Engine overruns

[qim]

Hi Camilo ~

 

When I first got my 3A the distributor was 180 deg. out. I was able to time the engine using No. 4 lead

but I decided that I'd prefer the distributor to be set as per the workshop manual.

 

This meant removing the distributor and then turning the distributor drive in the block by 180 deg.

You have to lift the drive up to disengage it from the camshaft drive. You also have to turn the oil pump

drive 180 deg. because the slot in the drive is off-set.

This would then make the rotor arm point to No. 1 plug lead.

 

Tom.

 

Hi Tom

 

I thought I had enough problems!

 

Anyway, from what you tell me, it seems that I don't have to take out the front apron/radiator, etc. Is that so?

 

I thought that the reason for this might have been that when the car was dismantled the guy who did it may have fitted the plate (whatever it is called) where the timing mark is the other way round. No?

 

And more to the point: how do I use the timing test light now? Does it make any difference?

Edited September 24, 2017 by qim

[Fireman049]

Hi Camilo ~

 

You don't have to remove anything except the distributor. Obviously make sure that No. 1 piston is at TDC with the timing marks lined up.

It's quite possible that your mechanic fitted the distributor 180 deg. out.

 

You then attach your timing light to No. 1 plug lead. Your distributor vernier should be adjusted so that the long 'notch' on the vernier

is in line with the distributor body. This is usually about three 'notches' from the end of the scale.

You can then rotate the distributor body to set your timing.

 

Tom.

[RobH]

Camilo - before you panic and start dismantling anything it is possible that Tom has started a red herring here. As Andrew W pointed out in post 39, the timing mark will be at the top for both 1 and 4 cylinder on compression. That does not mean the dizzy is 180 degrees out. Since your engine runs and the picture shows the rotor pointing to No4 lead in the correct position (bottom right as you look at the side of the engine) then all is correct and you can relax.

Edited September 24, 2017 by RobH

[Fireman049]

Camilo ~

 

RobH is quite correct. But all engines left the factory with the rotor arm pointing at No. 1 plug lead if you want to be strictly accurate.

 

(Check the Workshop manual ~ engine timing).

 

Yes, the engine will run perfectly with the distributor 180 deg. out.

 

No red herrings involved.

 

Tom.

Edited September 24, 2017 by Fireman049

[RobH]

Tom - that distributor does not look wrong to me. If it were 180 out then the HT leads in the cap would have to be in different places but the photo shows Camilo's are as standard.

[Fireman049]

Hi RobH ~

 

Yes the HT leads are in their correct positions but the distributor fires on No. 4 plug instead of No. 1.

I know because I've been there!

 

Are you saying then that the Workshop Manual is wrong?

 

Tom.

Edited September 24, 2017 by Fireman049

[RobH]

The ONLY effect of having the dizzy 180 out is to alter the lead positions. It does not alter how you set the timing. The distributor is supposed to fire on no 4 when that cylinder is on the compression stroke and that is what the photo shows. If Camilo had rotated the engine by a further revolution before he took the photo then the arm would be pointing to lead 1 with the marks aligned and this confusion would not have arisen.

Edited September 24, 2017 by RobH

[Fireman049]

What do other Forum members think?

 

I've obviously got my engine timing wrong!

 

Tom.

[Drewmotty]

The photo shows the distributor with no 4 at TDC on compression and No1 TDC on exhaust. Another full turn of the crankshaft will see the rotor arm pointing at No1 which will then be at TDC compression exactly as it should be.

The crank pulley TDC mark will be aligned in both cases.

Edited September 24, 2017 by Drewmotty

[Fireman049]

Hi Andrew ~

 

Are you saying that my engine timing is correct???

 

Tom.

[qim]

Thank you all.

 

I was coming round to this having remembered that the dizzy revolves twice for each revolution of that round thing... where the timing mark is. Or is it the other way round...?

 

Anyway I can relax again!

Edited September 24, 2017 by qim

[Peter Cobbold]

Thank you all.

 

I was coming round to this having remembered that the dizzy revolves twice for each revolution of that round thing... where the timing mark is. Or is it the other way round...?

 

Anyway I can relax again!

The crankshaft pulley ( 'that round thing') rotates at the rpm shown on the dashboard meter. The distributor shaft roates half as fast.

So 10 dgrees on the crankskaft correpsnds to 5 on the distributor.

This is becase of the 4 stroke cycle - the crank makes two turns between each spark: " suck>squeeze>bang>blow"

[Fireman049]

Hi Peter ~

 

Would you say that I've got my engine timing correct??

 

I only followed the Workshop manual (plus the fact that I've been working on TR engines since 1955!).

 

It appears from this Forum that my engine should fire on No. 4 cylinder??? (But it bloody well doesn't!!)

 

Tom.

Edited September 24, 2017 by Fireman049

[qim]

From MacysGarage

 

We’ve finally reached the point where we can set the initial timing, and the next thing we must do is determine when the #1 piston is at Top Dead Center (TDC). With the gearbox in neutral, you should be able to turn the engine (clockwise when viewed from the front of the car) by hand until the timing mark on the crankshaft pulley lines up with the pointer on the engine’s timing cover. As long as someone has not assembled the hub and pulley incorrectly (see the factory workshop manual for more on this), the #1 and #4 pistons should both be at TDC. You can set the distributor cap loosely in place and if the rotor points to the #1 or #4 terminal locations, you can proceed with the timing adjustment. If you go past the place where the two marks line up, don’t just back it up a small amount to align them. Back it up well past the correct location, and approach the spot again with a clockwise rotation of the crankshaft (to take up any possible “slop” due to a worn timing chain or gears inside the engine) or rotate the crankshaft another full revolution in the clockwise direction and try it again

 

Edited September 24, 2017 by qim

[Fireman049]

Well, I'm sticking with it firing on No. 1 cylinder regardless!! That's how it used to be and that's how it's staying ~ Amen!!!

 

The same goes for my 'E'-type Jaguar ~ as per the factory specification!!

(and don't forget that No. 1 cylinder on the 'E'-type is nearest the windscreen and not the radiator!!).

 

Tom.

[qim]

Hi Tom

 

You are probably right, even if from my needs it appears that it doesn't matter for setting the timing. As the crankshaft pulley goes round starting from the timing mark next to the pointer, the dizzy will go around twice and if it starts at #1 it will return after one full circle of the pulley to #1. If it starts at #4 it will return to #4. If the factory says that it should be at #1, so be it, although it appears that for the sake of timing it makes no difference.

 

i would certainly ike to hear all the opinions.

 

Camilo

[Peter Cobbold]

As the crankshaft pulley goes round starting from the timing mark next to the pointer, the dizzy will go around twice

 

Camilo

No - see post 62.

[Ian Vincent]

Hi Ian

 

Acuspark SP8000

 

My car is running fine but have not gone as far as letting it pink. Should I keep advancing it until it does, and then retard it a bit? By how much?

Yes, I would keep advancing until it pinks and then back it off by a couple degrees until it doesn't.

 

Rgds Ian

[qim]

Hi Peter

 

What do you expect from a decaying 71 year old brain? Yes, the dizzy goes from #1 to #4 with each turn of the pulley, and according to Macy's it does not make much difference which you line up with for timing purposes.

 

 

Hi Ian

 

Thanks. I will carry on after I get the car back from the paint shop.

 

Thank you all. I'm becoming an expert on dizzys to the point of getting dizzy!

Edited September 24, 2017 by qim

[Peter Cobbold]

Hi Peter

 

What do you expect from a decaying 71 year old brain?

Hi Camilo, Mine's 72...and decaying too. If you spend time to really understand the engine - what does what and when - it will be easier to make sense of instructions in workshop manuals or on here. SC Mudd wrote little books in the 60s and early 70s explaining the basics The AA Book of the Car from same period is also useful:.

https://images-na.ssl-images-amazon.com/images/I/51dwptViccL._SY466_BO1,204,203,200_.jpg

Peter

[Ian Vincent]

Camilo,

 

You can set the timing off either 1 or 4. But you must clamp the timing light to the appropriate lead.

 

Rgds Ian

 

PS an e type is. 6 pot engine so I'd need to think about it.

[Fireman049]

What has the number of cylinders to do with engine timing??

 

Tom.

[Drewmotty]

On a 4 cylinder TR 1&4 are at TDC together so the timing can be set on either (or average both)

Maybe not true on 6 cylinder cranks.

[Peter Cobbold]

On a 4 cylinder TR 1&4 are at TDC together so the timing can be set on either (or average both)

Maybe not true on 6 cylinder cranks.

1 and 6 on a TR6 as firing order is 153624

 

Not sure about Jag f/o, and cylinders numbered with 1 at the flywheel end, I think

[Ian Vincent]

Peter,

 

And presumably nos 1 & 6 are at TDC at the same time with one on a firing stroke and the other at the end of an exhaust stroke?

 

Rgds Ian