playing w/timing

[Smoke-This]

Well got my wrench from snap-on to get to bolts on injector pump.

waiting for $$ to get dial indicator setup from snap-on. but thought I would play a little . so I moved pump about 3/16" advance. well it almost elimitated exhaust temp but it also almost elimited boost went from about 22max to 10-12 max and truck had a whole different sound. moved back to almost orig position until I get the right tools dont want to wound anthing will keep posted on progress

 

[BushWakr - RIP]

A fairly close rule of thumb is ... . starting from were the two lines, one on the pump and one on the housing, are lined up, move the pump up about 1/8" and secure. This seems to be fairly reliable in getting about 15*advance, or roughly 1. 45-1. 5mm.

3/16" is getting up there and does result in some loss at low end, lower EGT, less smoke. The thing is the VE pump does not seem to like as much advance as the newer pumps and any more than 16 or 17* max. advance is high in my opinion.

You will hear a difference, have smoother idle, and the other things mentioned.

Remember, you only need enough boost to burn the fuel you injecting, any more is a waste of energy and at a certain point can actually be bad if too high.



Bob.

 

[NeedMoPower]

Do you have to find TDC before you move the pump? Also, what tools do you guys use to set the timing? One of those injector bolts looks impossible to get a wrench on. Do you have to heat and bend a wrench?

Thanks,

Cody

 

[BushWakr - RIP]

There are some "custom" tools/wrenches you can buy from Snap-On, but the one's I've seen used are 'custom heat N' bends'

The bolts can be a booger to get to.

Playing with the timing is about the only thing I have not done personally. I've let 'Mr. Wizard' do that for me...

You don't really need to find TDC if all you're going to do is use the 1/8" method.

If you want to find were you are now, and then set to a very specific advance or mm spillport setting, then yes you do need to go through with the TDC, etc. process.

The pump can be very tough to move if it's never been touched before.

There is a bolt under the pump that gets missed sometimes, also the injector line(s) MAY have to be loosened a bit, also there is a short fuel line (return fuel line I think) at the front of the pump near the KSB solenoid that may need loosening/bending a bit.

See... that's why I chickened out and let Mr. Wizard do it.

Advancing the timing really pays off when you put in larger injectors BTW.

They usually have a higher pop-off pressure and result in retarding your timing. Since they "wait" longer to release, the engine is further along in it's stroke, effectively retarding your timing.

I hope that makes sense...

Bob.

 

[NeedMoPower]

Bob,

That made perfect sense to me and thank you. I have been thinking about bumping the timing and have been sitting on the fence for quite some time. The only reason I havent so far is because I wasnt sure if the gains recieved form timing would be worth the effort.

 

[BushWakr - RIP]

Here's the tool/part # for you, I got it from another thread here, on the same forum, I'll include it below the tool listing. .



Try the following part number:

SP 144, Cummins Diesel Injection Pump Wrench

Snap-on web site

$22. 55 plus shipping and sales tax



Here's the link to the other thead with a good bit of info from PW>>

http://216.235.147.117/forums/showthread.php?s=&threadid=54211



Bob.

 

[Smoke-This]

spend the $$ for the snap-on wrench

would almost be impossible to reach bolts without it

in fact they were a little tough even with right tool

 

[NeedMoPower]

What size are the bolts that you have to remove? Just Curious.

Thanks

Cody

 

[Smoke-This]

the one at rear of pump is 10mm the other three are 13mm

 

[JFitzgerald]

wallyo, the sound of my engine changed a lot with the timing change. It had more of a harder rattle that I didn't care for. Later after Case500D and I set the valve clearances, it sounds pretty much like before changing the timing. Several of my rockers were fairly loose. We weren't sure if my valve covers had ever been off. The factory paint was still on the gaskets.



Here is another past post on timing and the wrench.