no its just you
starting rumors again that have been proven the other way around
why don't you put a single carb on your bug and find out.

its not fun to give bad advice you can't back.... (and then people have to repeat their work and expense) As you did with some of your conversion (motor mount)

Well, mine is tweaked the best it can be and, although it runs well, it is still cold natured as heck (in an area that isn't very cold) and sucks gas at a rate that isn't acceptable. Could I drive it forever this way? Sure. Would I like it to be better? Yes. How much do I want to spend? Not sure, but I"d sure like to know how I could do the Solex 40s if they can get high mpg.

tell your story...

you have nothing.


I watched the video of the single carbed car.
Sounded great. It was very smooth.
Nice running car.


KT

I have a single carbed car too. And I could have some great videos of it. BUT, let it get 40 degrees and rainy and things change, EVEN with my heat riser set up. It still runs, but it might as well be a 1972 Buick LeSabre for all the fuel efficiency it has. But, 80 degrees with low humidity and it might run great. . or vapor lock (I know, that's a fuel pump location issue which will be fixed upon the rebodying of hte car)

Has anybody tried two Holley/Weber progressive 2 barrels on a T4?

I think they'd mount on the single barrel Solex type intake manifolds with the standards bug adapters ...

Probably get decent mpg if you keep your foot out of it ... and when the secondaries did open ...

Any of the duel carb singles will work for you. Try The Samba, I've seen 34's and 40's both get great MPG. The car that Nonverbal is looking at has 38's as spares but I've not seen any 38's as of yet. I do know that if the carbs are in good working order that they will work for you. I have also seen a car set up with duel Weber progressive carbs and it worked well too.

Sorry Trek, but unless you've tried to tune the same car, before with one carb and then after with two, you don't actually know that it's running well with a single. You can't know. A single carb will run "fine" and you can be perfectly happy with it, until you know what the same engine is like with duals, then you realize it wasn't running all that well before. You need to try it, really, to see the before and after. The exception is single carbs with heat risers, not that common and still not as tunable as duals.

So if you have a single carb and like it, super! Bonus is you also have something to look forward to.

Let me clarify.

I would not seek out a single carb set-up on any vehicle.
If someone has one and is trying to get by, we should help them make the best of it and get to enjoying the 914.

Telling someone to put the fuel injection back on or spend $500-800 on a set of carbs isn't always helpful or practical.


KT

Excuse my lack of knowledge here, but why are the 38's so foreign?

Even from what I've read, the 44's don't seem all that common.

This thread has actually presente a whole slew of questions, but I'm probably getting ahead of myself asking them all before I've actually bucked up for the car. I'm going to try and find somebody to come have a look at with me...

That makes perfect sense, Trek, but it's not the same as what you were saying before about "putting the single carb myth to rest" or whatever. The "myth" I see regularly is someone pulling the fuel injection to put on a single carb, fully expecting all the wonderful sports car things you get from carburetors (plural).

You can get a set of used T1 Kadrons (Solexes) for $100-150 if you just look a bit, plus some T4 manifolds. Then if needed the rebuild kits are about $30 a pair, and worst case another $60 if they're worn out and you need to re-bush the shafts. Or a complete used Weber setup for $300-400, so it isn't that large a hurdle. Better than removing fuel injection for a single-carb setup, anyway.

Solexes definitely aren't Webers or Dellortos, but for the bucks they aren't bad. I've never gotten that kind of gas mileage from them, but I imagine you could if you didn't drive like an idiot.

Cool, nothing like a little empirical data. Just found before and after dyno charts comparing a stock 1600 T1 dual port engine running a stock single throat carb, then with a set of dual single-throat Kadrons (Solexes) installed. Here, horsepower:



And torque:



Page notes (http://kaddieshack.com/1600dynoresults.html) say:

Stock 1600cc Engine Dyno Results:
Best Horsepower Gain: 20HP @ 5000 RPM
Best Horsepower Percentage Gain: 50% @ 5000 RPM
Peak-to-Peak Horsepower Gain: 13HP
Peak-to-Peak Horsepower Percentage Gain: 26%

Engine tests performed with same stock, used, running dual-port 1600cc engine with stock exhaust and stock 34PICT carburetor, then after installation of dual Kaddie Shack carburetors with EMPI single Quiet Pack Exhaust, then again after installation of dual Kadron carburetors with Quiet Pack and 1.4:1 ratio rockers.


No, it isn't apples to apples because it isn't a T4 engine, it's just a before and after comparison of stock single carburetor (34mm) with dual Kadrons and a freer flowing exhaust. Since it isn't a T4 engine and isn't a two-barrel carb, it isn't definitive, is only indicative.

That seems like an interesting thought. Any other input?

Here, Trek, a better explanation. The examples are V8's, but the theory is the same. This is from my youth, a ridiculous Chrysler "cross ram" manifold:



Looks cool as hell, doesn't it? The carbs were out over the valve covers. They have the same long unheated runners a single carb T4 or T1 engine has, were awful around town, wouldn't idle, trailed a cloud of unburnt gas, but they produced excellent horsepower at high RPM's. A vintage drag racers dream.

Compare that with a single-throat per cylinder manifold like used for Webers on Cobra V8's, this design, an isolated runner manifold like for Weber IDFs:



That photo is of fuel injection of course, just for illustration (because I like it), but the discussion is intake design. There's a chart here (http://victorylibrary.com/mopar/intake-tech-c.htm) that compares the characteristics of each manifold type. For the crossram (T4 single carb type) mainfold the throttle response and idle quality are the wort of all the different manifold types. For the isolated runner (Weber type) those two things are the best. Each type had excellent power and top-end (high RPM) performance.

Type: Crossram (T4 Single Carb type)

Throttle Response/Idle Quality: --- Worst
Mixture Distribution: ----------------- Worst
Mixture Velocity: ---------------------- Excellent
Max Power Potential ----------------- Excellent

Type: Isolated Runner (dual Weber type)

Throttle Response/Idle Quality ------ Best
Mixture Distribution -------------------- Best
Mixture Velocity ------------------------- Excellent
Max Power Potential ------------------- Excellent

Sorry to be long-winded, but I've heard this discussion go on for too many years with a lot of bad advice being given. I don't ever want to speak badly of the setup anyone already has on their car, but if you're going to be making decisions about what to do, what's best compared to what you can or can't afford, then you need to have real facts to evaluate. Long runner single carb systems are lousy at low RPM's when compared to either the original fuel injection or to Weber or Solex dual carb systems. No seat of the pants or old wives tales, all of these things are quantifiable.

This was something seen on T1 engines back in the 70's when someone sold kits. The idea seems interesting but for some reason disappeared, probably because a well-tuned set of 36 Dells or 40 IDF's will do just about as well for economy, give better throttle response, and equal or outperform it at full throttle.

Gotcha. I'm thinking dual singles?

Talking about the 70's, I snagged a single progressive from a Capri 2600 V6, re-jetted it for an 1835 and installed it in my '67 bus. I didn't have an air cleaner, so I sandwiched some thick stainless steel screen material between two intake gaskets (mainly to keep large debris from being sucked into the engine). Unbeknownst to me at the time, a friend, who's a Porsche mechanic, informed me that the screen caused the fuel mixture to tumble, further atomizing the mixture

Bottom line, got good mileage on the primary, and hauled butt when the secondary opened up. Tail pipe had that nice medium gray color to it

I also installed a lever under the dash, connected a long lawn mower cable to a clamp on the dizzy, thus, allowing me to adjust the timing while driving. I needed to retard the timing slightly whilst climbing inclines, like the grapevine on I-5

Is this a good, bad, or ugly setup://

http://www.webercarbsdirect.com/product_p/wk412.htm

I think that sharing a 32mm venturi leaves a lot on the table...

Good

Your application:

PORSCHE 912E 2.0 Liter 1976 PORSCHE 914/4 1.7,1.8,2.0 Liter 1970-76

Give 'em a call

Even for a 1.7?

I thought he was looking for better mpg

He has a 1.8 I think (from the looks of his signature).

1.8 = 450cc per cylinder and with a guesstimated 4500rpm peak hp rating he could live well at sea level with 28mm venturies "per cylinder". 135 mains, 150 air correction and 45-50 idles but... that's just my thoughts.

I'm not sure what some of that means-? But yes, it is a 1.8 (a former1.7)

Let them know the displacement of your engine and your main desire (mpg, performance, or a combo of both) and see if they can recommend the best set up (vents, jets, etc.) for you.


Then call CB performance and do the same, so you get objective views (and pricing).

Engine 1800 / 4 = 450 / 1000 = 0.45
Peak HP 4500 (guessing) / 1000 = 4.5
Size x Peak HP Ratios = 2.025
Square Root of 2.025 = 1.423025
Venturi = 20 x Square Root number = 28mm Venturi

Main Jet = Venturi x 0.21 = 136 (size to 135)
Air Correction Jet = Main Jet x 1.1 = 139 (size to 140)
Idle Jet = Main Jet x 2.873 = 47 (experiment with 45-50)

Subtract 6% for every 3,000ft in elevation.

The mystery would be what emulsion tubes to use which are based upon cam profiles.

The rebuild was with a carb-specific (?) cam.

The day before I shot the Video of my single Carb Car, in the earlier postings, I traveled from home in York County Pa to the Air Show in New Garden Pa. (Kennith Sq area). Per GPS it's 60 miles each way or 120 Miles round trip. I burned ruffly 1/2 a tank of Gas, for the 120 Miles. The trip was back roads and highway. I tend to have a heavy foot, no traffic on most of the back roads, and I cuirsed on the highway at 60-75 MPH. With out a functional Odometer, and I never filling the tank, I can't say what kind of gas mileage I'm getting with the single carb. Guessing maybe 17-18 GPM?

Also, in the video I said I have a 1.7, dah... it's a 1.8, and my Yokohama P205-50-15 S Drives (Love 'em). I'm Running ANSA Exhaust and no Heat Exchangers. Winter's aren't so bad here no heat isn't a problem. Carb has a choke and it starts and warms up nicely. Not a daily driver but driven a lot.

As mentioned when Tony rebuilt the engine he tunned it well, and has it ready for twins when I'm ready. However, I don't want to put the car in the shop for several months just yet, it's too much fun. Eventually it will get twin daul 40's to keep everybody here happy....but I'm in know hurry.

Comment! Performance is measured individually and the fun of any car is driving it to the limit of it's envolpe. That's why an old Air cooled Porsche is so much more fun to drive then the new ones, you don't have to go as fast to enjoy ours, even if it's a single carb car.

Just under 15mpg

And at that mpg there's gotta be some unburned fuel messing with the rings and oil etc.

It cost you $7.00 more to go 45 miles. Your carbs will be paid for in 860 miles.

I want to know where you can get dual carbs, intakes, linkages, etc in bolt on condition for about $113. ~!!!!!

$133.77777777777777777

Joe's forte is "baking" not math and you're the music teacher!

Excuse me but when I did it that way I could not believe it. So I did it another way and it least sounded more real.

I just bought my first 914 earlier this year.

IMHO, there is much more to worry about with the purchase of a 914 then if it has FI or carbs.

Rust would be a deal breaker for me. A solid foundation is priceless, everything else is replaceable.

Amen to that. Rust makes parts of your car DISAPPEAR. Gone. Not there, no more. I'm all California, never quite learned how to deal with that and don't intend to. But I do know that it would be 1) difficult 2) expensive, and should 3) go East where they understand rust and LIKE to deal with it. [You guys do like that, right? Seems like it, anyway, by the zeal and enthusiasm]

"forte" for the baker and not the music guy?
Actually, I am now Dean of Humanities and Social Sciences at San Jose City College.

A bit off topic: I also sing in a group (Voices in Harmony) that will be doing two concerts on Saturday September 14th-2pm and 7pm. Would be great to have a few 914s in the parking lot and their drivers and driver's SOs in the audience.

Here's the ticket link: http://autumn-magic.brownpapertickets.com/

Or let me know when you can stop by my office at SJCC and I'll get you the "SJCC Group rate" of 20 bucks

Sean

Hey Sean,

The math doesn't add up here:

As of fall 2009, with enrollment of approximately 26,000 per semester, and an extremely diverse student population (Hispanic/Latino 32%, Black/African-American 6%, Asian/Pacific Islander 33%, American Indian/Native American 1%, White/Caucasian 17%, First Generation 60%) attaining educational goals reflecting 34% - AA Degree and Transfer to a 4-Year College/ University, the District's emphasis on student success makes it a recognized educational leader in the State.

.... 32
...... 6
.... 33
...... 1
.... 17
.... 60
-------
.. 149%

I guess I just don't understand that 'new math'

That's because "First Generation" shouldn't be added with the other populations. "First Generation" means first from the family to attend college/university. So, it would be 89% of students identifying as members of each ethnicity with 11% not identifying. Then, 60% of students are "First Generation" college students with 40% being from families with prior college attendees.

Hope that helps

I'm sorry to say we do not have an Auto Tech program of any kind though.

Sean

OK, I'll buy that. I have to admit, I had to look up 'First Generation'


Back to the ROI on carb upgrade vs. mpg

Just like anything else, the specialized lingo sometimes isn't easy to understand (maybe even more with carbs than academia)

Sorry to say, but it seems that with the path technology and academia are headed, somewhere down the road, evolution will eventually turn the human race into all thumbs

Click to view attachment

Wow,
All this discussion makes me think I need to drive more 914's other than mine in order to do a proper comparison.

I have a 1.7 with a single weber and I love the sound and torque for sure, but I have not calculated the MPGs since my odometer is broken. However, since I'm running 205 50's (smaller circumference than stock) the MPGs would be overestimated anyway (by 9% according to the tire calculator tool). I guess I need to GPS the miles for accuracy.

PS - I echo the "take someone knowledgeable in 914s with you". Last year when I purchased mine, I did not...... and paid for it in rust repair bills before I even had the chance to really drive it.

So. After all my blathering on, I DO have a set of some kind of Dellortos that came on a dead motor. I'm not sure what the REAL condition is, nor how much of the real linkage I have (I think I have a hex bar etc somewhere, but the other bits look like stuff found at a hardware store).

Tell me what I need to do to get y'all to evaluate my stuff (so to speak)

Sean

Host a big Bar B Que/Tech Day

Are you still thinking dual single barrels, or dual two barrels?

It's best to know what all's spinning around inside, especially the cam specs

Are they duals? Meaning two carburetors, each with two throats, looking generally like Weber IDF's? They should say "DRLA" in a circle somewhere on the carb body near the Dell'Orto logo. If so they're they're actually better carburetors than the equivalent Weber IDF's, flow more, are more adjustable and atomize better. They come in sizes 36, 40, 44 and 48mm barrels. They haven't been imported in 25 years or so, so there won't be any more. Dell'Orto also made twin singles, motorcycle carbs, and more.

The first check is to take off the carb tops and check in the bottom of the bowls for corrosion. If they were left full of gas they corrode there first, and if the bowl's corroded then the internal passages are almost inevitably shot. Check the CB Performance web site for parts and info,including the manuals. Claude's (CB) was the Dell'Orto importer, so is the best contact around. Also ACE (formerly Art Thraen, who's retired) in Utah can re-bush and rebuild, if they're rebuildable. They take the same manifolds, air cleaners and linkage as Weber IDF's, so if the carbs are good you're a lucky guy.

dellortos are 36,40,45, and 48. I agree they are better than weber.

Twin duals. The car ran (crappily) with the OLD motor and the Dellortos. . it was an old bus motor and is sitting somewhere in my former mechanics "crap pile"

The current motor is a rebuild from a place that has been bashed on here, but it seems fine and has a "carb" cam of some basic type. I'll probably not be able to find out more details than that.

Depends on your spare time and mechanical prowess, Sean. ... If the throttle plates open and close easily, that's a good start

First, grab all the parts you have and post some pix.

Main items:
Carburetors
Intake mainfolds
Linkage items

Books for Dells are available on line.

Click to view attachment


If you're game to rebuild them yourself, locate the exploded view diagram for your particular carbs and take one apart for evaluation.

Click to view attachment


Follow the cleaning/rebuild directions. Remove all rubber parts and soak all the hard parts in cleaning solvent (typically, Berrymans Chem Dip is what I use, but it's getting harder to find these days)

Blow out all the ports and passages in the carb body, jets, tubes, etc., with compressed air (and/or carb & choke cleaner). Depending on how they come out, they may need a second session.

With everything clean, reassemble with a new gasket kit

Second verse, same as the first ...


Or, you can always call Mark Bernardi, or Cap'n Krusty to see if they want to tackle the job

I'll do some pics soonest. Adjunct faculty orientation tonight, so a 12 hour day. . yay.

The throttles have to open and close easily and also open and close at the same time and the same rate. You can do this by adjusting the throttle linkage geometry.
Cheers, Elliot

Geometry ... here we go with that math stuff again