where should i be measuring the pump pressure on my new rons 1475 cfm kit with an 0 1/2 pump i saw a little bung on the underside of the grey barrell valve i could tee into this? what pressure should i get and at what rpm? thanks

If it's like my toilet barrel valve then no, it's after the spool so you only get the pressure at the nozzles so at idle it's hardly anything, only get a "true" reading at WOT. I ran a line off my pump and hooked a 0-100 lbs fuel gauge on it so I get a good idea of were I am at. It will change with differant pills and BV settings but it give me a baseline so I know if there is a big change.

Posted August 04, 2009 07:43 PM Hide Post
There is a port on the bottom of the BV Block you can use. I have 60psi in the 1/4 traps
0-1/2 pump (twin gear)
38 nozzle pills
76 pill



Paul Schultz Racing
PBIR 2008 Quick-16 Champ
1.06
4.57@152
7.20@184


this is what paul has said so can i or can,t i measure at the base of the barrel valve?

I'm sure Paul can answer that for you, but it does look like he is measureing that pressure at the finish line so the BV should be open all the way giving you true pressure even though it's below the spool valve. I'm thinking he is using a data recorder otherwise it would be hard to see the pressure at the stripe (but I dont know any of this for sure). My rons BV is black, it does have a port on the bottom, when I tapped it I would get not pressure at idle, only when it was at full throttle and the spool vavle was rotated all the way open. The only way I was able to get pump pressure from idle to WOT was tapping into my fuel pump. I'm curious to see what Paul says though, see if my BV is different or if I just missed something when I did mine.

If measuring the pressure at the port in the BV it is normal to see very little pressure at idle. That is because nearly all of the fuel is being bypassed back to the tank and very little is going to the nozzles.

You can measure either at the pump or at the BV port. The BV port will give you the actual pressure at the nozzles. At the pump will read higher than the BV usually and is the place to measure from if setting up high speeds and such.

If you are into calculations based on pressure through an oriface and how it compares to the amount of fuel flowed through the oriface then you need to measure at the BV port. IMO, it is useful to know the pressure at both locations for troubleshooting purposes.

Scott

One nice graph speaks a 1000 words!

Pressure measure at the lower tap on Purple block Same pressure as to nozzle


Here's on the pump outlet with a pressure relief valve (Enderly set for 180psi)


I have measured over 500psi when lifting on mine on the top end. Saw that and added the Enderly valve to keep it safe. When messing with this many years ago I took out two 100psi sensors before I figured out how high it was when dead headed. I think Ron's changed that in newer BV blocks, but never seen anyone with real data confirm that.......

If your Ron's Grey block is missing the 9th outlet port, just T off one of the 8 to the nozzles.

Hope this helps. Let me know if you need more.

quote:

Originally posted by adv ET 266:

I have measured over 500psi when lifting on mine on the top end. Saw that and added the Enderly valve to keep it safe. When messing with this many years ago I took out two 100psi sensors before I figured out how high it was when dead headed. I think Ron's changed that in newer BV blocks, but never seen anyone with real data confirm that.......

I have real data from a newer style block. What are you looking for?

Scott

The obvious... Pressure at the pump when you lift with no added valve to shunt fuel to the tank and cap pressure.

Well, I obviously got that data since I run a new style bv, a data recorder and a pressure sensor between the pump and BV.

I'll have to look up the actual #'s later but from memory mine spikes way less than 500psi. The new BV, when plumbed the normal way, doesn't have mods to lesson the spike though. Keep in mind that the spike is a direct result of the pump size, the size of the return pill, and the pump speed at the time the throttle is snapped closed.

Scott

This message has been edited. Last edited by: 358T,

Paul, I looked at some logs. I've seen spikes as high at 167psi. This was with a .500 gear waterman pump at 2:1 pump ratio, 88 return pill, lifting at 7500 rpms. What was your pump, pump ratio, return pill and rpm in relation to spikes?

Scott

Paul, are your graphs examples of the same pump, nozzles and return pill?

Scott