| Flat tappet Camshaft Break-in and maintenance |
| Mike Phillips Automotive Machine & Performance Philpot, KY |
| Over the past several years there has been a dramatic increase of premature camshaft failures no matter who it was ground by. There have been no changes in camshaft or follower materials or heat treatment from ANY of the cam grinders. By the end of 2004 it was finally revealed that the so called "improved" versions of all the major oil companies conventional and synthetic blends had greatly reduced the additives ( primarily zinc) from their content. This was the result of an EPA mandate to further decrease auto emissions, then under pressure from the major Detroit auto makers, the engine oil manufacturers removed most if not all zinc additive from engine oil. Most oil companies used to have about a 0.11 % zinc content as an extreme pressure, anti-wear additive. The zinc is only used when there is actual metal to metal contact in the engine ( when an engine is first started the lifters on a flat tappet cam are skidding across the lobes until the oil pump gets oil to the lifter and then it has to leak by the lifter bore to the lobe) the zinc compounds react with the metal to prevent scuffing and wear. The following oils are know to have the above minimum or more zinc content. Penn Grade 1 (formally Kendall) now made by Brad Penn Racing Oil Valvoline VR1 labeled off road use only Shell Rotella T and Chevron RPM DELO (A change in formulation has recently been made, so I'd make sure it is the old formulation) Rennegade Racing Oil (this is no longer a private label made by Brad Penn so I'd be careful here also) Redline Synthetic Racing Oil Amsoil Synthetic Racing Oil There are several sites that list amounts of zinc in other brands but some of these sites have not been revised in the last few years. |
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1- Coat the lobes of the cam with the lube supplied (I substitute Isky moly cam lube
on all the engines I build but you must just coat the lobes with it and not have
excessive amounts between the lobes and be careful not to get it on the journals, then
change oil after break-in)
2- Use a good high zinc content oil for break-in such as Brad Penn 30w break-in oil
and a container of Comp Cams # 159 break-in lube
alternatives -- Valvoline VR1 and Crane break-in lube
3 - Keep spring pressures under 250 lbs at full lift for break-in.
4 - Make sure the engine is primed, ignition timing is close to running specification,
carburetor is in good working order and full of fuel before cranking engine.
5 - Start engine and bring RPM's to 2,500 as soon as you see oil pressure. Run at
that RPM for a minimum of 20 minutes.
6 - Change springs, re-start and run for an additional 5 to 10 minutes at 2,500 RPM
7 - If the engine is to be dyno'ed change oil after ring break-in pulls have been made,
if it was in the vehicle change oil after break-in.
Use only oil with zinc content of 0.11 ppm minimum
I recommend not using full synthetic on drag race engines the first race, oval track
engines after hot lapping and qualifying and street driven vehicles for at least 500
miles.
on all the engines I build but you must just coat the lobes with it and not have
excessive amounts between the lobes and be careful not to get it on the journals, then
change oil after break-in)
2- Use a good high zinc content oil for break-in such as Brad Penn 30w break-in oil
and a container of Comp Cams # 159 break-in lube
alternatives -- Valvoline VR1 and Crane break-in lube
3 - Keep spring pressures under 250 lbs at full lift for break-in.
4 - Make sure the engine is primed, ignition timing is close to running specification,
carburetor is in good working order and full of fuel before cranking engine.
5 - Start engine and bring RPM's to 2,500 as soon as you see oil pressure. Run at
that RPM for a minimum of 20 minutes.
6 - Change springs, re-start and run for an additional 5 to 10 minutes at 2,500 RPM
7 - If the engine is to be dyno'ed change oil after ring break-in pulls have been made,
if it was in the vehicle change oil after break-in.
Use only oil with zinc content of 0.11 ppm minimum
I recommend not using full synthetic on drag race engines the first race, oval track
engines after hot lapping and qualifying and street driven vehicles for at least 500
miles.