Sorry for re-asking this, but as I begin fiddling with mechanical and electrical components for my project 6 conversion, I am still pondering this decision.

The car, when finished, will be shipped to Europe where my wife and I can use it when we're there, and do some rallies, trips and such. There will likely be (months-long) periods of no use.

Have most of the necessary stuff for the build, (included with the '71E motor-entire MFI, fuel filter/console, complete electrical board, fuel pump, etc) all from 'donor' car...

But I'm beginning to sense that the complexity of MFI (transducers, fuel system, micro-switches, etc.) could prove challenging. A good set of PMO's on the other hand: basic fuel pump and regulator, MSD 6AL, and a spray can of ether may be better suited, again given the intended use.

So, I welcome thoughts and opinions-thanks

MFI is amazing tech for that era. However, hard to fix by the side of the road or in some little European town out of the way.

I’d opt for carbs.

Agreed.
I went with new webers on my 6. For the simplicity.
Old carbs, no thanks. Tough to get everything happy and reliable.

I 100% agree; you can always swap out to MFI when you get the car back home.

Add in a fuel shutoff (look at the 356) so when you park it, turn off the fuel and let the car run till it dies.
This empties the carbs of fuel and gives you a better chance to keep the carbs clean in between each use.

I’m in 100% agreement on carbs .
You can fix them, and get parts, pretty much everywhere.
MFI will get you a lot of puzzled looks.

I’m thinking a lot like you, and building something similar to send abroad…..

Rich

You should consider an aftermarket EFI setup.


Modern, reliable easy to start, better gas mileage...


Jenvy makes Throttle bodies with all the EFI parts built in. Just add the ECU.

I am guessing the newer EFI systems will cost $5k for all the parts needed. The price should come down in a while, or go up. Who knows these days.

You can use fogging oil in the carbs for better storage. Fuel shut off is a good idea too. I use that on my lawn mower and works well.

bossboy302. Living in Wisconsin, time on the road is less than six months and then a big nap each year. I love the PMO's, installed a inline fuse for the fuel shut off and MSD. Nice simple setup that I understand. Best, MarkClick to view attachment Click to view attachment

Mfi once set up requires very little attention. If you are building a factory engine spec that used MFI then all the standard settings apply. If you deviate from factory specs with different cams, compression port sizes etc then there is a fair amount of custom tuning required whether you are using MFI or carbs.
On of the other issues with MFI is that 914 has no provision for hot air to the MFI thermostat from hear exchagers. On a 911 there is a hose off the heat exchanger to the thermostat housing on the MFI. With out this provision the car will not run right when warm, if permanently set at hot position the car will not start when cold. There are mechanical cable aftermarket systems to operate the cold start enrichment as a option. So many things to consider (carbs are a pain to tune correctly for many different reasons) on induction system.

john

Not 100% true. The majority of 914-6 heat exchangers don't have a provision for the MFI heater, However, there were heat exchangers that Porsche had built for the 916 program with the MFI heater connection. Those got put into the spare parts channel when the 916 program was cancelled. I know this is a fact. I have a set of them I used on my 2.4L 911S MFI motor.

On my carbed '74 914-4 I have a switch to the electric fuel pump. I just shut off the fuel pump and let the fuel bowls go down before turning off the engine. The Webers have a tendency to boil over if shut down after a good run on a hot day. If well hidden, the fuel pump switch also could help if someone tries to steal the car (with carbs) - it will start go a bit and then die leaving them stuck and perplexed. Not an anti-theft guarantee but everything helps.

Fuel injection can be very reliable. I love getting into my 73 turning the key and having it fire up right away. Less cranking before starting compared to the carbs. The thought of fixing the FI scares me if it ever fails.

IF there is ever a problem it will be more difficult to fix FI stuck in the middle of nowhere. Carbs are simple mechanical, FI uses electrons and it is hard to see what the electrons are doing at the side of the road after lifting the hood.

A lot of young mechanics don't know what to do if they can't find an OBD II port to see which part needs to be replaced.

Modern EFI that looks like carbs.

https://pmbperformance.com/products/jenvey-...058a5&_ss=r

We didn't forget about the -4 guys:

https://pmbperformance.com/products/jenvey-...058a5&_ss=r

EFI is nice and all but that wasn’t what OP asked about. Then there is that little issue of Tuning EFI.

I have yet to see any “auto tune” actually do what it implies. Awaiting the day. It’s getting closer but not there yet.

Still won’t have OBD with aftermarket EFI. You could actually end up in a worse situation traveling in Europe without a laptop should something go wrong. So average repair shop will be of zero help without the laptop to connect to EFI.

Let’s just say for a moment that the MS or whatever ECU takes a . What them? Try to import one to Europe overnight? I suppose someone in Europe may have them? You see where this is going? Open to be corrected - just thinking out loud.

OK, OK... Carbs to the OP?

ECU is Holley. Holley is "Self Learning" which is why we're moving all of our builds to those. In stock. Takes a crap about as often as a Motronic unit from a 3.2 Carrera or a 3.6??

If we all thought out loud like that we'd be whipping horses still.

Modern EFI is a quantum jump forward from carbs. I understand keeping it original. But carbs were only available on a Euro 1.8L, and MFI, other than a select few prototypes, was not available on a 914 at all. And there are less people out there these days that know MFI. There are lots of people who know programmable EFI. And with a laptop and an internet connection, the builder can troubleshoot it from anywhere in the world.

EFI is the future, at least for as long as we have internal combustion engines. I could hang a pair of PMO carbs on my 4.0L engine, but it won't make as much horsepower, and it definitely won't run as well as the Motronic I have, much less the MS3Pro I am going to use.

Why do you think the OEM builders don't use carbs anymore? Because they are as outdated as buggy whips.

I get it - I like EFI too but come on - Holly availability in Europe ?

You guys are missing the point of OPs question - not meant to rehash the carb vs EFI debate.

Honestly, it does bring up an interesting reality.
First, I would rule out MFI due to lack of skilled people fixing it abroad.

Carbs or EFI….seems like a toss up that might depend upon the region.
Seems to be a lot less skills with carbs now, and us old farts have to keep helping newbies.

I’m planning to build and ship a car also and I’m going to use EFI, once I have done plenty of research. I will also carry spares.

My vote goes to Webers.

I’m in the same camp today,,, until I learn more.
At the end of the day, what can realistically go wrong with carbs?
Not much.

I’m still focused on his use case.
Going abroad for a year, hoping shit does not break.

I’m lucky enough to have EFI, MFI and carb expert friends near me. I have carbs but am on the fence on EFI entry cost. I should have pulled the trigger 7 years ago when prices were lower.

OP: I’m sure I can ask my MFI guru who you can talk with in NorCal if you need an MFI tech.

Having a fuel pump cutoff is a great idea. I have a petcock on my 356 but often forget to run them dry and kick myself as I have to ungunk the jets and bowls

I’ll be in touch Eric

I’m in the other camp. If you have all the Mfi stuff and your engine configuration is stock and you have someone that can test and set it up properly you’ll never need to touch it. It can sit for extended periods of time without needing to be rebuilt like a carb. But- you need to replace all the old stuff including things like the cold start injectors etc. IF you have some one that can bring it up to “as new” standards it’s the best.

The cold start injection system can by used with a simple push button so that eliminates one electrical component. The microswitch system is not necessary. I have had mine disconnected the only difference is that it saves fuel on deceleration- so that’s another simplification. Then basically you have the thermostat, altitude compensator (an advantage over carbs) and those are both mechanical systems which are very well documented online.

So- if you have the right person to set it up- someone that has done it many times and you can afford the initial cost of pump rebuilds etc go for the better system.

Pete

https://www.youtube.com/watch?v=tP1PPjOJLgY


Dead stock carbs. Well maintained. Driven regularly.

Stuck float. Hydrolocked. Face full of gas.



I am considering these for Elwood. https://store.jenvey.co.uk/throttle-body-ki...ottle-body-42mm

Hide everything under the air cleaner. It would look stock and run way better. And it will be fully reversible and I will keep the stock carbs and fuel pump in case the next owner wants to go back to them.

Though unfortunate - it was fixed with no special tools, no EFI expertise with a cobbled aftermarket EFI, or parts that could be hard to obtain in a pinch.

Sort of makes the case why carbs might be a good option for the OP’s purpose.

I’ve got a carb sitting outside on a 1948 Case tractor. 75 years old and still working. Starts in below zero weather with nothing more than a pull of the hand choke.

Again, I love EFI . . . But carbs have been around for more than 100 years and they work without ECU’s, laptops to tune or diagnose, or external electronic sensing that can bring other failure modes.

Let’s not forget that on a modern car, a failed crank sensor leaves you walking with no hope of a roadside fix. Does it happen? Not often… but it does happen. I’ve seen the warranty data at two different OEMs so I know that it happens, and how unhappy customers are when it happens. There is no denying that EFI occasionally fails, just as there is no denying that your carb float stuck.

It’s about about tradeoffs that only the OP can make. Hopefully, the varied points of view and the lively debate are appreciated.

For the Jenvey carbs, is that price per, or for a pair? Ouch, that is pricey and I may have to upgrade my original estimate on price, a lot. Add a controller and all the other bits and bobs you need, it becomes very expensive. I do understand the allure of EFI though, especially after a face full of petrol.

There is a lot to be said for the simplicity of carbs. I actually fixed the float on the six with some "percussive maintenance" using a rubber mallet.

In Europe, like it is here in the states, carbs are obsolete. So the availability of parts is limited. However the only specialty part on any aftermarket EFI system would be the ECU. Aftermarket EFI uses sensors and actuators from current production cars. So I would argue that the availability of parts for EFI is better than carbs. And with a notebook computer or even a phone you can access the system and it will, for the most part, tell you what failed.

So I think your argument about parts being "hard to obtain in a pinch" is not true. I can walk into a FLAPS, and get a replacement for a failed injector, a TPS or a MAP sensor, because they are all sourced from production cars. All that is needed is a record of the part numbers for the sensors and actuators installed on the car.

Another advantage to EFI is that professional help with anything on the system is only a Webex meeting away. In today's connected world, the guy that built your EFI system can remote into your computer/phone and help to fix any issues with the EFI. Having an expert available to help, even remotely, is invaluable.

The Jenvy throttle bodies are designed to look like carbs. Most throttle bodies are way cheaper, but they don't look like carbs.

PMO throttle bodies are blatantly throttle bodies and do nothing to hide it. They are probably better throttle bodies than the Jenvey ones. What you are paying for with the Jenvey ones is the stealth factor.

O P here-first, thank you all for contributing great thoughts, experience, and opinions...

Second, hope thread doesn't end here-this a worthy discussion for sure...

Yes, intended use is Europe, hope car provides us with (trouble free-ish) use. Destination travel, a few tours and rallies. Plan to be semi-perm residents for 3 to 5 years, sell car there when done. Not too fussy about originality on this one...

To the car:

I found a very complete 2.2E with all the auxiliaries. I like it, looks cool, CAN work well. I was thinking there might be quite a few experienced MFI techs in Europe, what with diesel trucks and Mercedes....but those days may be far astern...

Webers are cool. Had a few '67S cars that never let me down (one was a daily driver when younger). Most experience with these.

The new EFI setups look/perform well and seem reliable. The newer tech may be less familiar to some for a while. Maybe the most set and forget option.

If someone had gun to my head this morning-Weber or PMO...for the moment

I look forward to more discussion...

Brian

I don’t know what languages the OP speaks or where he will travel. Having lived in a small town in Southern Italy for a couple years and not being fluent in Italian, I can only say that it won’t be quite that simple.

Ah, but that is the beauty of an interconnected world. You don't need someone local to you to help with the troubleshooting. You can get on a Webex/Zoom meeting with the guy in the US that installed and tuned the EFI system. He can remote in and help you with the troubleshooting. Then using Google translate, you can type in your parts needs in English, and be able to show them the Italian translation to get the correct parts.

From experience in Paris, communications is always an issue. But the internet is becoming the universal translator that Star Trek showed us.

Then there’s the real world. 6-8 hour time zone difference (Europe is ahead of US). Hope that OP only needs help during US business hours.

Then there is the issue of getting parts at a small town autoricambi. If you can get anything quicker than domani or dopodomani more power to ya’.

With carbs - more often than not - all the parts are right there - just need to clean a jet or maybe percussive maintenance (I love that! ) and you’re back on the road same day.

We (Americans) tend to think that we are the center of the universe but in reality, the rest of the world just goes on its merry way and has its own cultural nuances. There isn’t a NAPA in every small European town. Their definition of ASAP often differs from what we are used to.

Agreed, but there is more wine involved while waiting...so its not really a bad thing.

I will say, I learned on new term here.
Percussive Maintenance...classic.
Rich

That term comes from my IT background.

if the mfi is matched (T E and S are all different) and it is rebuilt, there is no comparison between it and carbs, and the mfi exhaust note is superb. However mfi is now old and with 4% CO and bit polluting. PMO carbs are new and as good as it gets for six cylinder Porsche carburation

Another thing to consider is the location where the car will be registered. I am not 100% sure, but I think an MOT in the UK requires that all the emissions components are functioning. The rest of the EU is probably the same, as they have some strict emissions laws.

I don't know which side that will come down on, but if this is a conversion from a four with fuel injection, it may not be legal to run carbs on it.

France: https://www.france.fr/en/holiday-prep/crit-...vehicle-sticker

Germany: https://www.germanemissionssticker.com/

UK: https://www.gov.uk/emissions-testing


I would suggest doing some detailed research on this before making a decision on which fuel system to use.

Great point!
So with permission, I'll start a new thread on relocating/registering a older US car in the EU. I have already been in contact with several members here who are contemplating a similar car shipment. I have some done some research and it could stir up some more...

Somewhere here is an old thread of a couple who shipped a 911 to Europe and toured for quite a while.
He did all sorts of research on registration and insurance.

Rivh

Register stateside and get an EU Carnet to bring into Europe temporarily assuming it will return. There are companies that can assist. Used to have them done for EU development and test trips.

If not returning stateside after the tour I have no idea of the implications.

@ClayPerrine
@bossboy320
Good point about emissions standards in the EU especially if planning extended stays.


What about altitude? Many major mountain passes and routes at fairly high elevations that you don't want to miss. Cold start at 8-9k feet Always nerve racking to drive when carbs aren't running their best.

If fuel cost a factor, FI more efficient too.

As I'm just getting to the engine running, break in stage and pmo tuning, I'm already seriously considering the next step to modern FI. It's a pretty compelling option considering all the advantages. Not as cool looking but...super drivable. Click to view attachment

MFI has altitude adjustment...

Just sayin.
Pete

Several pluses here, including sweet and reasonably simple to work on

Yea, MFI has altitude adjustment... and a FANTASTIC sound. But it runs quite rich most of the time, and you get terrible gas mileage. You are lucky to get 16 MPG out of it. And a cold start with MFI is a bitch. If you use the built in cold start system, you risk a fire in the stacks if the engine backfires, and that happens a lot when cold. And it will be 20 minutes of warmup before you can go anywhere. Early in the morning, it will be rather annoying to anyone else trying to sleep in hearing your car warmup.

Honestly, I LOVE MFI! It runs great at full throttle and sounds fantastic. I would put it on a race motor in a heartbeat. But from experience, I would rather live with EFI for a daily driver, and that is what we are talking about here.

We sell both the PMO and the Jenvey. Both are of the same quality. Jenvey is top notch.

Also the Jenvey will fit common IDF/IDA air cleaners, run standard IDF/IDA linkage, fit IDF/IDA manifolds, has PICO fuel injectors included, had TPS (throttle position sensor) included, has fuel rails included. We went down this road with Borla as an example... once you got all of the other parts, the price shot up there and, custom air filter bases had to be fabricated.

Price adjusted yesterday to meet current exchange rate.

ALSOOOO... here's a lower cost set if you already have the manifolds and linkage:

https://pmbperformance.com/products/jenvey-...-ida3-42mm-pair

Those heritage Jenveys are

Eric, have you done this under a factory airbox/filter housing yet? Already have crank-fire ignition, so this is pretty interesting.

Not yet Pete. Bob's was the early Sport air filters. These will bolt right up under a stock box though. Mine will probably be the first for that fitment. Putting together a system for Larry S. as well, just triple checking components. You'll still need a custom harness, ECU, Wide Band, etc. With the Holley, it will control the ignition and do it "extremely" well... something else to consider. Welcome to 2023.

OP asks A or B

Answer - you need C - and D, E, and F to make it work

Tons of information on MFI and EFI on the Pelican 911 Forum.

Ooooooooooooooops! Thread police!

^ Thanks, man. Looks like what I've been looking for is finally a thing…or nearly is.

To the thread police: Fwiw, I'm one who has considered MFI in the past (was priced out and went with carbs) and still thinks about MFI and EFI. So this thread is seriously interesting to me, and I learned something new that I had missed elsewhere.

For the OP: The most fun I've ever had in a 914 was a six with a 2.2S with MFI and short gears. The noises with that belt-driven mini six-cylinder on top of a flat six, the throttle response, the…well, everything. Just brilliant…until I started pricing an MFI build and tune. I ended up with Webers, which as others point out are far from bad (especially now that they're set up nicely) but I still want to get my car back to fuel injection.

MFI's cost and disadvantages mean that'll probably be with EFI. The Jenveys are seriously appealing to me because they may offer a chance do what carbs and MFI do under a factory air box. Thanks to all for the info!

Thread police here It’s all in good fun! I’ll let you off with a warning this time.

For anyone considering individual throttle bodies (ITBs) do your homework on the EFI tuning trade offs and drive ability issues with ITBs like PMO, Jenvy, and others. Don’t get sucked into the whole myth of self tuning - auto tuning thing. It isn’t there yet. Especially with ITBs that have a poor manifold vacuum signal.

Having said that, I’ll be doing ITBs eventually when I finally get around to taking care of induction for the 2.4L. Currently watching Bens conversion of Weber’s to ITBs on his 2.4L