Large diameter fuel line + Stock pump

When running a larger diameter fuel line (8.0mm) in combination with a stock mechanical pump, will there be any negative effects on fuel pressure?

From the tank to the pump, no.
From the pump to the carb? Possibly (but I've only ever used 5-6mm, so don't know).

For such a short pipe run to the carb I doubt it's notice unless you're running bigger carbs but then again for bigger carbs most upgrade to an electric pump for higher flow rates.

psimitar wrote:For such a short pipe run to the carb I doubt it's notice unless you're running bigger carbs but then again for bigger carbs most upgrade to an electric pump for higher flow rates.

Yep for dual carbs. Will come out the pump on stock line and then flare up to 8.0mm before a pressure regulator (acting as t-piece) and then split off to each carb. Stock diameter line will be limited to short sections to and from pump, rest will be 8.0mm. Hoping to maximise volume from stock pump.

Want to stick with a stock pump for reliability/ease rather than elec.

Stock pump can keep up with single venturi twin carbs like the ICT but I'm not sure for bigger twin venturi twin carb set ups.

A stock pump can keep a pair of IDAs fed.
They usually put out too much rather than not enough.

^^^^^ X 2, the stock fuel delivery system has no problem feeding twin carbs, there are plenty of 12sec IDA cars running stock

Joel wrote:They usually put out too much rather than not enough.

That is what I am banking on, hence running a fuel reg to keep a check on pressure at higher RPM. Just hoping to get enough volume through......... this is not a race motor so do not think there should be a problem.