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Triumph TR6 - 22Ddistributor curves

Hi TR6 enthusiasts.
I have just purchased a 76 TR6 and would like to know the curve that the 22D lucas distributor provides. It's numbered 41385A. Does anyone have the curve for this ?

Also any help on how to get a better curve than standard smog curve will be greatl;y appreciated.

Great cars eh ?

Tony in Alberta, Canada
Tony

Tony,
Where in Alberta are you located?

Doug
Doug Campbell

To Doug in Edmonton,
As you see I'm in Calgary (lived in Edmonton for a while too)
Do you have a curve for a Lucas 22D 41385A (fitted on my 76 TR6)? I would like to set it up for modern gas and no smog etc., I believe they were fitted originally to 1973 TRs. so may have a dynamic setting other than -4deg at 800rpm. Might even need re-curving ?

Tony
TONY

The mechanical advance curve for the 41385 distributor based on crank speed in rpm, and min, then max degrees advance at crank is:

1200 2 6
1800 8 12
2400 12 16
4400 21 25
5600 24 28

The advance cam and weights are the same in this distributor as in the 41352. However, the 41352 comes up the curve a little faster and has a touch nore total advance. This means the difference is tied to the springs which are different between the two.

There is big thread on mechanical curves in the archives from February of 2003 under "Machanical advance and Vacumm retard."

Pulling from that thread, I will ask again for some help as follows:

Now for the "I need everyone's help" part. I am trying to gather up info in the Lucas 22D6 and 25D6 family of distributors. Where I am falling down is on information related to car particulars. So if you have friends with things like MGCs, big Healeys, other 6 cylinder Triumphs (including salloons) and various 6 cylinder engined Jaguars (saloons and sports cars) try to find the 5 digit Lucas distributor number and if there is shop manual information, gather up as much mechanical advance curve information as you can, then send it to me. If they have 6 cylinder Lucas distributors sitting around they could look into to find the stamp indicating maximum potential advance, so much the better. If the advance cam can be verified in one fitted to the car, even more stuff to try and cross reference. Best of all, if you can find technical information on the spring constants Lucas used, that would be perhaps the most key bit out of the bunch.

So far I have determined the following on the 22D6/25D6 front. There are two different potential weight sets used in the 22D6/25D6 family. For the TR5/250/6 applications, one weight type is used in all but a single distributor (41542) used in some of the later PI cars, but that weight is also used for some Jaguar and GT6 (Lucas replacement for OE distributor). There are five different advance cams used across the TR5/250/6 range, but I can only pin down two advance limitations, a 13 and a 17 degree advance cam. Again, in some cases these cams are also common to Jaguar applications. Nine cams in total were found across the 22D6/25D6 family. The springs are all over the place application wise and impact the curves on distributors that are otherwise fitted with the same parts, kind of an obvious conclusion, but I can't seem to dig up info on the spring constants. Plates and action shafts seemed to pretty much be tied to a specific Lucas customer's engines and no cross over was noted between different manufacturers engine families.

So if you can get information to me on application, advance curves from manuals and max advance indicated by a given distributor, spring constants, we just might be able to pull a cohesive set of tuning information out of the bag and set it loose on the board.
SteveP

Hi Steve P,

Thanks for the info. Just what I was looking for. I would have thought it should come up even faster, however I don't have torque , Hp and RPM curves yet either. (Do you have a source for this ?) Got the car 3 weeks ago so all very new to me.

I did find that the 22D 41385A was a 1972 model and not a 1973 as I mentioned yesterday.

Where do I find the stamp to show the max potential advace for this distributor ? I see a 42 and 76 stamped on it ????

Cheers Tony in Alberta Canada
Tony

The numbers are stamped on the advance cam. You have to remove the breaker plate (sometimes refered to as the action plate) and may even have to pull off one of the weights to see it. Note however, that this number defines the degrees of advance at the distributor and not at the crankshaft.
SteveP

Thanks for the reply SteveP

I'll keep an eye open for any distributor data that I might come across.
Also I'll do a calibration on mine soon.

Cheers Tony
Tony in Alberta

This thread was discussed between 06/04/2005 and 07/04/2005

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