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Discussion Starter #1 (Edited)
I have done all the easy bits to get more power:
Power Commander -V with Autotune
Acropovic slip on
removed the TB sub plates
Opened up the airbox and installed a BMC air filter
Removed the Pair valve and related plumbing

Now I want more and am prepared to open up the engine to do so, however would appreciate some pointers on how to proceed. Buying a bigger bike is not on as they are expensive here and the Kawis are locally made and therefore relatively cheap

My goal is a more powerful, reliable, street motor, that will run on (ROM +MON) /2 95 octane E-10 fuel. How much more powerful will be determined by my reliability requirement and to some extent what I can get done here in Thailand

A bit of searching tells me the ER6 and Versys heads are different and it seems that the difference is in the combustion chamber, thereby yielding lower compression for the V. How to raise the compression:
Is it better to get an ER head, or mill the Versys head? I live in Thailand where these engines are made so parts are cheap and plentiful
How much to mill the V head? This is easily done here and cheap as chips
Run a thinner head gasket (I do not see one), or separate the layers in the stock gasket?
Head gasket mod + milled head or is this an either/or proposition?
I would rather not remove the base gasket at this point as the engine now has 31,000 Km and do not want to move the piston up higher into the ridge
Higher compression pistons?

My experience in building other engines suggests that money and effort are well spent on the head. Unfortunately this entails taking it to Canada or the US but if that is the only way then I will do so
I see that Invader mentions 32 mm intake valves - where can I source these, and is this a Kawi part?
Who is the porting guru for these heads - preferably in Canada (Invader are you listening?)

I have read the cams posts and note the difference between the ER and Versys cams. Using an ER cam in Combo with the Versys, or 2 Versys intakes, is easy and cheap to do
I like the torque of the Versys engine but if a change of cam is necessary to get more power then I am prepared to take that route

Seems a good subject for a sticky
 

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http://www.competitioncnc.com/the-black-art-of-head-porting.html

The Black Art of Head Porting

In the past, cylinder heads were ported by hand and tested on a flow bench. This was the norm for decades. With the production factory automotive heads of the past, this approach worked fine due to the very un-efficient ports of the day. Basically as long as you made gains in flow on a flow bench you usually made more power. But it was soon discovered that even though you kept enlarging the port and the flow kept increasing, the power didn’t keep going up. In many cases the midrange torque would start to suffer.

It was soon realized that average port velocities played a major roll in power production. Ports started to get smaller and more efficient. They were smaller but flowed more air. They were straightened out and valve sizes grew. To make these ports work the cam designs changed as well. You no longer needed massive cams with big duration numbers that didn’t like to idle. The midrange torque increased and high hp engines became more street-able. This trend continues today.

The modern shallow chamber 4 valve engines of today typically found in Japanese motorcycles has taken this a step further. The velocities in these stock production ports are very fast compared to port velocities just 15-20 years ago. As a result these engines are making nearly and in some cases more than twice the HP of the early 4 valve motorcycle engines.
But like every mass produced engine that has to meet the EPA standards of the day, there are compromises. These compromises are engineered in to the product for many reasons some of which are durability, cost of manufacturing, emissions requirements, drivability, etc. The OEM’s have to warranty these engines and they are designed to last many tens of thousands of miles.

These compromises in many cases cost HP and can be modified and or eliminated. We can do this on a race engine because we don’t have the wide operating and usage conditions that the OEM’s have to take into consideration. We can make the engine a more focused engine performance wise.

So now that we are free to “focus the engine” for a particular use, there are several things we can do to make major power improvements. These include raising the compression ratio and using bigger cams etc. But the cylinder head is where all the power is really made. Optimizing the ports for a focused application is a very complex engineering feat.
Yes you can keep making the ports bigger and flow more and more air but there is a balance, a proper ratio of velocity to flow that must be maintained. Raw CFM numbers are just one of over a dozen important numbers we look at. This is where the “black art” comes in.

The valve seat profile, valve size, seat choke, bowl diffusion, minimum cross sectional area, the MCSA location, port taper, length, localized velocities, velocity bias etc. all come into play. A mere .010” of increase in the ports MCSA can affect velocity by 10 fps or more. Take out your feeler gauge and see how much material that really is. Yes this is what it really comes down to with these ultra high efficiency ports, thousandths of an inch. Much, much different than your fathers old Chevy fuelie heads. Controlling the geometry of the port has become so critical to squeezing the last few % of hp from these engines that it has to be done in a computer. You won’t see any hand ported heads anymore in any form of top professional racing for a reason. Does your head porter know all of these critical dimensions of there port?
One of those reasons is also repeatability. With CNC porting the repeatability is incredible. Each port is exactly what the doctor ordered.

We offer our porting in stages, and we do this because the ports geometry is matched to the engine size and usage. For example, if you have a stock displacement Busa engine at 1299cc and its at 10,000 rpm it will draw a given volume of air and have a given average port velocity. If you have a 1441 cc engine at 10,000 rpm it will draw more air but you still want to maintain the same velocity in the port. A 1696 cc busa engine will draw even more air but you STILL want the same velocity in the port. When a ports localized velocity on a running engine spikes and exceeds the speed of sound, “a specific velocity based on the temperature of the air in the port” it forms a shock wave perpendicular to the direction of flow and acts like a restrictor plate. This is commonly called “sonic choke”. This typically happens on a port that is improperly sized at its MCSA for the size and RPM of the engine. This severely limits the hp output past the RPM that the shock wave starts to form at. Ideally every engine combination needs its own specific MCSA for that combination. But that’s impractical because of the number of engine and cam combinations available. So we offer 3 carefully sized ports that overlap to suit any engine and cam combination. This is why the first question we always ask is “what size is your engine” and “what are you going to be doing with it” before we can determine what port you need.

Does your Busa, zx12r or zx14 engine make .164 -.165 hp per cc?
Here are some very typical real world examples of our customers results on there OWN Dynojet dynos with mild compression ratios under 14 to1. With high compression engines over 15 to 1 you may expect slightly more.

Stage 2 Busa head on a 1397cc engine, 231 hp.
Stage 2 Busa head on a 1441cc engine, 238 hp.
Stage 2 Busa head on a 1507cc engine, 248 hp.
Stage 2 Busa head on a 1580cc engine, 258 hp.
Stage 3 Busa head on a 1650cc engine, 271 hp.
Stage 3 Busa head on a 1696cc engine, 278 hp.
Stage 2 ZX14 head on a 1417cc engine, 232 hp.
Stage 3 ZX14 head on a 1534cc engine, 254 hp.
Stage 3 ZX14 head on a 1570cc engine, 260 hp.
Stage 2 ZX12 head on a 1290cc engine, 213 hp.
Stage 3 ZX12 head on a 1427cc engine, 234 hp.

Competition CNC
 

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I'm wondering how a 675 triple would shoe in..
Why not just sell the Versys and buy the appropriate motorcycle?

I like my Versys for what it is, and it's just fine for around town. I also have the Ducati, and that's for Sunday mornings in the country. It has performance, and it also has brakes and suspension that are adequate to deal with that performance.

The Versys chassis is just adequate with the engine it has. It would be totally disappointing and probably dangerous with a 675 triple in it.
 

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Discussion Starter #8 (Edited)
I know all about ruining heads with a die grinder and looking for someone that can do a proper job. No doubt that there are guys here that will hog it out or I can give it a go myself, but that is not what I am looking for

Buying a bare ER head is an option, but I am interested in what is different about the Versys head and will milling it yield the same combustion chamber size and shape as the ER.
If so how much to mill?

There is no info on the web that I can find on how much to mill the head to raise compression to street fuel limits
 

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I thought the Yanks had a saying, if you want power there is no substitute for cubic capacity. Looks like things have changed and have gone the way of the Pom's, refinement.
 

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There is no info on the web that I can find on how much to mill the head to raise compression to street fuel limits
One thing you can do is cc the combustion chamber. Use a graduated cylinder of liquid - water with some food coloring works great. Lightly coat the valve seat area with oil to ensure a good seal. Fasten a piece of plexiglass to the inverted and level head, with a small hole drilled into the centre of it. Fill the combustion chamber with the liquid thru the hole in the plexiglass until full. Read the total amount of liquid used, and this is the cc of the combustion chamber. Add the compressed thickness of the head gasket, and this will tell you the total volume.

From there an easy calculation can be made for how much compression will be raised by how much material is removed - which will decrease the combustion chamber volume.
 

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I thought the Yanks had a saying, if you want power there is no substitute for cubic capacity. Looks like things have changed and have gone the way of the Pom's, refinement.
Only one saying of many.

There's a good reason that the Brits made do with small displacement engines, which is that their vehicles were taxed on calculated horsepower that utilized a formula based on cylinder bore and number of cylinders. More displacement, more horsepower. So they had to make more power out of a small displacement engine in order to keep the yearly tax rate down. Americans had no such restriction.

Today the driving force is fuel economy and emissions reduction. But we now have very effective electronic engine control systems and better engine design, and that's made it possible to get more horsepower from smaller engines while still maintaining driveability.
 

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Discussion Starter #13 (Edited)
Fdale - I know about cc'ing heads, how to do the calculation, and in fact have the little kit to do so.

What I am looking for is a proven method that will result in the biggest bang compression ratio and still run on our E-10 fuel while not hitting the piston.
Checking for valve/piston interference is easy enough, but I was hoping that someone had done it and save me the modeling clay exercise.

BTW, I also live in Chiangmai and am a Canadian too
 

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Will have to meet up in the fall when I return. In Yukon now getting ready for the Ice Road. Then construction season in April.
 

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Why not just sell the Versys and buy the appropriate motorcycle?

I like my Versys for what it is, and it's just fine for around town. I also have the Ducati, and that's for Sunday mornings in the country. It has performance, and it also has brakes and suspension that are adequate to deal with that performance.

The Versys chassis is just adequate with the engine it has. It would be totally disappointing and probably dangerous with a 675 triple in it.
I'm happy with the Versys as comes too. I was mainly offering a thought for the thread. An engine faster transplant can be far cheaper in the long run than a full blown worked engine with all the hassles and implications.. I'm with you, get a Multistrada
 

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I don't want to sound negative but this engine doesn't have much tolerance to give alot more hp without becoming a terminal time-bomb. What are the costs for a small gain. I'd be looking at what other more powerful engines standard will shoe in if you want some life to spare.
Doesn't add up for me.
 

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Blue Ridge Performance has been doing racing parts for the 650's for years, they might be a good source. Retro-Rocketeer on this site might be as well.
 

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I'm with you, get a Multistrada
I have wanted one for years, but the parts and service situation in Thailand is terrible.

This model off my list until the situation improves - I am not holding my breath.

Besides - us old hot rodders can't leave anything alone.
 
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