Injector to piston tolerance

Well you would just have to have it turned to where the balls are used to index it. I.E. they would be the ref point for the off center turning.
I'm not doing this because of the rattle. Heck, mine isn't bad enough to bother me. It is just that my truck is not running like it is supposed to and the cause isn't for sure yet but I figure this is a major reason. It's just been in the back of my mind and bothering the heck out of me. It wouldn't be so bad to tear it back down and mill the head and go with a smaller gasket if it is the reason but I don't want to unless it is the cause.
 
Bponci said:
I know that there is a ball in there. I dont see why one cant remove the ball and index it differently.
Click to expand...


If I remember correctly, it's actually two little balls in line with each other and there is a grove cut for them in the head.....
 
Smokem said:
I've done it, they didn't leak, I did not notice a difference. Changing the clearance does not alter timing, however 0.040" alteration would change the pattern by 2°.
Click to expand...


Damn!!! Really!!! No difference in sound / rattle???

:bang

Not worth trying??


You trying anything else that worked??
 
Bponci said:
I know that there is a ball in there. I dont see why one cant remove the ball and index it differently.
Click to expand...

If you grind the ball off you will run into a problem...the tube will turn when you loosen or tighten the injector line:doh:

Smokem said:
I've done it, they didn't leak, I did not notice a difference. Changing the clearance does not alter timing, however 0.040" alteration would change the pattern by 2°.
Click to expand...

X2
 
dragnsled said:
If you grind the ball off you will run into a problem...the tube will turn when you loosen or tighten the injector line:doh:



X2
Click to expand...




So you didn't notice a difference either....??

You don't think it's worth trying??
 
I'm running less injection pressure then you but, for me, nothing really !!! Maybe I raised my EGT a bit ! Like 25 degrees !!! Maybe I'm dreaming
 
Smokem said:
I've done it, they didn't leak, I did not notice a difference. Changing the clearance does not alter timing, however 0.040" alteration would change the pattern by 2°.
Click to expand...

So with the extra ~.035" mine is now it would be close to 2*. Is that enough to worry about to tear it back down or do you think I can get away with it?
 
What about modding the sensor ring on the crank for less timing? Its kind of backwards of what most people do, but maybe it will be a little easier and less chance of messing something up.
 
Then what is the purpose of different thickness washers for 12v's? Is it more of a fine tune thing or are the CR's not as sensitive to changes?
 
Has anyone milled the head a little deeper to allow the injector to seat further down? Obviously the hold down mating surface would have to be adjusted as well.
 
TheBigNasty said:
Then what is the purpose of different thickness washers for 12v's? Is it more of a fine tune thing or are the CR's not as sensitive to changes?
Click to expand...

I believe Cummins intended them to be used for rebuilds when the head has been decked to maintain proper tip protrusion.

Big Blue24 said:
Has anyone milled the head a little deeper to allow the injector to seat further down? Obviously the hold down mating surface would have to be adjusted as well.
Click to expand...

Or you could deck/surface the head and reset the valves. I don't know how much additional tip protrusion you would be able to safely get though.
 
TheBigNasty said:
Then what is the purpose of different thickness washers for 12v's? Is it more of a fine tune thing or are the CR's not as sensitive to changes?
Click to expand...

Not sure, most trucks came factory with .060 washers... The 97 5spd is the application for the .020 washers. At least that's the application I order for through my diesel parts supplier and that's what I get (anything else and I get .060's). Maybe it was an emissions thing; anyone know what the marine applications use?
 
You must log in or register to reply here.
Back
Top