2056 Timing, Looking for Analysis Of New Timing Values Options

[Mblizzard]

I have converted my 2.0 to a 2056 and added Micro Squirt fuel injection.

Ever since I did the 2056 conversion I have seen higher than norm cylinder head temperatures. In fact I cracked a set of heads from getting them too hot.

I played around with the timing with in the suggested 2.0 limits of around 27 degrees. but was really never able to influence the CHTs that much with changes in the timing. Adding more fuel at the right times with the Micro Squirt certainly allowed me to control the CHT much better but I always felt it was still getting too high.

Then I ran across this.



This is certainly a lot more advance than I ever added to the engine. So based on that I revised my timing table to:



Just love how easy it is to make changes with Micro Squirt.

So I am looking to see what the thoughts are on 35 degrees of advance and what impacts it may have on CHT. I am going to load this and test tomorrow.

[Mark Henry]

I got to admit looking at those tables is so confusing, the main reason I've never embraced MS or other data overload systems.
It's a fricken timing curve, not rocket science!

My SDS has one value per 250 rpm, that's it. Same could be said about a mechanical dizzy, sure springs but it's a simple curve.

I agree with Jake and Mark, idle too low I run 10* and 30*+ is too much advance on a T4, I run 28*. If anything I'd consider retarding the timing a bit as I approached 6000 rpm.

One of my tricks when tuning is I have a highway close by that has a long (10km) steady uphill grade and it's divided by a concrete barrier. When in the passing lane you are about 24" from the barrier and the sound bounces so you can really hear the engine mechanicly. I've tested 1.8, 2.0, 2056, 2270, and my 2600 T4's any time I push it to 30* I can hear the ping. I can also see head temps going up.
Ping is about the equivalent of hitting your piston top with a ball-peen hammer. Sooner or later it will kill your engine.

The chart above "Ideal 2056 Adavance Curve" that might work on a WC engine but I'd never consider it on an aircooled T4.