| Author |
Message |
Mitchell Minh Le (Yelcab1)
Junior Member
Username: Yelcab1
Post Number: 65
Registered: 11-2001
| | Posted on Wednesday, March 06, 2002 - 6:05 pm: | |
Yep
The distributor shaft that goes inside the intake camshaft has an o-ring that is about 5/8 of an inch in diameter. This o-ring needs to be replaced when you take it apart. You can get it anywhere for 25 cents each. I bought an assorted O-ring kit for $16 bucks, 400 pieces. I will use 10 in my lifetime, but sure beats having to chase it down each time. Also bought a snap ring kit, 400 pieces for $16 too, same reasons.
I had a big supply of brake / parts cleaner and that works well on the stuff that gasoline did not dissolve.
Good luck and don't make the same mistakes I did. |
david schirmer (David)
Junior Member
Username: David
Post Number: 226
Registered: 2-2001
| | Posted on Wednesday, March 06, 2002 - 5:57 pm: | |
Mitchell, when you pull off your distributor is there any seal or O ring there? I have been reading up on how to do this job and they say that there is some sort of seal that I need to worry about. Thanks for writing about your experience, I am probably a week or two behind you on this job. |
Mitchell Minh Le (Yelcab1)
Junior Member
Username: Yelcab1
Post Number: 63
Registered: 11-2001
| | Posted on Wednesday, March 06, 2002 - 8:32 am: | |
OK,
I decided to disassemble the other distributor and be very careful to preserve the setting of the springs. What I found:
1. Now that I know what to look for, the second time around goes about 3 times faster.
2. The distributor was covered in gunk and goop. I have no idea how that damp thing ever did work.
3. There were the same number of weights, springs, and spacer.
So, I put the other previously diassebled one back the same way. Then proceeded to clean and rebuild the second one. Much easier this time, and I did not dunk the bearing either.
I will probably have the advance checked by a Alfisti shop 1/2 a mile from my home (lucky me) they have a distributor calibrating machine. |
Timothy J. Dressel (Tjd)
New member
Username: Tjd
Post Number: 45
Registered: 4-2001
| | Posted on Monday, March 04, 2002 - 8:24 pm: | |
Mitchell, et. al.,
The distributors (2) on my gt4 were goofed up when I bought the car. As you probably know, the two weights on a Ferrari distributor are supposed to work symmetrically to control the advance. The previous-previous owner had changed the springs/shims on one of the two weights (on each of the two distributors). While this non-symmetry works fine on the Chevys, it caused severe wear on my distributors� advance components. After fixing the wear, I had to reset the springs and shims. I had a gun shop make some springs of the same gauge wire and diameter, which I cut and ground to size (several experiments). Then I experimentally fit my springs and shims and tested them using a crude system of weights to see how the assembles compressed against the outer ring/housing(?). When all four weights functioned as equally as I could get them, I assembled everything and tried the distributors on the car, using two timing lights. It was all shade tree, but I found on the first try that the curves of the two distributors tracked within a degree, right up the rpm range. I suspect my good results had a lot to do with a great distributor design (which I probably don�t fully understand) and a bit of luck. �tim d
|
Bill Sebestyen (Bill308)
Junior Member
Username: Bill308
Post Number: 110
Registered: 5-2001
| | Posted on Monday, March 04, 2002 - 6:57 pm: | |
Jeff,
That's some damn good back yard engineering. Very imaginative. Bill |
Jeff 77 GTB (Jbk)
Junior Member
Username: Jbk
Post Number: 56
Registered: 4-2001
| | Posted on Monday, March 04, 2002 - 6:45 am: | |
I had mine apart last year and found a number of shims under the springs that were used to adjust the advance curve. As the weights rotate out from the pivots due to centrifugal force, they sequentially press the springs against the outer housing. Adjusting the number of shims under the particular springs is what appears to be used to adjust the advance curve. If I remember right, one of my distributors had anywhere from 0 to 4 shims under the different springs, while the other distributor had 2 or 3 under each. This had me a little concerned so I made a mount on my drill press and rigged up a distributor test machine with a degree wheel. I mounted the distributor and drove it with a v-belt off the drill press. I also hooked up the coil and spark plugs on the same fixture so the full system would work. Then I just used a timing light to read the advance off the degree wheel as the distributor was turned at different speeds. I found the advance on the 1 distributor was at least 5-6 degrees off from the other one and was able to get them both to match the advance curve in the manual by adjusting the shims behind the springs. Was quite interesting. |
Brian stewart (Eurocardoc)
Junior Member
Username: Eurocardoc
Post Number: 197
Registered: 11-2001
| | Posted on Monday, March 04, 2002 - 5:32 am: | |
I don't have one to look at at this moment, but I think that as mentioned the two compression springs are equal and can go either side, the others go each side. The cams are the same so it matters noit which gets which expansion spring. It is always a good idea to bench test for the advance curve and to set the points if staying with them. |
Bill Sebestyen (Bill308)
Junior Member
Username: Bill308
Post Number: 109
Registered: 5-2001
| | Posted on Sunday, March 03, 2002 - 9:51 pm: | |
Mitchell,
Unless there is an obvious problem with the bearing, I would think a drop or two of engine oil will be fine. There is not a lot of load on these bearings and they spin at 1/2 the engine rpm.
Your ignition advance springs are a problem. I think the best way to sort this out is to put the distributors back together with a set of points and bring them to someone who has a distributor machine. Unlike most distributors I'm familiar with, the Morelli distributors use compression springs to counteract the weights. These springs may be difficult to find. Perhaps someone loacally who works on Alfa's or Fiats can help. They can mount them, measure the advance verses rpm, and swap out the springs as necessary. Both distributors should set up to advance the same. This is an iterative process that is much easier performed on a distributor machine then running it on the car. After the advance curve has been dialed in, you can remove the mechanical point set and install the XR700's. Bill |
Mitchell Minh Le (Yelcab1)
Junior Member
Username: Yelcab1
Post Number: 62
Registered: 11-2001
| | Posted on Sunday, March 03, 2002 - 8:26 pm: | |
Doc
What about the bearing, do I get a new one? Or is it dry? Or it it useable with a light oil?
What about the balance weights and the different spring, how do they go back? In whic location? Or does it matter? |
Brian stewart (Eurocardoc)
Junior Member
Username: Eurocardoc
Post Number: 195
Registered: 11-2001
| | Posted on Sunday, March 03, 2002 - 7:49 pm: | |
Grease is too heavy on the balance weights, use a light oil. |
Mitchell Minh Le (Yelcab1)
Junior Member
Username: Yelcab1
Post Number: 60
Registered: 11-2001
| | Posted on Sunday, March 03, 2002 - 11:36 am: | |
So this is my first Dist rebuild and I make two mistakes.
1. Did not notice the little weights are different: 1 short spring, 2 medium ones, and 1 long ones. How do they go back?
2. Did not notice the bearing in the back and dipped the whole shaft into a carb cleaner tank. I am sure the lubrication inside is gone, but the bearing balls survive. Do I get a new bearing (and where) or can I reuse with some kind of grease or lub?
I reassemble the components with tune up grease. Should I have left it dry?
Thanks.
Mitchell |