RC Flow Bench

[Mike Rappold]

The following is a few photos of a mini orifice type flow bench I built for checking engine parts on radio controlled 2 stroke engines. The engine I built this for has a dsiplacement of 0.67 cu inch.

I am still working at getting then bench up and running. Seveal questions have been posted in the Orfice bench forum.

I am using a shop vacuum with home made valve assembly to control the vacuum. The orifice plates are made out of 22 guage steel. i am using water to get the bench going but may later switch to light oil. In addition I have a hand held digital manometer I came across several years ago. I have been using this to "check" values as well.

To change the orifce, the side of the bench comes off.

Any comments and suggestions for improvement welcome.

Mike

[Mike Rappold]

Manometers - top is for test pressure and bottom for differential across orifice plate

[Mike Rappold]

Overpressure wells - one for each manometer

[Mike Rappold]

The side of the bench comes off to access the orifice plate

[Mike Rappold]

Inside of bench. Orifice plate in center with baffles on both side. The orifice plate is made from 22 guage steel.

[larrycavan]

Bench looks good. How much airflow improvements are we talking on something that small [motor that is]

[slracer]

Nice looking bench, Mike! It's a detail that may not need doing with your small flow requirement, but a big lip radius on your suction tube would help the flow.

Does the motor being worked on go into the Miss Budweiser in the background? What scale is the "toy"?

Do you "play" with the big boats too?

Doug

[blaktopr]

I used pvc pipe for my wells also. I put a cleanout on top to make it easy to fill with water. Bottom is glued, and for the threads, I used teflon joint paste. It seals 100%. I can't tell what you did with yours to fill, but if both sides get glued after fillup, it's hard to refil after a problem. Nice job so far.

Chris.

[Mike Rappold]

Thanks for the replies back about the bench.

To answer some of your questions;

I really do not know what kind of improvements are possible. Thus the project of building the bench to find out. I do not expect anything major. The main area I was planning on experiementing on was the inlet bell to the carb to start. I have several that are straight tubes and others that out more of a bell mouth. In the end it may not pan out with any noticable improvements but I will have learned alot and know more about what I do have.

The boats in the backgroud are 1/8th scale hydroplanes. They will do about 50-60 mph. I also run an outrigger hydro, which is faster - 70-76 mph.

Yes I am involved with full size boats as well. Not the Unlimited hydros but rather 1/4 mile drag boats. I help on a top fuel hydro.

With regards to the wells, attached is a picture. Sorry not the best. The PVC pipes are mounted to small boards that attach to the back piece. The back piece is slotted so I can move the wells up/down. The wells are held to the moutnign board with nylon ties. There is enough play in the ties that I can move them up/down to fine tune the zero point on the water scale.
The wells have a hose nipple on the bottom to connect to the scales. On the top I have 1/4 NPT plug to fill them. On the "top" well (test pressure), the vent hole to atmosphere is under one of the black nylon straps. It was not supposed to be but I had a brain fade when drilling it one night and put it in the wrong spot.

Mike

[bruce]

Nice simple design!

[blaktopr]

Oh, I see now with the pic of the other set, not to mention, I just caught the 2 scales on slight angles from what was discussed earlier. Nice. The "not the best" is wrong to say considering the application of the science to the cheapest of materials and works just as well as big dollar stuff.

Chris.