Engine/Transmission (1994 - 1998) Effects of Timing Advance

[crudd]

I bumped my timing up this weeked to around 16-16. 5*. So far I notice dramatically reduced EGT's, less smoke at idle, doesn't run as rich at idle, and less smoke period. I used to be able to black out the car behind me... can't do that now. Also, it feels like I may have lost some power. Can't be sure, but the truck feels a little bit slower.



My question... due to problems/inaccuracies with finding exact TDC (used every method in the book), I am not sure my timing is right on. What characteristcs would one notice if the timing is advanced too much? Anyone have any comments or advice regarding the location of exact TDC?



As always, thanks for the help TDR!

 

[Vaughn MacKenzie]

What tool did you use to set your timing after finding TDC?

 

[crudd]

I used the Snap-On SP500 kit.

 

[Joseph Donnelly]

More timing = more top end power, lower torque at 1500 rpm. You are noticing the loss of torque (not major, but you can notice it if you bump timing 3-4 deg. like you did). It is harder to feel the higher hp at upper rpm, but it is there, especially if you raise governed speed with a governor spring kit.

 

[JoshPeters]

There is a method by using a pulse (can't think of the name) meter and a timing light that you can check your timing. You hook the pulse meter up to the number one injection line, and the timing light up to that. You then use the timing light like you would on a 72 chevy... . I use the harmonc blancer and the crank position sensor as my timing "marks. " I also found true TDC by tightening the exhaust valve down 3 turns, roll the engine over till it touches, mark the balancer, back it off, loosten the exhaust valve, roll the engine past tdc, and tighten the exhaust valve down, back up the engine till it touches mark the balancer... . reset the valve lash... . Measure between the marks and that is true TDC.



Josh

 

[crudd]

I measured TDC by using the "valve method" you describe. However, it doesn't take much movement of the crank to significantly change the timing according to plunger lift. The fact that there is, in my recent experience, some inherent error in gear backlash and in determining the precise lineup of your mark on the harmonic balancer, leads me to question exactly where I set my timing... I know I must be close to 16-17* degrees, but if I am off a degree in either direction, I am not sure.



I would like to find out more about the pulse meter adapter... seems like that might be more precise. Anyone know what this is called or from where one may be obtained?



Thanks.

 

[boondock]

Have you dynoed your truck yet? Egts way hot with only a 35?



How much of an egt drop did you observe?



Sorry for the questions but next in line is timing at 16-18, then clutch, turbo, and 370.



Thanks

 

[crudd]

Boondock -



I have not yet put the truck on a dyno. However, I can control EGT's without a problem. I pull up to 20,000 lbs. fairly regularly and can run 70-75mph down the interstate at 1000*. On big hills I down shift into 4th and just keep the EGT's at around 1150-1200 (60-65mph usually). I have not towed with the the truck since the timing advance, but driving around town I've noticed that it takes significantly longer for EGT's to climb. I plan on doing to more "intense" testing this weekend and will report my results.



Thanks.

 

[Vaughn MacKenzie]

Crudd, did you also drop the timing pin into the hole? Did it match up with what you found with the Drop-Valve method? If the two jive then you should be within fractions of a degree. Did you double-check the timing after torquing down the pump nut?

 

[crudd]

I couldn't get the timing pin in the hole to save my life. I don't think it's broken off. I didn't pull the pin out to check as I read that it wasn't that accurate anyway. Is there any trick to getting the pin in the hole? I did not recheck it after I torqued it down... maybe I should do that.

 

[Forrest]

I bumped my timing up this weeked to around 16-16. 5*. So far I notice dramatically reduced EGT's, less smoke at idle, doesn't run as rich at idle, and less smoke period. I used to be able to black out the car behind me... can't do that now. Also, it feels like I may have lost some power. Can't be sure, but the truck feels a little bit slower.

Mine is a similar setup, 215hp pump but with timing @ 17, felt the same thing. Like Joe said, it's low end that's gone. Your rear tires will now last longer. :-laf



You can work on replacing that lost torque ... more air & injectors.

 

[crudd]

Mine is a similar setup, 215hp pump but with timing @ 17, felt the same thing. Like Joe said, it's low end that's gone. Your rear tires will now last longer. :-laf



You can work on replacing that lost torque ... more air & injectors.

I already have 370 injectors and decent turbo/airfilter/exhaust. What is your favorite/most noticeable advantage of the bumped up timing? I haven't driven it enough yet since the timing advancement to determine my new mileage, but I am definitely considering dropping the timing back down some. My EGT's were not out of control to begin with.