Is there a way I can test a engine to verify it is a 347, without tearing it down. I know its based on bore and stroke, but how can I measure the stroke?
that only works if the spark plug is perpendicular to the surface of the piston.
Here's a thought: fabricate your own tool.
1. Get the hose from a compression tester that screws into the spark plug hole.
2. Get a big syringe, or just use a balloon or bag that you can make air-tight to the end of the hose
3. remove the rockers from the valves on the cylinder you're testing and rotate to BDC
4. plug in your fabricated tool
5. Rotate to TDC
6. Measure the air that is pushed through the spark plug hole. A 347 should have 347/8 = 43.375 c.i. of air or 710.79 c.c. or mL (1cc=1mL)
I couldn't find any syringes big enough so I started looking for other ways to measure the volume of the air.
I'm not sure how accurate this is, but this is supposedly how to calculate the volume of a balloon: How to Measure Air Volume | eHow.com
Also, since the balloon actually pressurizes the air a big, I don't know how much that will throw off calculations.
Alternately, you could make another tool from a bottle that's at least 1L, preferrably glass, and a 50mL syringe or a Measuring cup with pretty accurate markings:
1. fill the bottle 50 or 100mL at a time with your syringe or measuring cup, and mark the bottle's water level
continue to do this until you can measure the water level up to 800mL
2. fill your bottle with water
3. Fill your sink with water
4. turn the bottle upside down and ensure that it is held in place above the water level in the sink
5. empty the air you trapped into the bottle and use the measurements you made to determine how much air you have. To avoid placing pressure or vacuum on the air in the bottle, raise or lower the bottle so that that water level in the bottle is at the water level in the sink
for reference:
302 = 618.6cc or mL per cylinder
331 = 678cc or mL
347 = 710.8 cc or mL
Yes, exactly. First, trap the air in a bag, balloon or whatever using the first tool, then empty the air into an inverted bottle that you've marked and see how much water is displaced.