Triple Weber Carbs - Pump, Filter & Pressure Regulator advice?

[Dave McDonald]

Thanks to everyone who has contributed to my deliberations.

Any more for any more??

Dave

[roy53]

Well Dave you have a lot of info coming in.

Re the pump position, i have red tops and in the 250 it is vertical above the tank level [ await flack ]  but in the 2 it is flat on the floor base of the tank and has been for 25 years and both cars work well. Why would you need a pre filter as the pump is fitted with a changeable filter ?

Location could also be in the vertical where the filter was fitted .

Yes a regulator is needed

Roy

[DavidBee]

Just a thought, Mike.

Unlike the Malpassi Filtre King, the Sytech regulator has one big shortcoming; you can't fine tune between, say, 2 and 2.5, or 2.5 and 3 psi. And yet such finer tuned adjustment might make all the difference.

[Andy Moltu]

Should you really need to be able to regulate the pressure to such precision?

The flow is determined by the float valve opening. You need sufficient pressure to provide sufficient flow at maximum demand, but without exceeding the operating pressure of the valve. If the carb is drawing fuel at a faster rate the float falls a little further opening the valve further to allow more fuel to enter.

[DavidBee]

19 hours ago, Andy Moltu said:

Should you really need to be able to regulate the pressure to such precision?

All I can say, Andy, without for a moment disagreeing with you about the float, is that a .5 change made the difference between popping and detonating all the time to doing it only within a certain rpm range. Other problems lurking, but this is what happened.

David

[ntc]

On 8/20/2021 at 10:13 PM, DavidBee said:

Just a thought, Mike.

Unlike the Malpassi Filtre King, the Sytech regulator has one big shortcoming; you can't fine tune between, say, 2 and 2.5, or 2.5 and 3 psi. And yet such finer tuned adjustment might make all the difference.

Not so my Sytech you can adjust in .5 increments 

[DavidBee]

36 minutes ago, ntc said:

Not so my Sytech you can adjust in .5 increments 

Yes, you are correct.

What I wrote was rubbish. 

I used my Sytech too.

The only point worth adding is that the Malpassi King allows finer adjustments than our Sytech, when connected to a gauge (the right size; I bought one, assuming the thread size was  a standard size, but  I was WRONG again! It's too small).