Camshaft Break In
Thread Starter
Instructor
Joined: Jun 2014
Posts: 178
Likes: 3
From: Pensacola FL
Camshaft Break In
Google searches and forums can scare the heck out of folks regarding a Flat tappet Cam or engine break in.
Failed cam lobes or lifters seem to be the new nightmare due to "low zinc oil". It's NOT the oil, its what its missing and how the cam is broken in.
Break in procedures that cam manufactures recommend today has really always been the "right way". Camshaft break in, in the past has been more forgiving because of the high zinc additive in the older engine oils. It provided an additional lubricity to forgive low speed lifter rotation.
Think about it. We are talking metal on metal contact between the cam and lifter faces at extremely high loads, only aggravated by high spring pressures, and only depending on a small amount of splash windage lubrication from the crank throws to get the job done. Crude indeed.
First you have to understand what is supposed to happen with a flat tappet camshaft.
Its simple. The cam lifters MUST rotate in the block as they ride on the cam lobes and open the valves. Lack of lifter rotation causes a flat cam lobe or wiped lifter. The constant rotation of the lifter on the cam lobe provides a new mating surface as well as oil lubrication each time the cam and lifter faces meet.
To make the rotation happen, the cam lobes are offset ground on an angle so the lifters are always running uphill, or "trying to climb" the ramp on the cam. Its all based on FRICTION to get the job done.
Friction is a bad thing in engines. It robs HP and fuel economy.. Welcome to low friction roller cams and modern oils that support them.
If you can afford to convert to a roller cam, by all means go for it and never look back! If you are restoring a car or simply can't afford other than a flat tappet cam, I offer the following break in advise that has worked well for me, and several of my customers engines.
1. Lifters don't spin well to mate with the cam face at low RPM's. You need at least 2000 to 2500 rpms for the first 20 minutes. Don't let the engine idle during this period. Never!
Its critical to have the timing properly set, oil system primed, a proven carburetor that will run, and proper valve adjustment to achieve a minimum of 2000 RPM and an instant start.
2. Have the carb bowl full of fuel via the vent tube and plenty of initial timing advance dialed in. Have the radiator full of water with a helper watching the coolant level, adding water as needed. Again, instant start and 2K RPMs
3. If the engine does not start right away or achieve a minimum of 2K rpm, shut it down immediately and figure out why. The lifters have to rotate on the cam lobes or you will kill the cam. I cannot stress how critical the first 20 minute high RPM's are.
4. Cranking the engine over with a no start is just wiping the break in lube off the cam, as will too many rotations during valve adjustment. If you don't know how to "cold lash" lifter pre-load with just 2 crankshaft rotations, get someone that does or google it. Remember, cam and lifter lubrication is splash oiled from the crank throws. Not very effective at idle RPM's.
The following is just my personal opinion from what has worked for me successfully over the years on many engines including a start up 3 days ago. Take it with a grain of salt..
Most flat tappet hydraulic or solid lift cams can be broken in with the recommended valve springs on a typical street engine. If you are around 100 lbs closed on the seat and 300 lbs advertised open pressure you will be fine. In other words a single spring with a damper. Double and triple race springs will require a break in spring rate, usually just running the outer spring for the first 20 minutes.
Use a good Moly based cam and lifter lube and liberally apply it to the cam lobes, distributor gear and lifter bottoms. As much of a Comp Cams fan I am, I don't like the red cam lube they recommend and prefer the old school grey thick stuff like Crane Cams provides .
Use a strait 30W motor oil like Castrol 30HD for break in along with a double dose of a high zinc additive. Cam companies stuff, Rislone or Lucas break-in additives work well. Joe Gibbs and others make good oil also but its expensive and I don't feel its necessary. DO NOT use a synthetic oil for break in. Its too slick and can prevent the lifters from rotating.
If the cam survives the first 20 minutes and it should, idle the engine and tweak the initial timing and carb adjustments.
Let it cool down some and change the oil and oil filter again. This needs to be done to get any break=in grit or metals out of the engine. Fill the crankcase with a quality MINERAL based oil plus a zinc additive supplement of your choice. After 3000 miles you can go synthetic if you choose to do so.
We blame failed cams on the manufacture producing "soft" cores. I seriously doubt that is the problem, and cam companies blame it on the lack of zinc in today's oils that pollute Cats and don't provide flat tappet lubrication. That's a maybe at best as all oils are supposed to be backwards compatible. So, add some zinc additive and hope for the best!
Remember, the first 20 minutes is the critical time of weather a cam lives or not.
Failed cam lobes or lifters seem to be the new nightmare due to "low zinc oil". It's NOT the oil, its what its missing and how the cam is broken in.
Break in procedures that cam manufactures recommend today has really always been the "right way". Camshaft break in, in the past has been more forgiving because of the high zinc additive in the older engine oils. It provided an additional lubricity to forgive low speed lifter rotation.
Think about it. We are talking metal on metal contact between the cam and lifter faces at extremely high loads, only aggravated by high spring pressures, and only depending on a small amount of splash windage lubrication from the crank throws to get the job done. Crude indeed.
First you have to understand what is supposed to happen with a flat tappet camshaft.
Its simple. The cam lifters MUST rotate in the block as they ride on the cam lobes and open the valves. Lack of lifter rotation causes a flat cam lobe or wiped lifter. The constant rotation of the lifter on the cam lobe provides a new mating surface as well as oil lubrication each time the cam and lifter faces meet.
To make the rotation happen, the cam lobes are offset ground on an angle so the lifters are always running uphill, or "trying to climb" the ramp on the cam. Its all based on FRICTION to get the job done.
Friction is a bad thing in engines. It robs HP and fuel economy.. Welcome to low friction roller cams and modern oils that support them.
If you can afford to convert to a roller cam, by all means go for it and never look back! If you are restoring a car or simply can't afford other than a flat tappet cam, I offer the following break in advise that has worked well for me, and several of my customers engines.
1. Lifters don't spin well to mate with the cam face at low RPM's. You need at least 2000 to 2500 rpms for the first 20 minutes. Don't let the engine idle during this period. Never!
Its critical to have the timing properly set, oil system primed, a proven carburetor that will run, and proper valve adjustment to achieve a minimum of 2000 RPM and an instant start.
2. Have the carb bowl full of fuel via the vent tube and plenty of initial timing advance dialed in. Have the radiator full of water with a helper watching the coolant level, adding water as needed. Again, instant start and 2K RPMs
3. If the engine does not start right away or achieve a minimum of 2K rpm, shut it down immediately and figure out why. The lifters have to rotate on the cam lobes or you will kill the cam. I cannot stress how critical the first 20 minute high RPM's are.
4. Cranking the engine over with a no start is just wiping the break in lube off the cam, as will too many rotations during valve adjustment. If you don't know how to "cold lash" lifter pre-load with just 2 crankshaft rotations, get someone that does or google it. Remember, cam and lifter lubrication is splash oiled from the crank throws. Not very effective at idle RPM's.
The following is just my personal opinion from what has worked for me successfully over the years on many engines including a start up 3 days ago. Take it with a grain of salt..
Most flat tappet hydraulic or solid lift cams can be broken in with the recommended valve springs on a typical street engine. If you are around 100 lbs closed on the seat and 300 lbs advertised open pressure you will be fine. In other words a single spring with a damper. Double and triple race springs will require a break in spring rate, usually just running the outer spring for the first 20 minutes.
Use a good Moly based cam and lifter lube and liberally apply it to the cam lobes, distributor gear and lifter bottoms. As much of a Comp Cams fan I am, I don't like the red cam lube they recommend and prefer the old school grey thick stuff like Crane Cams provides .
Use a strait 30W motor oil like Castrol 30HD for break in along with a double dose of a high zinc additive. Cam companies stuff, Rislone or Lucas break-in additives work well. Joe Gibbs and others make good oil also but its expensive and I don't feel its necessary. DO NOT use a synthetic oil for break in. Its too slick and can prevent the lifters from rotating.
If the cam survives the first 20 minutes and it should, idle the engine and tweak the initial timing and carb adjustments.
Let it cool down some and change the oil and oil filter again. This needs to be done to get any break=in grit or metals out of the engine. Fill the crankcase with a quality MINERAL based oil plus a zinc additive supplement of your choice. After 3000 miles you can go synthetic if you choose to do so.
We blame failed cams on the manufacture producing "soft" cores. I seriously doubt that is the problem, and cam companies blame it on the lack of zinc in today's oils that pollute Cats and don't provide flat tappet lubrication. That's a maybe at best as all oils are supposed to be backwards compatible. So, add some zinc additive and hope for the best!
Remember, the first 20 minutes is the critical time of weather a cam lives or not.
Le Mans Master
Joined: Oct 2007
Posts: 7,455
Likes: 977
From: RI, Now Franklin/Nashville TN
Some pretty good advice here^ but I would add a few comments:
1. The perception from some in the aftermarket mod world is that Roller retro fit cams do not need to be broken in-NOT TRUE. All cams need to be broken in but it is more critical for flat tappet cams than rollers. i just did my roller in the spring following the cam manufacturer recommendation, my builder for the short block, and the Vette magazine article in the oil sticky on this forum. Instant startup and 30 minutes varying the engine speed between 1,800-2,500 RPM.
2. I would not use a straight 30 weight oil for breakin nor breakin ZZDP enhancers added to the oil. A straight 30 weight oil is too thick for the initial start up, especially for the first several minutes. Use a conventional breakin in oil made for breakin like Driven 5W-30 BR or Driven 15W-50 BR which has the appropriate amount of ZDDP for older engines and both of which are multi Visocisty conventional oils that will flow and protect the cam better at initial startup than the straight 30 weight oil and have the same viscosity when hot (Driven 5W-30) and better high temp protection (Driven 15W-50 BR) than a straight 30W oil.
3. Change the oil and Filter after the 30 minute breakin to a conventional oil (I used Driven 15W-50 Hot Rod High ZDDP) oil based on the builder's experience and recommendation). Run the conventional oil for about 500-750 miles and the cam-flat tappet or Roller as well as the engine) should be good to go for synthetic, if you choose to run it (I am switching to Mobil 1 0W-40 European Formula Group IV-Roller cam though, not flat tappet @ 700 miles).
4. FWIW-A good Friend who owned a High Performance Part store in the 80's told me that he sold more cam replacements back then for all V8's since after about 100,000 miles or less, the cams were shot and they were made of junk material from the OEM's and that was back when the oils had high ZDDP. The cams back then were junk and now the cams are better but now the oil is not optimized for long flat tappet cam life-thank the EPA for that-saving all of us from ourselves....
Hope that helps!
1. The perception from some in the aftermarket mod world is that Roller retro fit cams do not need to be broken in-NOT TRUE. All cams need to be broken in but it is more critical for flat tappet cams than rollers. i just did my roller in the spring following the cam manufacturer recommendation, my builder for the short block, and the Vette magazine article in the oil sticky on this forum. Instant startup and 30 minutes varying the engine speed between 1,800-2,500 RPM.
2. I would not use a straight 30 weight oil for breakin nor breakin ZZDP enhancers added to the oil. A straight 30 weight oil is too thick for the initial start up, especially for the first several minutes. Use a conventional breakin in oil made for breakin like Driven 5W-30 BR or Driven 15W-50 BR which has the appropriate amount of ZDDP for older engines and both of which are multi Visocisty conventional oils that will flow and protect the cam better at initial startup than the straight 30 weight oil and have the same viscosity when hot (Driven 5W-30) and better high temp protection (Driven 15W-50 BR) than a straight 30W oil.
3. Change the oil and Filter after the 30 minute breakin to a conventional oil (I used Driven 15W-50 Hot Rod High ZDDP) oil based on the builder's experience and recommendation). Run the conventional oil for about 500-750 miles and the cam-flat tappet or Roller as well as the engine) should be good to go for synthetic, if you choose to run it (I am switching to Mobil 1 0W-40 European Formula Group IV-Roller cam though, not flat tappet @ 700 miles).
4. FWIW-A good Friend who owned a High Performance Part store in the 80's told me that he sold more cam replacements back then for all V8's since after about 100,000 miles or less, the cams were shot and they were made of junk material from the OEM's and that was back when the oils had high ZDDP. The cams back then were junk and now the cams are better but now the oil is not optimized for long flat tappet cam life-thank the EPA for that-saving all of us from ourselves....
Hope that helps!
Last edited by jb78L-82; Nov 27, 2014 at 08:27 AM.
Thread Starter
Instructor
Joined: Jun 2014
Posts: 178
Likes: 3
From: Pensacola FL
Some pretty good advice here^ but I would add a few comments:
1. The perception from some in the aftermarket mod world is that Roller retro fit cams do not need to be broken in-NOT TRUE. All cams need to be broken in but it is more critical for flat tappet cams than rollers. i just did my roller in the spring following the cam manufacturer recommendation, my builder for the short block, and the Vette magazine article in the oil sticky on this forum. Instant startup and 30 minutes varying the engine speed between 1,800-2,500 RPM.
2. I would not use a straight 30 weight oil for breakin nor breakin ZZDP enhancers added to the oil. A straight 30 weight oil is too thick for the initial start up, especially for the first several minutes. Use a conventional breakin in oil made for breakin like Driven 5W-30 BR or Driven 15W-50 BR which has the appropriate amount of ZDDP for older engines and both of which are multi Visocisty conventional oils that will flow and protect the cam better at initial startup than the straight 30 weight oil and have the same viscosity when hot (Driven 5W-30) and better high temp protection (Driven 15W-50 BR) than a straight 30W oil.
3. Change the oil and Filter after the 30 minute breakin to a conventional oil (I used Driven 15W-50 Hot Rod High ZDDP) oil based on the builder's experience and recommendation). Run the conventional oil for about 500-750 miles and the cam-flat tappet or Roller as well as the engine) should be good to go for synthetic, if you choose to run it (I am switching to Mobil 1 0W-40 European Formula Group IV-Roller cam though, not flat tappet @ 700 miles).
4. FWIW-A good Friend who owned a High Performance Part store in the 80's told me that he sold more cam replacements back then for all V8's since after about 100,000 miles or less, the cams were shot and they were made of junk material from the OEM's and that was back when the oils had high ZDDP. The cams back then were junk and now the cams are better but now the oil is not optimized for long flat tappet cam life-thank the EPA for that-saving all of us from ourselves....
Hope that helps!
1. The perception from some in the aftermarket mod world is that Roller retro fit cams do not need to be broken in-NOT TRUE. All cams need to be broken in but it is more critical for flat tappet cams than rollers. i just did my roller in the spring following the cam manufacturer recommendation, my builder for the short block, and the Vette magazine article in the oil sticky on this forum. Instant startup and 30 minutes varying the engine speed between 1,800-2,500 RPM.
2. I would not use a straight 30 weight oil for breakin nor breakin ZZDP enhancers added to the oil. A straight 30 weight oil is too thick for the initial start up, especially for the first several minutes. Use a conventional breakin in oil made for breakin like Driven 5W-30 BR or Driven 15W-50 BR which has the appropriate amount of ZDDP for older engines and both of which are multi Visocisty conventional oils that will flow and protect the cam better at initial startup than the straight 30 weight oil and have the same viscosity when hot (Driven 5W-30) and better high temp protection (Driven 15W-50 BR) than a straight 30W oil.
3. Change the oil and Filter after the 30 minute breakin to a conventional oil (I used Driven 15W-50 Hot Rod High ZDDP) oil based on the builder's experience and recommendation). Run the conventional oil for about 500-750 miles and the cam-flat tappet or Roller as well as the engine) should be good to go for synthetic, if you choose to run it (I am switching to Mobil 1 0W-40 European Formula Group IV-Roller cam though, not flat tappet @ 700 miles).
4. FWIW-A good Friend who owned a High Performance Part store in the 80's told me that he sold more cam replacements back then for all V8's since after about 100,000 miles or less, the cams were shot and they were made of junk material from the OEM's and that was back when the oils had high ZDDP. The cams back then were junk and now the cams are better but now the oil is not optimized for long flat tappet cam life-thank the EPA for that-saving all of us from ourselves....
Hope that helps!
2. Its a matter of opinion on oil. The cam lube should take care of the first 20 minutes. I don't think 30 wt oil is too thick at 80 degrees outside temps. If I lived up North, thinner would be better.
Actually, a few extra quarts of oil in the pan could provide beneficial additional splash lubrication to the cam during beak-in.. Grooving the lifter bores to direct oil to the cam, lifters with an oil hole in the lifter face and a nitrided cam can help also if you spend the money.
High Zinc Oil is a good thing, but its meant for long term protection as it slowly becomes embedded from heat in the engines metal surfaces. An overdose of ZDDP can actually cause surfaces to become brittle and flake off overtime. But.. as you said, why take a chance and if the cam craps on start up, its not the lack of quality break-in oil.
3. I used to run all engines 500 miles before the first oil change. The diesel oils like Rotella 15-40 were a great oil to run due to high zinc but not anymore. Still should be better outside of a true racing oil.
I am still a big fan of Rislone and Lucas zinc additives, but careful, as some of the ZDDP replacements contain no zinc at all to keep catalytic and O2 sensors happy.
4. I pulled wrenches at a GM dealership and a machine shop during the early 80's and cam failures were very common, especially on Chevrolets.
To save money on production costs, Chevy stopped Nitrite Harding the cams, a process that had been done for 40 years prior. They also turned out some of the poorest low nickel block castings. Remember the days of having to use a ridge reamer to get a piston out of the block, and lucky to get the bore to clean up at an .030 overbore? We won't even talk about severe casting core shift issues, deck square and thin wall cast heads. Absolute junk was made, but it made me money.
Its not uncommon today to get 300K plus miles out of a small block Chevy. Improvements in metallurgy, like high nickel castings, piston ring design and tighter tolerances has all contributed. The "Big Three" had to do something as imports from Japan were kicking there butts.
Not to mention the wonderful thing called "Overdrive" . It became common place to meet Government mandated fuel economy, but a bonus is how long an engine today last because of it. Engines today idle along at 1700 to 2000 RPMs running 70 MPH. Instead of 2500 plus a few years back.
A good trivia question to ask gear head friends is: "How many RPMs does a top fuel Dragster turn in the 1/4 mile?" The answer will likely be numbers around 8 to 12 thousand....
Well how about 600 RPMs or less from the time it leaves the starting line to the end of the track.
Do the math. Revolutions Per Minute, not revolutions per second.
Ask all the questions you can and run a quality oil or additive, but don't expect a flat tappet cam to provide high mileage, they never have really. If it survives the first 30 minutes you are half way home. If it survives the first 500 miles its in the bag. Drive the Damn thang!!
Last edited by PcolaPaul; Nov 29, 2014 at 06:09 AM. Reason: typo
Le Mans Master
Joined: Oct 2007
Posts: 7,455
Likes: 977
From: RI, Now Franklin/Nashville TN
#1 Roller cams do need break in, but much more forgiving. Way more forgiving than a flat tappet. As discussed, the high RPMs are needed do to the poor lubrication as designed. Add a windage tray and it only gets worse. Biggest problem with most folks with a new performance cam is they want to here how it sounds at idle, as we all do. Bumpity-Bump.. Letting it idle during crucial cam/lifter break-in.
2. Its a matter of opinion on oil. The cam lube should take care of the first 20 minutes. I don't think 30 wt oil is too thick at 80 degrees outside temps. If I lived up North, thinner would be better.
Actually, a few extra quarts of oil in the pan could provide beneficial additional splash lubrication to the cam during beak-in.. Grooving the lifter bores to direct oil to the cam, lifters with an oil hole in the lifter face and a nitrided cam can help also if you spend the money.
High Zinc Oil is a good thing, but its meant for long term protection as it slowly becomes embedded from heat in the engines metal surfaces. An overdose of ZDDP can actually cause surfaces to become brittle and flake off overtime. But.. as you said, why take a chance and if the cam craps on start up, its not the lack of quality break-in oil.
3. I used to run all engines 500 miles before the first oil change. The diesel oils like Rotella 15-40 were a great oil to run due to high zinc but not anymore. Still should be better outside of a true racing oil.
I am still a big fan of Rislone and Lucas zinc additives, but careful, as some of the ZDDP replacements contain no zinc at all to keep catalytic and O2 sensors happy.
4. I pulled wrenches at a GM dealership and a machine shop during the early 80's and cam failures were very common, especially on Chevrolets.
To save money on production costs, Chevy stopped Nitrite Harding the cams, a process that had been done for 40 years prior. They also turned out some of the poorest low nickel block castings. Remember the days of having to use a ridge reamer to get a piston out of the block, and lucky to get the bore to clean up at an .030 overbore? We won't even talk about severe casting core shift issues, deck square and thin wall cast heads. Absolute junk was made, but it made me money.
Its not uncommon today to get 300K plus miles out of a small block Chevy. Improvements in metallurgy, like high nickel castings, piston ring design and tighter tolerances has all contributed. The "Big Three" had to do something as imports from Japan were kicking there butts.
Not to mention the wonderful thing called "Overdrive" . It became common place to meet Government mandated fuel economy, but a bonus is how long an engine today last because of it. Engines today idle along at 1700 to 2000 RPMs running 70 MPH. Instead of 2500 plus a few years back.
A good trivia question to ask gear head friends is: "How many RPMs does a top fuel Dragster turn in the 1/4 mile?" The answer will likely be numbers around 8 to 12 thousand....
Well how about 600 RPMs or less from the time it leaves the starting line to the end of the track.
Do the math. Revolutions Per Minute, not revolutions per second.
Ask all the questions you can and run a quality oil or additive, but don't expect a flat tappet cam to provide high mileage, they never have really. If it survives the first 30 minutes you are half way home. If it survives the first 500 miles its in the bag. Drive the Damn thang!!
2. Its a matter of opinion on oil. The cam lube should take care of the first 20 minutes. I don't think 30 wt oil is too thick at 80 degrees outside temps. If I lived up North, thinner would be better.
Actually, a few extra quarts of oil in the pan could provide beneficial additional splash lubrication to the cam during beak-in.. Grooving the lifter bores to direct oil to the cam, lifters with an oil hole in the lifter face and a nitrided cam can help also if you spend the money.
High Zinc Oil is a good thing, but its meant for long term protection as it slowly becomes embedded from heat in the engines metal surfaces. An overdose of ZDDP can actually cause surfaces to become brittle and flake off overtime. But.. as you said, why take a chance and if the cam craps on start up, its not the lack of quality break-in oil.
3. I used to run all engines 500 miles before the first oil change. The diesel oils like Rotella 15-40 were a great oil to run due to high zinc but not anymore. Still should be better outside of a true racing oil.
I am still a big fan of Rislone and Lucas zinc additives, but careful, as some of the ZDDP replacements contain no zinc at all to keep catalytic and O2 sensors happy.
4. I pulled wrenches at a GM dealership and a machine shop during the early 80's and cam failures were very common, especially on Chevrolets.
To save money on production costs, Chevy stopped Nitrite Harding the cams, a process that had been done for 40 years prior. They also turned out some of the poorest low nickel block castings. Remember the days of having to use a ridge reamer to get a piston out of the block, and lucky to get the bore to clean up at an .030 overbore? We won't even talk about severe casting core shift issues, deck square and thin wall cast heads. Absolute junk was made, but it made me money.
Its not uncommon today to get 300K plus miles out of a small block Chevy. Improvements in metallurgy, like high nickel castings, piston ring design and tighter tolerances has all contributed. The "Big Three" had to do something as imports from Japan were kicking there butts.
Not to mention the wonderful thing called "Overdrive" . It became common place to meet Government mandated fuel economy, but a bonus is how long an engine today last because of it. Engines today idle along at 1700 to 2000 RPMs running 70 MPH. Instead of 2500 plus a few years back.
A good trivia question to ask gear head friends is: "How many RPMs does a top fuel Dragster turn in the 1/4 mile?" The answer will likely be numbers around 8 to 12 thousand....
Well how about 600 RPMs or less from the time it leaves the starting line to the end of the track.
Do the math. Revolutions Per Minute, not revolutions per second.
Ask all the questions you can and run a quality oil or additive, but don't expect a flat tappet cam to provide high mileage, they never have really. If it survives the first 30 minutes you are half way home. If it survives the first 500 miles its in the bag. Drive the Damn thang!!
