Couple of comments regarding superduty's post.

1. The teeth and gap between are not the same size. Each tooth is about 1/3 of the total space, with the gap about 2/3.

2. If I was doing this again ... before loosening the bolts, mark a tooth and a reference point on the c/s pulley with a scribe. Then loosen the bolts enough to be able to wiggle the tone ring. Then find the center of the "slop" and you could assume that is where the stock design point is. Then you could easily see where your engine was biased from the factory.

Then remove the wheel and file the slot plenty (more than .03") in the advance direction. Reassemble with the bolts loose, and just use the marks that you made originally to set the timing wherevery you want - knowing that 1 degree = 1.83mm (.072") on the circumference.

I'll wait to post any mileage info as I like to have a few tanks to see a trend.

Mathew

 

If the 555 guys are getting an improvement with 2 degrees, I wonder if the 600s should have more.

To see these kinds of MPG and EGT improvements, Cummins must have the timing pretty retarded.

We should hook an oscilloscope up to the CPS and injector wires and see what kind of timing these engines really have. The thing is there is a delay between electrically firing the injector and when it actually delivers fuel. It isn't like on a P7100 where you can figure out how many degrees BTDC the fuel is being delivered by the port closing point.

It would still be interesting to compare the 555 timing with the 600 timing.

BigBlock: did you notice I PM'd you the other day ?

 

I have a 4" exhaust with a Banks downpipe and Nelson 51" muffler. Also, I have an AFE drop-in airfilter and some airboxs mods too. I wouldn't be surprised if the tone wheel mod complimented these mileage enhancing add-ons that I have to produce a greater mpg gain than a stock truck.

With the price of diesel surpassing $3.00gal recently in SoCal, I'm very happy at anything that can provide a mileage improvement. Shoot, I might even pony up some $$$ for a PDR/Schied camshaft swap as those are supposed to provide at least 2.0+ mpg improvements. I'm sure at this rate, it would pay for itself in the near future.

Overall, it would be interesting to have a vehicle to produce better mileage than my BMW (23mpg) that weighs twice as much, has lousy aerodynamics, and has an engine twice the displacement with 60% more horsepower!

 

"1. The teeth and gap between are not the same size. Each tooth is about 1/3 of the total space, with the gap about 2/3."

I haven't looked a my engine yet. 1 "tooth plus gap" equals 6 degrees. If a tooth is 1/3 of the 6 degrees, then a tooth is 2 degrees.

I don't like filing things this precise. I'll probably be using a mill with a DRO to machine mine.

How hard is it to remove the CS pulley ?

I wish I would have done this before I put the engine in the truck...

 

Thats why I can't wait for Quad to have the timing only box ready. I wonder how much timing these 3rd gens can take?

MikeyB

 

I've got an electronics background... it would be very easy to advance the tone ring about 10 degrees and then build a small circuit to sit between the CPS and the ECM that retarded the timing a variable amount. With 0 retarding you could get 10 degrees of advance and with 10 degrees of retarding you could get stock advance.

It would also be easy to hook into the PCI bus and change the curve based on load, temperature and engine RPM...

 

Only problem is the camshaft has a sensor also. The computer checks the rationality between the two. Go to far with the crankshaft timing and the computer will probably throw out a error code.


MikeyB

 

I've got the 05 shop manual and the camshaft position gear is just a half moon plate. I doubt it is a really precise target. All it really does is indicate whether cylinder number one is at TDC on the compression stroke or the exhaust stroke.

Furthermore, the ECM won't know we've advanced the tone ring 10 degrees because the retarder box will retard it X degrees and if X is big enough, it will match. The ECM will be comparing the retarded signal with the camshaft signal to see if they make sense.

 

Hats off to the guys at Rokk Tech! I ordered my modified CPS last Friday and it was in my mail box today. I installed it and went for a spin.

First impressions:

-Power comes on much smoother
-Not much, but definitely noticable, more power below 2100 RPM. It feels like I gained back some of the power I lost by putting the 315s on it.
-The vibration I had at 2k RPM is less noticable
-I don't have gauges, so I have no idea what my EGTs are.

Too early for a mileage report, but I'll report back once I run a tank or two through it.

All-in-all, I feel it is worth the money

Has anyone tried Rokk Techs vibration elimination kit yet? Their web site says that it eliminates the vibration in the pedals and steering wheel. I might just have to order it and try it out.

 

I don't want to get over excited yet but.... Just filled today in prep for a 550 mile road trip this weekend. 253.2 miles of to/from work (short hwy and some 30 and 40 zones. 11 miles each way) used 12.929 gal (filled up to top of neck) That works out to 19.58 mpg hand calculated. By far my best tank yet. Prior to mod this trip was in the 16.9 to 17.4 range.

Could be a fluke, my roat trip should prove or disprove the improvment. It will be 550 miles of 80-90 percent hwy @ 75+ mph and some Denver and CSprings city driving. This trip has netted from 16.3 to 17.2 in the past

I will let you know on Sunday.

 

Superduty,

I would say that the sensor is VERY accurate--if it wasnt the truck would run like crap.

The timing advance is NOT recognized by the ECM, Everything is still on time according to the ECM. It like advancing the timing on a mechanical.

I too am very interested in the MPG report.

 

Any "600" mpg increases yet?

 

"I would say that the sensor is VERY accurate--if it wasnt the truck would run like crap."

The CRANKSHAFT sensor IS very accurate. It needs to resolve the timing down to sub degrees of accuracy.

The CAMSHAFT sensor doesn't have to be and probably isn't. It only has to tell the ECM which REVOLUTION the engine is on.

The ECM detects TDC #1 by the missing tooth on the tone ring. Actually that missing tooth is probably a certain number of degrees BTDC so that that ECM just has to retard the injector firing from there.

The camshaft sensor just tells the ECM whether cylinder #1 is TDC on the exhaust or compression revolution. The injector is only fired ever second revolution and the camshaft sensor tells the ECM which revolution the engine is on. Its margin for error is large and I'll bet that one could advance the tone ring 15 degrees and the ECM couldn't tell.

This would be very easy to check by putting an oscilloscope on both the camshaft and crankshaft sensor wires.

 

"Only problem is the camshaft has a sensor also. The computer checks the rationality between
the two. Go to far with the crankshaft timing and the computer will probably throw out a error code."

In my 05 manual I don't see a camshaft/crankshaft rationality code. There are such codes for other things, such as the throttle sensor. I'm looking at Section 9 in Volume 3, Pg 9-1217.

I see the following codes:

P0219- Crankshaft Position Sensor Overspeed
P0335- Crankshaft Position Lost
P0336- Crankshaft Position Sensor Signal
P0337- Crankshaft Position Sensor Signal Too Low
P0338- Crankshaft Position Sensor Signal Too High
P0340- Camshaft Position Lost
P0341- Camshaft Position Sensor Signal

I don't see any rationality check on the matching of the crankshaft-camshaft signals.

They probably didn't anticipate that guys like us would pull the tone ring and advance the timing a handful... tisk tisk.

P0111- Intake Air Temp Sensor Rationality is an example of a rationality check code.

 

I think it would be a cool Mod to build.
Make the programmer so that it has a +-5 degree parameter so you can't accidentally go crazy with it. It sounds easier to get right on the money with out unbolting and guessing where it should be like trying to set the dwell on a set of old points.
I say go for it! If you can stick a Cummins into a Ford then you can probably build that programmer.
OilGuy