Newbie Questions.

[FlyNLoRacing17]

Hello everyone. My name is Dale and I live in Moulton, AL. I found this forum through Google. I am building a flowbench using the "Car Craft" design. I have a few questions regarding this. First of all, this bench is for my own personal use, so really, getting exact numbers doesn't matter. Basically just getting the flow difference between unported and fully ported heads that I will be working on. I've got the design down pretty good but the pages from Car Craft that I have are kinda fuzzy. The U-tube manometer is no problem, but building the inclined manometer is a problem. Basically I have no idea where to start. Also on the exhaust tubing that connects the plenum box to the vacuum box, the pictures I have are pretty much unreadable. So if anyone has some insight into this type of bench please help out. Here is a link to the Car Craft type bench. I got this link off of Performance Forums. The Car Craft bench is the "Article 3"


Thanks for any help you can give me.

[bruce]

[FlyNLoRacing17]

Thank you for the quick reply. I will look more into the search.
THANX!!

[Tony]

Welcome to the Forum Dale.

Bruce is right, the very best way to begin your project is to spend many hours reading through some of the previous threads here. Everything you could possibly ever want to know is buried in here somewhere, but it may take time to dig through it all, but it will be time well spent.

[FlyNLoRacing17]

Thanks Tony, I believe I have found most everything I'm going to need for now. I still have to find/figure-out the scale for the inclined manometer. This forum is very informative, when I first started thinking about this project I figured I wouldn't be able to find much information on it, but I was wrong!! Thanx!!

[86rocco]

[Scott]

Rocco, You're just like the parts guys of yesteryear....." I need a set of points for a smallblock chevy" he just walks over to the shelf and hands a set to you......Nowadays, the geeks look all bewildered, an tell you they cant get them unless you have the year and model of the car...then they dick around for 20 minutes in a book that only goes back to 84'

All hail the guy who knows where the stuff is!

[larrycavan]

Dale,

Welcome to the forum! I know you mentioned that you're not concerned with accuracy of your bench but I think that's likely to change as you progress through the project and especially once you start using it. Either way, there are a couple of things that you should take notice of.

1. Forget the flow rates in the MSD bench article and use the spreadsheet to calculate single hole orifice ranges.

2. It takes more engineering than what's indicated in the article to prevent your disk from leaking during exhaust testing.

3. Even if your don't get all caught up in calibration accuracy, you will want a leak proof flowdisk.

Good Luck
Larry C

[Tony]

Dale, the inclined manometer uses a very simple inverse square law scale which is fairly easy to make yourself. The actual scale can be made any length that is convenient for you, and exactly the same scale will work on any flowbench or on any flow range.

The trick is to adjust the slope to suit the pressure drop of the measurement orifice at maximum rated (100%) flow.

If your particular orifice develops a certain pressure drop, it will force the water up the inclined manometer to that height. Only the height matters, and you can change that by adjusting the height of the high end. The actual length of the sloping manometer tube and it's scale does not matter.