1974 914 1.8, the mystery of the EC-A and EC-B Options

[Van B]

@wonkipop
I remember you saying that about the sway bars before. But mine did not have them... still doesn't.

Personally, I kinda like it. Since this car isn't fast, that roll into the corners makes the drives more fun lol!

[wonkipop]

@wonkipop
I remember you saying that about the sway bars before. But mine did not have them... still doesn't.

Personally, I kinda like it. Since this car isn't fast, that roll into the corners makes the drives more fun lol!

my recollection is from the late 80s when i bought mine.
at the time i was trying to chase a 2.0 (as was everyone).
the late 80s was a time there was actually a bit of surge of interest in 914s.
turned out to be a false dawn.
but prices were rising.
and i found i did not have enough $ to manage to get a good one.

we are talking these kinds of dollars.
i found one good six in chicago. tangerine. steelies+ hubcaps. $15K from memory but maybe it was more - $23K bit fuzzy on that as i only ever found one for sale.
73-74 2.0s in very good original condition. low miles. $9-10K and some even higher.
i had about $6K in my pocket, i had just finished grad school.
i stumbled into a little porsche workshop there somewhere near lincoln park where i lived. bunch of 356s, karmann ghias and 914s were in there.
and i talked to the main guy there and asked him if he knew where there might be some good 2.0s for sale to suit my budget.
he owned a 914 and knew plenty.

he was the one with the advice to look at a 74 1.8.
said don't listen tot he nay sayers, they are good cars.
and gave me the info that most of them were speced up standard to a high level.
with roll bars, a kind of apperance group package (with a bin console, not guages) etc.

sure enough when i started concentrating on 1.8s for sale, most of them were like that.
with the roll bars etc.

in the end i found a good one just north of chicago in wisconsin.
flat bedded it to his shop and he got it on the road for me.
it had been sitting for about 5 years.

so that is where i got the info on the spec set up for most 74 1.8s from.
story from a mechanic who knew the cars and dealt with a lot of them in chicago at that time.

the sway bars really helped it when it had its original shocks fitted.
they were boges and quite soft for comfort.
so the car would have rolled a lot more without the sway bars.
now i have bilsteins and its a lot firmer.

what shocks does your car run?

[Van B]

Its got some PoS KYB on the rear and who knows what’s on the front..old and dirty. I noticed when I got it home that the right rear sags… and like a fool I planned to make a chassis overhaul my first project.

[wonkipop]

Its got some PoS KYB on the rear and who knows what’s on the front..old and dirty. I noticed when I got it home that the right rear sags… and like a fool I planned to make a chassis overhaul my first project.

i noticed that photo of your hauling rig and the car on it.

chrome bumpers. nice. you got one over me. the jaffa has black painted night curfew look. ode to the wobbling goblin?

kyb probably better than bombed out boges.

mine used to sag very slightly right rear too. i could just pick it.

springs go weak. or are unequally mounted.
fixed it all with the suspension rebuild/recommission. sits level now.
took everything apart. front and rear. rebushed etc.
did not replace original rear springs. we just set them up equally and it worked.

[StarBear]

Mine has the appearance group, sway bars and the black bumper panels (see avatar). Peppy but no barn burner for sure - not enough horsepower for that but out cornered my friend’s GTO when rat racing in an office complex off hours MANY years ago. (IMG:style_emoticons/default/biggrin.gif)

[wonkipop]

for @Van B

came across this image in obscure part of vw museum website.

AN engine in a 74 VW 412 in collection. one of their company cars.
did 185,000k. they looked after their own staff cars. engine is real clean.
same spec as 914 version. 85 hp.

only vac advance distributor. no emissions bureau in europe.
just autobahns you had to go as fast as you could on, even in a VW.

dual carb linkage looks real solid. if you have ever owned a twin carb type 3 - this is the carb linkage you were hoping for on that car but never got. (IMG:style_emoticons/default/headbang.gif)

[wonkipop]

VAPOR EMISSION CONTROL SYSTEM

update information.

the emission warranty booklets included with cars when sold new provide the data that settles questions around the update change to the arrangement of the hoses to the charcoal canister that occur in 74 model year.

1.
1973 emissions warranty.
schematic diagram shown in booklet conforms to porsche design for hose hook up from 1970 model year on and agrees with diagrams in the factory workshop manual.
canister location front trunk.
canister type = metal, then plastic.
(source for diagram page - jeff bowlsby).





2.
1974 emissions warranty.
schematic diagram conforms to porsche design for hose hook up.
canister location = front trunk.
canister type = plastic.
emissions warranty dated VIII/73 = August 1973 (commencement of 74 MY production).
of note - emissions warranty is unique in applying only to 2.0L on cover.
this confirms that for 74 MY only 2.0 L cars were produced for the USA market from Aug to late Oct 1973 - 1.8 L cars commence production from late Oct/early Nov 1973.






3.
1974 emission warranty.
schematic diagram conforms to porsche design for hose hook up.
canister location = front trunk.
canister type - plastic.
emissions warranty dated X/1973 = October 1973.
this emissions warranty applies to the first batch of 1.8 L cars that are produced from late Oct 1973 until Nov 20 1973. For a period of approx 3 weeks 1.8 L cars are produced with front trunk mounted cans.
note - cover now includes both models, 2.0L and 1.8L as per all previous MY 914 emissions warranties.






4.
1974 emissions warranty.
schematic diagram is altered and hose hook up to canister conforms to VW design for all VW USA models since 1970. fan bleed hose and air cleaner intake hose alter positions on the can.
canister location = rear wall of engine bay.
canister type = plastic.
emissions warranty dated XI 1973 = November 1973.
this emissions warranty applies to the 1.8 L cars produced after Nov 20 1973 with the canister position revised to the engine bay location.
(the emissions warranty came with a car produced late Jan 1974).






5.
1974 emissions warranty.
as per #4.
(the emissions warranty came with a 1.8L model produced in April 1974).
the XI/73 emissions warranty is used through to the end of 74 MY production covering 1.8L and 2.0L models.






6.
1975 emissions warranty.
no examples of 1975 emissions warranties were submitted by members.
data will be posted if available in future.
canister location = engine bay position 2 (battery tray mount).
canister type = plastic.
EDIT SEPT 2023 - 2 examples of 75 emissions warranty submitted.
(both from 1.8) warranty dated VII/74 (July 74 - commencement of 75 production).











schematic shows a hook up consistent with with 1974 cars post Nov 1973 using VW design.
canister position = engine bay position 2 (battery tray mount).
canister type = plastic.


7.
1976 emissions warranty.
the separate emissions warranty booklet appears to have been deleted in 1976 and the warranty incorporated into the main glovebox owners operating manual.
note - only 2.0L cars produced for 76 MY.
schematic diagram shows a hose hook up consistent with 1974 cars post Nov 20 1973 using VW design.
canister location = engine bay position 2 (battery tray mount).
canister type = plastic.





--------

Front Trunk Mount.
Plastic Cannister.

applies:
early 74 2.0L cars produced from August 73 to late Oct 73.
74 1.8L cars produced from late Oct 73 - 20 Nov 1973.
fan feed hose connected to end of canister with vapor line.
air cleaner intake feed hose connected to opposite end of canister.





Engine Bay Mount (rear firewall)
Plastic Canister.

applies:
all 1974 MY 1.8L cars produced post Nov 20 1973 to end of model year.
possibly all 2.0L cars produced post Jan 1974 when 2.0L production resumes -
this data has not been confirmed and was not part of 1.8 L-Jet research - however the emissions warranty would appear to indicate 2.0 L cars are consistent with 1.8 L cars after the change to engine bay canister location.
air cleaner intake hose connected to end of canister with vapor line.
fan feed hose connected to opposite end of canister.
of note - criss cross layout of fan feed and aircleaner intake hoses in 1.8 L cars.

EDIT - JUNE 29 2022

refer page 2 of this thread. locating date of canister location changeover.
an example has been located with a probable production date commencement of Friday Nov 16 1973. the changeover seems centred around the weekend 17/18 Nov 1973.
the cars are not necessarily chronologically arranged in terms of Vin numbers during this changeover. so some frunk can cars may have been completed after engine bay can cars. the date however would be appear to be located at the very end of week 46 and the commencement of week 47 production in 1973.







EDIT SEPT 2023.
original condition 1975 1.8 (49 states car) showing mounting of canister in battery location with correct hose connections - matching schematic in emissions warranty booklet.






this information is not intended to offer technical explanation for the operation of the vapor emissions systems.
the information is data that has been confirmed and shows the system was changed.
there have been many discussions on this forum as to how this system works.
what has not been commented on in previous discussion is that Porsche were designing the system in 1970 with provision for a major vapor load after shutdown from a twin 3 barrel carburettor engine in the 914/6 and 911. VW were designing a system for either a much smaller vapor load from a single carburettor (beetles), or in some cases a twin single barrel carb set up on some buses, but by and large an EFI system with vapor load only from the fuel tank.
After 1973 Porsche cease to sell carburettor variants of their engine in the USA.
This likely explains the update to using the VW arrangement after that time.

updated vac hose layout diagrams for 1974 L jet cars to follow at a later date.
covering EC-A/EC-B throttle body to distributor vac hose hookup variations and
vapor emission hose hook up variations.

[Van B]

@wonkipop
My car was not a frunk can. It is a rear firewall car with the OE stud and everything. I can also see, thanks to the original tank, that at no point was an evap can ever mounted there.

[wonkipop]

@wonkipop
My car was not a frunk can. It is a rear firewall car with the OE stud and everything. I can also see, thanks to the original tank, that at no point was an evap can ever mounted there.

i know @Van B .

two possibilities.
given when your car was made (dec 73).

1. cars with early engine bay cans could have got frunk can emission booklets until printed stocks of emission booklets were used up or if the emissions warranties were not withdrawn from stocks it got included with the car, or stocks of Nov edition had not arrived from printers for inclusion.

2. PO of your car replaced a missing emissions warranty with a new one and its not the one that came with the car. StarBear has done that for instance - his emissions warranty did not come with the car.

its probably #1.

given that you have a december 73 made car.
and we know there is a november edition warranty that replaced or superseded oct version. by rights your car should have come with a later nov edition warranty?
common sense says that.

we don't even really know where and when they put the warranties in the car.
did they do it at the factory and slip it in the glove box?
did they do it at the VW North America warehouses after the cars got to the USA?
did they do it at the dealer and they just had boxes of warranties to fill out and drop into the cars?

my guess would be that the warranties get included with the car close to the final point of sale. if nothing else for security.

its not hard to imagine a dealer with an out of date box of warranties not keeping up with things and you get these kinds of overlaps. esp so where there is a quick sequence of revising editions.

that would be my explanation.

what we do know is there was an Oct edition, thanks to the one you have.
and we know that there is a month worth of frunk can 1.8s that ends Nov 20 1973.
and after that there is a Nov edition and it goes to the end of 74MY and after Nov 20 there is an engine bay can and it goes to the end of 74MY.

and the two editions one month after the other track the change in the system and it accords with the change in components in the cars.

(IMG:style_emoticons/default/beerchug.gif)

[Van B]

Well, it may be inductive reasoning, but given the stack of records I have, I doubt my copy is a replacement. In other words, I am confident that when the orig owner took delivery, this was the book.

As far as the other aspects you mentioned. I’ll probably live the rest of my life not knowing the answer lol!

[wonkipop]

Well, it may be inductive reasoning, but given the stack of records I have, I doubt my copy is a replacement. In other words, I am confident that when the orig owner took delivery, this was the book.

As far as the other aspects you mentioned. I’ll probably live the rest of my life not knowing the answer lol!

thats right @Van B .
it is inductive reasoning on my part based on what evidence we have.
thats all it is. its about as close as you can get based on what we popped up.

but......we did get the evidence - more than anyone has been able to collect before-hand.

at least we are no longer dealing with previous assertions and non factory diagrams that assert the engine bay can cars had the same plumbing as earlier model year and 74 cars with frunk cans. we know something happened and we know it was changed. and i pretty much pinpointed that production date when the frunk cans change to engine bay cans. i'm 99% on that one with the examples i found that got within 8 karmann numbers of each other. so that is very reasonably reliable info. and we know the emissions warranty changes from one edition to another over that same time period.
so none of the reasoning is out of whack.

your car is in the smudgy territory in between that lasts a month or two where it becomes an administrative act in the sales chain as to how the warranties are actually included with the car.

as to why its got an oct dated edition warranty with a post Nov 20 engine bay layout i can only guess at some explanations. i tend to think its explanation 1 which is its the warranty that came with the car and because we don't know how and when warranties were included, it is open to the possibility that an older warranty is included with a newer car. i include the other explanation because thats also true 50 years on.
we have people restoring cars and seeking documents missing from the car they have restored. thats why emissions warranties are for sale on ebay. we now know as a result of this research thats a fraught exercise for a 74 MY car, because there were at least three of these warranties throughout the model year and those three different warranties apply to different variations of the car. its all tricky stuff. but at minimum the conversation has now been moved past the blanket assertion that there was one way only that the hoses were hooked up and anything else is wrong. that notion can now be refuted.

it would have been nice to have someone volunteer a 75 emissions warranty.
its pretty clear from engine bay photos of original cars that the battery tray mount cans were hooked up in a way that matched the 74 engine bay cars as well.

i think the big area of interest is for owners of 74 2.0 L models.
i'm not sure its ever been raised before but it does look extremely likely to me there is one hook up for the earlier 74 2.0L with the frunk can and another for the later 74 2.0L with the engine bay can. thats a matter for those with an interest in restoring 74 2.0L and a bit of information they need to resolve.

if you were not a member of this website we probably wouldn't even know there was an Oct edition of that warranty! we probably still would all be going around in circles.
(IMG:style_emoticons/default/beerchug.gif) at least we got to something that approaches logic and filled in the big gaps in explaining things.

in the end i am in the same position as you. i know the emissions warranty i have came with the car and i know the hoses in the layout they were in was also original. i've owned it since 89 and am the second owner. so its nice to finally know i was right about the car and those telling me the hoses were incorrectly plumbed were straight out wrong.
or suggestions that the emissions warranty was a misprint were a little off the mark.
its amazing after 50 years since the cars were made that this bit of detail seems to have slipped past people and been forgotten and lost.

[JeffBowlsby]

Wonk,

You deserve an award for this charcoal can research, it’s well documented and clearly presented.

Can’t speak for others but changing the airflow direction thru the can, especially knowing how the can is actually constructed without the long internal supply tube as depicted in the booklets basically creates a short circuit nearly eliminating the intent and actual functional efficiency of the system.

Don’t understand the factory logic for the change. What did they know that is not obvious to us? Did they not see the internal plumbing within the can? I’m inclined to keep with the early air hose routing scheme because it seems like the best technical solution.

[wonkipop]

Wonk,

You deserve an award for this charcoal can research, it’s well documented and clearly presented.

Can’t speak for others but changing the airflow direction thru the can, especially knowing how the can is actually constructed without the long internal supply tube as depicted in the booklets basically creates a short circuit nearly eliminating the intent and actual functional efficiency of the system.

Don’t understand the factory logic for the change. What did they know that is not obvious to us? Did they not see the internal plumbing within the can? I’m inclined to keep with the early air hose routing scheme because it seems like the best technical solution.

thanks mr b.

i'm not even going to attempt to explain the function of the cans.

only thing i can think of is- something to do with carbs when it comes to why porsche did it the way they did starting in 1970, using the exact same components as VW.
........don't ask me to explain why. (IMG:style_emoticons/default/confused24.gif)
i'm just a disinterested historian with an interest in my 1.8 L jet. (IMG:style_emoticons/default/smile.gif) (IMG:style_emoticons/default/beerchug.gif)

[wonkipop]

Wonk,

You deserve an award for this charcoal can research, it’s well documented and clearly presented.

Can’t speak for others but changing the airflow direction thru the can, especially knowing how the can is actually constructed without the long internal supply tube as depicted in the booklets basically creates a short circuit nearly eliminating the intent and actual functional efficiency of the system.

Don’t understand the factory logic for the change. What did they know that is not obvious to us? Did they not see the internal plumbing within the can? I’m inclined to keep with the early air hose routing scheme because it seems like the best technical solution.

somewhere in my research last year i did come across the details of the actual EPA test procedure for the evap emission system.

this is from memory but i could probably find it again.

but it went something like this.
drive the car for a prescribed period of time, it was a fairly long period of time and i think a certain number of miles were involved and it was a kind of simulation of a typical commute drive.

car then driven into special sealed room and switched off. the room contained hydrocarbon sensors. (70s primitive tech sensors?).

car left in there for prescribed period of time. something like an hour or two.

hydrocarbons detected in the atmosphere of room had to be under a certain threshold of x ppm.

pass or fail.

so the test was for the static phase of the operation of the canister system after switch off. the test was not for a dynamic phase (ie purge). manufacturers were expected to keep a fleet of test cars and monitor the system for 50,000 miles or 5 years. at the time the tests were introduced cars had not had the system installed for 5 years. so that was in the future. but if systems failed in the long term manufacturers would have been expected to replace faulty components under warranty. VW or porsches view would have been replace the canister.

i know how it works in my industry. anything required to be certified is designed to pass the test. nothing to do with the real world. ie a fire rated window that has to be certified to be 1/2 hour bushfire rated is that. if it lasts 31 minutes it passes. if it lasts 29 minutes it fails.

i think the canister is all about that. cobbling up a system, using shared universal parts, to get very different types of cars through the test.

getting a cabied 914/6 or 911 through the test would have been a nightmare? they would have exposed as much cross sectional area of charcoal as they could between the carb connected hose and the fan feed (atm vent) hose. so they plugged that carb hose line into the end of the can with the small plenum created by the spring - there is hot fuel in a carb bowl after switch off thats gassing like no tomorrow?

getting a fuel injected 914 or VW through would have been a breeze.
some fuel vapor coming down a tiny hose from the fuel tank which would have been far less heated or subject to heat after switch off. they would have positioned the open hose to atm (fan) with as much charcoal between it and tank vapor line as possible with a view to the long term life of the can as it would have walked through the EPA test. the hose to the air cleaner has the filter between it and the atmosphere to help it and to "seal" vapors in. the EFI cars just would not have been dumping in anything like the vapor load of a carb car at hot shutdown.

i think the early 4 cylinder 914s just got the system porsche tuned for the 914/6 by default? then someone at the factory woke up and said, hey we are not building 914/6s anymore and we can get the cans to last longer the other way around. one thing is for sure, VW had the penny counting overlords going over everything. they would never have missed a trick where a $ was concerned.

i think there is an element of cynicism involved? in the sense of getting through the certification process number 1 rather than necessarily operating well over 5 years.
and they were cynical.
everyone is.
thats why the EPA caught them out in 73?
and again more recently?

pollution gear is funny stuff. all about very specific govt. authority tests conducted within almost laboratory parameters.

(IMG:style_emoticons/default/beer.gif)

[wonkipop]

After all that research and thanks to all members with 74 L jets who contributed generously -

hose diagrams.
some clarity now how it went in 1974.

- all hose specs come out of the PET.
some sizes will be difficult to get these days.









additionally.
video by @Van B showing vac hose layout for 74 1.8 EC-B

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

[JeffBowlsby]

Niiiice. I see that architects hand... (IMG:style_emoticons/default/drooley.gif)

Was the EGR system an overlay to this system for the cars that had it or integrated with it?

[wonkipop]

Niiiice. I see that architects hand... (IMG:style_emoticons/default/drooley.gif)

Was the EGR system an overlay to this system for the cars that had it or integrated with it?

i did them in the style of your drawing of the 2.0 (IMG:style_emoticons/default/beerchug.gif)
a nice way to spend a wet and very cold sunday.
dusted off the drawing board. good to get away from the CAD screen.

the EGR for calif in 75 was more an integration rather than an overlay.
it used the TB of the 74 EC-B to operate the EGR vac valve and it fed the recirculated exhaust into a line that replaced the PCV valve hose with a Y branch metal tube fitting.
tells you that the EGR only operated with engine vacuum at steady state part open throttle - ie cruise. to some extent the 75 with EGR (calif) was mimicking the 74 EC-B (49 states car) with vac advance, going for fuel economy and cooler running at cruise.

the 75 EC-a 49 states was virtually identical to the 74 EC-A Calif except that the decel vavle was of a different design.

which i think explains the mystery of why VW use the upper case A in 74 and lower case in 75. it had us confused if you recall when we started this research last year. you know - how come the 49 states car in 74 was a (B) and then a (a) in 75? similarly the 74 calif is (A) and then a (b) in 75? initially we were all thinking why would they not be consistent using the A and B classification and would apply it to the state/territory the car was equipped for.

In an odd way they are consistent.
if you consider that the 74 EC-A goes on to be the 75 EC-a and its the layout that is consistent - it just happens to be it fits calif regs in 74 and then complies with 49 states in 75, to more or less the same design.

and if you squint with one eye, the 74 EC-B (49 states) kind of goes on to be the prototype of the 75 EC-b (Calif) with the vac advance timing function on distributor transformed into an EGR operated by the same TB port and with the EGR bringing the same benefits in a different way (and more expensive way) as the vac advance.

if that makes sense.
i think its the best explanation for why the A and B classification get swapped around from 74 to 75 and is altered from upper to lower case.

(IMG:style_emoticons/default/confused24.gif)

i could probably do some diagrams for 75 if there is another very cold and wet weekend this winter and i need to sit by the heater rather than drive my 914.

[StarBear]

@wonkipop @Van B At this weekend’s NE Gathering I met a fellow from Buffalo NY that travelled to South NJ. He has an early 74 with the charcoal canister in the front. It is and was a NY state car; he’s the third owner. Configured just like the blue and orange ones on page 3. Pics below.
VIN 4742908253; DOT 11/73
K chassis #4619568 (mid Nov 73, Monday)
Dual vacuum can and dual TB
Only 2 weeks before mine (VIN …2909…; chassis 483… Nov 28)
So, this really narrows down just when that changeover from front to back happened.
I didn’t think of capturing the engine tin, emissions sticker, or TB number as not a CA car.

[wonkipop]

great stuff @StarBear

looks like you guys had a good get together judging by the photos up in the thread about the gathering. am envious.
you car looked great in the photos steve.
where you responsible for the special beers?
(IMG:style_emoticons/default/beer.gif)

handy to have that K number.

so that ones a monday week 46 car (12 Nov) and definitely frunk.

the derelict one with an engine bay can in the backyard unfortunately did not have a K number. it was vin --08765. thats 512 cars after the monday car you have posted.
the monday car looks like it was 68th car for day and they were building approx 100 per day at that point so.......maths says the derelict car might have been a friday 16 Nov or Monday 19 Nov car as previous guess.

but just to throw things out.
there is the blue car which shows evidence of being a frunk car on the basis of the fuel tank. and its a later vin. ---09096. but no K #.
and member ferg's car. later vin ---09104. but no K#.
using other cars with nearby vins and known k#s these two might have been Tuesday Nov 20 cars but they could just as easily be earlier commencement build cars with later completion dates when they got their Vins.

so we got some overlap still.

i suspect you can't go off Vin #s for this change, but have to use K# to get the day and date.

what is interesting is the red car you have posted up has a K# 4619568 which is day before R. Rietman's car K#4629552, (RR's maybe 100 cars at most later = a days production?) but the red car is Vin ---08253, which is 537 after R. Rietman's car V# ---07716. !!! we can see how much the K numbers (commencement of build) are out of synch with the vin numbers (completion of build). the red car is a great bit of information for showing the degree of that out of synch-ness
so you would definitely expect there could well be what looks like a smudge or overlap if you went off Vin numbers.

you could pinpoint a date for sure with K#s.

pity there was no K# with that derelict car. or those two later frunk can cars that come after the derelict car.

its still all pointing toward the end of week 46/start of week 47. 16/19 Nov 73.
but can't get much closer than that still.

(IMG:style_emoticons/default/beerchug.gif)

[StarBear]

Yep; darn close to pinning it down, I’d say. Great minutia.
Yes with the beers. May post images of the full bottle labels later today. A blast of a time. While I didn’t win any of the oil change auction items, got a sweet pair of led headlights!