[venturesomerite]

I have a Holley 650 Street Carb with vacuum secondary and electric choke. I have suspected that my engine should be a little stronger than it is, although it is essentially a stock motor. I just always felt like it had more in it. I suspect that my secondaries are either not opening fast enough, or full enough, if not both. Does anyone have any experience with this carb, and can maybe point me in the correct dirrection? Holley makes a 7 spring change kit I was thinking of buying to change them out and see if it helps.


This is a picture of the paper clip test. I'm not sure of far it should open, but this was a run around hitting WOT a few times.

Thanks, Brian

 

[Nova_Guy]

From what I remember on a Vac sec Holley the rear barrels can open only as far as the front barrels do. If when you floor the car the front barrels only open 1/2 the rear barrels can only open the same amount. There is a linkage that limits the rear barrels opening to the same as the front.

 

[6NOVA4]

research on the holley website or buy a book on holley carbs so you understand how vacuum secondaries work(assuming you don't...sorry)
Then you can change the vac pod springs to tailor when you want the secondaries to open. In all my vac sec carbs I used the yellow spring and remove the check ball.

 

[MarkW]

You should think about putting a quick change cover on your vacuum secondary housing. The diaphragm is easily torn and the kit lets you change springs very easily. Here is a complete kit I found...http://store.summitracing.com/partd...925239+4294839063+4294736832+115&autoview=sku

 

[venturesomerite]

Seems to be worth the extra 10 bucks.