While Marvel Mystery Oil would be a good choice, most tech is done with either ATF, or diesel injector test fluid, as far as I know, both are pretty much used as the Industry Std. The problem with much of anything besides a bore and stroke ck gets expensive, and the cc by bore and stroke is also an Industry Std, why make it harder on yourself. There is another method, that utilizes the "swept volumn" of the cylinder, which is what Nascar uses in it's initital after the race checks, before they actually do a teardown, and measure the bore and stroke, but that SV testing equipment is expensive, difficult at times to get consistant readings, requires the valves be disabled on at least one cylinder, which means a lot of work on a twin cam engine, and still leaves a lot of doubt as to if it was done correctly, and how accurate it was. If you want to keep it simple, you can do a cc ck, or a bore and stroke ck, and visually do a cam timing ck, and keep on moving, anything else will require taking the motor apart, and running off the owners, there are so many ways around a compression ck it isn't funny, and again, not of much value, as these engines run at such hi RPM, even a low compression ck at cranking speed is of little value, I think you are on a witch hunt, trying to keep or establish a "level" playing field, it isn't all motor. I don't have a dog in this hunt, but have built race engines for years, and motors are motors, some are just better than others, and better at different times, even on the same night, I'd keep it as simple as possible, to keep the racers happy, amongst themselves, no one wants their motor torn down in a dirt track enviornment, even if it is someone elses. JMHO! Bob

Dad..........always appreciate your input. Enlightening. I will educate myself on the top of the piston and the things you mentioned. I have noticed the machined spot on the top of the piston and the valve reliefs when using a bore scope but how do you measure that spot in relation to the two lines you referred to with confidence?

Didn't realize that "supposedly stock configuration" pistons slightly raised the compression. At least enough to make any difference in performance. Individuals have complained they can't get certain stock pistons and are forced to go to aftermarket. That is the main reason we accept them. Right or wrong. And then.....that is why we want to verify combustion chamber volume while at TDC. Do whatever you want piston wise.....stock or aftermarket.......mill the head to save it.......whatever..........but that head better take the correct amount of oil at TDC when you get done or you have a problem. I just want to know if this is a truly workable system. Different motors and different years have a range of cc volume. From 21.2 cc all the way up to 23 cc. Now........is that oil to the bottom of the spark plug hole or the top? How far out of plumb can the cylinders be and not create an air pocket that prevents oil from filling the chamber? I will test my info on my two motors and see where it comes out for now.

When we CC a head we remove it from the engine place it on a level bench upside down with the spark plug installed, place a plexiglass cover over the combustion chamber and poor a light oil through a hole in the cover until it fills up and into the hole without any entrapped air, the #'s you have were probably achieved this way. It's awfully hard to get rid of that air without rocking the engine back and forth. Like bleeding your brakes. A good spit is 10 CC's. You are measuring drops in a very unfriendly environment.

Been their done that.

Honest Dad himself

Phil

Your phone # doesn't work.

Honest Dad himself

TQ29m.......All good and valid points. I have been around racing long enough to realize and agree with all you have said.

However.......our area group decided we need to so something to insure we were all on as level a playing field as we could get when it comes to stock versus "built" motors. Cost controls is the thing driving this issue. Plus, someone not stinking up the show consistantly. People can tolerate being out driven and out setup but no one likes to be extremely out motored in a supposedly "stock" class. We are adults and know that certain motor might be better and even a particular batch of the same motor might be better. We are combating the obvious here though. Built motors. The racers spoke, MALS is trying to listen and do something to police some of this. Everyone is hoping most of these procedures will not need to be used on a weekly basis but we all agree, we need some workable procedures in place in case something needs to be addressed. Something to keep the honest a little more honest.

And no..........no one wants a teardown at the track. That is why we are investigating simpler ways to obtain certain usable pieces of information as easily as possible. If this is going to NOT achieve the desired results or any useful information......that's what I want to hear from people that know and I will go waste my time on some other procedure.

Dad........did you call (913) 371-5212 (office) or my cell at (816) 223-1009?

DAD, I know what you are trying to achieve, I just don't think it's possible in the real world, a "stock" engine, in my HO, is just too much to keep in spec, I would think you would have to "give" a little, for parts stack up, as they call it in the industry, you know, a little plus and minus in most cases, but I guess it's a lot like the guy said, when asked if his new girl friend was pregnant when they started dating, yeh, but just a little bit. Bob!

Bob----My little brother, an artist had a better saying : "PERFECTION IS TOO DAMNED DELICATE".

From racing go-karts you know how "ANAL" some people and rules can get, I've been DQ'd over being .001 out of spec. We are racing some pretty high tec stuff now days and they don't leave a lot of room for improvement.

People like me and you like to play and rich folk just like to pay and there is always someone wanting to protect both of us from ourselves.

Keep the rules simple and easy to check Bore, Stroke, cam lift and valve size, heck you could even check for stock appearing shaped piston crown, but worrying about compression pressure and even compression ratio gets to be too involved about a modification that won't net much Horse power.

Mini-Sprinters need to worry more about the fuel that is being used. Methanol is not nor has it ever been the power enhancer that race groups think should require a racer to add 25-50 pounds on to their race car to keep things on the up and up. However some of this off the shelf and maybe slightly doctored $20.00 a gallon race gas should be considered an enhancer with a 5% to 10%+ Hp improvement guaranteed by the company's that sell this stuff. This is equal to about a "20 HORSEPOWER" improvement over stock HP ratings on our little engines. This is more than you could ever get with just a set of high compression pistons****** go figure.

And some of this stuff has even been proven to cause "CANCER"!!

Honest Dad himself

The one thing I have noticed over my few years of racing is!!!!

THE FASTEST*** "CHEATER"*** MOTORS ARE ALMOST ALWAYS IN THE> BEST DRIVEN> BEST HANDLING CARS ON THE RACE TRACK.

Honest Dad himself