tdc tool

[BDI]

 I need a top dead center tool but they are pricey so I made one from a spark plug.First I chucked up the plug in the vice you can't cut strait threw the plug because of the ceramic. You have to rotate the plug until you cut all the way around. Then I cut off the electrode. Then I taped the ceramic portion of the plug out with a punch light taps is all it takes it comes right out you should use safety glasses. Then I cleaned it up on my belt sander top and bottom. then I removed the crush washer with some dikes. Then I drilled it out to fit my dial indicator with a 3/8 drill bit I did not go all the way threw I stoped at an existing point. This would be best done in a drill press but none the less mine had a machined fit when I was done. I plan on using this tool to verify squish and finding top dead center. I will be posting about the way I plan to verify squish from now on using this tool.

[maddoggy]

thats a great idea BDI, and a real good tool. i make tools alot due to the high price of specialty tools. i think i got it from my dad. he is always making tools. when i was younger i thought he was a cheapskate for building them instead of buying them. now that i'm older i realize the genius of his ways. MADDOGGY

[BDI]

thats a great idea BDI, and a real good tool. i make tools alot due to the high price of specialty tools. i think i got it from my dad. he is always making tools. when i was younger i thought he was a cheapskate for building them instead of buying them. now that i'm older i realize the genius of his ways. MADDOGGY

    I make all kinds of stuff like that. I still want to put a set screw in it but Im going to machine an aluminum coller so the screw does not push derectly on the dial indicator.

[BDI]

well It's done and it works sweet. with just a light snug on the set screw it is affixed to the dial indicator very tightly and it does not leave a mark on the tool. 

[stewart]

do you plan to market these

[BDI]

I had not thought of it but it sure would be cool to do so.

[stewart]

i would buy one ,,could be your first customer you can make money and buy more kx stuff ...thats what i work for every day

[fluffy]

why is your workbench so clean?

[BDI]

I would say it's dirty but it is as clean as it is because I am severely anal-retentive. why do you call your self fluffy?

[kx666]

Great idea! i would buy one

[KXcam22]

Nice home made tool. I like to see that. Cam.

[BDI]

Well this is why I made the tool I plan to use it to verify squish and this is how I will be doing that from now on. I am kind of jaded with the solder method. I know it is a good way to check squish with out taking the engine apart but the only time I want to check squish is when I have built an engine so this works for me. I thought about this long and hard and this is what I came up with, this Is reverse engineering. First I installed the tool in the head then I found T.D.C. then I zeroed the dial indicator. I pulled the head and place it derectly on the piston with the tool in place, this would be absolute zero squish. Now I can see that the difference is .053 thousands. That's my squish with out a doubt there is no way this is wrong It can't be.Now when I put the engine back together I will do the exact opposite.I will put the tool in the head and zero it on the piston then I will put the engine together and place it on T.D.C. with the tool in place. Then I can see what my squish is for sure with out a doubt. This rules out piston rock,rod deflection and play in the bearings, these all impact the solder method and foul your results.

[stewart]

good thinking bryan

[YUNGGUNNAZ]

nice job.good point made.the soldier method is good but not the most accurate as yours is.soldier has a tendency to squirt away from cylinder wall along piston crown angle.example:this one motor (not kx)showed .054 squish with soldier.dome step was .078.motor was having deto. problems.but with indicator zeroed on piston edge at tdc,then step off to cylinder deck it showed .050 out of the hole.now the math showed this.078+.005(o ring)=.083-.050=.033 actual squish.clay method also was closely at .033.piston crown angle,squish band width and chamber angle is important things to consider.good tdc tool to have.

[BDI]

That's been my experience also,we did a jet ski engine not to long ago. My buddie thought he had .050 of squish according to the solder method we checked squish my way and found out he really had .030 . Funny those numbers are very close to yours. I did some experimenting with a connecting rod in my bench vice. I put the big end in the vice and put a piston and wrist pin on the small end then I set up a dial indicator with magnetic base to measure rod deflection. I stuck a rod threw the wrist pin so I could hang wait on it. I found that with only a few pounds of wait I could cause the rod to deflect a bunch. Even though solder is soft it takes more wait to squish it then it does to cause rod deflection so even if you check it over the wrist pin the piston still rocks in the bore. In my opinion the solder method only gives you useless information.