PICTURES ENCLOSED... This is how I closed up the squish band clearance the simple way

[joeak47]

Ok, here are some pictures to show all of you what I did (so far) to close up the squish band. I'm also working on a cutting another head as I type this.... I'll show you that one in a bit.

I do things in a different way to save money on parts. This head is amazing. I'm just getting warmed up. I have many things that I'll be trying. The other head I mentioned above should be done today. It will have a smaller chamber for more compression,but I think I'll keep the same sqish band clearance.

The reason I did it this way is....

#1 Why cut material off the top of the cylinder when you don't have to?
I think that way sucks,because what happens if you want to go back?
You can't. Most folks cut material off the top of the cylinder to bring
the head closer to the piston. Cylinders = expensive & Heads = cheap.


#2 Heads are cheap and I can scew up many (haven't yet),or I can just re- cut and try something else. Think about it.


#3 I could drop the cylinder a little bit to bring the cylinder head closer to
the piston by removing the base gasket,or using a thinner one, but that
would change the transfer port timing,and you can only change so much
by changing,or removing a gasket.

#4 I removed the head from my blaster in 8 minutes (including the tank)
and then cut the step cut in under 5 minutes while in my shorts and
flip flops,re-assembled the head onto the engine, re-torqued head,and
assembled bike in about 15 minutes. Yeah baby! gotta love 2 strokes!


10 hours of use,and just removed from the cylinder. Nothing wiped off.
First 5 hours... REDLINE OIL and oil injection. Second five hours Maxima Castor 927 mixed 20 to 1 ratio! NICE AND CLEAN!

Exhaust port is nice and clean.

10 Hours on the clock! And 10 hours on the "cheap cast piston" that everybody loves to hate.

Now its time for the step cut.....

Here is the step cut.

The step cut fits flush with the copper head gasket. Here's a good picture (no flash) that shows the gasket sitting in the step cut.

Here's another good picture (no flash) the shows the two components and the step cut.

This kind of explains what I did (short form) and a flash picture.

 

[Triple_B]

Re: PICTURES ENCLOSED... This is how I closed up the squish band clearance the simple

Great stuff once again joeak! Keep up the good work!

 

[joeak47]

Re: PICTURES ENCLOSED... This is how I closed up the squish band clearance the simple

Nice work im digging the army jeep in the back ground.

Thanks! But... SHAME ON YOU! Thats no jeep (I like jeeps too).

Thats a Dodge M37 weapons carrier.

 

[joeak47]

Re: PICTURES ENCLOSED... This is how I closed up the squish band clearance the simple

Flash pictures smoestimes help with detail...

A flash picture with a pointer showing the step cut.

Assembled together...

Another angle showing the two components assembled. Flash picture.

This head is producing 130 PSI compression with my "cheap cast piston". Before the step cut cut it it was 115 psi compression.

 

[Triplecrown421]

Re: PICTURES ENCLOSED... This is how I closed up the squish band clearance the simple

good info Joe, the topend looks good
Best and I just got a new head made up. designed after good old ktm
ill have a tread up soon

good stuff

 

[joeak47]

Re: PICTURES ENCLOSED... This is how I closed up the squish band clearance the simple

good info Joe, the topend looks good
Best and I just got a new head made up. designed after good old ktm
ill have a tread up soon

good stuff

AWESOME!!!

Thats the next one I was planning to try! I can't wait to see your results!

 

[joeak47]

Re: PICTURES ENCLOSED... This is how I closed up the squish band clearance the simple

No sh*t?

Got any better pix?Id love to see it in full!!!

Toughest truck I've EVER owned!

I don't want the thread to get off topic,but here you go...

 

[sicivicdude]

Re: PICTURES ENCLOSED... This is how I closed up the squish band clearance the simple

Ok, here are some pictures to show all of you what I did (so far) to close up the squish band. I'm also working on a cutting another head as I type this.... I'll show you that one in a bit.

I do things in a different way to save money on parts. This head is amazing. I'm just getting warmed up. I have many things that I'll be trying. The other head I mentioned above should be done today. It will have a smaller chamber for more compression,but I think I'll keep the same sqish band clearance.

The reason I did it this way is....

#1 Why cut material off the top of the cylinder when you don't have to?
I think that way sucks,because what happens if you want to go back?
You can't. Most folks cut material off the top of the cylinder to bring
the head closer to the piston. Cylinders = expensive & Heads = cheap.


#2 Heads are cheap and I can scew up many (haven't yet),or I can just re- cut and try something else. Think about it.


#3 I could drop the cylinder a little bit to bring the cylinder head closer to
the piston by removing the base gasket,or using a thinner one, but that
would change the transfer port timing,and you can only change so much
by changing,or removing a gasket.

#4 I removed the head from my blaster in 8 minutes (including the tank)
and then cut the step cut in under 5 minutes while in my shorts and
flip flops,re-assembled the head onto the engine, re-torqued head,and
assembled bike in about 15 minutes. Yeah baby! gotta love 2 strokes!


10 hours of use,and just removed from the cylinder. Nothing wiped off.
First 5 hours... REDLINE OIL and oil injection. Second five hours Maxima Castor 927 mixed 20 to 1 ratio! NICE AND CLEAN!

Exhaust port is nice and clean.


10 Hours on the clock! And 10 hours on the "cheap cast piston" that everybody loves to hate.

Now its time for the step cut.....

Here is the step cut.

The step cut fits flush with the copper head gasket. Here's a good picture (no flash) that shows the gasket sitting in the step cut.

Here's another good picture (no flash) the shows the two components and the step cut.

This kind of explains what I did (short form) and a flash picture.

I removed the pictures simply for length...

I LOVE it. It looks very good, keep up the good work.

One suggestion that I have is one best and I discussed in the "squish, mystery or not" thread. Your squish area appears to be less than 50% of the bore size (by area) which lends itself to a high rpm range "tune" from a squish hemi head stand point.

You can increase the compression some more by making the combustion chamber area smaller but that WILL require you to increase the squish clearance because the farther you have to push the charge, the more room it will need to keep the speed below the point where you're pushing in enough energy to get it to spontaneously combust!

good info Joe, the topend looks good
Best and I just got a new head made up. designed after good old ktm
ill have a tread up soon

good stuff

Take good pictures!

 

[joeak47]

Re: PICTURES ENCLOSED... This is how I closed up the squish band clearance the simple

SICIVICDUDE... Thank you for the info!

I prefer the higher RPM range "Tune",so I'm thinking of doing this...

Cut all the dimmensions on the next head the same as the head on this thread (DT 200 specs) ,but make a smaller combustion chamber (for more compression 160 to 170 psi),and leave out the step cut.

I feel that I can incrementally add the "step cut" later to decrease squish clearance a little at a time to see the effect on power.

MORE POWER HERE WE COME!

 

[sicivicdude]

Re: PICTURES ENCLOSED... This is how I closed up the squish band clearance the simple

SICIVICDUDE... Thank you for the info!

I prefer the higher RPM range "Tune",so I'm thinking of doing this...

Cut all the dimmensions on the next head the same as the head on this thread (DT 200 specs) ,but make a smaller combustion chamber (for more compression 160 to 170 psi),and leave out the step cut.

I feel that I can incrementally add the "step cut" later to decrease squish clearance a little at a time to see the effect on power.

It will look JUST LIKE this:

And if it does, you're doing it right. That head is designed for 7,500 rpm (mx bike) on premium gasoline with the parameter's basically optimized for mid throttle response. It's the culmination of using a head design program and my own (nearly) destructive testing to figure out the sweetest spot on a blaster head. I'm loath to give up every single detail (especially since my experiments may not apply to your exact situation) but you've arrived through trial and error at nearly the same place I see!

Good job!

 

[little3mil]

Re: PICTURES ENCLOSED... This is how I closed up the squish band clearance the simple

good stuff and great work Joe!


reps given

 

[joeak47]

Re: PICTURES ENCLOSED... This is how I closed up the squish band clearance the simple

It will look JUST LIKE this:

And if it does, you're doing it right. That head is designed for 7,500 rpm (mx bike) on premium gasoline with the parameter's basically optimized for mid throttle response. It's the culmination of using a head design program and my own (nearly) destructive testing to figure out the sweetest spot on a blaster head. I'm loath to give up every single detail (especially since my experiments may not apply to your exact situation) but you've arrived through trial and error at nearly the same place I see!

Good job!

Wow! Thanks again! I'll use that as my model. How many cc's is that head?

 

[sicivicdude]

Re: PICTURES ENCLOSED... This is how I closed up the squish band clearance the simple

Wow! Thanks again! I'll use that as my model. How many cc's is that head?

That's where I will draw the line Joe, sorry buddy. Plus, the volume of the head has a lot to do with the trapped volume of the engine too so exhaust port duration will have a lot to do with that adjustment. More duration needs less volume in the head.

I will tell you that I cc'd it so I know what the cranking compression SHOULD be (haven't heard back yet for confirmation) and it should run quite well. That head is over 50% area and has a narrow break area on it.

 

[best]

Re: PICTURES ENCLOSED... This is how I closed up the squish band clearance the simple

Toughest truck I've EVER owned!

I don't want the thread to get off topic,but here you go...

<GREAT PICTS SNIPPED>

Too late, minor derailment...

Sweet Joe! The Canadian Army still had a very few of these when I joined in 1977. Flathead 6 that I recall. Grunt and crawl through anything. Tough, tough, tough.

Kind of interesting era to join, they still had 1950s jeeps and Deuces and Vietnam era M113s that were bought in huge quantities during the cold war.

Back on track:

Excellent job on the head Joe. Perfectly following the theory.
The hemi shape supports higher rpm better than the toroidal too.

About the stock step, it is there to keep the cylinder and rpm low.
Raising the cylinder with basegaskets also tends to raise the rpm range.
You have it right stepping down into the head for a high rpm motor.

Love it! Great picts! Cannot wait for the report...

 

[joeak47]

Re: PICTURES ENCLOSED... This is how I closed up the squish band clearance the simple

105MM RECILESS RIFLE!!!

I need one of those!!!

Very interesting how they work. I wonder If I could mount one on a blaster8-|

 

[best]

Re: PICTURES ENCLOSED... This is how I closed up the squish band clearance the simple

105MM RECILESS RIFLE!!!

I need one of those!!!

Very interesting how they work. I wonder If I could mount one on a blaster8-|

I am SURE you could Joe, but there would be no challenge in it,
it has sort of been done before:

If the French could mount one on a Vespa, you would have no problem on a Blaster.
Our unit was nominally "anti-tank infantry" so I fired lots of M72LAWs and Carl Gustav 84mm. This was the "Big Daddy" of our unit.
Oh, and don't be fooled by the "recoilless" part, it is still a hell of a bang!

I guess as more mature members here we should be keeping on thread... but the door was opened...

 

[joeak47]

Re: PICTURES ENCLOSED... This is how I closed up the squish band clearance the simple

Mr BEST... Right you are! Back on topic...

I just finished head #2 and it cc's at 16cc's. Thats 6 cc's less than my first head.

The weird part is that the compression reading is still 130 lbs. I think the larger chamber on head #1 (22 cc's and 40% squish band) is the same volume as head #2 (16cc's an 55% squish band).

I was stunned to say the least.

I believe that a tight squish is where its at. Testing continues......

 

[speedemon17]

Re: PICTURES ENCLOSED... This is how I closed up the squish band clearance the simple

wonder if anyone ever shot one of those mopeds and how hard they kissed the front of it while the back shot out from under them

 

[best]

Re: PICTURES ENCLOSED... This is how I closed up the squish band clearance the simple

wonder if anyone ever shot one of those mopeds and how hard they kissed the front of it while the back shot out from under them

It is recoilless, the gun tube does not kick back like a rifle or artillery cannon does. There is a heck of a big explosion however. The tube shakes and can bounce off anything hard it is set against. filaments in any lightbulbs nearby are broken, some bulbs pop completely. Your clothes compress against you, then balloon out and compress again, your ears pop even with your mouth open. A ball of flame and blast shoots out the back, burning the ground, throwing rocks and sand around. You feel the front blast on your face, especially your cheeks, but also in your stomach. It leaves you stunned for a moment, then my next thought was usually "Quick, gimme another round!"

I'm telling you, the Army is a heck of a lot of excitement in between the boring stretches.

I just finished head #2 and it cc's at 16cc's. Thats 6 cc's less than my first head.

The weird part is that the compression reading is still 130 lbs. I think the larger chamber on head #1 (22 cc's and 40% squish band) is the same volume as head #2 (16cc's an 55% squish band).

I was stunned to say the least.

I believe that a tight squish is where its at. Testing continues......

Joe, that compression seems low, especially for your cc volume.
Is it possible your rings were dry of oil?
I'd expect you'd be up in the 180 psi range with 20cc or less.
Rings or bore might have some issues too. Will affect cranking compression and low rpm, but not so much top end power.

Run it! Listen and feel for detonation. I'd suggest backing timing off to stock or further.
Have you played with timing to see what it does?

 

[joeak47]

Re: PICTURES ENCLOSED... This is how I closed up the squish band clearance the simple

BEST...

My timing is stock. It runs perfect where its at. I was expecting more also.

I inspect the bore each and everytime the head is off. The top end looks perfect and has 10 hours on it.
When I was doing the compression test's, I did it multiple times,and also shot oil through the spark plug hole (a healthy ammount) and got the exact same readings (maybe 1 pound difference).

I was stumped,so I re installed my old head and got the same reads (130 psi which is what this head had),did the oil thing,and the same readings appeared.

The "MAC" tools compression gauge works perfectly! When I kick over the kick starter,they feel the same too.
Hmmmmmm:-/

The engine runs beyond awesome with either head,phenominally actually,and ther is ZERO DETONATION!