 |
 | Home | Contact Us | FAQ | Search & Site Map | Link to Us |
 | Sign In | Join | Other 45 Sites in Network |
Car Forum / Volkswagen / Air Cooled Volkswagen Cars / July 2005Funny timing behavior
Hi ramva! I just finished cleaning up the engine (cleaning inside out, changing all gaskets, fixing exhaust studs) and it definetely feels crisper. I checked the compression (twice), changed the spark plugs and wires, adjusted the valves and adjusted the carb on idle. there is something weird going on with the dizzy though. It is a toyota electronic distributor installed by a PO. It's suposed to be a centrifugal-vacuum type, but the vacuum port is broken and there's no hose, so I statically timed it to 7.5 BTDC and fired up the engine. All good so far. Connected the timing light and checked again the RPM's, 900, ok. Then pointed it to the marks on the pulley and when pressing the throtle, the marks move to the right! aren't they suposed to move LEFT? moved the dizzy a little and noticed the RPMs go up when advancing, maximum RPM's close to 30 BTDC!!! Press the throtle and it goes down to 8-10 BTDC!!! Isn't this proof that it is retarding the ignition? How should I set this? TIA, Karls > Hi ramva! I just finished cleaning up the engine (cleaning inside out, > changing all gaskets, fixing exhaust studs) and it definetely feels crisper. [quoted text clipped - 13 lines] > TIA, > Karls Maybe Toyotas spin opposite? Junk the dizzy; you'll never make it work right and could damage the engine...  SignatureSpeedy Jim http://www.nls.net/mp/volks/ Well, maybe this one does spin oposite, but I've heard of people using toyota/nippondenso dizzys succesfully. I'll swap the toyota dizzy with a new 009 I got lying around (I hate points) until I can find a way to make it work or I can get a SVDA with an electronic module. Is there a website somewhere that describes the toyota-vw dizzy conversion? is there a way to make it work clockwise? Karls > Maybe Toyotas spin opposite? > > Junk the dizzy; you'll never make it work right > and could damage the engine... taken from google; original from Bob Hoover hth Roger >To All: >My casual mention of modifying a Toyota distributor for use on a Type I VW >engine produced enough responses to justify a general post on the subject. >So here it is :-) >First off, it's not a bolt-up. You have to do quite a bit of machining on the >Toyota distributor. That means you need access to a lathe and know how to use >it. >So why did I call it a fairly simple modification? Because it is, if you >happen to be a machinist and understand a few basic principles of both machine >work and engines, one of which is the fact that, at least in theory, the >distributor from ANY four-cylinder Otto cycle engine can be used on any other >four-cylinder Otto cycle engine. In theory. That's because the cam, reluctor, >electronic switch or whatever has four poles. Trying to use a distributor from >a six or eight cylinder engine would increase the complexity of the task by >several orders of magnitude, making it so difficult you'd probably be better >off to start from scratch. But if you have a distributor from a four cylinder >engine you're already about 90% of the way to your goal. >The other aspect has to do with machine work. You don't have to be a rocket >scientist to understand that it's pretty simple to SHORTEN a shaft that's a bit >too long... you just cut the thing off, whereas trying to LENGTHEN a shaft can >be blindingly difficult. By the same token, if you have a bar of metal 2" in >diameter it's a simple chore to turn it down to some SMALLER size... but >virtually impossible, within practical limits, to turn it into a size LARGER >than 2". This also applies to holes. If you already have a hole, making the >hole LARGER is a trivial task whereas making it SMALLER is extremely >difficult... you would have to weld it up and remachine, being careful to >preserve your center. >So how does all of that apply to the modification of a Nippondenso distributor? > First off, the spigot shaft of the Toyota distributor is EXACTLY the same > diameter as the spigot shaft of a Bosch distributor - the thing will plug into >the hole in the Type I crankcase without any machining. It won't FIT but only >because the Toyota distributor's spigot shaft is TOO LONG. But as I pointed >out above, shortening things is pretty easy. Finally, the Nippondenso >distributor has a LOT of extra metal in its base. You can machine away nearly >a quarter of an inch off the Toyota distributor without weaken it, plus you can >saw off the clamping lug and a couple of casting bosses, allowing you to use >the standard VW distributor clamp. (Which is a rather shoddy piece of goods >but it saves you having to figure out a better method of clamping.) >The distributor's shaft is too long but it's almost exactly the same diameter >as the Bosch distributor shaft -- you simply cut the thing to the proper length >and drill it to accept the dog gear from the VW distributor. Along the way, >you will have to move the lower bearing in the Nippondenso distriubutor but >here again, the machine work is relatively easy - you simply deepen the >existing bore. >So why would you want to do all that? Because a new (or nearly so) Nippondenso >composite distributor is about a hundred times better than what you're probably >running in your VW right now. >Like all modern vehicles the Toyota used a composite distributor, having vacuum >sensing to provide the necessary sensitivity, combined with a centrifugal >advance mechanism to provide a wide dynamic range. This is a completely sealed >distributor, with an O-ring between the body and the distributor cap, which is >installed with screws rather than spring-type clips. Best of all, it comes >complete with a modern electronic ignition system. >Inside the Nippondenso distributor is a magnetic pick-up coil. Instead of a >cam on the distributor shaft operating a set of ignition points, it has a >four-lobed reluctor. Each time a lobe of the reluctor sweeps past the magnetic >pick-up it induces a voltage in the pick-up unit. That voltage goes to a solid >state 'ignitor' - a tiny amplifier and a husky transistorized switch -- >attached to the ignition coil. The 'ignitor' is connected to 12v and ground >and controls the discharge of the coil, just like on a modern car :-) >So why isn't everyone using Toyota distributors? Well... quite a few guys are. > But the distributor is physically larger than the Bosch and can't be used with >some mechanical fuel pumps. On the other hand, the later model Toyota's use an >HEI system -- the coil, pick-up and ignitor is all built into the cap of the >distributor. Once you get it set up it's a virtually bullet proof system that >can win you the race. For your daily driver, it's a zero-maintenance ignition >system, other than checking the air-gap every 50,000 or so... about the same >time you need to replace the plugs, if you're running platinums. >If your stock Bosch unit is still within spec there's no reason to replace it. >But if your shaft is showing some wobble you might want to look into the mod. > As for Toyota (or Nippondenso) part numbers, there's a bunch of them, just as >there are for the different Bosch distributors. The one I've modified came off >a 22R carburetted engine and the data plate reads '19100-35130,' which I think >is the Nippondenso part number, followed by '29100-8801,' which I think is the >Toyota p/n. But I don't really know (or care). In the process of fooling >around with this mod I've accumulated several Nippondenso distributor (at about >$20 each). The castings are identical but the numbers are different. That >also applies to the ignitor & ignition coil, of which I've used two. Both >worked exactly the same (same connections, etc) and while physically identical, >they had different part numbers. >Finally, I've no idea how well the thing will hold up. In the Toyota the >driven-end of the distributor shaft is supported by a bushing. When modified, >the driven end is free (ie, as with the Bosch unit). I suspect the lack of >support will lead to accelerated wear of the shaft bearings but I've no idea >how long it will take for the thing to fall out of spec. One thing I do know, >it's a hell of a lot easier (and less expensive) to find a good-condition >Nippondenso distributor than it is to find a VW distributor that's still within >spec. >-Bob Hoover > Well, maybe this one does spin oposite, but I've heard of people using > toyota/nippondenso dizzys succesfully. I'll swap the toyota dizzy with a [quoted text clipped - 12 lines] >> Junk the dizzy; you'll never make it work right >> and could damage the engine... There is something weird here. According to Mr. Hoover, the toyota dizzy used to make the mod is a HEI system with the coil inside the cap. The one I have installed is NOT like that. I got a bosch blue coil with an external resistor. Maybe I should get some pics so shine some light on the matter. Thanks a lot, Karls > taken from google; > original from Bob Hoover [quoted text clipped - 181 lines] >>> Junk the dizzy; you'll never make it work right >>> and could damage the engine... It's probably some cobbled together thing that will never work right. EVen a 009 which is somewhat designed for a VW engine makes more sense than one which has no real history of use in a VW engine! > There is something weird here. According to Mr. Hoover, the toyota dizzy > used to make the mod is a HEI system with the coil inside the cap. The one I [quoted text clipped - 189 lines] > >>> Junk the dizzy; you'll never make it work right > >>> and could damage the engine... Both You and Jim are right. The dizzy is not a toyota/nippondenso, it has "Tec" written all over it. The Machining looks like it was done by hand with a hacksaw and instead of an o-ring, there was a 4mm section of rubber hose!!! Don't you just hate PO's? His pride was to say he had an electronic dizzy from a toyota. I'll use the 009 in the meantime. Everyone hates it, but at least it will not blow my engine. And weird enough, it feels better with it, faster acceleration and better top speed. BTW, is there a tutorial of how to adjust the advance on the 009? Do I need extra springs or other parts? Thanks to all for your help. Karls > It's probably some cobbled together thing that will never work right. EVen > a 009 which is somewhat designed for a VW > engine makes more sense than one which has no real history of use in a VW > engine! |
Reply to this Message |
 Sign In
 Join
 My Latest Posts My Monitored Threads My Blog My Photo Gallery My Profile My Homepage Start New Thread Enable EMail Alerts Rate this Thread
|
©2009 Advenet LLC Privacy Policy - Terms of Use
This website includes both content owned or controlled by Advenet as well as content owned or controlled by third parties.