Carbs or Fuel injection ? Options

[Jack Standz]

Yes, modern FI is better compared to the 914's systems (either carbs or FI). But, we're talking about 50 year old motors that never came with the improvements in FI of the last 50 years.

Converting to such a modern sytem is expensive, time consuming & requires quite a bit of understanding. As bbrock nicely points out, carbs have their difficulties too. For some, keeping their 914 stock is the way to go, for others "stock sucks" (i.e. Dave Kindig, whose shop we recently toured at the Red Rocks Classic event).

"The VW based Type IV motor was designed with fuel injection from the start." I'm not criticizing, but, I remember our Westfalia with a VW Type IV motor coming from the factory with dual carbs. Just saying. Now the 914 Type IV motor did have a camshaft optimized for FI and was much lighter than a VW bus. However, the point is that even VW itself bolted carbs on Type IV motors. Later VW did upgrade buses to FI.

[rgolia]

I have 75k miles with FI and 75k miles with carbs on my 914. Got stranded on the side of the highway many times with FI issues, switched to carbs and it never happened again. That said the car certainly did not run as well with carbs, but it ran. If someone would have been able to fix the FI back in the early 80s I would never has switched. Now the engine is a 2056 with a carb cam and it is a blast. Of course the carb issues like gas smell, difficult starts remain. I would love to go to modern FI and I am on the wait list for a dual throttle body system.

Keep the FI if you can......and most importantly enjoy the ride. (IMG:style_emoticons/default/driving.gif)

[Mikey914]

But Carbs sound cooler. (IMG:style_emoticons/default/stirthepot.gif)

[Jack Standz]

A Fuel injected LS motor in a 914 sounds cooler. Or maybe a Ferrari motored 914? (looking forward to hearing that one)

[JamesM]

2. no altitude adjustment - I live where a day's drive can take me through a range of several thousand feet elevation. My carbs are adjusted at 6,000 ft. but when I go over high mountain passes, the engine gets wimpy, and I worry about running too lean if I go too low. I honestly don't know how D-Jet compares as I never drove my car at altitude when I was running it, but the megasquirt I plan will have real time barometric adjustment.

D-jet used on 914s has altitude correction built in as a function of the MPS. It works very well.

On more than one Colorado mountain pass my D-jet 1.7 has zipped by carb conversion guys stalled out on the side of the road.

[930cabman]

A Fuel injected LS motor in a 914 sounds cooler. Or maybe a Ferrari motored 914? (looking forward to hearing that one)

Great idea, I have an extra F 355 (5 valve/cyl) engine collecting dust. (IMG:style_emoticons/default/piratenanner.gif)

[Rand]

It is a dumb argument that baffles me that it is still going on.

[Rand]

is it kids still asking this?

[wonkipop]

its (IMG:style_emoticons/default/biggrin.gif) how the circle turns.

back in 89 when i bought my humble 74 L jet 1.8 most folks i ran into in the USA thought the L jet was rubbish and i should tear it off. D jet was superior etc.

anyway i kept it because i bought it for the L jet. call me a nerd. (IMG:style_emoticons/default/biggrin.gif) (IMG:style_emoticons/default/biggrin.gif)

these days down here in aus, i probably have the only fully original intact L jet on the road. i've never run across another one in the flesh. though nihil44 up in brisbane has the set up but i am not sure if its original or he has pieced it back together from other sources. there are still a few d jet 914s on the road down here - but generally most of them seem to have been converted along the way to dual carbs.

funnily enough i now get a little bit of respect from mechanics who look at the car.
they often come up to me in the street to ask about the car and then i find out talking to them they are mechanics or retired mechanics. once i open the engine lid they are in there looking it over. their interest is purely for the historical curiousity i guess of the first L jet system on a car.
kind of like looking over a model T ford or something? (IMG:style_emoticons/default/smile.gif)

but boy some of these parts have now entered the realm of long gone and it will be a shame if i have to start departing from the original condition of things.
wouldn't make as much sense to be keeping it then. the point from where i stand is to preserve it as a bit of technological archeology.

i don't think there is anything wrong with converting to carbs. if you have to you have to.

[930cabman]

It is a dumb argument that baffles me that it is still going on.

Why dumb? I might like my hair spiked, is that also dumb?

Run your 914 with water power if that floats your boat.

I like carbs and always will, but am considering a stock FI system for my next build. Back in the '70's and 80's I had several VW L jet, D jet and CIS systems and enjoyed them all, but they were not 1/2 century old

[bbrock]

George mentioned this earlier but even 50 year old engines benefit from better fuel management offered by FI. Running rich or lean is not good for an engine no matter what vintage.

As for cost. New webers are not cheap. Add a cam and you are approaching parts cost for a simple Microsquirt install. I made an assessment of the condition of my D-Jet parts and did a rough estimate of what it would cost to refurbish them all. It was comparable to buying parts for a tricked out Megasquirt install.

As for complexity, I think it is subjective which is more complicated. FI makes a lot more sense to me than the Rube Goldberg contraptions called carbs.

I get that there are reasons to install or keep carbs. I've been there. But I think with all the options and info available, FI will be the better choice 90% of the time for a stockish engine.

[lesorubcheek]

On the topic of fuel injection, my son ran across the Bendix Electrojector during some of his automotive searching. Amazing stuff! Searching here, looks like it has been discussed already, but thought worth mentioning in case anyone missed it. The Bendix Electrojector looks like the first attempt at electronic fuel injection. A failed attempt in the late 50s on a few AMC and Chrysler cars, its patents were purchased by Bosch and evolved into the D-Jetronic system! I never would have believed it.

Dan

[burton73]

https://www.youtube.com/watch?v=fBK_CoVb1MI





Sold the new 46 PMOs and went with this by PMB Performance

Bob b

[wonkipop]

On the topic of fuel injection, my son ran across the Bendix Electrojector during some of his automotive searching. Amazing stuff! Searching here, looks like it has been discussed already, but thought worth mentioning in case anyone missed it. The Bendix Electrojector looks like the first attempt at electronic fuel injection. A failed attempt in the late 50s on a few AMC and Chrysler cars, its patents were purchased by Bosch and evolved into the D-Jetronic system! I never would have believed it.

Dan

(IMG:style_emoticons/default/beerchug.gif)

d jet - born in the USA.
i think chicago to be precise?

it did not exactly fail, the bendix system. it just kind of faltered.

and from stumbling well....the idea could basically plug into the tail end of the whole post world war 2 marshall plan type idea.
the germans were like the japanese and just folded into the american vision of the world and were on the look out. and not on the look out for the european vision of the world that had really screwed things up in the first half of the 20th C.

those germans just plain dedicated themselves to sorting out the transistors or diodes,
whatever it was that could not take the engine bay heat. thats pretty much all they did to make the bendix system work.

but L jet is their work of genius. thats where the krauts went....."there has to be a better way". and its typically german. reduced. minimalist and modernist.
just like kraftwerk music. and thats around the same time!!!
L jet is to cars what mies van der rohe was to architecture. and what car got L jet first (or a close second to be more accurate)?

.........and mies ended up in chicago!

i love the USA. must get back there before i kick the bucket. (IMG:style_emoticons/default/beerchug.gif) (IMG:style_emoticons/default/beer.gif)

bendix electrojet is kind of like a reverse moon shot technological exchange?

[mlindner]

On the topic of fuel injection, my son ran across the Bendix Electrojector during some of his automotive searching. Amazing stuff! Searching here, looks like it has been discussed already, but thought worth mentioning in case anyone missed it. The Bendix Electrojector looks like the first attempt at electronic fuel injection. A failed attempt in the late 50s on a few AMC and Chrysler cars, its patents were purchased by Bosch and evolved into the D-Jetronic system! I never would have believed it.

Dan

(IMG:style_emoticons/default/beerchug.gif)

d jet - born in the USA.
i think chicago to be precise?

it did not exactly fail, the bendix system. it just kind of faltered.

and from stumbling well....the idea could basically plug into the tail end of the whole post world war 2 marshall plan type idea.
the germans were like the japanese and just folded into the american vision of the world and were on the look out. and not on the look out for the european vision of the world that had really screwed things up in the first half of the 20th C.

those germans just plain dedicated themselves to sorting out the transistors or diodes,
whatever it was that could not take the engine bay heat. thats pretty much all they did to make the bendix system work.

but L jet is their work of genius. thats where the krauts went....."there has to be a better way". and its typically german. reduced. minimalist and modernist.
just like kraftwerk music. and thats around the same time!!!
L jet is to cars what mies van der rohe was to architecture. and what car got L jet first (or a close second to be more accurate)?

.........and mies ended up in chicago!

i love the USA. must get back there before i kick the bucket. (IMG:style_emoticons/default/beerchug.gif) (IMG:style_emoticons/default/beer.gif)

bendix electrojet is kind of like a reverse moon shot technological exchange?

Wonkipop, thanks for that great information. Mark

[sithot]

I'll do whatever I can to keep the FI on mine going.


OTOH, for those of you with a real 6 or 6 conversions running Weber carbs, the full radius trumpets in the link really work.
I learned of them from Paul Abbott @ Performance Oriented. Paul is a guru on Webers. He recommended these to Ed Mayo (PCA Ed Mayo) to deal with a running/tuning issue.
He built a pair of 42mm for me. They're on a "warmed over" 2.7.
https://www.dellorto.co.uk/shop/car-accesso...mm-x-50mm-long/



Paul's work in progress:


Completed:





The car now running a Clewett Engineering crank fire ignition. No further distributor rebuilds. The car had one done by "the best" before I owned it. It's a museum piece now.
These coils can fire a fat mixture and the car which was already strong is more so now. Timing is spot on 100% of the time.
It starts easier too.

[930cabman]

I'll do whatever I can to keep the FI on mine going.


OTOH, for those of you with a real 6 or 6 conversions running Weber carbs, the full radius trumpets in the link really work.
I learned of them from Paul Abbott @ Performance Oriented. Paul is a guru on Webers. He recommended these to Ed Mayo (PCA Ed Mayo) to deal with a running/tuning issue.
He built a pair of 42mm for me. They're on a "warmed over" 2.7.
https://www.dellorto.co.uk/shop/car-accesso...mm-x-50mm-long/


I'll bet she rocks it out
Paul's work in progress:


Completed:





The car now running a Clewett Engineering crank fire ignition. No further distributor rebuilds. The car had one done by "the best" before I owned it. It's a museum piece now.
These coils can fire a fat mixture and the car which was already strong is more so now. Timing is spot on 100% of the time.
It starts easier too.