damaged lifters: thoughts/opinions wanted
10-25-2006, 05:26 PM
#21
Originally Posted by juicedz4
I come up with 155# seat pressure and 330#open.
I have a total lift of 0.306 x 1.60 = 0.4896"
So thats another 0.4896 x 317 = 155# on top of the seat pressure of 155# = 310#.
Right?
I have a total lift of 0.306 x 1.60 = 0.4896"
So thats another 0.4896 x 317 = 155# on top of the seat pressure of 155# = 310#.
Right?
Yep, did it quick at work while on a phone conference
Your lifter load would be 496 lbs, whereas mine is 595 lbs.
10-26-2006, 08:16 PM
#25
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This happend to me on my LT1 with LT4 cam,springs with rocker ratio 1.6 oem is 1.5
This has nothing to do with oil pressure!!
Eiter you have too tight valve lash or to low spring pressure,could be both
Are the pushrods in the correct lengt?
This has nothing to do with oil pressure!!
Eiter you have too tight valve lash or to low spring pressure,could be both
Are the pushrods in the correct lengt?
10-27-2006, 03:49 PM
#27
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Ok. I just took a look at my valve stems. I can see where the rocker was contacting the valves. It is between the center of the valve stem and the intake side of the stem. I belive this is exactly where they should be, correct? Well, without actually measuring, which will be hard with the head off now.
Dan
Dan
10-27-2006, 05:07 PM
#28
Just looked at my trusty, Cummins Engine failure book.
The cam failure shown is the same as yours. They call the failure "sliding pressure". The reasons they list are:
1. Improper adjustment.
2. Defective fabrication.
3. Corrosion.
4. Overspeeding.
What do the bottoms of the retainers and guides look like?
All else fails, send the parts to CC, or some other cam grinder, and ask them. I'd surely do that, before I'd "assume" a fix is going to work, and then have it occur again... Just my $.02.
The cam failure shown is the same as yours. They call the failure "sliding pressure". The reasons they list are:
1. Improper adjustment.
2. Defective fabrication.
3. Corrosion.
4. Overspeeding.
What do the bottoms of the retainers and guides look like?
All else fails, send the parts to CC, or some other cam grinder, and ask them. I'd surely do that, before I'd "assume" a fix is going to work, and then have it occur again... Just my $.02.
10-27-2006, 08:12 PM
#29
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I didnt take the retainers/valves/springs out yet. So Im not sure how they look. Other than the loose hardened tip on the one intake valve.
Good thought on sending the cam out to CC. Im pretty sure my builder knows the guys there well. Plus they did the regrind.
Dan
Good thought on sending the cam out to CC. Im pretty sure my builder knows the guys there well. Plus they did the regrind.
Dan
06-18-2007, 09:39 PM
#30
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Well, another piece of the solution to my problems arrived last wed.
One off custom billet cam with mechanical roller profiles. My shop turned the blank and comp did the grinding etc.
has about 18% more lift, and 10% more duration than the stock cam.
Now, they just need to see if the lifter bores need to be sleeved to accomodate the 0.842" Crower keyed roller lifters we got.
Dan
One off custom billet cam with mechanical roller profiles. My shop turned the blank and comp did the grinding etc.
has about 18% more lift, and 10% more duration than the stock cam.
Now, they just need to see if the lifter bores need to be sleeved to accomodate the 0.842" Crower keyed roller lifters we got.
Dan
