Holley ECG5
 

So I ordered a couple of carb kits for my Holley ECG5 two barrel. It has 1 1/16" venturis. The Daytona Parts representative indicated 7.5 power valve when used as a single carb and 5.5 power valve when used as duals.
What's your recommendation of which power valve to use, it's a single carb on a mild Mercury engine.
I have found that it works best with the #57 jets that it originally came with.
For your info the carb kit is #601 ($42.00) The kit comes with 7.5 power valve.
The 5.5 power valve is #3200-55 ($8.00)
I have both power valves so can go either way. Looking for your actual real world experience, Thanks, Ted

Re: Holley ECG5
 

Re: Holley ECG5
 

It's a mild Winfield cam, 4" stroke, .030" cylinder over bore, single two barrel carb. Daytona lists only the two options for power valve. Which one would be closest to what was original in this carb?

Re: Holley ECG5
 

Do like 'Ole Ron said. Use the cam to decide (see what the manifold vacuum is at idle, then divide it in half, and use the closest power valve to that vacuum rating.) Stock was probably close to a 7.5. My Holley manual just has part numbers without the vacuum rating. With any cam that has more overlap than stock, I would bet on the 5.5 power valve. I do know Daytona is supposed to have the best quality valves (ethanol resistant).

Sal

Re: Holley ECG5
 

So, vacuum at idle is 14-15, indicating the 7.5 power valve should do it. Now to see what the modification is that Charlie NY talks about. Thanks Ron and Sal.

Re: Holley ECG5
 

Sounds like a good plan. Good luck with everything.

Sal