Distributor Fitting

[Pettifordo]

It seems that the distributor cap be slotted into the cam drive so that the rotor arm is pointing in one of two directions - is their a “right” way and how can I tell if the rotor arm is pointing in the right direction ?

I assume that I first get the engine to TDC…..and that at this point the rotor arm should be pointing in a specific direction ?

[JohnD]

Do read your workshop manual!   They all document that the slot in the top of the camshaft pinion is offset to one side.  It's slight and not easily seen by eye.

The dog in the bottom of the dizzy drive shaft is also offset, of course.   It is possible to get them engaged the wrong way around, if you are heavy handed!

Good luck!

John

[Colin Lindsay]

At TDC on the compression stroke the dizzy rotor arm should be pointing to No1 spark plug. The dizzy won't fit into the gear if it's correctly orientated but the drive is 180 degrees out, (rotate the rotor arm and the dizzy will drop down with a clunk - you'll feel it engage properly, otherwise it will be just resting on the drive and sitting proud of the housing) and if both drive and dizzy are 180 degrees out, the rotor will be pointing in the opposite direction.

[Pete Lewis]

as  john says you can force the dog drive in and have the offset 180 deg out    seen it before  

never struggle it should be an easy fit , 

to get  tdc it must be on compression stroke 

so put in  4th gear and a push with the rocker box off  get the tdc pointer to align the mark on the timing cover   the rockers on compression should both have a gap 

if one is down you are in need of one more turn of the crank 

then when you drop the dizzy in the rotor will point towards the caps Number 1   terminal

fit No 1 lead there and then   342  anticlockwise from your No1 to get the correct firing order 

if replacing a different dizzy they can have different clamping diameters just to make a simple swap more difficult as this needs a new clamp

Pete

[Iain T]

What about getting the correct dizzy depth, is there an easy method to calculate the correct shims required? 

Iain 

[NonMember]

The distributor itself isn't that bothered about exact depth - it has a dog that engages in the drive gear for a good few millimetres, and that's all that matters. The shims (or rather the selective gaskets) are to space the pedestal to get the right end-float on the drive gear. You fit with no gasket, measure the gap with a feeler gauge, and add the required float.

[Pettifordo]

On 02/07/2022 at 08:44, JohnD said:

Do read your workshop manual!

I have a resto manual and the hayes manual which I do read but they always seem very brief…….

Thanks for your answer.

 

[Pete Lewis]

steve may cover what you want  or get a prpoer wsm from club shop on your wish list    even a used off the bay 

Triumph Car Service manuals - Vitessesteve

Pete

[JohnD]

Pettifordo,

Manuals are necessarily terse, and sometimes don't emphasise important points.  Well done for getting both books, they complement each other, but they need careful reading.

And they do contain errors, even the official WSM!  Not in this case, but if something doesn't seem right, do ask.

Bests 

John

 

 

 

[Iain T]

To determine if anything requires further work on end float is a quick check to (carefully) pull up the drive shaft to see if there is excessive play? 

Iain 

[Pete Lewis]

you realy only need to worry about the drive gear end float if you disturrb the pedestal from the block 

remove /ritting a dizzy has no effect on the drive gear end float 

it is quite important as too much makes agood rattle and too little can end up as seized 

if the dizzy is out you could grip the gear drive and see if it has a small updown clearance 

but if its been ok for years theres little chance of any change unless you do remove the pedestal base  maybe to seal an oli leak or similar 

its best left alone 

Pete

[Iain T]

5 minutes ago, Pete Lewis said:

but if its been ok for years theres little chance of any change unless you do remove the pedestal base  maybe to seal an oli leak or similar 

The reason why I would like to check it as I've had the engine refurbished but they didn't fit the distributor and the PO had the engine supplied by a company I do not trust. I've just refitted what the PO supplier fitted hence my concern. 

Iain 

[Pete Lewis]

the specified float is 0.003" to 0.007"   so a  target of   0.005"  is good  

there is a number of ways to check in the WSM  

i guess the simlest is remove all old gaskets  , sit the pedestal on top of the gear 

, 

with feelers measure the gap between pedestal and block face   add 0.005" to the dimension found and make up gaskets to this thickness

refit and nip up the two bolts   get hold of the gear and check it has a little 0.005" lift 

if no lift add more gaskets

but before you start  .......... if you can detect a small float  leave it alone 

Pete

[Iain T]

52 minutes ago, Pete Lewis said:

but before you start  .......... if you can detect a small float  leave it alone 

The shaft pulls up around 1mm so lots of float! 

Iain 

[Pete Lewis]

time to loose a gasket or two then  

(by shaft you mean the gear ??? )  

Pete

[Iain T]

No the shaft that the rotor arm pushes onto. I think I need to take a closer look......

Iain 

[NonMember]

In that case I think we've been talking at cross purposes. That shaft movement has nothing to do with drive gear end float or the fitting of the distributor. It's indicative of some play internally within the distributor, and may not necessarily be an issue - I don't know what the spec is for that shaft end-float but I think it's fairly slack.

[Iain T]

Thanks, I need to have a poke around before I have any further questions!

Iain 

[Royston W]

And make sure that the rotor arm that sits on top of the shaft is correct , I had a Delco Remy Rotor arm sitting on a Lucas dizzy and it took me AGES to work out why the timing was 180 degrees out. The rotor arm fitted perfectly but its design meant that the "blade" and the driving " notch" were both on the same side whereas on the Lucas they are opposite. 

Mechanic AND detective to solve that one !!