When would you run a power valve plug

[plymouth,ct]

Just curious have a strip only car and thinking about running one.

[SubLime440]

I plug my Power Valves (Primary and Secondary) (Holley 850 DP) but that's my preference for Bracket Racing... Make sure you jet up about 7 sizes though... I think it just add's to consistency on each run....
As far as ET goes... I didn't see much of a change....

[PRO]

I dont ever run one,why plug the enrichment circiut? you have to jet up of course but then your over rich at low speeds a definate prob for a street car ,I think if there was power to be gained holley would incorporate it in their into their "race " carbs,like sublime said He didnt see much et change.Ive heard of several people over the years who leaned out their engines enough to melt down a few pistons because they were too lean initially,just my .02...............PRO..........

[340king]

I help a friend who runs a smallblock Duster at the strip. We have a BG carb on it that uses a plug type of setup. We are going to switch back to a power valve. The reason is that when you want to clean out the car by revving it to like 2,500 rpm, you can't clean it out because it is too rich like Pro said. Just a little sperience.

[Jims451]

I run a PV plug only on the Secondary side of the carb. The PV can't enrich the circuit if the fuel sloshes away from it in the rear fuel bowl. I also run rear jet extentions and the notched rear float.

[Leigh]

Jim, you mean on the primary side, right? I've always plugged the secondary side and jetted up 6-8 steps, but know a few racers who don't run any power valves at all. I'ts a matter of how much you are willing to tune. I see very few reasons to not run a primary valve.

[Leigh]

Jim, maybe I should have my reading comprehension tested after I log off!

[djswwg]

Power valve plugs are no good on the street and I don't like them on the drag strip either. (for all the above mentioned reasons) I think they are designed more for road or stock (oval track) racing. Dave Emanuel's book on Holley carbs mentions them briefly but is vague on application and purpose. I have 2 I'll sell REAL cheap..................djs

[Jims451]

My carb is a Holley 4150 Pro series 1,000+ CFM vacuum secondary with annular boosters which makes it a very responsive carb for it's size.
The Primary side is pretty much stock with a 4.5" Power Valve, the secondary (rear) of the carb has the blocked Power Valve, jet extentions, notched float, and the jets are about 8 sizes richer than the primary side. I drive the car on the street quite a bit, and since about the only time I get into the secondarys is at WOT, the pluged PV and rich rear jetting isn't a problem.

[bbaspense]

I used to have a problem popping power valves so I took it out. I've been driving on the street every day ( a hundred miles a week) without one with no problems. It is a little fat on the bottom but I can deal with that.

It sure beats changing power valves at the track!!!