Did you read the details on the Sequence IIIG test? Highlights: engine (V6, push-rod, pig-iron, flat tappet cam) is essentially running WOT under load for 100 hrs. with the oil heated to 150°C for the entire test.
Modern oils bad for flat tappet camshafts
- Thread starter k1xv
- Start date
- Status
- average cam plus lifter wear: max 60 microns
Sequence IIIG test as noted above. Note: this includes breakin wear.
- cam wear average: max 90 microns
Sequence IVA Test.
This test measures scuffing wear, which is wear that occurs during the break-in period of the engine. That is, no special lubricant/grease aids cam breakin on a 1994 Nissan KA24E 2.4-liter, overhead camshaft, non-roller finger followers.
7 points on the cam lobe nose, between 14° before and 14° after max lift, are measured and ADDED TOGETHER, and then the average is taken for all cam lobes.
- bearing weight loss: max 26 milligrams
Sequence VIII Test.
This test's main purpose is to test for bearing corrosion under high-temperature operating conditions using unleaded fuel. It also measures measure viscous shear stability under high-temperature operating conditions using unleaded fuel, but the test rig is a 42.5 C.I.D. carbureted, single-cylinder, spark ignition, with an external oil heater circuit, that most consider obsolete. This test will most likely be replaced by a bench test for GF-5.
[ February 28, 2006, 06:58 AM: Message edited by: 427Z06 ]
- Joined
- Jun 2, 2003
- Messages
- 23,591
I had to drop everything and chase racoons out of my garage. By now I have read the whole test descriptions. I guess those test sequences are pretty elaborate after all.
Yes mori, after you dig through all the tests you realize that these SM/GF-4 oils are very comprehensively tested. 10 years ago the ACEA might of been ahead, but I think at SM/GF-4 levels, they're in the same league now.
One thing that should be taken into consideration is that Competition Cams is not selling stock OEM flat tappet cams. Some of the camshafts they sell have agressive .050 numbers. The camshafts they grind are much more agressive than anything found in an OEM application.
Combine this with performance (not race) valve springs and their could be a problem. I have read articles of cams going flat at break-in and within 10,000 miles.
Who knows if the camshaft and lifters were properly installed or the break-in was correct.
Maybe a bad core?
There are only a handful of American suppliers of cam cores. I believe the "rockwell" rating on a standard flat tappet cam is 53 while an optional P-55 (55 hardness) is offered. I think the rockwell rating on the lifters is 56.
Cam design is a science. Maybe with reduced additive packages or changed packages, the agressiveness of the lobe design is not compatible for long term longevity of the cams....
or
Maybe the cams have pushed the envelope of design and are as far or farther advanced than the materials they are constructed of.
There are lifters available that are made out of materials other than iron, and there are interesting stories on how long they live and claims of "going the distance" with no problems.
The cam that I am running, the manufacturer recommends "as little idling as possible" and they estimate the cams life to be 40,000 miles at the most.
I have not decided which oil I will run, but I have been giving it carefull consideration.
I should be able to judge the wear, it is a solid lifter, and will require periodic adjustment.
Combine this with performance (not race) valve springs and their could be a problem. I have read articles of cams going flat at break-in and within 10,000 miles.
Who knows if the camshaft and lifters were properly installed or the break-in was correct.
Maybe a bad core?
There are only a handful of American suppliers of cam cores. I believe the "rockwell" rating on a standard flat tappet cam is 53 while an optional P-55 (55 hardness) is offered. I think the rockwell rating on the lifters is 56.
Cam design is a science. Maybe with reduced additive packages or changed packages, the agressiveness of the lobe design is not compatible for long term longevity of the cams....
or
Maybe the cams have pushed the envelope of design and are as far or farther advanced than the materials they are constructed of.
There are lifters available that are made out of materials other than iron, and there are interesting stories on how long they live and claims of "going the distance" with no problems.
The cam that I am running, the manufacturer recommends "as little idling as possible" and they estimate the cams life to be 40,000 miles at the most.
I have not decided which oil I will run, but I have been giving it carefull consideration.
I should be able to judge the wear, it is a solid lifter, and will require periodic adjustment.
use delo diesel oil or RL
bruce
bruce
- Status
Similar threads
