Midrange ping. Considering quench/squish

If they are hemi's then I would think they are not quench engines. In a car engine quench is acheived mostly by changing the compression height of the piston. Secondary effects can include the thickness of the gasket. Most often this is done with closed chambered heads. It can be done with a hemi with careful measurments. I too also shot for .040" as it's a good and safe number. However, I'm not sure the effort is worth it on a street motorcycle, or if such parts are even available for Kawa's. Someone else will know.

This is a very popular approach to power in a 2 stroke.
Also very popular with 4 stroke race motors.
No special parts are necessary. Just mill the cly block. Very simple.

mark1122 wrote:

Put 2 pieces of solder into the plug hole. direct 1 to each side of the piston, above the wrist pin. While holding them in place, turn over the motor by hand. now measure how much the solder squished down to.

All great info Mark! Thanks. I like the solder trick. Soooo much simpler than what I was originally thinking about. Will try this and let you know the results.

TeK9iNe wrote:

Took the words right out of my mouth :laugh:

A great octane booster is toluene!
Some info:
Toulene
R+M/2...114
Cost...$2.50/gal
Mixtures with 92 Octane Premium
10%...94.2 Octane
20%...96.4 Octane
30%...98.6 Octane
Notes: Common ingredient in Octane Boosters in a can. 12-16 ounces will only raise octane 2-3 *points*, I.e. from 92 to 92.3. Often costs $3-5 for 12-16 ounces, when it can be purchased for less than $3/gal at chemical supply houses or paint stores.

Works fantastic

What ignition setup do you have right now? As bountyhunter said, perhaps the advance curve is sloppy...

Good luck!

what does the ratio of toulene work out to for a gallon of gas for us simple minded types? i know a guy who makes same stuff but hes tight lipped about his rocket fuel formula! :laugh:

No trouble . Glad to help.
Just think of all your work, as a science experiment. don’t just believe the 1st measurement. repeat the tests until u get repeatable results. U want to put the solder over the pins to reduce piston rocking.
U can do this for valve to piston clearance as well.
Have fun.

TeK9iNe wrote:

Took the words right out of my mouth :laugh:

A great octane booster is toluene!
Some info:
Toulene
R+M/2...114
Cost...$2.50/gal
Mixtures with 92 Octane Premium
10%...94.2 Octane
20%...96.4 Octane
30%...98.6 Octane

The real problem is how much you have to add to get any decent increase in octane. Also, toluene likes to dissolve just about everything on earth. Tetraethyl lead was and is the best octane booster and the Supreme 130 stuff is the only place I know that still has it. You only have to add maybe two ounces per gallon and get like a 3 octane boost.

I pinch the pennies tight and the supreme 130 gives you way more for your money than the junk in little cans. It is still pricey, I think it was like $100 for a case of twelve quarts (32 ounce bottles) when I bought it. That's about 25 cents per ounce, but you really only need a couple of ounces per gallon of gas so you are basically bumping the cost of gas about 50 cents per gallon so increases rider's cost roughly one cent per mile to run. Not good, but the cost of gas on a bike is really low on the list of cost to operate items anyway.

About 1 pint to a gallon is what the guys I know use.
They say its about 95 octane when thier done.

They used to use the stuff in F1 before they changed to stricter regulations.
Considering I can get a 5 gallon barrel for about $25, its probly really not that great for a daily rider...
More like strip.



Then again, if you cant run pump gas without getting ping because of engine mods, then you cant fairly call it a "street" machine can you :laugh: :laugh:

Gotta add octane booster just to get to work, now thats my kinda ride...

oops

So here are some preliminary results from Mark's solder squish test

The top piece of solder shows the tightest area of the combustion chamber near the cylinder wall. This is the quench area and measure 0.055".

The second piece of solder (solder wrapped solder) shows the contour of the CC and is accurate up to the green tape. After that the chamber gets wider than the diameter of the spark plug hole.

I was able to measure the distance between the top of the piston at TDC and top of the CC at the center of the cylinder using a different setup and compiled the complete combustion chamber shape as an ACAD drawing at the bottom.

Here's an approximation of the head, gasket, cylinder and piston

Obviously not a "quench style" head. Still I'd like to reduce the quench areas at the perimeter of the cylinder to around 0.040". Also thinking about using a copper head gasket. It might be thinner than the composite gasket(reducing the quench area) and transfer more heat away from the head and into the cylinder block...?

Any thoughts on this?

copper head gaskets are usually the same thickness as the composite. The composite is a better choice for longevity on a street ride. copper tends to leak oil sooner. This is well documented.
Copper is just for ease of disassembly and can be reused.
Been there.
Nice work on the cad.
Did u find that 1 side of the clearance was slightly dif?