Lifter surprise????



SCARBROW: What were you running and do you have any theories on what could have caused your lifters to flake apart? Did you cam bolts ever loosen allowing the cam to walk?
SCARBROW: What were you running and do you have any theories on what could have caused your lifters to flake apart? Did you cam bolts ever loosen allowing the cam to walk?
Scarbrow's pics show what the non-encapsulated version looks like.
i am pretty sure that the cam lobe is chewed up too
Parts:
Original Lifters (stock non-encapsulated), 918 Springs, Ti Retainers, 216/220 .525”/.532” cam, CC hardened pushrods, 6660rpm limit. Lifters have 32k miles (15k w/cam/springs, 4k track miles).
Background:
Noticed one small pieces of metal on drain plug after Summit Point track weekend. Took valve covers off, checked valvetrain (rockers, springs, etc.). Everything looked fine. Attended another track weekend at Watkins Glen (~150 roadrace miles).—Car performed fine. Noticed a clicking/tapping sound when taking car off trailer and pulling in garage. I then had my buddy listen to the car while idling. He thought it sounded like a lifter on #X cylinder. We then pulled the fuel pump fuse and cranked the motor over a few times, he definitely leaned towards the same cylinder. After taking the heads off, I found ONE lifter to have a bunch of flat spots on it like it had been skipping, and some rough material on the edge of the wheel. That cam lobe on the cam was also missing a decent amount of material (the cam was 5X worse than the lifter). The plastic lifter tray for that pair of lifters was slightly deformed enough to allow the lifter to rotate ~10-15degrees and allow the lifter to be very loose in the tray. A few other lifter trays showed a bit of wear, but nothing significant.
Possible causes:
I’ve talked over the situation about my lifter with my mechanic/racer/engineer buddy. He came up with a few ideas for failure:
1. Lifter bore holes in block are slightly off (not drilled at the proper angle from the factory)
2. Cam lobe failure caused the lifter to fail.
3. Weak valve spring allowed the lifter to skip on the cam for a while doing damage to both the lifter and the cam.
4. Plastic lifter trays deformed and allowed the lifter to rotate ~10 degrees on the cam lobe.
5. Combination of all of the above.
Upgrades:
I’ve done the following in order to help the situation and prevent it from happening again:
1. New Comp OEM (850-16) Lifters. (supposedly similar to stock, but better, encapsulated)
2. LS2 Lifter Trays. Seem a bit beefier than the LS1’s. (need (4) at about $7/piece)
3. ¼” holes drilled in lifter trays to allow oil to be relieved at high rpm.
4. New 918 Springs (this may have been a reason for failure….I’ve yet to get my springs checked to see if they were in spec, the one that failed in particular.
5. LS6 Lightweight Valves (reduce load on valvetrain)

I had these kind in my 98' when I tore it down
So today I'm tearing apart my 2004 LS6 motor and guess what? It has the older type of lifter installed!!! WTF?? Anyone else have this issue?
This is my third LSX motor and the first one I've seen with this.
So now I'm thinking I have to purchase a set of new lifters...................

The Best V8 Stories One Small Block at Time
I would be curious to know the wheel diameters on each. I would assume the encapsulated is smaller in diameter. If so and the cam is designed for a .720" wheel then this will effect the duration numbers.
I would be curious to know the wheel diameters on each. I would assume the encapsulated is smaller in diameter. If so and the cam is designed for a .720" wheel then this will effect the duration numbers.
I can't measure the wheel on the new Comp 850-16's, but to the inside of the encapsulating part of the body was .720", so I would venture to say the wheel is in the .700"-.710" range?
I wish the timing chain damper had come from the factory on LS1's. It now does on LS2's and LS7's. The stock lifter have been proven up to 7000 rpm and well over 800 hp. If I had the cash and were swapping out a cam I would go with the Schubecks lifters. But if I were on a budget, Mellings or the GM's.
3. Weak valve spring allowed the lifter to skip on the cam for a while doing damage to both the lifter and the cam.
Do you have the LS2 part number for the lifter trays, were they a plug in fit?
Do you have the LS2 part number for the lifter trays, were they a plug in fit?
P/N1259365-LS2, P/N12551182-LS1
-Dennis
GM doesnt differentiate between the two types of lifters, both are the same part number. Went to a dealership today to find this out. Also went to Auto Zone today to see what they had. They carried Mellings (fully encapsulated) for $13.99 ea. Not bad if you need em in a hurry but I called Futural and they have the Mellings on sale for $165 a set! Thats a good deal.
Along the same lines: The LS motor hemmorages oil internaly due to it being aluminum and that it expands quite a bit more than CI. Becasue of this the oil pressure is increased (this is the reason most go to a ported oil pump) to compensate for the increased clearances. Now back to the lifters...the non-encapsulated due to design will make the condition even worse. This is due to the positioning of the lifter body in the bore, even more so with a higher lift cam;so the NE type will show less oil pressure. When we changed to a encapsulated type the oil pressure remained high and show very little drop when hot, everything else remained constant. Another good reason to switch.
1. At what ramp rate/lift does the encapsulation hit the ramp?
2. What is the roller size of each?
If the roller is different, it will spin faster, and the ramp of the cam will be interpreted differently to the valve.
The LS motor hemmorages oil internaly due to it being aluminum and that it expands quite a bit more than CI. Becasue of this the oil pressure is increased (this is the reason most go to a ported oil pump) to compensate for the increased clearances. Now back to the lifters...the non-encapsulated due to design will make the condition even worse. This is due to the positioning of the lifter body in the bore, even more so with a higher lift cam;so the NE type will show less oil pressure. When we changed to a encapsulated type the oil pressure remained high and show very little drop when hot, everything else remained constant. Another good reason to switch.
I don't understand this at all. What does aluminum block vs. iron block have to do with oil pressure and the need for a ported oil pump? I think the increase in oil pressure was more likely due to the lifter body design rather than the mere fact it was encapsulated, or is that what was meant.


