I am close to getting my 3.0l engine back from rebuild and trying to finish some prep work such as oil and fuel. I am looking for suggestions on where to mount my fuel pressure regulator. I purchased the PMO unit and also have the SS lines from Rotary14 (member vendor). I am thinking about installing it on the rear firewall but not sure if it will be in the way and if it makes sense based on where the fuel lines feed in to the carbs. If anyone has some pics that would be great. Thanks.

Fuel lines

Stock fuel line location is fine. My PMO box was where the fuel pressure regulator was. I took it out for lack of fuel and then found it was just shut off.

I mounted mine in the old battery location and it works well, although you might have to modify your fuel lines for that location. It can go anywhere you can secure it to the car and you wont melt any fuel lines. Make sure you run a 3-5 psi fuel pump.

It looks like your car was once fitted with an AC compressor due to the cutaway on the passenger side engine shelf. You might want to close that off before reinstalling the engine for proper airflow around the engine.

I know this will sound crazy to some but with the PMO Pressure Control Unit you can use the FI pump.
The PMO unit bypass and returns to the tank much like how a FI fuel circuit works, so to use a FI pump you definitely have to use the return (to tank) line.

I knew to look for this because I've seen Mike at mikes914 do exactly this with no issues using a PMO Pressure Control Unit and an FI pump.


Below is a C&P right off the PMO site http://www.pmocarb.com/bulletins.htm

BTW the pump they suggest at the end of that quote, the Mallory 4110, is a 7psi 110gph pump.
https://www.summitracing.com/int/parts/maa-4110/overview/

Just make sure all of your hoses and fittings are rated for hi pressure before the pressure regulator if using the injection fuel pump. Which means no hose barbs and use fuel injection rubber tubing, don't want that hi pressure line to slip off or explode.

I run the CB performance 4.5 psi pump, it works great!

I would do exactly as PMO recommends. If you want the best result do what the guy that makes the carbs says to do.

yeah, but what about old school Webers guys? There are dozens of solutions on low pressure carb metering at 3 to 5..

cheers

Use a Pierburg fuel pump. It's internally regulated to the right pressure and is small enough to fit up front by the steering rack to remove it from the engine compartment.

I would do exactly as PMO recommends. If you want the best result do what the guy that makes the carbs says to do.

I agree about using FI hose between the pump and regulator, but I doubt if pressure is near as high as you suggest. I would think the pressure would only be say 4lbs, after that the fuel, thus pressure, is being bypassed and returned to the tank.
Pressure builds in a single line system because the floats are a plug, an on/off valve. In a two line system the pressure only builds to what the regulator is set at, then all the rest of the fuel is sent back to the tank. If you look at the PMO reg it obviously has a fuel return, it has 4 ports I assume in/out and one for each carb.

Also 914 stock FI (about 40lbs) uses barbs ends on the tubes with correct FI clamps, so I don't see the barbs that the OP has are an issue. On a FI 914 you only really need FI hose from the output of the pump to the regulator. Before the pump and after the regulator sees lots of flow, but it's just a low pressure system.

I highly doubt PMO would suggest using a FI pump if there was risk of it "exploding".


mmascari do you have the PMO pressure control unit instruction sheet? could you take a pic and post it?
I can't find it on the PMO site or doing a google search.

Makes sense. I just wanted to prevent him from having a beejay incident (hi-pressure line slips and catches car on fire).

Good to know on the factory FI hose barbs with correct clamps, my car never had the original fi stuff.

Hey Mark, here is the instruction sheet included. It does have the return so it restricts the flow back to the tank thus lowering pressure.

Thanks for sharing. I have this same unit, but I didn't get the instructions. So I changed my fuel pump anyways...

Pmo makes some good stuff!!

Hey Justin, let me know if you ever bring your car to a Cars and Coffee. I would like to see your conversion. I am in the midst of a conversion myself and like to see how things were done on various cars.