Barrel Valve Leak Down

7/9/10, 11:38 AM

We just finished a new motor and purchased a used hilborn injection for it. After some work of trying to fire it we found the barrel valve was way off. Finally we got the hole lined up off center and she fired. We took it to practice the next day and it will fire and idle, but on the gas under load it just bogs down. We went home and looked at our other motor and the barrel valve on it opens the opposite way. Is the valve not clearanced equal to open right or left? So, now we have swapped the direction to match our good running motor and we were going to leak it down to see what % it was at and just match the new motor to it. During leak down at 100 psi the barrel valve will not give a reading on the 2nd gauge. Is it possible at idle it could lose all 100 psi. The lines are not capped only the return line off the barrel valve is capped. Am I doing this correctly? I appreciate your help.

TQ29m · 7/9/10, 2:42 PM

Best google Hilborn, they have most of the basic stuff on their website, how to locate the rotor in the metering valve, and they'll answer all your questions for free, on the phone, or email. When in doubt, go to the source, and yes, it is possible to lose 100% thru the metering valve, if the rotor is installed wrong. Bob

dant · 7/9/10, 2:44 PM

'During leak down at 100 psi the barrel valve will not give a reading on the 2nd gauge. ' I'm confused.When you set the at 100psi on the first gauge-with out conecting to the barrel valve ..the second gauge should read 100 psi. then when you conect the tester to the fuel inlet line on the barrel valve-what does it read?0-100 psi, it can't 'not give a reading'....to answer your other ?..a barrel valve rotates one way-you expose a portion of a hole to set the valve at idle but when the arm link is turned the proper way it exposes a ramp that widens as it coninues to rotate -allowing more fuel to be feed as the throttle opens....someone may have assembled the barrel valve wrong or put the linkage on backwards......

TQ29m · 7/9/10, 2:52 PM

If it's rotating the right way, and installed correctly, anything over about 20 degrees of rotation, should be full open on the ramp, and you'll need to disconnect the hoses to the nozzles, and seat the butterflys on a .002 narrow piece of feeler stock to set the idle portion, probably 18-28% to start with. Bob

jdperform · 7/9/10, 6:30 PM

look at the top of the bv housing. There is a wide side and a short side the spool works off of the short side. With all fittings removed from housing look down through the top hole. You should see your s-valve hole. And as you open the throttle the hole will disapper and the ramp will start to appear. If you have it in backwards or working off of the wide side leak down will actually go down as you rotate the throttle. Leak should be a smooth transition from idle setting to wot. Not up then down.

Hurryinhoosier · 7/9/10, 8:27 PM

Im going to throw this out there.....

100 psi on the first gauge will show 0-100 psi on the second...depending on where the regulator on the leakdown gauge is set. So it is possible for it to show 0 if its screwed down.

7/9/10, 2:42 PM	#2 Re: Barrel Valve Leak Down
TQ29m Senior Member Join Date: Aug 2008 Posts: 6,598	Best google Hilborn, they have most of the basic stuff on their website, how to locate the rotor in the metering valve, and they'll answer all your questions for free, on the phone, or email. When in doubt, go to the source, and yes, it is possible to lose 100% thru the metering valve, if the rotor is installed wrong. Bob __________________ "Being old, isn't half as much fun, as getting there"! Ole Robert I!

7/9/10, 2:52 PM	#4 Re: Barrel Valve Leak Down
TQ29m Senior Member Join Date: Aug 2008 Posts: 6,598	If it's rotating the right way, and installed correctly, anything over about 20 degrees of rotation, should be full open on the ramp, and you'll need to disconnect the hoses to the nozzles, and seat the butterflys on a .002 narrow piece of feeler stock to set the idle portion, probably 18-28% to start with. Bob __________________ "Being old, isn't half as much fun, as getting there"! Ole Robert I!

7/9/10, 11:38 AM	#1 Barrel Valve Leak Down
dirt4life Posts: n/a	We just finished a new motor and purchased a used hilborn injection for it. After some work of trying to fire it we found the barrel valve was way off. Finally we got the hole lined up off center and she fired. We took it to practice the next day and it will fire and idle, but on the gas under load it just bogs down. We went home and looked at our other motor and the barrel valve on it opens the opposite way. Is the valve not clearanced equal to open right or left? So, now we have swapped the direction to match our good running motor and we were going to leak it down to see what % it was at and just match the new motor to it. During leak down at 100 psi the barrel valve will not give a reading on the 2nd gauge. Is it possible at idle it could lose all 100 psi. The lines are not capped only the return line off the barrel valve is capped. Am I doing this correctly? I appreciate your help.

7/9/10, 2:44 PM	#3 Re: Barrel Valve Leak Down
dant Member Join Date: Apr 2008 Posts: 191	'During leak down at 100 psi the barrel valve will not give a reading on the 2nd gauge. ' I'm confused.When you set the at 100psi on the first gauge-with out conecting to the barrel valve ..the second gauge should read 100 psi. then when you conect the tester to the fuel inlet line on the barrel valve-what does it read?0-100 psi, it can't 'not give a reading'....to answer your other ?..a barrel valve rotates one way-you expose a portion of a hole to set the valve at idle but when the arm link is turned the proper way it exposes a ramp that widens as it coninues to rotate -allowing more fuel to be feed as the throttle opens....someone may have assembled the barrel valve wrong or put the linkage on backwards......

7/9/10, 6:30 PM	#5 Re: Barrel Valve Leak Down
jdperform Member Join Date: Apr 2008 Posts: 60	look at the top of the bv housing. There is a wide side and a short side the spool works off of the short side. With all fittings removed from housing look down through the top hole. You should see your s-valve hole. And as you open the throttle the hole will disapper and the ramp will start to appear. If you have it in backwards or working off of the wide side leak down will actually go down as you rotate the throttle. Leak should be a smooth transition from idle setting to wot. Not up then down.

7/9/10, 8:27 PM	#6 Re: Barrel Valve Leak Down
Hurryinhoosier Member Join Date: Jul 2007 Posts: 172	Im going to throw this out there..... 100 psi on the first gauge will show 0-100 psi on the second...depending on where the regulator on the leakdown gauge is set. So it is possible for it to show 0 if its screwed down.