cooltoys61

I have gone to V6 modules from 24 deg V8 modules due to a need for less total advance on my vortec heads. When looking at the initial advance ,and to a less noticable degree ,total adv the timing moves up and down about 3-4 degrees. Is this normal ,and do I avg out the reading or use the high end for safety? I'm running about 18 initial and 28 tot. I'm not really concerned with the initial setting but just noticed the pronounced bounce there. I'll be using the high reading 'til I here otherwise from you guys.

cstraub69@comcast

You will get some fluctuation due to the timing chain tension. Normal. Cam Correct tension system will get rid of this.

Chris

BadDog

Does it still fluctuate while on plane at 3000 RPM?

Badtoon

If it's carbed there is a wire( I think it's purple and white) that """WITH THE ENGINE OFF""" you ground it out and it puts the module in basic timing mode so you can set initial and check total. If it's injected then you gotta ask someone else.

Badtoon

If it's a Thunderbolt V that's the way you set timing and carb if it's something else then you got me by the sneakers.

bpine

I agree with Sutphen30, should be rock steady! thats not good at all for your motor! In this case I would have Just Replaced the whole Dist. with a pre set Advance unit from Performance Distributors!
http://www.performancedistributors.com/

Bryan

formula31

ROTOR, moving on the shaft. get a new one and locktite it on.

BadDog

I would bet it is a TB5 in which case you need to ground something to set base timing. I am not familiar with which pin or wire but I know a local that spent 6k on a motor and the engine builder did not ground the correct pin when he set the timing. He just averaged it as it was jumping around. It turned out that he was actually running way too much timing and destroyed the motor inside of 3 hours. Get a book and read up.

Badtoon

BadDog

What I said and if the rotor is not loctited on it will throw timing all over a friend of mine found that out

bpine

Something doesn't sound right to me with 18 initial, that means you only have 10 degrees advance?

I have found the best performance with running 10-12 initial 600rpm or below and 30-32 total?All advance should be in at 3000 rpm.

Are you using an dialback timing light,marks, or degree tape on dampener?

some HEI systems don't like dialback lights! I have found it to be off as far as 3-4 and some times flutter wildly?
Also make sure you Dist. is not bottomed out on the oil drive shaft! this can also cause that symptom! The best method for checking the distributor to find out if it is bottomed, drop the distributor in the engine with no gasket. Also, make sure the cap and rotor have been removed for this test. Firmly hold the distributor against the intake with one hand and with the other, pull on the top plate of the main shaft. Very Important! Make sure you grab the top plate where the weights and center cam are riding. Do Not grab the reluctor (the part the rotor attaches to) because this part has up and down movement at all times. By grabbing the top plate you are checking for any up and down play in the shaft. If the shaft has up and down movement, you are now ready to install the distributor permanently by adding the gasket and installing your hold-down clamp. If there is no up and down movement in the shaft, then the distributor is bottomed on the oil pump. You will need to add a nylon distributor shim of correct thickness until the up and down play is achieved.

I hope this helps!

Bryan