Brain Fart - Distributor Question - Not Enough Adjustment

[mikedsilva]

So I have had this distributor rebuilt for this engine. 3.0SC.

BUT I can only achieve 4 or 5 BTDC at idle as max advance before the black plug for the green wire on the side of the dist. housing, hits the side of the fan strap.

So I pulled the dist out, and rotated the shaft, 1 tooth advanced (anticlockwise).

But now, I can only retard it so far as to get 16 BTDC at idle before I hit the other edge of the slot on the locating stud.

What am I missing?

It's as if I need to alter the relationship between the rotor and the drive gear a 'smidge'.
Is that possible?

[Alan L]

Mike, My SC is typically sitting about 5-10mm shy of the RH end of the slot, and the green wire is jammed up fairly close to the fan housing. Uncomfortably close - in that the wire has a tight bend in it.
Dunno if that helps.
Alan

[Alan L]

Did you take the gear off the dizzy?
Does it change things if you rotate it 180 deg? Asymmetric mounting?
Alan

[Alan L]

What sort of timing are you trying to get? Nowhere near my car or manuals right now, but I think idle is close to zero and the mech adv takes you to 25 approx at 4000.
Alan

[mikedsilva]

Hi Alan
I didn't take the gear off.. I'm not sure if the shop that rebuilt it did. Not sure if rotating it 180 would help. I think there are 12 teeth evenly spaced.

I think the shaft that connects the rotor to the gear is in 2 pieces. Not sure how they are locked together tho.
I'll contact them again and see if there is a solution.

The shop told me the numbers of degrees at what rpm it was built to. It's quite soft. Maybe 22 at 4000. If I can only set it to 5 at idle, that means it might get to 27 degrees all in.

I'd like to be able to set it at 10 at idle.

Hoping someone who is versed in the art of distributor rebuilding could chime in!

[Alan L]

Right - The SC spec is 5 deg, which is where you are at. You still have a bit of slot left, on the RH end I think. Which would be correct. But the green wire end is preventing you using it to get a few more degrees - correct?
Yes, the shaft must be able to separate in to two, because the upper piece rotates around the lower bit for the mech adv - correct?
Is it possible it is an after market bit of green wire plug in the dizzy? Has it been replaced - new?
Alan

[Alan L]

But I do suspect I would not get another 5 deg out of my SC timing either.
From memory the wire or the plug is near touching the housing.
Alan

[mikedsilva]

Originally Posted by Alan L

Right - The SC spec is 5 deg, which is where you are at. You still have a bit of slot left, on the RH end I think. Which would be correct. But the green wire end is preventing you using it to get a few more degrees - correct?
Yes, the shaft must be able to separate in to two, because the upper piece rotates around the lower bit for the mech adv - correct?
Is it possible it is an after market bit of green wire plug in the dizzy? Has it been replaced - new?
Alan

Correct: the black plastic plug for the green wire is preventing me from rotating any further.
The plug is aftermarket; are they different from the original?
I might have to cut a slot out of the fan strap to make clearance... not really wanting to do that tbh...

The 5 degrees BTDC is a pretty conservative setting and the thought of leaving "free" hp on the table goes against my core beliefs!

[Alan L]

"Correct: the black plastic plug for the green wire is preventing me from rotating any further.
The plug is aftermarket; are they different from the original?"

No idea if aftermarket different - but quite possible - (lot of issues with aftermarket stuff these days) . Just casting around for an answer for you.
I am not at my car right now, but happy to take a pic in a day or two when I get back.
But... looking at your vid, the plug does 'seem' extended further that I would expect. A mm or two would be enough to snag you. There is a retaining clip on the dizzy that locks in to that groove - but you don't seem to have it locked. Is it not sitting far enough in to lock?
Alan
Edit - I see now, you do have the clip in. If no one else chips in, I will get a pic of mine when I get to the car.

[porschedude996]

Is this your number 1 spark plug wire?

[Alan L]

You can see the dizzy is fully retarded in that pic.
Thats my take on it anyway.
Alan

[mikedsilva]

Originally Posted by porschedude996

Is this your number 1 spark plug wire?

no
that's #5.

In that screen shot you took, i have already pulled out the dist, and rotated the shaft 1 tooth on the drive gear = REALLY advanced.. so thats what it is as RETARDED as I could locate the dist in that photo.

There are 12 teeth on the dist drive gear ... 360/12= 30 degrees. So moving the rotor shaft only 1 tooth, moves it a whole 30 degrees. Which is too far.

Today, I decided to shave off a couple mm of the black plastic of the plug.

With this 'modification' I was able to correctly index the rotor, and with the dist fully ADVANCED, I can get it to 8degrees, BTDC.

[LJ851]

The green wire exits the distributor in such a lousy spot. When I created a “functional” distributor for my carbureted 3.2 liter, I modified the magnet portion inside and rotated it to exit out a new hole that has plenty of room around it.

[boyt911sc]

Originally Posted by mikedsilva

no
that's #5.

In that screen shot you took, i have already pulled out the dist, and rotated the shaft 1 tooth on the drive gear = REALLY advanced.. so thats what it is as RETARDED as I could locate the dist in that photo.

There are 12 teeth on the dist drive gear ... 360/12= 30 degrees. So moving the rotor shaft only 1 tooth, moves it a whole 30 degrees. Which is too far.

Today, I decided to shave off a couple mm of the black plastic of the plug.

With this 'modification' I was able to correctly index the rotor, and with the dist fully ADVANCED, I can get it to 8degrees, BTDC.

Mike,

The #1 scribed MARKER is located between the GREEN WIRE PLUG and CAP metal clip. And the next ignition from the 1-6-2-4-3-5 sequence (CCW) is #6. You might have inadvertently installed the ignition cables incorrectly. Double check your work.

Tony

[TJJSC]

from my (running) 3.0SC ROW, maybe it helps

[porschedude996]

Originally Posted by mikedsilva

no
that's #5.

In that screen shot you took, i have already pulled out the dist, and rotated the shaft 1 tooth on the drive gear = REALLY advanced.. so thats what it is as RETARDED as I could locate the dist in that photo.

There are 12 teeth on the dist drive gear ... 360/12= 30 degrees. So moving the rotor shaft only 1 tooth, moves it a whole 30 degrees. Which is too far.

Today, I decided to shave off a couple mm of the black plastic of the plug.

With this 'modification' I was able to correctly index the rotor, and with the dist fully ADVANCED, I can get it to 8degrees, BTDC.

Whoops, I meant to use my photo. #1 as shown.

[Alan L]

Yes, I think it is your aftermarket dizzy plug that is the problem.
I have plenty of clearance on my SC - to go as advanced as I want.
Alan

[mikedsilva]

OK
so had a friend over yesterday and he has a lot more experience than me.
The distributor in this engine does not have a vacuum canister at all. In fact it doesnt even have the cutout and the pressed steel dust cover for where a vac canister could have been mounted.

What's the deal?
Which 3.0SC motors and for which country, didnt have ANY vacuum advance or retard?
Aso, the throttle body ONLY has 2 vac ports - one toward the rear of the car which is the atmospheric connect to the top of the WUR.
The port on the other side of the TB (front of car) is under vacuum and that goes to the T piece on the decel valve, and the vac port on the side of the WUR.

[mikedsilva]

OK
so had a friend over yesterday and he has a lot more experience than me.
The distributor in this engine does not have a vacuum canister at all. In fact it doesnt even have the cutout and the pressed steel dust cover for where a vac canister could have been mounted.

What's the deal?
Which 3.0SC motors and for which country, didnt have ANY vacuum advance or retard?
Aso, the throttle body ONLY has 2 vac ports - one toward the rear of the car which is the atmospheric connect to the top of the WUR.
The port on the other side of the TB (front of car) is under vacuum and that goes to the T piece on the decel valve, and the vac port on the side of the WUR.

[PeteKz]

I'm thinking that someone before you changed or modified the ignition system. There might have been some SC's without vacuum advance somewhere in the world, but I've never heard of them. Certainly not in the US. And all the CIS throttle bodies I've seen have 4 or more ports (not all of them are vacuum).

Does your dizzy have the SC size cap and rotor, and the 6-pin Bosch CDI box? It's hard to tell from the pictures, but the cap on your dizzy looks smaller than the standard SC cap (which is larger than the earlier dizzy caps). Possible that this is a dizzy from an earlier model car, and someone swapped the gears to rotate in the SC (CCW) direction? Or maybe it rotates in the earlier (clockwise) direction?