Which New Carbs; Best Mileage?

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Somebody bought my carburetors~~!!! booooo...

Well, such is life. No need to rush i suppose. I just got my Honda going today, so i can drive that little speed lover for a bit. (it's funny, i got a lowered 2D Honda on one side, and a VW van on the other.. jejjeje. )

If you were thinking of getting another CDI unit, go to the website i put up. The units are running around 140 $ with shipping included. They reply promptly.

As such, i'm holding on until Alfa gets to rebuilding a new pair of gems...

Any pictures you get to take from your van will be sweet! For one, i just want to see your van, for two, i'm a very picturesque kind of guy. I like pictures

i'll keep you posted as to what happens with all the Van stuff! :)

Thanks for all the information !!

Miguel

PS: not sure if i should make a new post for this question. But, was in Oregon, where they fill your gas for you. Well, they toped it off, and thustly the gas return thingie got full of gasoline and started leaking like a crazed maniac, right next to where the vent was... Is the best way to prevent this to put some hose clamps on all the connections? or do i have to take out and replace something? (BTW, there's no carbon gas collector... and i have quick easy access to the tank from the top - a custom "door" to the tank - should i just plug all the exits there? What would be the damage / danger of doing such a thing?

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The process has begun!!!

Bought the carbs from Gabe, the parts and books from CB and the Universal Tiger 581 CDI unit. Now i wait.
Unless you think i can get started on the crankcase vent system / fuel vapor system ? I know you're buisy, so whenever you get a chance get some pics of your ingenuity

I'm happy right now. So happy.
Cheers!!

Miguel

[Amskeptic]

Air intake preheat helps warm-ups - cold engines tend to start and run better if the intake air is warmer, and if the incoming mixture is richer... which is why factory air-preheat and factory chokes are nice.

Cold engines will not start better with intake air preheater, because there will be no warm intake air, but they will idle and respond better after the choke sequence is done and the intake runners are still chilly

The spark plugs need to be regapped to take advantage of the hotter spark, but you will get easier starts in cold weather (and pretty much most of the time), lower emissions and vastly improved fuel mileage.

I have been hearing different and conflicting accounts of spark plug gaps.
The classic argument found in marketing copy is, of course, Hot! Hot! Hot! Get your Hot! spark Today! Better Everything and cures cancer besides!

But in more subtle internal combustion physics treatises, I have heard that the optimum spark is actually dictated by the orientation/distance of the plug from the piston crown. The argument here, is you want a flame progression that expands pretty much "just in time" to meet the piston fully. If you have too large of a gap, the flame front fills the combustion chamber too quickly and riccochets back, a propensity to spark knock is the result. A gap that is too small gives a smaller flame front hitting the piston with lots of cooler unburned HCs likely at the periphery of the combustion chamber. Studies have shown that power output at high rpms with full combustion chambers prefers a smaller spark gap, whereas idle quality and less HC production prefers a larger gap. Of course GM and its HEI system and Ford too, went straight to .060" gaps. . . not for performance but for the hated emissions requirements, and you also know that spark knock (clap-trap Mustang II anyone? ) was one of the Great Sounds Of The 70's.

So, just because we have a sizzling spark does not mean we want to to pry open the electrodes to .060" necessarily. Your thoughts?
Colin

[Amskeptic]

I can't say as I've had plugs hold that steady a gap, or look worth a sh*t past 10-12K miles on points.
UniCorp boxes to be very friendly to plug wires and rotors.
I'm told that they WILL chew up the standard 5K ohm resistor rotors
- but I've sidestepped that issue by having converted many years ago to the "wide-tip" style rotor with the Hall-style ignition systems. That particular style only sports a 1K ohm internal resistor - and I have yet to lose one in 10 years running with the UniCorp boxes.

It is a funny thing about eaten ignition components. Why do they get eaten? It sure as hell isn't combustion. It is, however, an imbalance between voltage, amperage, and resistance. We want high voltage and little amperage. The resistance is the moderator. Too much resistance and misfire city here come we. Too little resistance and hot coil and eroded rotors and eroded plug electrodes (which can also erode from preignition and dust-laden air of course). My stock old as dirt ignition system had some 5K ohms in the rotor, 1K ohms in the connectors, and no ohms at all in the wires. It also misfires readily at high rpms/loads the better which to cool the valves with

The late bay/Vanagon Hall system is a beauty. It allowed my Vanagon to start with southern California 20-50wt oil at 43* below 0 at a cranking speed of approximately 120 rpm.
Colin

[dingo]

since we're on the topic....here is some info, (abbreviated by myself)

1. It generates energy levels substantially in excess of any other present ignition system, and can be readily controlled

2. Spark voltage rise time using a conventional coil is much more rapid than in Kettering or solid-state ignition systems. Rise times of up to 1/20 are possible

3. Condition of the points is relatively unimportant, as is dwell time. Breaker-point current is only 250 Milliamps, and only Battery voltage appears across the contacts

4. The current load of the CD system on the battery and charging system is substantially less than that of Kettering/points and only 20% that of solid-state...

5. CDI runs at 75%-90% efficiency

6. The capacitor is charged in 0.6 milliseconds....hence to outpace the ability of CDI to provide consistant spark, the engine would have to be running at higher than 17,000 rpm before the electronics would limit engine operation.

7. The short 2 microsecond rise time of the CD ignition will continue to to fire fouled plugs long after solid-state and points systems ( 80 and 200 microsecond rise times) have given up. Plugs and breaker points can last up to 50,000 miles before requiring a change.

8. CD ignition system draws approximately 1 amp continuously, rather than 3 to 4 amps for conventional points and 5 to 7 amps for solid-state, allowing for easier starts in cold weather or with weakened battery. With CD systems, the spark output will be about the same from full battery voltage down to about 6 volts...

9. A deteriorated ignition cable will not stand the hot CD spark, will arc over and cause misfiring.

10. CD system fires slightly earlier than the other systems, because the voltage rises to a higher peak value, and thus, reaches the firing voltage of the plug sooner.. This amounts to less than 1 degree of crankshaft rotation at idle.....at higher speeds however, this time advance could amount to a few degrees..and should be taken into account when setting distributor timing.


*Automotive Electronics Graf/Whalen

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I have to say i really enjoy reading all the stuff you guys post. It's groovy. =D>

Ok, Regarding gaps, .040 or .045"? .045 translates to about 1.1mm right? (I'm a metric guy) And, (i'll probably sound really stupid asking this) do i want to buy new spark plugs or actually grab some pliers and have at it with the gaps until they are 0.04_ ?
The latter one sounds like fun, but rather risky.

Where do i find this 5K ohm internal resistor and how do i go about changing it? And, i need to find a 79 van that i can steal the 1K or can i buy that easily? :P

Who is Mr hoover and where do i find this mysterious person?

Cheers!!

Miguel

[dingo]

a variety of Euro cars of the 80s with Bosch used the 1K rotors..very common in junkyards. ..just make sure the diameter of the hole that fits on the shaft is the same

if you cant find one, i can send you one.

* Also there a Bug dude that recommends simply dremel out the resistor on a 5k rotor and soldered in a copper wire. Then fill with JB weld.

[hypercircle]

That's right, the carbs, linkages, manifolds, and tiger CDI have arrived
I'm going to contact my local VW aircooled junkyard dealer and get a 1k rotor from him.
I'm going to start with the CDI installation, then once i get that working, i'll go ahead and work on the carburetors. Speaking of which, i'm still not 100% about the special modifications i need to do for the crank case ventilation. I haven't been able to find the guy online... Mr Hoover. Is he here at Itinerant or at Samba? or elsewhere?

Wish me luck, and so, hopefully next weekend i will have the CDI unit running with the old carburettors. The electronics look pretty chill.

Miguel

[tristessa]

The late bay/Vanagon Hall system is a beauty. It allowed my Vanagon to start with southern California 20-50wt oil at 43* below 0 at a cranking speed of approximately 120 rpm.

It also allowed me to recently drive (and running well!) with what turned out to be a 0.055-0.060 plug gap -- "funny, I thought I set them to 0.035 .. er, last spring? Guess I need to check my plugs more often..."

[tristessa]

Where do i find this 5K ohm internal resistor and how do i go about changing it? And, i need to find a 79 van that i can steal the 1K or can i buy that easily?

The internal resistor is under that goop on the top of the rotor. You could dremel it out as Dingo said some guy suggested, or just get a rotor with the right resistor from the get-go. '79-'83 California aircooled Bus/Vanagon, '83-'85 watercooled Vanagon, bunch of other cars. Last time I bought one I said I had an '84 GTI I think .. whatever.

Standard Ignition p/n GB344, Bosch # 04038. Bosch is the obvious first choice, but I've never had problems with Standard either .. unlike Niehoff or GP Sorensen. No idea who makes the NAPA Echlin parts...

[hypercircle]

I see, cool. I will go look at my van and tinker with the rotor to identify this thing. That way i will know exactly what i need. I will stay away from dremels considering i am a NooB at the whole thing. I can't imagine a junked rotor would cost more than 15$ ?

Cheers!!

Miguel

[tristessa]

Depends on where you are of course, but locally to me a new rotor is less than $15. I'm in Oregon, USA ..