New Fix For Weber Carbs

 

OK, so I'm late to the party.

Youse guys were right. This is, hands down, the best fix for Weber carburetors ever invented.

And it's not new idle jets or jet doctors or jet gurus or jet cleaners or anything that has anything to do with jets. My engine was jetted to perfection and just purred.

Well, sort of.

There was that little, almost imperceptible, nothing you'd hardly notice, wee bit o' fuzziness between when you first stomped on it and when noise happened and you'd start to move out. Nothing you couldn't get around by stomping down a little harder. Nothing worth bothering about.

Except, well, like it was always there. And OK, maybe it might have bothered me just a little.

In my gut I knew what the cause was, but actually doing something about it was harder than swapping in new idle jets and messing with the mixture screws. So, that's what I and most other guys with Webers would do every now and then when the old girl just needed a tune.

But last week, I finally got off my butt, got online, and got to work. Saturday, the brown truck arrived.

It wasn't that much harder than swapping in new idle jets. There was about the same amount of reaching for stuff that you can't actually see and maybe about twice as much cursing. But nothing you couldn't do in the privacy of your own garage.

I still don't know how it makes the Webers work better, though, since it doesn't connect to them in any way:

 

Magnaspark

 

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Ah, the curve's the thing!

My old Pertronix had two curves. There was the one around idle, and the one that went from around 2200 on up.

In between, there was so much 'scatter' that you couldn't see the timing marks when you pointed a timing light at the pulley. And that's just where the, uh, 'fuzziness' in the throttle response was. I don't think there was anything wrong with the Pertronix module - just with the crappy, mechanical advance mechanism underneath. Another stunning example of Chinese repops that look like the original but don't work half as well.

I also have a theory about how dizzies curved for basic VW engines don't work so well on Type 1's like the ones most of us drive, with hotter cams, but that's for another day.

 

More often than not, a carb or Weber problem is an ignition problem.

I also had MASSIVE spark scatter with the Pertronix and 009. The whole reason I did the Megajolt crankfire ignition. Nothing else fits with a 911 shroud. Mallory, Pertronix, all the bigger distributors don't fit. If they do, great for you, easy fix.

Now it purrs like fuel injection. Of course, after a few burps and farts during the warmup-without-chokes period.

Good on you, Mitch!

Sacto Mitch posted:

 

Ah, the curve's the thing!

My old Pertronix had two curves. There was the one around idle, and the one that went from around 2200 on up.

In between, there was so much 'scatter' that you couldn't see the timing marks when you pointed a timing light at the pulley. And that's just where the, uh, 'fuzziness' in the throttle response was. I don't think there was anything wrong with the Pertronix module - just with the crappy, mechanical advance mechanism underneath. Another stunning example of Chinese repops that look like the original but don't work half as well.

I also have a theory about how dizzies curved for basic VW engines don't work so well on Type 1's like the ones most of us drive, with hotter cams, but that's for another day.

 

exactly why the Wilhoit distributor works so well on Whitecloud, the advance is early and precise, the Bosch cast-iron distributors were/are well made options though expensive

 

This is the CB Performance Magnaspark II - the same one Robert put in about two years ago (his post is here). They offer it in a kit with their own dry coil (not oil filled) and plug wires. I got the distributor alone, as they say it will work with a traditional (Bosch-style) coil - and it seems to. My engine is a pretty mild tune and doesn't need a really hot spark to run well. I did have to get their wires, though, because the terminals on the distributor are male - not the female ones on a Bosch (or Pertronix) dizzy. Dizzy alone is $150, wires an extra $25. Here's the web page.

For a long time I thought this wouldn't fit with a mechanical fuel pump, but there are apparently two styles of mechanical pump (early and late) and it works just fine with the later one I've got.

Robert noted his engine started up much easier from cold with this dizzy. Mine seems to also. I think that's because it gives more initial advance than most Bosch dizzies curved for VW. You can set the range of advance and rate of advance with included sets of springs and bushings, but the widest range of advance is about 20 degrees (I was getting about 25 degrees with my Pertronix).

So, if you set max advance to 30 degrees, advance at idle is about 10 degrees (mine measures out at about 12). With the Pertronix, my advance at idle was about 5-7 degrees. I think the engines most of us have - around 2 liters with a slightly hot cam - like to see more initial advance and a quicker rate of advance than, say, a Bosch 009 provides.

You can go a lot fancier than this - both from CB Performance and other suppliers - and probably get better performance still. This allows some control of the advance rate, but nothing like the customization and control you get with separate, computer-mapped units (which are compatible with and can be added later to this dizzy).

But, I'm not going racing or trying to beat DannyP off the line. I just wanted a smoother throttle response off idle and this finally fixed that in one fell, and moderately-priced, swoop.

 

F20E382E-1CF8-4CC0-92C0-CEC2A10244CF92CD8DB7-42CE-44B6-A74C-B6B2D2BEBF2EDFCD9BFA-DC06-43C7-BE4A-F194F5FC6C27Will Hesch posted:

No "retro-looking dizzy for me, I have a real John Wilhoit re-curved Bosch BR18, it gave that proverbial flat-spot the boot!

 

 Do you any of you have the set up that’s on my speedster? My engine is a 1966 912 1600cc with this distributor/coil combo. I don’t have any flat spots and I have dual Webbers.

 

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I think I've heard good things about the Davis units, although they're more than twice as much as the Magnaspark (but do include the coil right on the dizzy).

There's nothing really remarkable about the Magnaspark. It's no more reliable than an original Bosch - if you could buy a new, made-in-the-fatherland original Bosch.

I do like that you can access the advance mechanism on the Magnaspark easily (just pop off the rotor). You can work the advance plates and feel if they're moving smoothly, and lube the pivot points if they're not. And you can monkey with the springs, too, if you want to alter the curve. Not much chance to do that on the Bosch.

I don't think it's too likely that the repop pseudo-Bosch units (like the Pertronix) are ever put on a timing machine and calibrated to a spec in the course of manufacture.

The Magnasparks seem to be a lot more consistent from one example to the next than the ersatz Bosch stuff, too.

 

 

For a while, the Mallory unit was the ticket. Then they changed production (I believe they went to China to make more money) and they were unreliable and varied quite a bit. 

I don't have experience with any of them except an 009 of what vintage I don't know.

 

Full disclosure: The Magnaspark is made in China, too.

It could be that CB is holding the factory to a tight enough spec to get some consistency in the production run. Or doing some QC of their own?

Also, Pertronix does offer a 'billet' series dizzy that looks an awful lot like the Magnaspark. But I don't think its advance curve is adjustable. Anyone using one?

 

Will Hesch posted:

Al, it's a re-curved BR18. John can re-curve the BR18 or the 022

Thanks, Will. Being cast iron bodie'd and with the same advance curve, either would be a good choice (after being re-worked) for a dual carbed VW engine.

Sacto Mitch posted:

Youse guys were right. This is, hands down, the best fix for Weber carburetors ever invented.

And it's not new idle jets or jet doctors or jet gurus or jet cleaners or anything that has anything to do with jets. My engine was jetted to perfection and just purred.

Well, sort of....

 

It wasn't that much harder than swapping in new idle jets. There was about the same amount of reaching for stuff that you can't actually see and maybe about twice as much cursing. But nothing you couldn't do in the privacy of your own garage.

I still don't know how it makes the Webers work better, though, since it doesn't connect to them in any way:

 

Magnaspark

 

As you've found, Mitch, a distributor with the correct advance curve is the ticket! 

Sacto Mitch posted:

 

I think I've heard good things about the Davis units, although they're more than twice as much as the Magnaspark (but do include the coil right on the dizzy).

There's nothing really remarkable about the Magnaspark. It's no more reliable than an original Bosch - if you could buy a new, made-in-the-fatherland original Bosch.

I do like that you can access the advance mechanism on the Magnaspark easily (just pop off the rotor). You can work the advance plates and feel if they're moving smoothly, and lube the pivot points if they're not. And you can monkey with the springs, too, if you want to alter the curve. Not much chance to do that on the Bosch.

I don't think it's too likely that the repop pseudo-Bosch units (like the Pertronix) are ever put on a timing machine and calibrated to a spec in the course of manufacture.

The Magnasparks seem to be a lot more consistent from one example to the next than the ersatz Bosch stuff, too.

 

 

I remember the DUI ads in the VW magazines years ago, and the only real criticism was that they were expensive. And I disagree- while the Magnaspark seems comparable to an original German Bosch, the extra spacing on the cap between terminals allows you to use more voltage (a big plus right there, as a blue coil puts out enough voltage that a smaller cap distributor can start to crossfire at higher rpm's when the cap itself gets a little older) and the adjustability of the advance curve of the Magnaspark make it a much more user friendly piece.I haven't used one, but know guys who have, and the general consensus is CB got it right.

You're also right about all the 009 made in China copies (including the Pertronix); spark scatter like crazy and no consistency of the advance curve make any of them a dubious choice at best. If you do any reading on any of the VW sites, this is a constant issue- and for every guy that says his works fine (and remember, most of the time it's some yokel who's bolted it on and the only testing is it fires up and runs, so "yup, it runs reeaalll goood!") there are numerous complaints about timing scatter and the advance curve just generally being all over the place by those who have taken the time to check. This is not what you want when trying to get the most out of your engine and it living the longest life possible.

@IndianBob- It may not be a popular set up, but since it works well, don't question it!  Al

PS- The problem is not that everything these days is 'made in China', the issue is people having stuff made at a price point so they can undercut the competitor. They can and do supply to very high quality standards when required. When they build to a price point, though, and you've got a market like the VW crowd (who are generally a cheap-assed lot who haven't figured out that the more expensive piece can actually be cheaper in the long run), let's face it, we're doomed. We're getting what we deserve.

 

On the same path.

I have a MSD 6Al with distributor,wires and coil and finally got around to installing it and as Danny said and many before, carb problems are really ignition problems.

I had been running an 050 mechanical with points and the car runs well and has been reliable so why change anything, then again why not. Well I did the change over yesterday and made all connections plug and play so that in the event of a failure I can change it out ie i'll be wearing suspenders with my belt until I'm convinced the system will hold up.

The first test drive did reveal a difference in performance so a little tweaking of the carbs and some additional mileage and I should be Carlisle ready which will include the old coil and distributor in my spares kit.

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