PTS Flowbench Forum

Hi guys,

I'll give you a little background. My name is Josh, I live in central North Carolina, USA. I own a small scooter repair and tuning shop that I run out of a very small garage on my property. I hope to someday expand and build a larger shop, and hire a couple of people to work with me, but for now, I'm in the small shop. I've been a bit of a lurker lately, and I'm interested in building my own flow bench, like so many others here. You guys have a really nice forum! I'm glad to have access to the resource.

In the past year, I have started using data acquisition for tuning projects. The DAQ includes the AIM Mychron 4 datalogger, and a DynoJet 150 dynamometer equipped with Performance Trend's DataMite hardware and software. I also have a Technoresearch Centurion-M scan tool, which is really neat but I have only used it a couple of times so far. I feel like a flow bench added to the equipment that I already have would compliment my shop nicely, and be a vital step to taking my tuning to the next level.

Anyway, my friend happened to have this new but old-stock ring compressor kicking around, and he (as well as I!) would like to see it put to good use. Before I start really sorting out plans, I was hoping to get the advice from some of the guys here who have "been there, done that".

Here is the pump:




You can see a sectioned cylinder head in the above photo. Most of the work I would be doing is going to be small-engine valves that are 1.010" and smaller. The head pictured above is a 50cc, with valves that are not much bigger than a half of an inch... I'd like to experiment with flowing 2-stroke engines as well, but I feel that due to the nature of 2-strokes, it's probably a whole separate topic to get going on that. I have no idea what kind of CFM I'm going to need. I was hoping that this pump/vacuum could get me started though, as it's available for peanuts.



I realize just by the size of the fittings on the pump that I won't be able to flow things like air filters, and larger manifolds at 28", but I was thinking this could be an easy way for me to get started. The plan, would be to get a 1 to 3 phase VFD to control the motor. I assume that I could easily use the VFD to get the appropriate test pressure and record my flow rate from there.

Any advice, or comments are most certainly welcome!

Kind Regards,

~Josh

it looks like your opening is threaded so I would screw in a piece of threaded tubing/pipe and totally block the vacuum source and have a pressure gauge installed there so you can see just how hard that little guy sucks. You may find that if you have a shop vacuum around you may want to use that at first on the little heads you have. I can suck 12" h2o through a fairly good small blcok chevy with 2 shop vacuums.

John

Somewhere on the old tractorsport forum archive there is some testing I did with a rather large Ring Compressor and it would not create a lot of depression. It was about the same as a dust collector blower. I'll have to look when I get a chance but it was around 2-3hp and had over an 1-1/2" to 2" input/output

It's been sitting under my lathe now for more than a few years and is in the plan to be used on a small porting bench for the vacuum source.

Thanks guys! It sounds like I should write this one off for flowbench use after reading what Bruce had to say. It would have been convenient to build with what I have on-hand. Oh well.

John - I considered the shop vac idea. In fact, for my small engines, I may be able to use these bucket vacs from Lowes. I use one in the shop pretty regularly. For $20 a pop, I could rob the new motors out of them and just use 4 motors and build it up on the cheap. I'm still in the "research" phase of my build (and likely will be for a while). I will be sure to share my project as it gets off the ground.

Best,

~Josh

Bruce - I like the idea of a nice quiet porting vac! I might have to borrow that idea.

~Josh

go down to your nearest vacuum repair shop and you should be able to get some full working motors for around 10$ or under.

I know you are only interested in flowing very small engines, but I think that ring compressor may be too small for even that.
Ring compressors also develop a most piercing characteristic whine that will drive you nuts if running the bench for any length of time.

My suggestion would be to use one, or maybe two decent vacuum cleaner motors which would be well up to the job.

If you've been lurking you have probably seen the posts about the very inexpensive vacuum motors that Surplus Center currently has. A couple of those should do you & won't be much more than the used ones mentioned.

Bambi4010 wrote:If you've been lurking you have probably seen the posts about the very inexpensive vacuum motors that Surplus Center currently has. A couple of those should do you & won't be much more than the used ones mentioned.

Thanks for the info Bambi! I guess I haven't been lurking quite good enough, because I didn't know about them until you mentioned it.
http://www.surpluscenter.com/item.asp?Item=16-1446 - Would that be the one?

Best,

~Josh

If you have 220v available this one gives a little more flow.

http://www.surpluscenter.com/item.asp?i ... 7&catname=

Note the flow numbers at about 44 inches of water. 56 cfm @ 59" vs 38 cfm @ 57"