Cylinder Head miscellaneous photos

[triton28]

For those who haven't had occasion to work on a Voyager XII cylinder head here are some photos.
These are after I polished the intake and exhaust ports, ported the exhaust only, and planed the head gasket surface. I have yet to lap the valves to the seats.
This is a long process and using a Dremel with a spherical cutter next to the valve seat inserts can be unnerving.
Final polishing was accomplished using an air die grinder with straight/full taper cartridge rolls mounted on a 6" mandrel.
All totaled there were 11 grams of aluminium flash and lumps removed/polished out.






Exhaust ports 1 and 2


Intake ports

Once I get this installed with honed cylinder block and new rings the engine should breath a little better and may rev/run quicker and smoother, but that's a long way off yet.

[cranky]

... right pretty!!! Thanks!!!!

[Jimvoyager01]

Your cylinder head looks better than beautiful ,,,,,Looking at it i cant help but think that it took a lot of engineering and machining to manufacture.. :

[cushman eagle]

That is one impressive piece of art :perfect10:I wonder how long it took Kawasaki to design that so it works so well.

[hank43]

What is the idea behind using 2 intake valves per cylinder? I can understand 2 ex valves, to better get rid of the burnt gasses, but for the intakes, why not just use a larger single valve? using 4 valves /cyl to me just means a more complicated cam - Is this done to improve the dynamics of the combustion process? When the Honda cars came out with the CVCC engines, I noted that mine had three valves per cylinder I think...
Anyway, those are gorgous pictures!

hank43

[cushman eagle]

Hank,the three valve engines had two intake,and one exhaust.Atmospheric pressure,which fills the cylinder is only about 15 psi,whereas exhaust is many times higher.
Four valve engines using smaller valves need less spring pressure per valve and flow more air at less valve opening than two large valves.
The power band we see on four valve engines typically is very wide.

[Chris near Kansas City]

Draw a big circle. Let's pretend that is the cylinder or combustion chamber. Now draw 2 smaller circles in side the big circle as big as you can make them without touching each other or touching the big circle. See all the extra space?

Draw another big circle the same size as before. Now draw 4 smaller circles inside the big circle as big as you can make them without touching each other or touching the big circle. See the extra space? Hint: it's less space than the first cylinder with 2 circles (valves).

Your valves can only get so big in the combustion chamber. The only way to get more air in and out naturally, is more valves. 2 smaller valves can move more air than one bigger valve.

Surface area.

Real estate.

Math/geometry. Ungh. Those teachers were right. We did have to use that info one day, LOL.

Some engines have all 4 the same size. Some have 2 one size and 2 another. Some engines have 3 valves. Some, have 5. I think there is a Maserati head out there with 6 valves per cylinder.

[hank43]

Hmmm.... Good info, but
The Honda CVCC engine I was thinking about had 1 ex per cylinder, 2 intake per cyl, and one "aux intake" per cylinder.for a total of 3 intake, 1 exhaust per cylinder!!
SEE=======>http://repairguide.autozone.com/znetrgs ... 050c97.jpg

I bought a CVCC when they first came out, we lived in Ohio, and my wife worked at Packard Electric in Warren, OH, a division of GM. She was a tool and die maker, our little Honda was not much appreciated by her fellow workers. We bought another Honda Civic, and later when the Accords became available in 1976 one of those. Three of the best card I ever owned. The Accord made it out to California in 1981, and we drove it until about 1985, then sold it to someone that needed an engine. The body was trashed from Ohio winters, the strut towers came thru the hood, but the engine started after sitting a couple of years in our driveway, The engine had about 150,000 miles on it, the guy was very happy to get it!

Now about 4 valve engines, how many valves are intake vs exhaust?
My Kawasaki 1700 engine has 4 valves per cyl, but I don't know how many of each, book doesn't say, and I can't see which valves are bigger - .

hank

[hank43]

Chris, I think you answered my question, we both posted within a couple minutes of each other!

Anyway, all of this could be solved by simply using square combustion chambers and square valves.......maybe

BTW, does anyone know why man hole covers are round? Think about it!

hank

[Thadbaker86voyager]

I think the hive of honey bees has the most efficient use of space. The 6 sided holes they store the honey in. Now that would be an interesting looking cylinder/valve shape! With most engineering challenges, it's the most effective solution that you can actually make work. So round shapes are the trade off at some loss to efficiency.

[Gator Mike]

Hank I also owned a cvcc. Great little car. The 3rd intake valve was a very small valve that was a "pre ignition " valve in a small chamber. Honda tech told me that it ignited a small amount of fuel micro seconds before the fuel was drawn in to the main combustion chamber. This small combustion caused the regular combustion to burn completely. Don't know if he was feeding me a line but it sure did get good mpg and ran great..............Gator MIke

[hank43]

Yeah Mike, same thing my dealer told me. All of our Honda cars were great! Great mileage, only mechanical problem I ever had was when there was a recall for bad head gaskets, took mine in for recall, dealer disassembled the BOTTOM END of the engine, put it all together with the bearing caps on backwards, bearing caps were just put back on any where. Wern't marked when taken apart. I know this because I stopped by the dealers shop and saw the car up on the hoist, bolts, bearings, both conn rod and main, laying on the floor, nothing properly torqued etc. I got a new engine out of that, but had to call American Honda in So California to get the problem resolved. I did that call from the dealers office. He was upset when I handed him the phone after talking to Honda.....for some reason. That was my 1976 Accord, it was about 2 months old at the time.

hank43

[Chris near Kansas City]

Anyway, all of this could be solved by simply using square combustion chambers and square valves.......maybe...

The Honda NR750 had oval pistons and 8 valves per cylinder, er, oval.

[hank43]

The bike became the most expensive production bike at the time when it was selling for $50,000 and with the rarity, nowadays they rarely change hands.

WOW! That puts it in the Harley price range
Never heard of this.

BTW, no one can solve the challenge of the man hole covers?
How about why carpenters pencils are flat, instead of round??

hank43

[dsmmrm]

manhole cover: So you can't drop it in the hole.
pencil: so they won't roll off a table.

[cranky]

[hank43]

manhole cover: So you can't drop it in the hole.
pencil: so they won't roll off a table.

Us Ohio folks are pretty smart, huh
posting.php?mode=quote&f=15&p=83549#

[Gator Mike]

shoot Hank, all this time I thought it was so somebody could sell those weird little pencil sharpeners for flat pencils.
Gator Mike

[hank43]

My dad, a carpenter, had one of those, it folded in half, he said it was for "whittling", what ever that is.....(1909-2005) Taught me how to play a harmonica, too.

hank43

[cushman eagle]

My dad, a carpenter, had one of those, it folded in half, he said it was for "whittling", what ever that is.....(1909-2005) Taught me how to play a harmonica, too.

hank43

Hank,I bought a harmonica to try to learn how to play it ! I found out it is a whole lot harder to play than my Trumpet