Adjusting timing with NuRex

1crosscut

1crosscut

Well-known member
In setting the timing with the NuRex wrench the mark on the wrench is supposed to touch the post for #4 on the distributor housing. If one wanted to set timing either advanced or retarded what side of the post would you set the mark to and how much of a change would each 1/8" make?
 
If you want it advanced go beyond the post. Retarded not to the post. I’m not sure of the distance but it doesn’t take much.
 
daren007 said:
And why would you do this?
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Installing a higher compression head limits the amount of distance the spark lever can be moved down before the engine begins to ping under load. I'm thinking that if it was set slightly retarded it would allow for a bit more room for adjustment for different driving conditions.
 
1crosscut said:
Installing a higher compression head limits the amount of distance the spark lever can be moved down before the engine begins to ping under load. I'm thinking that if it was set slightly retarded it would allow for a bit more room for adjustment for different driving conditions.
Click to expand...


Very good reason.


Most people try to run too much advance with the higher compression heads.


Chris W.
 
I don't have a high compression head but I always set my timing to 30* BTDC max. The A engine doesn't need a lot of advance up to 40* unless you are turning it 3000 RPM. I never turn mine engine over 2000 RPM so 30* is plenty. With a high compression head I would set the timing even less. I have heard around 25-26*.
 
My car with a 6.1 and nurex starts better if I go past the post about 1/16 of an inch. That places the rotor arm a little bit left of the #1 post.

So in stead of the left side of the rotor arm being inline with the left side of the post as per normal, it is now about 1/16th of an inch and to the left (more retarded) of the post.
 
Slight retard works better with HP heads. I use a timing light and set it 2-3 deg ret.
That works well with max advance of 26 deg but I only run the level max of 3/4 down.

I am using electronic ignition which is very stable curve.
 
I fiddled with setting the timing this morning and found that going past the post (to the drivers side of the post) by about 3/16 of an inch retarded it just about right. I can adjust the spark advance lever down to about the 9:00 position and when I retard it fully I get a nice brisk puckety puck at idle. I think I can go just a wee bit more but will stay with this for a while to see how it behaves.
Nice having a bit more range on the advance lever.
I added a 6:1 head to go along with a freshly installed Warford overdrive.
 
1crosscut said:
Installing a higher compression head limits the amount of distance the spark lever can be moved down before the engine begins to ping under load. I'm thinking that if it was set slightly retarded it would allow for a bit more room for adjustment for different driving conditions.
Click to expand...

I did that on my engine by setting the timing just after the pin dropped in the dimple on the cam gear. Like you I feel it gives more wiggle room with a high compression head.
 
Even with a standard head, I set the timing a little retarded. There is plenty of advance available and I like the ignition to fire just after TDC when the lever is all the way up and I'm cranking it. Then, there is NO chance of a kick back. With a HC head, I do as others have said here.
 
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