Cam break in theory and Matrix Garage break in

Before installing your cams it is a good idea to lap your cam caps. http://www.matrixgarage.com/content/how-flat-lap-cam-caps

Different cam manufacturers will have different recommended break in procedures. Some may even have different procedures for different cams. Always use your manufacturers recommended break in procedure.

Some cams like Tomei Poncams don't really have a recommended break in procedure but that doesn't mean there won't be any benefit to knowing and applying some break in theory.

If you research break in theory across the internet you will find a huge array of opinions and methods ranging from "It's not necessary" to "You must absolutely sit there for 20 minutes reving your engine up and down or your cam will melt.
The most important thing is if you don't use the manufacturers recommended break in and something does go wrong they are going to have pretty good reasoning for not wanting to warranty your part.

This discussion will be primarily focused on motors that run cam followers otherwise known as cam caps or lifters.

First let's talk about the purpose of breaking in a cam. Cams are supposed to float across the cap on a thin layer of oil. Technically they shouldn't actually make contact. When you put a new cam in though you have two surfaces that have never made contact with each other so it is very likely that there will be small imperfections that will make contact here or there. The break in process is intended to make this happen in the safest way possible and allow the two surfaces to mate to each other without any binding or galling.

 

There are three main points that are at the heart of all the various break in procedures you might read or hear about.
The first is oiling. While getting oil to the top end is always important it's especially critical during the break in. While the lobes and caps are trying to conform to each other a lack of oil could cause dangerous metal on metal contact.
This is why you will usually hear it suggested that you don't let it idle much during the break in. Whatever the break in method it is a good idea to keep the revs and oil pressure up.

The second is making sure the caps rotate. Cam caps are meant to rotate and you definitely want them rotating while they are breaking in. Different RPMs can cause the caps to rotate differently and at certian RPM it could even allow the cap to stall or not spin much at all.
This is why they usually suggest varying the RPM.

The third thing to consider is the force applied to the cam cap.
The higher the RPMs the harder the cam is hitting the cap and the more pressure it's applying to the oil film between the lobe and the cap.
This is why you wouldn't want to jump out and start bouncing off the rev limiter on a brand new cam.
It is also why break in becomes more important on more agressive builds.
More lift will try to accelerate the cam cap faster applying more force from the lobe to the cam cap.
Stiffer valve springs again create more resistance so the lobe has to apply more pressure on the cam cap to push it down.
This means the bigger the cam and the stiffer the spring the more it tries to push that oil film out of the contact patch between the cam and the cap.

 

 

I don't believe it should be necessary to sit in your driveway reving your motor up and down for 20 minutes for most cams but the bigger the cam the more critical cam break in becomes.

Small cams may very well be fine without any break in but paying attention to the above factors can do nothing but help. The bigger your cam gets and the stiffer your springs get the more important these factors become.

So again if your cam manufacturer has a recommended break in procedure follow it as best you can if for no other reason if something goes wrong at least you can say you followed their break in procedure.
If your cam has no break in procedure at least you know the big concerns and why some manufacturers recommend a break in. Taking those things into consideration will be better than not.

 

Matrix Garage cam break in
Our cams are made by TED components so to be covered for any warranty work we recommend you use their break in procedure. Our cams are quite small compared to most of TEDs grinds and may not need as much of a break in but if any issues do arise it will help your case a lot if you followed their break in procedure to a T.

 

Note: New lifters must be installed with your new camshaft prior to Installation:

• Check the compatibility of the camshaft with the remainder of the valve train components (valve springs, lifters, shim, etc.)

• On race type, high spring load applications, use lighter load springs or remove the inner spring (dual spring application) just for break-in.

As a point of interest, the most critical time in the life of a flat tappet/lifter camshaft is the first 20 minutes of break-in during which the bottoms of the lifters "mate-in" with the cam lobes.

There are some oils with additive packages that are better for camshaft break-in. These include, but are not limited to: Brad Penn or Joe Gibbs racing or a race only petroleum-based oil, also include a lube/ZDDP additive. Do not use API rated SL, SM, or SN oil.

Use of synthetic oils is not recommend for break-in. Prior to installing the camshaft and lifters, it is recommended that the crankcase be drained and filled with new, clean oil as listed above. The oil filter should also be changed at this time. Proper flat tappet camshaft break-in starts with the cam installation and includes the following steps:

1. Before installing the camshaft and lifters, wash them thoroughly in clean mineral spirits to remove the rust preventative that is placed on the cam before shipping, as per cam card.

2. DO NOT "pump-up" hydraulic lifters before use (2ZR-FE). This can cause the lifters to hold a valve open during engine cranking, which will cause low compression. The low compression will delay engine start-up and is very detrimental to proper camshaft break-in.

3. Use a moly paste lube to coat the bottom of the lifters, cam lobes and distributor gear. Use an assembly lube on all other surfaces and components.

4. Set your valve lash or lifter preload (2ZR-FE). Try to minimize the number of times that you rotate the engine, as this can displace the moly paste from the lobes and lifters.

5. If possible, prime the oiling system. When priming, rotate the engine at least two complete revolutions to assure oil gets to all valve train components. Valve covers should be off to assure that all cams are oiling. 6. Preset the ignition timing to start the engine at a fast idle. It is important that the static ignition timing is set as close as possible and if the engine has a carburetor (Pre-1984), it should be filled with fuel. The engine needs to start quickly without excessive cranking to insure immediate lubrication to the cam lobes.

7. Start the engine and immediately bring to 3,000 rpm. Timing should be adjusted, as quickly as possible, to reduce excessive heat or load during break-in. Get the engine running fairly smooth and vary the engine speed from 1,500-3,000 rpm in a slow, to moderate, acceleration/deceleration cycle. During this time, be sure to check for any leaks and check out any unusual noises. If something doesn’t sound right, shut the engine off and check out the source of the noise. Upon restart, resume the high idle speed cycling. Continue the varying break-in speed for 20-30 minutes. This is necessary to provide proper lifter rotation to properly mate each lifter to its lobe. Should the engine need to be shut down for any reason, upon re-start it should be immediately brought back to 3,000 rpm and the break-in continued for a total run time of 20-30 minutes.

8. Let the engine cool, and then drain the crankcase and properly dispose of the oil and oil filter. Refill the crankcase with a premium petroleum-based oil that contains the flat tappet compatible additives, not a synthetic oil. At this point the initial break-in is complete. The engine can be run normally. It is recommended that you change the oil and filter after 500 miles. You might want to put another 5,000 miles on the cam before switching to a synthetic, if that is your preference.

Additional Information:

Spring Pressures: For extended camshaft life, flat-tappet cams should not be run with more than the recommended open valve spring pressure. Racing applications will often need to run more spring pressure at the expense of reduced camshaft life. In order to break-in a camshaft with high open pressures, the inner springs should be removed to reduce break-in load. The inner springs can then be reinstalled after initial break-in is complete.

Lifter Rotation: Flat tappet cams, the lifters appear to sit offset from the lobe centerline. This will induce a rotation of the lifter on the lobe. This rotation draws oil to the mating surface between the lifter and the lobe. View the lifters during break-in, they should be turning. If you don’t see a lifter rotating, immediately stop the engine and find the cause. Never use old lifters/top-shims on a new cam. On flat tappet/shims cams, the lobes and lifter bottoms mate together. if the lifters are removed from the engine, they must go back on the same lobe from which they were removed. It is recommended that new lifters/shims be used to prevent premature cam or lifter wear. If shims or lifters are being reused, ensure that they are lapped within 2 light-band flatness. Turning over/flipping the adjusting shim over, may cause the shim to pop-out of the lifter.

Hand lapping is acceptable providing that the lifters be checked for flatness, lapping compound can mask a bad lifter and cause lobe failure. A rudimentary method of checking for flat is put a very thin film on the used lifter or shim before lapping; draw the part across a known flat surface or a piece of thick window pane, this will indicate if the part is fairly flat. This can be repeated after lapping to ensure proper procedure.
Lapping should be done on a lap plate with 2500 then 3800 compound and finished with

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