Anyone know of an adapter for a full scale compression gauge to nitro? I know the scale may be a bit high because mine reads to 250 psi, but it can save me some money if it works. Thanks for any help.

u can mashine it out in any mashinery shop

There is a compression gage made for use with model engines. Saw it in a hobby shop.

Jim

DJ:

Ir can be done, but the information wont be very good. You mentioned scale, and that's the problem. But not the scale on the gauge, it's the sheer size of the ordinary automotive tool.

You have to remember that a compression gauge is measuring the pressure not only in the engine cylinder, but the piston has to compress all the air inside the hoses and pipes of the gauge unit as well. The auto tool is fairly large, the enclosed volume can be close to the same size as the model engine you want to test. The result of the larger volume within the automotive tool is the piston's having to pressurize so much space that you will never get a reading even approaching the actual compression pressure. The testers made for model engines have a much smaller enclosed volume and are therefore much closer to reading the actual pressure developed.

Bill.

Using a compression tester on a model engine is a waste of time anyway. JUST FEEL of the compression.

Enjoy,

Jim

I know my compression is really low, I can FEEL it when I turn the flywheel. That's common sense. I am re-sleeving my engine and I just want to gauge how much compression I lose over time per gallon. Anyway I saw one for $25 but it only goes up to 30 psi and I'm not sure if that's enough for big blocks .21 and over.

Bad compression = difficult to start and poor or impossible to keep idling. After you has primed the engine then you can see in the exhaustport there are much airbubbles out of between piston and sleeve when you are turning crankshaft.

Jens Eirik

The regular compression in a "serviceable" four stroke engine is 130/160
psi. I don't really know what the normal compression in one of our glow
engines is....feeling the compression by hand, and observing how the engine
runs is how I guage the condition of the engine.

FBD.

I would highly recommend using a tire pressure gage. I digital one would be best and easiest to use. it would be very easy to make an adapter . Higley makes a tap for the threads of a glow plug. If you asked, I'm sure they would also tell you what size and thread you would need. Get the appropriate die. Thread a piece of copper or brass tubing for the adapter. I just checked the size of a tire valve stem and it is very close to the appropriate size. You might even be able to use a valve stem for an adapter.

Just my .02

For comparative tests consistency is most important and the value of the reading is kinda irrelevant for what you want to do. Try it, it may work.