Please help me set my timng.
#855150
11/16/10 11:47 AM
11/16/10 11:47 AM
|
Joined: Jun 2006
Posts: 834 Beavercreek, Ohio
OA5599
OP
super stock
|
OP
super stock
Joined: Jun 2006
Posts: 834
Beavercreek, Ohio
|
Car is a low compression 340 with a hughes whiplash cam, tight 10" converter, and 3:91 gears. Car runs best at 5 degrees initial timing with my current single point distributor, and I know this is not right from just about everything I have read. I am sure that my curve is off and I am leaving a lot on the table performance wise. I have been doing a ton of research and just this morning ordered an MSD E curve distributor as it seems to be about the best thing going out there after reading many reviews on many different distributors. When it gets here i will need to set my timing and curve. I have never mastered the science of timing and I read through all of the achives before I posted. I have both a standard and dial back timing light. Can anyone help me step by step on how I will know exactly what my initial will need to be and what my full advance will be...in laymam's terms? I know that can only be completely answered by experimenting, but I just need to know the correct way to experiment instead of just cranking the distributor and winging it. Bonus points will be given if you have experience with the MSD E-Curve. If you need to know anything else about the car that would be helpful, please let me know. I have googled until turning blue trying to save someone the trouble, but this is what it has come down to. Thanks a ton,
Last edited by OA5599; 11/16/10 12:02 PM.
|
|
|
Re: Please help me set my timng.
[Re: OA5599]
#855151
11/16/10 12:20 PM
11/16/10 12:20 PM
|
Joined: Jul 2006
Posts: 4,319 Puyallup, WA
StealthWedge67
master
|
master
Joined: Jul 2006
Posts: 4,319
Puyallup, WA
|
I'm no pro crew chief, but here's my 2-cents: First, go buy a vacuum guage. best tuning tool in your box! get the car warm, then you'll put the vacuum guage on a full time port (below throttle blades) on the carb. Its pretty simple really, you're looking for the highest vacuum reading you can find at an idle. You'll have to adjust the idle screw on the throttle as you go, because you want to keep the motor at an idle, and on the idle circuit. Find the highest vacuum reading and lock the distributor down there. Then, take your timing light and find out where you are with that initial you just set. Lets just say its at 8* for discussion purposes. Now, you get to decide what your total will be. I'm a big block guy, and they like between 34 -38. I currently run mine at 36. experienced small block guys will chime in with a good suggestion for your motor. For discussion purposes, lets say 34* Subtract your initial from your total: 34-8=26. 26 is what you'll key into your advance. Nows where it gets a little tricky.... the speed of the curve. You're distributor will come with directions on how to control the curve (My mallory is controlled with springs). It will likely suggest a certain curve that works best with stock or slightly modified engines. I'd use that one. bang, you're done. Now, next time at the track, play with total advance a little. Your E-curve should make this real easy. For most of us, we adjust the initial and live with it being a little off in order to effect the total. Then when you come to a conclusion on what total actually works best for your motor, you'll go back and re-do the math, and adjust the advance to make sure the initial is still at 8* (or wherever you tuned to). Make sense? Good luck!
LemonWedge - Street heavy / Strip ready - 11.07 @ 120
|
|
|
Re: Please help me set my timng.
[Re: StealthWedge67]
#855152
11/16/10 12:47 PM
11/16/10 12:47 PM
|
Joined: Feb 2007
Posts: 5,080 organ
maximum entropy
master
|
master
Joined: Feb 2007
Posts: 5,080
organ
|
that's good advice. here are some rules of thumb: performance engines like more initial timing, and faster advance. try 15 degrees initial, 35 degrees total, all in by 2500 or so. some like it advanced sooner- maybe 2000. these baseline numbers should get you real close. and yes, vacuum gauges are one of the most underutilized tools in the box. i have one in my car!
for what is the good life if not doing things thoughtfully?
|
|
|
Re: Please help me set my timng.
[Re: StealthWedge67]
#855155
11/16/10 03:43 PM
11/16/10 03:43 PM
|
Joined: Oct 2003
Posts: 7,506 Az
Crizila
master
|
master
Joined: Oct 2003
Posts: 7,506
Az
|
Quote:
I'm no pro crew chief, but here's my 2-cents:
First, go buy a vacuum guage. best tuning tool in your box! get the car warm, then you'll put the vacuum guage on a full time port (below throttle blades) on the carb. Its pretty simple really, you're looking for the highest vacuum reading you can find at an idle. You'll have to adjust the idle screw on the throttle as you go, because you want to keep the motor at an idle, and on the idle circuit. Find the highest vacuum reading and lock the distributor down there.
Then, take your timing light and find out where you are with that initial you just set. Lets just say its at 8* for discussion purposes.
Now, you get to decide what your total will be. I'm a big block guy, and they like between 34 -38. I currently run mine at 36. experienced small block guys will chime in with a good suggestion for your motor. For discussion purposes, lets say 34* Subtract your initial from your total: 34-8=26. 26 is what you'll key into your advance.
Nows where it gets a little tricky.... the speed of the curve. You're distributor will come with directions on how to control the curve (My mallory is controlled with springs). It will likely suggest a certain curve that works best with stock or slightly modified engines. I'd use that one. bang, you're done.
Now, next time at the track, play with total advance a little. Your E-curve should make this real easy. For most of us, we adjust the initial and live with it being a little off in order to effect the total. Then when you come to a conclusion on what total actually works best for your motor, you'll go back and re-do the math, and adjust the advance to make sure the initial is still at 8* (or wherever you tuned to).
Make sense? Good luck!
Good explaination
Fastest 300
|
|
|
Re: Please help me set my timng.
[Re: Crizila]
#855156
11/16/10 05:19 PM
11/16/10 05:19 PM
|
Joined: Aug 2005
Posts: 403 30 miles west of EuroDisney
fbernard
mopar
|
mopar
Joined: Aug 2005
Posts: 403
30 miles west of EuroDisney
|
with what was said above (identifying optimum idle setting with the vacuum gauge). Some people determine optimum total advance by using detonation (if you can here it and recognize it, it's pretty obvious once you know the noise). For example, set total timing at 38 and do a test drive with a strong acceleration (warm engine). If it pings, let go of the throttle, back off timing 2 degrees, retry. Once you know the optimum initial and total timing, you can decide on the curve you will be setting in the E-curve : 25, 20, 15, 10, or 0 degrees, so you'll have to make concessions : if you need 18°, get 20° on the dist and back off initial timing 2 degrees so you can keep total timing where you want it. You should do all of your testing before you install the E-Curve, it will be easier with the standard distributor. You can also do the testing with the E-Curve in locked out-mode (with start retard). The E-Curve will make it easier to try different curve angles (check the SMD documentation, it's fairly straightforward). Installing it is not, however, since the distributor itself needs to be advanced a lot (as any fully-electronic setup, it only retards from a maximum advance position, so it needs a lot of advance). I don't remember how the vacuum advance is set, but you're probably aiming for 10 or rather 15° on a not-too-fast curve. One thing I must add, though -and the only relevant thing in my post ) : I have a MSD E-curve (right now an expensive paperweight). I strongly advise you to use Loctite on the rotor screws. The cap and rotor is the same as most other MSDs. If the rotor screws turn out and leave on a standard MSD distributor, chances are they won't do much damage (you might be in for a new pickup though). On the MSD E-Curve, if that happens, say at 6500 RPM on the finish line, you will experience some problems. The screw will fall under the rotor, totally destroy all of the delicate surface-mounted electronic components that are there, and leave you stranded with a very exotic distributor no-one has parts for (and of course, this will not happen in your backyard, or when you decided to be on the safe side and trailer you car to the strip).
|
|
|
Re: Please help me set my timng.
[Re: RodStRace]
#855159
11/23/10 01:26 PM
11/23/10 01:26 PM
|
Joined: Jun 2006
Posts: 834 Beavercreek, Ohio
OA5599
OP
super stock
|
OP
super stock
Joined: Jun 2006
Posts: 834
Beavercreek, Ohio
|
Thanks to everyone who chimed in. Very good info on this thread. We will see if we can get the car closer to dialed in during the long weekend. Thanks to all, and I will keep you updated on our progress. Hey Mods, I didn't find another thread like this on here. Any chance it could go in the archives?
|
|
|
Re: Please help me set my timng.
[Re: OA5599]
#855160
11/23/10 03:33 PM
11/23/10 03:33 PM
|
Joined: Aug 2003
Posts: 43,719 Bend,OR USA
Cab_Burge
I Win
|
I Win
Joined: Aug 2003
Posts: 43,719
Bend,OR USA
|
Remember that you can adjust the initial and restrict the advance so you can set the total timing when revved up also Work on the initial first and then shorten up the advance to get the total timing you want when revved up, there both important
Last edited by Cab_Burge; 11/23/10 03:34 PM.
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
|
|
|
|
|