Posted: Sun Nov 30, 2008 1:49 pmI want to put together a guide or list to help anyone looking to try wetflow testing. This is based on a draw through system.
1) The settleing box to capture the liquid. Not that difficult but something that has to be designed for your bench. If there is enough interest, a PTS wetbox plan can be done to compliment the PTS bench.
2) Clear cylinder. Acrilic tube found at McMaster Carr in 12" lengths. Can also be machined to get an exact bore size. I didnt do mine so I cant tell you how. Bruce helped me out on that one. Once machined, fine grit sandpaper and a buffing wheel in a drill press will get the cylinder about 90% to perfect. Enough to still see everything. I tried the heat trick and it started to warp the tube. Stick with the buffing and you will be fine.
3) Wax the cylinder. Helps keeping the fluid from attaching to it and forming more of a puddle on the tube wall. After about 10 tests, you can do it again to keep up on it. The droplets are easier to see on the wall and the drop size stays for longer.
4) Distilled water. I've done tests with tap well water and the distilled is a little better. The pattern is the same but droplet sizes seem to be slightly different.
5) Don't use dish soap to try to reduce surface tention. It will foam up screwing with the results. I only use the water.
6) Simple food coloring dye.
7) White Dykem for the visual contrast with dark colored water. The Dykem spray goes on thick. You may have to experiment with spray nozzles to get a finer spray. The stuff goes on thick and runs to low spots. You don't want that. Take your time, get a thin even coat and be sure it is not on the seats. Will mess with the results.
I don't think we can produce enough black light to mimick the professionals. But for DIY'ers, there is alot to learn without going that route.
9) Fluid delivery. A 1/16 tube with a .0025 hole at the end of the side of the tube. Close the open end and seal. The hole size can vary but the smallest you can get is better and the amounts can be still added through that small hole.
This is what you can do...
A) A simple water bottle to start. Epoxy two tubes into the cap, brass. One tube just below the cap, one tube down to the bottom of the bottle. The short tube is your high pressure side, the other the low. Fill the bottle. Hook the low side with some hose to the end of your 1/16 tube and leave the high side open to air. The little hole faces down the port and draws fluid in. You can also hook a hose to the high side and stick it in your mouth while making a test run. Just blow into the tube and you will introduce more fluid into the port. This is good if there is a position away from the port you put the probe or when testing at lower lifts where there is slower speeds in the port.
B) Same bottle setup but with the high pressure side hooked to the exhaust pressure from the bench or an air compressor. Use a cheap air valve or regulator to adjust the pressurization of the bottle. This setup can also be used when using a perimeter injection device found at the port entrance.
I'll give more info when I compile some things about the effects of the amounts of fluid used. It really dont change the pattern. Plus some other things.
Chris.
1) The settleing box to capture the liquid. Not that difficult but something that has to be designed for your bench. If there is enough interest, a PTS wetbox plan can be done to compliment the PTS bench.
2) Clear cylinder. Acrilic tube found at McMaster Carr in 12" lengths. Can also be machined to get an exact bore size. I didnt do mine so I cant tell you how. Bruce helped me out on that one. Once machined, fine grit sandpaper and a buffing wheel in a drill press will get the cylinder about 90% to perfect. Enough to still see everything. I tried the heat trick and it started to warp the tube. Stick with the buffing and you will be fine.
3) Wax the cylinder. Helps keeping the fluid from attaching to it and forming more of a puddle on the tube wall. After about 10 tests, you can do it again to keep up on it. The droplets are easier to see on the wall and the drop size stays for longer.
4) Distilled water. I've done tests with tap well water and the distilled is a little better. The pattern is the same but droplet sizes seem to be slightly different.
5) Don't use dish soap to try to reduce surface tention. It will foam up screwing with the results. I only use the water.
6) Simple food coloring dye.
7) White Dykem for the visual contrast with dark colored water. The Dykem spray goes on thick. You may have to experiment with spray nozzles to get a finer spray. The stuff goes on thick and runs to low spots. You don't want that. Take your time, get a thin even coat and be sure it is not on the seats. Will mess with the results.
I don't think we can produce enough black light to mimick the professionals. But for DIY'ers, there is alot to learn without going that route.9) Fluid delivery. A 1/16 tube with a .0025 hole at the end of the side of the tube. Close the open end and seal. The hole size can vary but the smallest you can get is better and the amounts can be still added through that small hole.
This is what you can do...
A) A simple water bottle to start. Epoxy two tubes into the cap, brass. One tube just below the cap, one tube down to the bottom of the bottle. The short tube is your high pressure side, the other the low. Fill the bottle. Hook the low side with some hose to the end of your 1/16 tube and leave the high side open to air. The little hole faces down the port and draws fluid in. You can also hook a hose to the high side and stick it in your mouth while making a test run. Just blow into the tube and you will introduce more fluid into the port. This is good if there is a position away from the port you put the probe or when testing at lower lifts where there is slower speeds in the port.
B) Same bottle setup but with the high pressure side hooked to the exhaust pressure from the bench or an air compressor. Use a cheap air valve or regulator to adjust the pressurization of the bottle. This setup can also be used when using a perimeter injection device found at the port entrance.
I'll give more info when I compile some things about the effects of the amounts of fluid used. It really dont change the pattern. Plus some other things.
Chris.