Most every enthusiast dreads the break-in procedure for a flat-tappet cam. Break-in is a twenty minute process where the lifter and lobe surfaces wear an initial pattern together. Proper oiling is absolutely critical to avoid overheating and warping the surfaces.
While most break-in’s go without a hitch, it is inevitable that over the course of your enthusiast career you will eventually run into a wiped cam lobe. The initial reaction is to blame the cam company and suspect poor manufacturing or cam lobe hardness. While these factors are not without merit, a recent tech bulletin by Comp Cams indicates that the problem may actually be in the oil itself.
Comp reveals that today’s oils no longer contain many of the additives, such as zinc and manganese, that were once mixed in the oil to help the longevity of flat-tappet cams and other iron based engine components. While the lubricity of oil has changed due to changes in engine materials, Comp says it is also a direct result of EPA efforts to reduce environmental pollution.
Comp is recommending that flat-tappet camshaft owners use Shell’s Rotella T oils. Since that line of oil is primarily developed for diesel engines, Comp says the oil makeup contains many of the additives that many of the newer oils are lacking.
Comp Cams also points out that a successful break-in also relies on using proper lifters. They caution that many of the imported lifters lack appropriate manufacturing tolerances, which can result in a lifter that doesn’t spin in its bore, or provides inadquate oiling to the cam lobe.
Read the entire Comp Cams Tech Bulletin #225
I inherited a 1983 4.9 F100 XLT from my grandfather. I live in Austin, Texas. I have been reading articles about new oil and older engines (mine has 78,000 original miles) but since I am not a mechanic or engineer I need help sorting through all the info.
What oil should I be using in this engine? HM oil by Valvoline seems a good choice but just not sure. Thanks for any and all help!
By Jane. April 17th, 2008 at 7:31 amFound that bulletin the night before I was doing my first break in with a comp cams - cam. So far so good with 250 miles on the motor. As long as it’s for sale, I’ll be using it as it has more detergents and keeps older engines cleaner.
By Tom. March 5th, 2007 at 6:50 pmi have a 93 ford f150 4.9 leater how dos gas get into the oil on this engen
By charles. September 16th, 2006 at 3:49 amHere in Southern Oregon, Rotellla T has been pulled off the shelves and replaced with a new Rotella oil formulation. The new forumula has no “C” ratings.
By Mike. June 26th, 2006 at 6:04 am