123 Distibutor

[Peter Vernon]

I have fitted a 123 distributor, the standard item not the type to connect to a computer.

 

I have checked the forum and the setting that some have used is No 7. The car is running well but I just wanted to check that I am on the correct setting. I have a std cam with a 150 BHP engine if that helps.

 

Everything is smooth enough and seems to pull better at low revs but I just want to check if I can get better performance.

 

Peter

[stuart]

When fitted to a 6 I would use setting "B"

Stuart.

[Fireman049]

My 3A is also fitted with a '123' distributor. She has a 2.2 L engine and a Piper Road/Rally TR3BP285 camshaft

and a TR4A 511695 unleaded head, four branch extractor manifold and single silencer.

What should the setting be for the '123'?

 

Tom.

[TriumphV8]

I just want to check if I can get better performance.

 

 

Question is how far you want to go?

 

First the better point for setting up is not the idle but high revs

where the engine should have 30 deg advance.

 

To get that perfect you should carefully match the marks on the pulley finding the correct TDC.

None of the cars I prepared had that really perfect keyed in!

 

Than put the max advance to the 30 degrees and test.

Now the other way round the ignition becomes more aggressive

the smaller the number of the switch becomes.

 

So its a good idea to start with the "B" as Stuart says and keep in mind

that always when you change the curve with the switch you have to strobe for the 30 degree again!

 

Unfortunately you have choosen the 123 ignition and not the "tune" because with the PC controlled tune

version you can employ part throttle advance. I know that Peter has a different opinion on that

but I recently set up a PI with that and it works wonderfull!

 

But to be honest there is not that gain in performance that people claim.

Being away one degree from perfect timing costs about one HP, not more.

On lower revs the difference is also less......

 

What often is felt as a really better response is too much advance at low revs because

engine has no part throttle advance but would need it and there are not missing one or two degrees

but more than ten degrees, so one should feel a real difference with more advance.

As long as one does not apply full throttle an engine benefits from such a timing

but may pink badly under full load and its worse for the engine.

[TriumphV8]

What should the setting be for the '123'?.

 

Would also take "B" and 32 degrees max advance.

Engine tend s to pink at 2000-2500 rpm what can

be avoided with "E".

 

If pinking is still there the 43 must be reduced to 30

[Dave Larnder]

My 3A is also fitted with a '123' distributor. She has a 2.2 L engine and a Piper Road/Rally TR3BP285 camshaft

and a TR4A 511695 unleaded head, four branch extractor manifold and single silencer.

What should the setting be for the '123'?

 

Tom.

Hi Tom

 

My 3A is set on 7 with std. camshaft, unleaded head and TR4 inlet manifold with 4 branch banana.

 

Dave

[Peter Vernon]

Thanks all for your help. I have changed the setting to "B" and there is a marked improvement in the tick over and pick up.

 

I was not after the performance increase but wanted to get a smoother drive and removal of a flat spot that I had with the Lucas distributor.

 

Thanks all for your assistance.

 

Peter

[Guest ntc]

Thanks all for your help. I have changed the setting to "B" and there is a marked improvement in the tick over and pick up.

 

I was not after the performance increase but wanted to get a smoother drive and removal of a flat spot that I had with the Lucas distributor.

 

Thanks all for your assistance.

 

Peter

Guess who found that one out

[Fireman049]

Pardon my ignorance but when you quote 30 degree maximum advance am I correct in thinking

that I use my strobe light with the engine running on fast idle (2000 rpm) I advance the distributor

until I read 30 degrees on the strobe?

 

Tom.

[Lebro]

I think I would rev higher than 2000, max advance means just that the maximum the distributer will go to awith increasing RPM

If you wath the strobe, & "rev" the engine you will see the timing advance as revs go up, then stop - this max advance. At this point move the distributer till strobe reads 30°, & lock.

Bob.

[Fireman049]

Thank you Bob. Very helpful as usual!

 

Regards ~

Tom.

[stuart]

Dont confuse the two engines as 4 cylinder max advance isnt the same as 6 cylinder quoted earlier in this thread.4 pot wont in normal form run as much.

Stuart.

[Fireman049]

Hi Stuart ~

 

Thank you for that. What is the maximum advance setting for a 3A?

 

Tom.

[TriumphV8]

Hi Stuart, I received several Dyno sheets from TR3 and TR4

where also the ignition was optimized.

They ended with figures around 32 degrees but at higher revs than TR6.

Some are done at Viktor Günther Cologne, well known Dyno since years.

 

What is your recommendation?

Edited July 16, 2015 by TriumphV8

[stuart]

They are all different depending on what has been done to the engine, its no good saying a certain degrees is correct, You may get 32 degrees (4 static + 28 advance ) but if your head has been shaved too much or the air temp/humidity/altitude is different/the fuel isnt very high octane or whatever then that may not be possible. R/R or real world road testing is the only way to get as much as you can and then if you want to know measure it after. Martin (Distributor Doctor can give you better chapter and verse if you need it.)

Stuart.