question How far retarded?

[Tony B]

Not me, Degsy! But out of intrest how far can you retard the timing before a petrol engine would stop? I've finally got around to checking the Timing on My WC54 Katy, initial timing showed 22 deg before TDC. Now at 7 before thanks to Phil P's advice, and it starts easy! :wow: And why would you go past TDC?

[Richard Farrant]

Not me, Degsy! But out of intrest how far can you retard the timing before a petrol engine would stop? I've finally got around to checking the Timing on My WC54 Katy, initial timing showed 22 deg before TDC. Now at 7 before thanks to Phil P's advice, and it starts easy! :wow: And why would you go past TDC?

 

According to the Dodge TM, they have timing at 2 degs After TDC, but dependant on grade of fuel and altitude. A lot has happened to fuel formula in 70 years, so each engine performs in different ways, if you have an ear for tuning and can identify pinking it puts the timing in the right area, then fine tune one way or the other.

[Ed Batchelor]

Some older distributors had a manual fine tune available to set timing according to fuel available. I have been told (although not tried myself) that using this to set timing just after tdc can help avoid nasty kick backs when hand cranking an engine.

[Richard Farrant]

Some older distributors had a manual fine tune available to set timing according to fuel available. I have been told (although not tried myself) that using this to set timing just after tdc can help avoid nasty kick backs when hand cranking an engine.

 

As we did with the old motorcycles, fully retard and they would start easily, forget it and it sends you into orbit

[Pete Ashby]

As we did with the old motorcycles, fully retard and they would start easily, forget it and it sends you into orbit

 

Yep got the scar to prove it

 

Pete

[Tony B]

I will now have a picture of Richard doing a Poor Man's NASA in my head all day! :-D The Dodge has two curved slots for the distributor timing, one for 'Coarse' the other for 'Fine'. I used all the fine adjustment to get back to where I wanted. I've read the Octane adjustments in the manual, but was there a master list or such of the settings, or was it wiggle till works?

[Pete Ashby]

I will now have a picture of Richard doing a Poor Man's NASA in my head all day! :-D The Dodge has two curved slots for the distributor timing, one for 'Coarse' the other for 'Fine'. I used all the fine adjustment to get back to where I wanted. I've read the Octane adjustments in the manual, but was there a master list or such of the settings, or was it wiggle till works?

 

Your best bet Tony is to be confident that your static timing is correct then adjust by ear (or if you feel a bit flush buy a vacuum gauge). This will give you optimum settings across the power range and will take into account the ware in your specific engine components and variations in burn rate depending on the type of fuel you are using.

I have to say I've never used a vacuum gauge but am considering investing in one, I know some who claim amazing feats of timing and divinity using them........ any one out there wish to comment ? .

 

Pete

[Caddy]

Not me, Degsy! But out of intrest how far can you retard the timing before a petrol engine would stop? I've finally got around to checking the Timing on My WC54 Katy, initial timing showed 22 deg before TDC. Now at 7 before thanks to Phil P's advice, and it starts easy! :wow: And why would you go past TDC?

 

The only real military engine I can speak of is a meteor, which has a 2 pronged rotor: the main one that's fed from the mag and a starter that is fed from a coil. On our meteor the mag is setup to fire 8deg BTDC, the starter prong is about 35deg after the mag prong so it fires 27deg ATDC.

I guess they did this to reduce the amount of stress running through the con rod and into the crank. Also the starter motor only turns the engine over at 30rpm so firing BTDC might send the engine backwards.

It's a big balancing act - power against stress: the faster an engine can run the more advanced you can run the ignition.....

 

 

.... up to a point