New! Tool for measuring Squish Band Clearance

[Dale P]

Hey guys I have two new items that make measuring the squish band on your engine easy and accurate. One is for nitro engines and the other is for gas zenoah engines.

It's easy to use and very accurate. First you remove your glow plug, and screw in the gauge. Turn over the engine by hand until the gauge reaches the highest point. (This is the top dead center) Set the dial on the gauge to zero. Then remove the cylinder from the engine and insert the piston in to the cylinder as far as it will go. You can leave the piston and crank connected together it only needs to come out of the crank case to allow the piston to reach the top of the cylinder. The gauge will show the difference between the two measurements and this is your squish band clearance. Now you know what size head gasket you need to use to get the compression you want. This tool is also handy for finding top dead center when reworking an engine.

This method is much more accurate then squishing solder and measuring it.

Gas engine gauges can be used for any engine with a 10 mm spark plug, such as the Zenoah 260, 231, Sikk and clone engines.

Great for gopeds and 1/4 scale cars too. Custom adapters can be made for other engines.

Both gauges come with a 1" dial indicator and the custom adapter.

The cost for the Zenoah gauge is $32.00 plus $5.95 for shipping in the states.

The nitro gauge takes more time to build and is $36.00 plus $5.95 for shipping in the states.

If you want to use pay pal my account is under [email protected]

Questions? Just E-mail me at [email protected]

Thanks for looking! Dale P.

 

[Dale P]

I have more pictures, but can't seem to post. Just E-mail me if you need more, or one of the gas gauge.

Thanks, Dale P.

[email protected]

 

[Buckshot]

This would only work with a non-dished piston right?

After zeroing out the gauge at TDC, wouldn't you remove the head button and press it against a flat surface and then read the gauge to get a head clearance measurement? Again, only on non-dished pistons.

-Buck-

 

[waltr]

Buck,

It seems to be the same style Bill was selling @ Speedmaster.

Works great on non dished pistons.

Not very Mac friendly.

 

[Buckshot]

All the motors I have are dished. CMB and MAC .21 thru 1.01. I guess the NR's are flat tops? I duno.

-Buck-

 

[tnrcboatracer]

To measure a dished piston, you need to make one more piece. It is a short cylinder (or thick washer, ~10mm) that is about 16mm OD (for the 21) with a 1/4-32 hole tapped throught the center. The end of the cyclinder is faced off square. Place the standard gage in the cylinder, and zero it on a flat piece of stock. Put it on the top of the piston (still in the cylinder) and measure the dish. Now you know the depth of the dish of that piston. Record it, and measure the head clearance with the gage the standard way. Subtract the dish depth from the measured clearance to the piston dish to get the squish clearance.

I hope I didn't just give away my secret. I'll make some for sale if folks are interested. Hows $12.50 shipped sound? Tell me the engine bore, and I'll make one that is 0.5mm smaller in OD than cylinder. No need to worry if it is centered.

And yes, standard NR pistons are flat. The latest 35 Plus 21 may be dished; I forget.

 

[Tim_Duggan]

And yes, standard NR pistons are flat. The latest 35 Plus 21 may be dished; I forget.

Hi John,

Not all standard NR pistons are flat. The one in my late RX21 is dished.

I'd say if it came from Speedmaster it would be a safe bet to say it had a flat top piston though. (Obviously mine didn't come from there)

As for the 35 plus 21;

Tapered and dished. Nothing a quick skim on the lathe won't fix.......... enough material there to make it a flat top without problems. (ask Nitrocrazed)

Sorry for the side track DaleP. Nice looking guage by the way.

 

[jeff baham]

And yes, standard NR pistons are flat. The latest 35 Plus 21 may be dished; I forget.

Hi John,

Not all standard NR pistons are flat. The one in my late RX21 is dished.

I'd say if it came from Speedmaster it would be a safe bet to say it had a flat top piston though. (Obviously mine didn't come from there)

As for the 35 plus 21;

Tapered and dished. Nothing a quick skim on the lathe won't fix.......... enough material there to make it a flat top without problems. (ask Nitrocrazed)

Sorry for the side track DaleP. Nice looking guage by the way.

i have the speed master head clearance gauge and what i do for dished piston is put a piece of .010 brass on top of piston and measure that ,then subtract the .010 for the readings. works for me.

 

[tnrcboatracer]

i have the speed master head clearance gauge and what i do for dished piston is put a piece of .010 brass on top of piston and measure that ,then subtract the .010 for the readings. works for me.

Yes, sorry to get off topic. I'll start my own thread for my parts.

Jeff, You've got to be careful to shim the head cap up if you are running 0.007~0.008 squish. Putting a 0.010 shim in a 0.007 gap is hard on the rod bushing. :blink: You could put the same 0.010 shim under the button as well, so the net effect on the reading would be zero.

 

[Dale P]

Hey guys, looks like I will have to include some picts or drawings on how it works. It's actually much easier than your making it to be.

I'll post some in a day or two, but in the mean time, I will try to explain.

If you remove the end plates from a nitro engine the piston will no longer be connected to the crank shaft. You can then reach inside the engine and push the piston up so far that it will touch the top of the head button. When the piston touches the head button you now have NO clearance, or a zero squish band clearance.

What this gauge does is measure the difference between the zero clearance and the clearance when the engine is put together. It doesn't matter if the piston is dished or domed. The only engines that this wont work on are ones with dual plugs because they are on an angle.

Place the gauge in the glow plug hole and turn over the engine till the needle reaches the highest point. Zero out the gauge and leave it in the glow plug hole. Now remove the end plates of the engine so the piston is no longer connected to the crank shaft. Then push the piston up till it reaches the top of the head button. The measurement shown on the gauge is the clearance your piston has between the head button. It's the same reading you get when you place a piece of solder in the engine and have the piston compress it against the head button. My gauge just makes it easier to do and is much more accurate then trying to measure a piece of squished solder. You can then adjust the head shims to attain the clearance you desire.

Also, the plunger on my gauge has over 1/2" of travel so it will have no problems reaching a dished piston if that is what the worry is. Adding .010 shim to the top of the piston and then subtracting it would make the reading the same. Guess I haven't seen the speedmaster gauge, it might be made different?

Hope this helps!

Dale P.

 

[jeff baham]

i have the speed master head clearance gauge and what i do for dished piston is put a piece of .010 brass on top of piston and measure that ,then subtract the .010 for the readings. works for me.

Yes, sorry to get off topic. I'll start my own thread for my parts.

Jeff, You've got to be careful to shim the head cap up if you are running 0.007~0.008 squish. Putting a 0.010 shim in a 0.007 gap is hard on the rod bushing. :blink: You could put the same 0.010 shim under the button as well, so the net effect on the reading would be zero.

sorry ment to say .004 or .008 and i run .012on my 67 cmb.s

 

[AndyBrown]

Ummm.....I think there is no possible way it will work on a Zenoah......or am I dazed and confused?? :unsure:

Oh, OK I see how it works! Seems like squeezing solder is easier than disassembling the engine.

 

[tnrcboatracer]

It is often impossible to run the piston on a Nitro engine up to touch the head button, especially with the crank removed and the head bolted down. The taper fit of the sleeve is too tight to push it all the way up without the leverage of the crank. It's hard enough to pop a new engine over by the flywheel. It would probably work well on a ringed piston gasser, though.

 

[Dale P]

Ummm.....I think there is no possible way it will work on a Zenoah......or am I dazed and confused??

Gas engines adjust the compression by changing the base gasket of the jug instead of head gaskets since the head is one piece. Several sizes of gaskets are on the market. To change the gasket you have to take the jug off so using the gauge is no extra work. I use to try and measure this change by using a depth micrometer, but this tool made the job fast, easy, and accurate. The zen gauge looks a bit different, but works the same. I can E-mail picts of the gas version.

As for the tapered fit of the nitro engine, your right some motors may be hard to work with. Guess mine are worn out and easier to push the piston up. I included a vent in the gauge to allow the pressure to escape when the piston is pushed up, so the compression of the engine won't be a problem.

I looked on Speedmasters web site and didn't see the gauge for sale, I would love to see a picture.

[email protected]

Dale P.

 

[Buckshot]

I see what you’re saying Dale but I'm with Jon. There is no way you can push the piston up the sleeve to touch the head button in any motor that I run. If you can than you need more than a head clearance gauge to get the motor to run right.

The only motor that I know of that you could push the piston through the top of the sleeve was on the P.I.P. "A" motors. Zero sleeve taper but TONS of compression.

Sorry to get your thread off topic Dale.

-Buck-

 

[moparbarn]

i agree, on a "tight" piston & sleeve, getting the piston to touch the head button could be an issue. but on a "race ready" motor, it shouldn't be too big a problem B) .

 

[Buckshot]

"race ready" motor

Is there such a thing?

-Buck-

 

[moparbarn]

only for a VERY short while.............

 

[Buckshot]

Oh, you mean the .21 motor in the 90mph heat racer.



-Buck-

 

[troytron1]

It will work on dished pistons as well. Take the piston out and set the head button right on top of the piston and remeasure.