Not sure where to post this question.
I just installed a new Hamilton 188/220 flat tappet cam in my 1999 Dodge Cummins Diesel.
They are very specific about the break-in procedure, add 1 bottle of ZDDP to the engine oil, start it and run it at 2000 rpm for 20 minutes, and I (think) understand why.
Correct me if I'm wrong;
1) 2000 rpm’s which is 1000 cam rpm is needed to ensure there is sufficient oil throw off from the crank to properly lubricate the cam lifter interface and,
2) 1000 cam rpm’s is necessary to enable a hydrodynamic fluid film to be established between the cam and lifter interface which minimizes contact allowing a slow controlled process where high spots are leveled and which also allows the surfaces to become work hardened.
What I would like to know is;
Does the manufacture perform this operation?
If not then why don't cams fail in new engines? I realize roller cams don’t require this process.
Back in the 60's & 70's all cams were flat and I'm sure they didn't run every engine 20 minutes for this break-in process.
Why didn't cams fail back then at a high rate?
I’m aware that today’s oils are lacking in anti-wear additives and are the cause of premature cam failures.
Back in 1990 when I bought my first new Dodge CTD I believe they gave each engine a hot run to verify all systems GO.
Do the still do this?
Do OEM’s spike the factory oil fill with ZDDP?
Thanks
Ducati996
I just installed a new Hamilton 188/220 flat tappet cam in my 1999 Dodge Cummins Diesel.
They are very specific about the break-in procedure, add 1 bottle of ZDDP to the engine oil, start it and run it at 2000 rpm for 20 minutes, and I (think) understand why.
Correct me if I'm wrong;
1) 2000 rpm’s which is 1000 cam rpm is needed to ensure there is sufficient oil throw off from the crank to properly lubricate the cam lifter interface and,
2) 1000 cam rpm’s is necessary to enable a hydrodynamic fluid film to be established between the cam and lifter interface which minimizes contact allowing a slow controlled process where high spots are leveled and which also allows the surfaces to become work hardened.
What I would like to know is;
Does the manufacture perform this operation?
If not then why don't cams fail in new engines? I realize roller cams don’t require this process.
Back in the 60's & 70's all cams were flat and I'm sure they didn't run every engine 20 minutes for this break-in process.
Why didn't cams fail back then at a high rate?
I’m aware that today’s oils are lacking in anti-wear additives and are the cause of premature cam failures.
Back in 1990 when I bought my first new Dodge CTD I believe they gave each engine a hot run to verify all systems GO.
Do the still do this?
Do OEM’s spike the factory oil fill with ZDDP?
Thanks
Ducati996