Converting from Fuel Injection to Carbs, Need Fuel Distrabution help Options

[Robin914-4]

Hey Everybody. I have been searching for an hour with no luck. I have a 1976 914/4 that I have converted over to 44mm Empi's. Now I am setting up the fuel system, new low pressure pump, stainless lines, presure regulator, etc. what I can't figure out is what to do with the extra line I have on the fuel tank. Should I cap it? Vent it? I did run both stainless line back to the engine bay so I could t them in or what ever. I just need some guidance.

Thanks in advance.
Robin

[sb914]

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[Bob L.]

Just cap it. It's needed as a return line for the FI.

[dangrouche]

www.914world.com/specs/SirAndyCarbFuelPumpRelay.php

here is some information for wiring of the fuel pump

[rgalla9146]

Put the pressure regulator in the return line of a loop past the carbs.
So.....tank to pump (front mount) to carb 1 to carb 2 to regulator to return.
You already did most of the work.
OR.... with a low pressure pump, feed from pump to a T between the carbs and cap the return line.

[Robin914-4]

Excellent! Thanks for the replies, I will just cap it. Yes I have already put all of the lines in so it is T-ed and ready to go. So I guess I will post a couple of pictures. I have had this car for 5 years but it sat for 3 of those because of working out of state. Now I am trying to get back on it and get it going again. This is not my first Porsche but it is my first air cooled boxer.

What have I done so far? Motor rebuild with big bore kit. Ported and polished the heads myself. 901 (I think that was the number, it's supposed to be THE distributor for a type 4 motor) distributor, electronic pick up, MSD 6A ignition box, flame thrower coil. So as soon as I get the fuel all situated and working I will get the ignition system set up and see if I can make it run for the first time in 5 years. Have done some work to the body, fiberglass front airdam, reworking ugly bumpers into the car... Then, the fun part. Making all of the rest work and look good.

Robin
1976 Porsche 914 2.0 (before the kit)
2003 Victory V92DC
1964 BSA A65
1982 Yamaha Vision 550 twin

[Robin914-4]

www.914world.com/specs/SirAndyCarbFuelPumpRelay.php

here is some information for wiring of the fuel pump

Excellent!!! I didn't think of this, I just wired the new fuel pump to the wires for the old. This help a lot when I was wondering why I wasn't getting fuel! Thank you!

[Dave_Darling]

Looks like you don't have the thermostat flaps. YOU NEED THOSE FLAPS. Your engine will run way too hot without them.

--DD

[SirAndy]

Looks like you don't have the thermostat flaps. YOU NEED THOSE FLAPS. Your engine will run way too hot without them.

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Also, using the return line is beneficial on a carbed engine. The constant fuel flow through the lines helps preventing the fuel from getting too hot.
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[PancakePorsche]

I also agree and highly recommend using pump around method so keep return line in use. Use Holley regulator made for return to tank installed after carbs, not the dead head model before carbs. Set at 3.5 PSI

[Robin914-4]

Looks like you don't have the thermostat flaps. YOU NEED THOSE FLAPS. Your engine will run way too hot without them.

--DD

Man you are good noticing those were gone. I have actually re-engineered some of the ducting to eliminate the flaps. They were in really bad shape so I have opened up the bottom and will be hand making air diverters to hopefully combat the problem. I have also thought about adding some external fans but haven't thought through that one totally.

I like the idea of using the return line. Not sure about buying a Holley regulator but I can see the benefit of constant fuel flow. Hell all of the lines are all ready in it's just a matter of adding another T and doing a little rerouting. Thanks for all the advice! It is very helpful!

R

[rhodyguy]

Get your fuel lines off of the engine! It only serves to heat the gas up. If you look at the rear verticle engine tin you can run the line to dr side with a split piece of vacuum hose wrapped around the fuel line and secure the affair with 2 line holders. For me, the linkage on the rear of the carbs was less than optimal. You need to figure out how you're going to deal with the vapors from the open tube on the oil fill tower. Your engine compartment will wind up an oily mess. Rethink your position on the cooling flaps. They are simple and do the job. A rotary pump (the filter should be prior to your pump) verified at the correct pressure, eliminates the regulator and gauge. fewer fuel line connections and clamps equals less leak potential. Especially, when in all probability it will happen over the top of the engine, while you're driving and then you can watch your car burn up.

PS one filter will do the job. Get a stock FI filter with the same size fittings on either side.

PSS I noticed in your sig you have a Vision. I had one. Fun bike but a bit futuristic for it's time.

[rgalla9146]

Your carbs are configured for flow through fuel feed.
All you need is one more nipple per carb across from the present feed.
I also agree that a regulator is unnecessary if you use a pump designed for carbs.
There is a Pierburg rotary pump available recently.
A rotary is modern, quiet, low vibration and dependable.

[Elliot Cannon]

Did you change the cam to a carb compatible one when you overhauled the engine?

[Robin914-4]

Get your fuel lines off of the engine! It only serves to heat the gas up. If you look at the rear verticle engine tin you can run the line to dr side with a split piece of vacuum hose wrapped around the fuel line and secure the affair with 2 line holders. For me, the linkage on the rear of the carbs was less than optimal. You need to figure out how you're going to deal with the vapors from the open tube on the oil fill tower. Your engine compartment will wind up an oily mess. Rethink your position on the cooling flaps. They are simple and do the job. A rotary pump (the filter should be prior to your pump) verified at the correct pressure, eliminates the regulator and gauge. fewer fuel line connections and clamps equals less leak potential. Especially, when in all probability it will happen over the top of the engine, while you're driving and then you can watch your car burn up.

PS one filter will do the job. Get a stock FI filter with the same size fittings on either side.

PSS I noticed in your sig you have a Vision. I had one. Fun bike but a bit futuristic for it's time.

Good advice. I was thinking of a different way to route the lines, I am sure I can get them off the engine. The vent will be taken care of, just not there yet. I actually have the stock EFI filter before the pump, the Empi filters were more for looks and to verify flow. Maybe I will just delete them all together. I will look into the rotary pump but I just installed a new 9psi "noisy" pump and that one sounds expensive.

I do not have the cooling flaps anymore between the two moves over the last 3 years they have been misplaced/lost. Do they really do that much? It seems to me they would decrease air flow causing more issues. I have change out the stock heavy heat soaking exhaust manifolds for headers to get that heat dispersed faster.

Heater? Going with a 12 volt one custom installed. It's south Georgia, don't need heat very often.

Oh yes, I have one of the original Victory's. Yellow and black 03 Deluxe Cruiser. I was lead chassis designer for Victory from 98-01.

[Robin914-4]

Did you change the cam to a carb compatible one when you overhauled the engine?

Ummm, this is the first I have heard of a EFI cam not working fine for a Carb motor. I looked into more performance cams to go with the jugs and pistons I put in but there was, as always, budget concerns.

[rick 918-S]

Change the cam or be sure not to toss the F.I. parts. You will regret it. Also go to the classifieds and post a WTB: ad for all the correct ducting. There have been many an engine builder (some who charge 10K+ as a starting build price and have done lots of dyno time) who have tried and failed to make a better cooling system than the Porsche engineers. You will also need the NLA T-Stat.

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[rhodyguy]

It would appear that you have 12 fuel line connection points in the engine bay alone. A tad excessive.

Carbs can be made to work with a FI grind cam.

[Dave_Darling]

It works better with the t-stat, but the cooling system will still work without it. It will take longer to warm up, of course. But leaving the flaps out sill keep the air from going the places that it is supposed to go, and your engine will not like you for it.

We have seen these engines go from "TOO DAMN HOT" to "normal operating temps" just by installing those flaps.

--DD

[SirAndy]

It works better with the t-stat, but the cooling system will still work without it. It will take longer to warm up, of course. But leaving the flaps out sill keep the air from going the places that it is supposed to go, and your engine will not like you for it.

We have seen these engines go from "TOO DAMN HOT" to "normal operating temps" just by installing those flaps.

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Without a thermostat the cooling flaps will simply sit in the "full cooling" position which is OK if you're fine with the longer warmup times.

However, running an engine without the cooling flaps will result in a quick and ugly heatstroke death.
Among other things, running without the flaps means you will have NO air going through your oil cooler.

It's a sure way to turn that engine into a boat anchor.
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