building an orfice bench? search the past topics

[bowtie482]

if you are building a bench from scratch. make sure that you go through the forum. search all info that you can think of. the search has a designation at the bottom that will allow u to search "from the begining" this info is so valueable it shouldnt be free. as a beginner bencher i am only starting to find the info. also if you starting to build a new bench there are some excellent ideas on the fourm and very informative articles that some intelligent people have posted. there are many ideas and some very refined ideas as well. the type of bench is your decision. i bought some plans from merdog and also had the msd plans and found that neither of them have the basic info that is need to operate and calibrate the orifice style bench. if i built my bench again i would purchase plans from bruce or i would search endless topics and build one from the info. i probably wouldnt build the msd style bench. also the info on the manometer scales is very good info. it covers the scientific end of the operation and there are also spreadsheets that will make sure you have the right amount of rise for your fluid type and test pressure. i will try to post a picture of my bench. so if youre planning on building a bench use the honor system. "if your on her say on her if your not on her get on her." thanks for the info on this great site it has made a dream come true for me. the info here has helped me understand some of the basic things that i didnt know about the bench and also the operation of this machine

[bowtie482]

picture of the bench

[bowtie482]

i have an idea for the orfice disc in the msd style bench. i will make some plans and post them. first one is. the orfice disc can seal fairly well in the mercdog msd plan, but what if i sandwiched the disc between 2 pieces of material such as 3/4 in particle or mdf. i would router the diameter plus .125 for some variations in material and craftsmanship. and then router the amount of the thickness of the disc plus enough room to rotate the disc. i think this would allow the disc to be easily movable and yet allow the disc to still seal in either a vac or blow configuration. now for plan 2. i have seen some info on a baffle above the original hole on the msd style bench. i am gonna throw this idea out there. could i make a plate that fit above the orfice disk and under the feed hole that rotated with the disc that kept the air from going directly from the test piece to the orfice disc. i will post some drawings and see what we come up with.

[bowtie482]

having some trouble uploading my drawing. i will try tommorrow

[bruce]

[Tony]

The merdog plans were a huge step forward at the time for home flow bench construction, simply because that is all there was available.
It opened up air flow testing to the average guy to do in his own garage that most ordinary car nuts could afford.

But the original plans have a few well known problems, and ways around them. We have now come a very long way since those early days.

There is a VAST pool of knowledge stored away in many of the threads here on this Forum. It is all here somewhere, but it will take a lot of searching, and a lot of reading to get a complete education on Flow Bench design, use, and construction. But it is well worth the effort.

For anyone just starting out at this, the very best thing you can do is purchase Bruce's plans. They take the very best ideas, and the latest thinking, and it is all there laid out for you, for only fifty bucks.

Reading all the info on the Forum is still well worth the trouble, but having a set of plans means you will get it right first time without having to go back and start changing things around to solve problems.

[bruce]

Did you use plywood? I like the wood finish.

[bowtie482]

i built the bench out of oak veneer particle board that also has a melamine backer on the inside so it is completely sealed other than the joints. on the joints i used a product called "through the roof" which is designed to seal anything that goes through the roof. it is a product that i use alot on door and window installs. easy to use and also its clear and dries fairly fast. only drawback is that it only cleans up with solvent. so if you use it be careful to only get it where you want it. if you have some excess you can razor blade it off after drying. the rest of the bench i stained and sealed with polyurethane satin clear. i am in the process of building the cylinder head adapters, valve opening fixture and also the intake and exhaust plates. the exhaust tubes will be a few different sizes and shapes. i am certainly looking forward to logging in some hours on using the machine.

[Half-Inch Stud]

My Bench design is "Modular", like a Hi-Fi stereo, any part of it can get updated:

Manometer: 83" dynamic range stand-up. <-- done ($23, "ACE is the Place")

Valve Holder & Dial-caliper bracket. <-- designed, not done.

Portable Bench ( 34" x 7.3" X 7.3"). <-- designed, 4.21" bore done. :blues:
Vacuum source(s): Low-lift=House Vac. & High-Lift = Leaf Blower. (yea, we'll see how much water these can pull, upgrades expected.)

CFM hole standards: gonna go with 100,200,300. Designed, Fab=BUY.

Overlap Flow eval: Exhaust Header flange with home vac attachment for each port. Designed, not done.