Tractorsport Flowbench Forum Archive

Posted: **Wed Nov 23, 2005 9:54 pm**

Re: MSD/Mercdog Style Bench

For those of you who have already finished your benches and logged some actual testing time, I have a question about the approximate operating range of the intake valve or bowl.

I'm using a bowl like the MSD article suggests and wonder how far the bowl typically moves out (in inches) from the seated position to being open enough to achieve maximum testing pressure? Is it 2" or 4" or x, or roughly the distance equal to the depth of the bowl?

One reason for asking is that I don't want any more of the threaded rod sticking out of the front of the cabinet than necessary. The other reason is I don't want to over pressure the vertical manometer on start up if thats possible to do.

Just wondering

Thanks.

Dom

Posted: **Wed Nov 23, 2005 11:25 pm**

Dom,

That's an excellent question. You've definitely been thinking about this whole process.

It depends on a couple of things such as:

The particular piece you are flow testing.
The range you have selected.
The number of motors you have turned on.
The strength your motors.

I think you'll find that you will be able to eventually trim down the threaded rods to aproximately 3" [possibly less] if your motors are strong and you're testing at 28". WAIT UNTIL you have verified before you cut them though. It's really dependent upon the size of our largest orifice.

To get the feel for it, I would suggest selecting a middle range. Open the Intake Control Valve a couple of turns from the seated position. Turn on 1 motor and get the feel for the bench. Then close the control valve and turn on another motor...then open the valve slowly.

For me..it was always the test pressure manometer that would get over pressurized.

You'll soon get a feel for it.

Larry

Posted: **Tue Nov 29, 2005 12:31 am**

I was thinking that you could use a valve window calculation to figure out how much air flow valve opening you need. I found this link to a spreadsheedt on speedtalk.com:

To read the entire thread, go to this link:

The same info may be on Larry's spreadsheet, too. I can't check it as I am at home now, and don't have excel on this computer

Tractorsport Flowbench Forum Archive

Amoun t Of Air Valve Travel During Intake Testing?