ausmini :: View topic - Distributor drive gear and drive dogs

Uuumm no. That's why there's an offset.

If you look at the top of the drive it has a slot. One side of the slot goes through the middle of the drive while the other side is obviously offset from the centreline. This means that one segment of the circle you see when looking straight down on the drive is larger than the other.... ie the slot is offset on one side.

However, if you don't use the proper logic in setting up the timing and just rely on the falacious logic that No1 plug lead connects at "2 oclock" then .. yes, the timing can be 180 degrees out.

Cheers, Ian

Yeah, when i measure the offset and have the drive gear installed per the manual instructions with the larger segment (0.060" ish larger by my calipers) on top, this results in the no 1 position being 180 deg out. i.e. at 7 oclock instead of 1 oclock.

The pin on the drive dog on the distributor shaft has some marks indicating it has been knocked out at some point by someone. If this could be 180 deg out, then it would explain the oddity above. I take it the shaft and dog don't have a particular indexing like the dog to drive gear offset.

Need to know because i have a new electronic distributor on its way and i want to set it up to receive correctly.

cheers
michael

I had always thought the partial offset was deliberate!

Pfft...the british..

mickmini wrote:

The dog has obviously been fitted to the dizzy 180deg out.
You can turn it around, but will have to stick a 3/16" drill through both, or the drive pin won't fit properly, as the hole is never drilled dead thru the centre of the shaft.
This is the case with all Lucas dizzies, the Chinese made ones bay be better if CNC machined.

He has not got his equivalent of the accuspark black box up and running yet, so i will have to get one of those shortly.

Just swap the plug leads around. It isn't rocket surgery.

It is possible to assemble a dizzy so that it is 180° out internally.

Author:	mickmini [ Wed Jul 23, 2014 7:03 pm ]
Post subject:	Distributor drive gear and drive dogs
What defines "large offset" on the drive gear? Is it possible for a drive dog to be fitted to the shaft 180deg out? cheers michael

Author:	1071 S [ Wed Jul 23, 2014 7:31 pm ]
Post subject:	Re: Distributor drive gear and drive dogs
Uuumm no. That's why there's an offset. If you look at the top of the drive it has a slot. One side of the slot goes through the middle of the drive while the other side is obviously offset from the centreline. This means that one segment of the circle you see when looking straight down on the drive is larger than the other.... ie the slot is offset on one side. However, if you don't use the proper logic in setting up the timing and just rely on the falacious logic that No1 plug lead connects at "2 oclock" then .. yes, the timing can be 180 degrees out. Cheers, Ian

Author:	mickmini [ Wed Jul 23, 2014 8:02 pm ]
Post subject:	Re: Distributor drive gear and drive dogs
Yeah, when i measure the offset and have the drive gear installed per the manual instructions with the larger segment (0.060" ish larger by my calipers) on top, this results in the no 1 position being 180 deg out. i.e. at 7 oclock instead of 1 oclock. The pin on the drive dog on the distributor shaft has some marks indicating it has been knocked out at some point by someone. If this could be 180 deg out, then it would explain the oddity above. I take it the shaft and dog don't have a particular indexing like the dog to drive gear offset. Need to know because i have a new electronic distributor on its way and i want to set it up to receive correctly. cheers michael

Author:	bent65 [ Wed Jul 23, 2014 10:16 pm ]
Post subject:	Re: Distributor drive gear and drive dogs
1071 S wrote: Uuumm no. That's why there's an offset. If you look at the top of the drive it has a slot. One side of the slot goes through the middle of the drive while the other side is obviously offset from the centreline. This means that one segment of the circle you see when looking straight down on the drive is larger than the other.... ie the slot is offset on one side. However, if you don't use the proper logic in setting up the timing and just rely on the falacious logic that No1 plug lead connects at "2 oclock" then .. yes, the timing can be 180 degrees out. Cheers, Ian Dizzy to drive shaft can only go one way. Drive shaft to cam can go on any tooth. Doesn't matter which one. One of the manuals or maybe vizard book has incorrect instructions to have large offset upwards to result in no 1 lead pointing to plug 1. (2 o'clock) To rough time it. Rock no 1 to tdc on fire stroke, and rotor button should point to this lead. Then dynamically time it or use test light. It doesn't matter what cam tooth you set dizzy on but having number 1 lead at 2 o'clock gives the neatest plug lead layout IMHO. Hope this helps.

Author:	mini_mad_matt [ Wed Jul 23, 2014 11:29 pm ]
Post subject:	Re: Distributor drive gear and drive dogs
The most common mistake is that when using the workshop manual, you time the camshaft in with no.1 cylinder rocking. The instructions for fitting the distributor drive into the block is for no.1 cylinder firing. So if you have just timed the cam in and go to put the drive in without changing anything, you will be 180degrees out

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Author:	drmini in aust [ Thu Jul 24, 2014 8:15 am ]
Post subject:	Re: Distributor drive gear and drive dogs
mickmini wrote: Yeah, when i measure the offset and have the drive gear installed per the manual instructions with the larger segment (0.060" ish larger by my calipers) on top, this results in the no 1 position being 180 deg out. i.e. at 7 oclock instead of 1 oclock. The pin on the drive dog on the distributor shaft has some marks indicating it has been knocked out at some point by someone. If this could be 180 deg out, then it would explain the oddity above. I take it the shaft and dog don't have a particular indexing like the dog to drive gear offset. Need to know because i have a new electronic distributor on its way and i want to set it up to receive correctly. cheers michael The dog has obviously been fitted to the dizzy 180deg out. You can turn it around, but will have to stick a 3/16" drill through both, or the drive pin won't fit properly, as the hole is never drilled dead thru the centre of the shaft. This is the case with all Lucas dizzies, the Chinese made ones may be better if CNC machined.

Author:	Mick [ Thu Jul 24, 2014 9:38 am ]
Post subject:	Re: Distributor drive gear and drive dogs
I had always thought the partial offset was deliberate! Pfft...the british..

Author:	gtogreen1969 [ Thu Jul 24, 2014 10:10 am ]
Post subject:	Re: Distributor drive gear and drive dogs
Mick wrote: I had always thought the partial offset was deliberate! Pfft...the british.. Yes. Probably designed to ensure excessive wear by off-balancing the rotating mass.

Author:	mickmini [ Thu Jul 24, 2014 3:29 pm ]
Post subject:	Re: Distributor drive gear and drive dogs
drmini in aust wrote: mickmini wrote: Yeah, when i measure the offset and have the drive gear installed per the manual instructions with the larger segment (0.060" ish larger by my calipers) on top, this results in the no 1 position being 180 deg out. i.e. at 7 oclock instead of 1 oclock. The pin on the drive dog on the distributor shaft has some marks indicating it has been knocked out at some point by someone. If this could be 180 deg out, then it would explain the oddity above. I take it the shaft and dog don't have a particular indexing like the dog to drive gear offset. Need to know because i have a new electronic distributor on its way and i want to set it up to receive correctly. cheers michael The dog has obviously been fitted to the dizzy 180deg out. You can turn it around, but will have to stick a 3/16" drill through both, or the drive pin won't fit properly, as the hole is never drilled dead thru the centre of the shaft. This is the case with all Lucas dizzies, the Chinese made ones bay be better if CNC machined. Thanks Kev. Most of the other responses seemed to neglect the question about the dog to shaft alignment. I suppose they assume that the dog is permanently fitted to the shaft. New cap is side entry so if it is 180 deg out the leads will point downwards! I got one of Tony's 45D electronic jobbies, so it should be good. Not sure where his are made, but at least if there is an issue he is only a phone call away. He has not got his equivalent of the accuspark black box up and running yet, so i will have to get one of those shortly. cheers michael

Author:	drmini in aust [ Thu Jul 24, 2014 4:46 pm ]
Post subject:	Re: Distributor drive gear and drive dogs
Michael, I'd be inclined to leave the dog as is and just turn the dizzy driveshaft 180deg. Who would know...

Author:	mickmini [ Thu Jul 24, 2014 5:39 pm ]
Post subject:	Re: Distributor drive gear and drive dogs
More concerned about the new one than the old at this point.

Author:	Morris 1100 [ Thu Jul 24, 2014 5:42 pm ]
Post subject:	Re: Distributor drive gear and drive dogs
Just swap the plug leads around. It isn't rocket surgery. It is possible to assemble a dizzy so that it is 180° out internally.

Author:	Mick [ Thu Jul 24, 2014 5:46 pm ]
Post subject:	Re: Distributor drive gear and drive dogs
mickmini wrote: He has not got his equivalent of the accuspark black box up and running yet, so i will have to get one of those shortly. I'm keen to try fitting up one of these from Convertible Mini. They're in country now?

Author:	mickmini [ Thu Jul 24, 2014 5:48 pm ]
Post subject:	Re: Distributor drive gear and drive dogs
He has *not* got his equivalent of the accuspark black box up and running yet for clarity, i will be getting the accuspark shortly

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Author:	mickmini [ Thu Jul 24, 2014 5:50 pm ]
Post subject:	Re: Distributor drive gear and drive dogs
Morris 1100 wrote: Just swap the plug leads around. It isn't rocket surgery. It is possible to assemble a dizzy so that it is 180° out internally. I know. Lived with it 180deg out for 6 years. Even won class victory in NL with it that way so it can't be all bad. Just want the new one to be the right way round for novelty. cheers michael