Power Valve Passage on Six Pack Base

[PurpleBeeper]

Does anyone know for sure which hole on top of a six pack center carb (#4375) is the one you drill out to install a Holley #125-500 "Power Valve Check Ball Kit"? I'm going to rebuild my carbs in the next week or two and I thought I might go ahead and do this upgrade while I'm at it. Thanks!

 

[silversedan]

http://www.jegs.com/InstallationInstructions/500/510/510-125-500.pdf

your welcome!!

the front half of the four barrel should be the same as the six pack or close to it.

 

[lewtot184]

you drill the base plate.

 

[PurpleBeeper]

Thanks Silver..... I've got that diagram..... I'm just scared that I will drill the wrong hole on a six pack. Can anyone verify the hole to drill? And yes, I should have mentioned in my original post.... what hole on the base plate?

 

[440+6]

Here is a pic of one installed, I did my center carb a few years ago.

 

[PurpleBeeper]

Thanks Silver..... I've got that diagram..... I'm just scared that I will drill the wrong hole on a six pack. Can anyone verify the hole to drill? And yes, I should have mentioned in my original post.... what hole on the base plate?

Thank You 440+6! I appreciate the confirmation.

 

[lewtot184]

if your popping power valves then there's a cause. somewhere along the line you'll need to find that.

 

[PurpleBeeper]

Hey Lewtot184.... please elaborate. What should I be looking for?

I have from time-to-time in the past wondered about my power valve. I'm adding this little Holley gizmo as a safety precaution to keep the power valves good for sure. I do run adjustable rockers and have had a "cough" or two over the years and every time it happens, I just pull the carbs and put in a new power valve "just in case" I blew it.

 

[lewtot184]

usually a "cough" thru the carb is the sign of a lean condition or the timing too late. i've looked into the blow-out check valve for the 6pak before and, if i remember correctly, i thought there might be an issue with the base plate configuration. i'll look again and re-visit that.

 

[383man]

Hey Lewtot184.... please elaborate. What should I be looking for?

I have from time-to-time in the past wondered about my power valve. I'm adding this little Holley gizmo as a safety precaution to keep the power valves good for sure. I do run adjustable rockers and have had a "cough" or two over the years and every time it happens, I just pull the carbs and put in a new power valve "just in case" I blew it.

Did you check to see if the power valve was actually blown when you pulled it out ? They dont blow out as easy as some think is why I ask. I run my car in the winter every now and then and I have had a few backfire's over the years starting it in colder weather. Not many but a few and it has never blown the power valve. And my 850 is an older one without the power valve protection. But it is still a good idea to put it in as all the newer Holley's I have worked with had it. Ron

 

[PurpleBeeper]

Thanks 383man.....well, I've never seen one of my power valves popped like a balloon, or at least if they ARE blown, they don't look like it. Maybe I've changed my power valve 5-6 times when I didn't need to (likely), but they're not too expensive and it's one of those, "Well, I've got this apart, what else should I do while I'm in there?" things, so I just change them every time I pull the carb(s) open.

And I did get a slightly different piece than I expected to fix the power valve issue. Instead of a check ball, I got a little brass restrictor (Mr. Gasket) that seems like it does the same thing as the Holley 125-500. Has anyone used this little gismo? I will probably drill my center carb baseplate to put it in this week unless somebody pipes up and tells me why not. Thanks Everyone!

 

[62MAX]

For what it's worth,direct from Holley.

 

[PurpleBeeper]

Wow 62Max... interesting read. I've got a vacuum hand pump, so I might have to check one sometime. I think I will still put in that little brass restrictor for the power valve circuit just in case.