I have a 75 GT4, with only one set of points in each distributor (thats good). But I seem to have some problems with the advance mechanism. At idle the timing (inductive timing light) on the 1-4 bank dizzy as measured at the flywheel jumps around much more than on the 5-8 dizzy. Also as a sympton, the car has a big flat spot off of idle, but is nice and strong after about 2500 rpm. I set up the dizzy at 34 degrees at 5000 rpm, but when reving higher, the timing continues to advance, at least a little. (I thought the dizzy was supposed to top out at 34 degrees). After setting timing at 34 degrees at 5000 rpm, at idle it is only about 7 degrees. (If I had the second set of retard points installed this would be OK, but I dont.) So if I read the F manual correctly, timing at idle should be about 14-16 degrees. The dizzys obviuosly need some work, particulary on the mechanical advance mechanism. I am planning to install a advance band width limiting bushing (as suggested by Phil in Melbourne AUS) so that advance at idle is about 12 degrees, and at 5000 rpm is still 34 degrees. But I think that the 4 centrifugal advance 4 springs etc also need some work too. I could sure use a tutorial on how these work and how to set them up. Where do I buy spare parts (springs) etc, and how do I identify where each spring goes? Thanks in advance for help. Martin Jansen Agoura Hills, So Cal.
Most people will probably say that it needs to go to someone with a distributor setup machine. That's probably a reasonable statement. I think there was some discussion maybe in the old Fchat archives, about someone making up a template to put under their distributor while spinning it with a variable speed drive. You could go look for it and see if it's worth the hassle to you.
You really need a machine, especially for the duel set up of a Ferrari. With a single distributor, one can trial and error it with a spring assortment, bending little bits of metal and a friend to hold the RPMs of your car in 1000 RPM increments while you scope it after each trial. This will take hours and hours...and you have to do it twice! Eventually you WILL get a reasonable advance curve provided you know what you need to begin with. It sucks when you have what you think you want and it's still bogging off the line! If a competent guy can use a machine and spend an hour on it, it's well worth it IMHO, especially on a duel system. Ken
Martin, We can check them on my machine but since i haven't figured it out yet. I have the number of my friend who is an expert at setting them up. Not sure what he will charge but it wouldn't hurt to ask. He is near palmdale so I am sure he could do it in a short time? Rob
I've been working on a write-up on how to set up these distributors, but it is too long to post here. Send me an email with your direct email address and I'll send it to you. Rob, there will be one on its way to you, too!
Mike is the expert here, will be waiting your essay with baited breath! How is it going out there? Rob BTW these guys were supposed to help me with my distributor machine but instead stole all my bling bling! Martin I am giving them your address. Image Unavailable, Please Login
I am new to fchat. I had a simular problem with advance. Graeme VIncent in Melbourne in Australia. He solved my problems with programable electronic advance and current ignition system. Its orginal and runs terrific. His mobile is 0418.308355 I will look up his email if interested.
Hi Mike I can host is at http://dino308gt4.com, its about time I added something new up there for all the patient and loyal visitors I might even get my Allen Tester working this winter. So far it is only sort of working. Gerrit
Hi guys, Finally got the document onto my web site. thanks go to Mike for a fabulous write up. I know I will be setting both mine up this winter using this description. See Downloads at http://dino308gt4.com (any of you who bookmarked dino308gt4.com/Ferrari will now have to drop the Ferrari, I streamlined a few things)
Thanks both of you, Geritt & Mike for the article, looks fantastic. Also, Geritt, thanks for posting the new URL, I'll have to change the link at my site... Mike, this is so cool, as I just bought the exact same dizzy machine! It's not as clean as yours, but it's the same model. I put the word out through my local club (Vintage Car Club of Canada) and within one day, I had leads on several. I settled on the Allen machine offered by one of the members. I'll be picking it up in a few days (I need time to clear out other crap in my garage to make room for it). Looks like I'll be needing that adapter that you use. Please email or PM me for details of where to get one. So I got my tired, worn-out distributors, I now have a machine, now I just need to get new parts (I have a lead on that which I need to check into). Guys, were your advance parts this worn out? My biggest need are the pins, the cup has superficial wear (but there is wear nonetheless). These pins, in my opinion are too worn out to re-use (seems stupid to shim these if they're that flat-spotted): Image Unavailable, Please Login Image Unavailable, Please Login
Peter: I PM'd you with the details on the adaptor. In my opinion this distributor falls into the category "severely worn out" I have no idea on where to source the pins (Marelli?), and that wear to the inside of the distributor case really scares me. Do the weight arms bounce when the pins hit those divots? I'd put the word out to your magic vintage car club that you are in the market for some new distributors, and maybe start spending some time on eBay!
Im not an expert but I do have 6 distributors!! All four of my used ones have the same wear on the drum and some of the pins are even worse looking some even look like uposltery buttons with several flat sides!!! Superformance has replacement weights, pins and springs in a set, I bought a set but they are all steell it says for longer life, except for the drum life!! I have a brand new set of drums and shafts but they have the early dog drive so the are useless in a spline drive gt4. I have heard that some people weld up the drums and then machine them out, but that sound like a lot of work. If I were you I would get a new set of innards from superformance and go from there. BTW in my original distributors half the weights were removed aand the remaining ones had half bronze (or brass) pins and half steel?? go figure The drums and pins wear from their pressure and movement on the inside of the drum. I have heard the drums are hardened steel, but not sure, If you give up I have a freind that sets them up for TR and would rebuild your if you send them to him, he has hundreds of parts he has beeen collecting ove a lifetime. BTW TR has rebuilt and set up ones for about 1000$ minus your old ones Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login
The pre-calibration is the only way to go, IMO. Way to go finding the machines, guys!!!! Ferrari of Atlanta had two NOS complete 308GTB distributers several years ago. Mine were sent out and were a LONG TIME coming back and I was exploring 'worst case".....which buying two at $800 each would have been....
I bought those NOS from them but they were converted for an early gt4 they actually have A lables with a scratch through it and a B stamped on the side.
Good show! Small world......mine eventually came home...plug and play!!!! Horizontal position isn't kind to them, after long periods of disuse....and of course the old '25 year old grease' factor comes into play.......
Maybe this will help, My PO, an electrical engineer for Raytheon, Dumped the idle/smog points. Put two sets of points in one distributor, to simplify timing, the second distributor only has to be close, as does the advance stuff - simplify. Installed two MSD-5 ignition boxes to boost the spark output and decrease the amperage across the points, (which makes them last about 5-10 times longer. Any CD setup will do this. I got frustrated with the rubbing block wearing out and went to the Norwood conversion, Inexpensive chrysler magnetic pick up, $16.00 chevy, cap. The two MSD -5 boxes were mounted on a fiberglass board that was mounted in the left trunk well. I found out that to use any optical or magnetic pickup it is necessary to move up to the MSD-6 series. A few bucks more gets you the MSD-6al, which has a soft rev limiter I have set at 8000rpm. If you still want to play with points, i will sell my two MSD-5 boxes with mounting board for $50. hth, chris
As an experiment, I have tried to weld/hard-surface the drum and pins of one dizzy, but ended up ruining those items. Seems to be a special, hardened alloy steel, which didn't like being heated up by a TIG torch... And I wasn't using too many amps either. It's not a loss though, as I'm in the process of using only one dizzy for both banks (both XR700 I.R. trigger units will run in the one dizzy - see photos below), so I have this last unit to work with by just replacing the pins. The one I ruined will strictly run as a dummy dizzy - no advance in it. I've got leads on another source of parts which I'll look into. Will use SF only as a last resort. Mike, I got your PM and will email you soon. The divots in the drum are like I said before, superficial. I haven't measured them yet, but it looks like it's only a thou or two deep. I suspect the drum is much harder than the pins and is that way on purpose for servicing/replacement issues (cheaper and faster to replace pins than the drum, thus the fact the pins are much worse than the drum). The following photos are of my custom dual XR700 I.R. trigger bracket I made to run the engine using the advance of one dizzy. This is to allow exact advance rate for both banks. The simple idea is to have both triggers 90 (engine) degrees apart, which has been used successfully by those who have Pertronix systems. I never liked Crane's brackets as I found they twisted around while tightening down to set them, plus, it would've been trickier if I used them both in this one dizzy. As always, I go overboard when I make things and this was no exception. Twin screws allow a secure fastening while restricting movement in a solid, constant arc in respect to the shaft axis. To those who would want one, give me time and I'll make a bunch. I won't take orders now, as I'd like to put miles on this system and work out any bugs and fitment issues. Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login
Wow! That is a super piece of fabrication work on the mounting ring, given as precise as it has to be (and lots of room for adjustment/alignment). I also like the idea of running a common advance mechanism for both banks. Elegent solution.
In my case, the pivot holes of the advance weights were wallowed out in one distributor, causing them to bind and not advance properly. The pins and drum were in good shape. The weight holes in my other distributor were fine though, so I used that one for my Pertronix conversion. Here is a shot of the two Pertronix modules mounted on the custom mounting plate I designed. Having both triggers using one advance really smooths out the engine. Image Unavailable, Please Login
Hi Peter Very nice fabrication. If you can't weld it, then it probably can't be done. I also notice, as any Canadian handy person would, that use are using the superior Robertson screws Next best thing to Allen head screws. Has anyone priced out an aluminum version of your bracket using http://emachineshop.com ? Gerrit
Hi (Couldn't edit my previous post so new one to add to my total) I played witht eh cad tool from eMachineshop for an hour and got nowhere building a similar part. I am old-school and prefer a drafting table with sharp pencils. If someone with a bit of Cad experience can draw this part using eMachineshop and getting a quote, it might be feasible going that route. I doubt Peter wants to get into the fabrication business. If I am wrong Peter, just give me a kick I envisage bulk of the mount being milled away from a donut of steel or aluminum, leaving perhaps .125 (or 5mm) all around with 2 raised sections perhaps .4" high? (And when you figure out how to get eMachineshop's Cad to do that, let me know so I can learn. I can see myself needing their services sooner rather than later.) Gerrit
I was wondering if someone would notice that! Ha ha! Honestly, I was looking for Allen-socket cap screws, but couldn't for the life of me, find them in this size. 8-32 fits the XR700 I.R. bracket slot the best and these Robertson screws were all I could find. And yes, just as good as Allens! It may be easier to have these things milled out on CNC machine, as I wouldn't mind making them, but it was fairly labour-intensive to bend the angle supports, drill and tap them, make matching clamping plates and weld the whole lot together. Darrell, where did you have your bracket made for your Pertronix system? If they could make yours, it should just be a easy to make it for the XR700's (which is another popular system for 308's).
