 carbs, 10.25 to 1 compression, 5 speed box. it pulls from anywhere, revs for fun. Pure pleasure.
This season I will be running a Maney 920!!! Back to grunt! Plus a 5 speed Triumph\Nourish box, & I cant wait!!!!!!!!
Chris

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That is good to know, I look forward to getting one on the flowbench to see what it looks like. Jim

Hi guys

Looked at your Nourisk 8 valve discussions with interest. I took a Triumph TR6 engine, change the crank to a shortstroke Norton crank (to get more rew),
change the camshafts to Nourish, change the bronce bearings to roll bearings, change the cylinder (850cu) & top to Nourish 8 valve. Boring the timing wheels
Nourish 8 valve top, the rest .. gear etc is std. Ohh I change to dry belt as well in the primær side. Keihin 38 mm flat carbs. Run it as normal street machine.

On the dyna it have 82 HK on the backweel. I won a dragracing contest this summer, against 4 other Nortons, one have direct injection - sorry

Have a nice Chrismas

Ole Veggerby
Denmark

That's impressive successful adaptations galore, but which brand engine is it with such a hybrid of parts ? Not clear which mskr head 8 valve installed if basic engine stated is Triumph. Did it take a while for your widened grin not to hurt?

lcgtr said:

What about twin spark? or is it a waste of time with modern sparkplugs

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It would be interesting to see where the second plug went,bearing in mind the cast on rocker box.

Take a look at Mez Porting in the UK for twin plug heads & other interesting things.

http://www.mez.co.uk/mezporting/page6.html

Not sure how you get at the spark plugs in the middle though.

Didn't WASP / Robin Tutt in combination with somebody else make 4 valve heads for their motocross sidecar outfits? Isn't this the fore runner to the Norvil non offering?

People think Nortons make horsepower / torque from zero revs, this isn't true, look at a dyno curve for any 750 / 850 Norton twin & there is a BIG hole in the rev range just before 3000 rpm.

pouchy750 said:

Take a look at Mez Porting in the UK for twin plug heads & other interesting things.

http://www.mez.co.uk/mezporting/page6.html

Not sure how you get at the spark plugs in the middle though.

Didn't WASP / Robin Tutt in combination with somebody else make 4 valve heads for their motocross sidecar outfits? Isn't this the fore runner to the Norvil non offering?

People think Nortons make horsepower / torque from zero revs, this isn't true, look at a dyno curve for any 750 / 850 Norton twin & there is a BIG hole in the rev range just before 3000 rpm.

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Not with the Fullauto Technologies head I'd be prepared to bet. The power really starts off idle and is noticeably stronger from there on.

I don't think Mr Canaga would mind my posting a link to the scanned 8 valve article that he posted a while back. Ken would you have the rest of the article?

http://media.photobucket.com/image/nort ... 2.jpg?o=72


Rj