running in cams

[stumac77]

as above how many miles should i run them in for

[jeffchiz]

0 miles

[stevo1600]

When I fitted my cams in I was told to hit 2k revs for so long. According to Newman anyways,

[jeffchiz]

theres alot of different rumors about runnign in cams, i personally think its a load of bollocks, the first thing poeple do when they fit cams is head towards the nearest duel carridge way and give it some lol thats what im gonna be doing when i get my cams and bodies fitted *awaits saxp police*

[adamskiTNR]

it is not essential. but wont hurt. unlike piston rings cams are put under stress with high rpm not high engine load. with rings you want to be at high rpm at a lower gear to reduce engine load. with cams the opposite is true. but if running cams in was so important then race engine rebuilds would be ridiculous. an engine with a 30hr life cannot spend that tootling about for 5 of them

[Richyhotrod]

Most Common way is once fitted start up & check for leaks etc.. Then 2 to 3k rpm for 20min you need to do this to harden up the cam lobes else they will wear quickly.

[raunchz]

it is not essential. but wont hurt. unlike piston rings cams are put under stress with high rpm not high engine load. with rings you want to be at high rpm at a lower gear to reduce engine load. with cams the opposite is true. but if running cams in was so important then race engine rebuilds would be ridiculous. an engine with a 30hr life cannot spend that tootling about for 5 of them

Im pretty sure the cam lobes are put under more stress idling than at a higher rpm.

The idea behind running them in into harden the camshact material to minimise the wear on the lobes over time.

I was told to run the engine at 2-3k for 20mins to run them in. it is so that you harden them without a lot of pressure/load on the lobes idling

[adamskiTNR]

so i really don't see the difference between doing this and running the car as normal afterwards. as normal driving is in that range

[adamskiTNR]

and most good cams are hard faced anyway. a thin layer of a hard nickel alloy. so you wont easily be able to harden this without proper heat treatment

[LSOfreak]

theres alot of different rumors about runnign in cams, i personally think its a load of bollocks, the first thing poeple do when they fit cams is head towards the nearest duel carridge way and give it some lol thats what im gonna be doing when i get my cams and bodies fitted *awaits saxp police*

lol that wouldve been my first thought aswell, hit the m4 and give it death :p

[Olly]

do what the manufacturer suggests imo...

[yr51ocw]

Low engine speeds (idle) will put higher hertz stresses on the camshaft lobes. Hence why it is recommended to run them in at a higher speed for a short period of time (20mins usually). This is not to harden the cam lobe, as already said it should be hardened already and running in an engine will not be able to increase the hardness. The running in process is to remove and high spots left on the lobes/followers from manufacturing.

The actual rpm is difference for every cam profile and valve train, as it is a function of the valve lift acceleration and mass to give the inertia, this is where careful valvetrain design is required - to make sure that the valve acceleration and jerk does not cause loss of valve motion control (causing potential damage to engine components, and loss of torque if the valve is bouncing during reseating due to low stiffness of the valvetrain or surge of the spring) and excessive contact loads (which can lead to pitting of the surfaces)

[enthrone]

Im sure rickyrpm posted a while a ago they should be revved up through the range, then up and down through it.

im sure it was him who posted that.. myself i have no idea.

[raunchz]

Low engine speeds (idle) will put higher hertz stresses on the camshaft lobes. Hence why it is recommended to run them in at a higher speed for a short period of time (20mins usually). This is not to harden the cam lobe, as already said it should be hardened already and running in an engine will not be able to increase the hardness. The running in process is to remove and high spots left on the lobes/followers from manufacturing.

The actual rpm is difference for every cam profile and valve train, as it is a function of the valve lift acceleration and mass to give the inertia, this is where careful valvetrain design is required - to make sure that the valve acceleration and jerk does not cause loss of valve motion control (causing potential damage to engine components, and loss of torque if the valve is bouncing during reseating due to low stiffness of the valvetrain or surge of the spring) and excessive contact loads (which can lead to pitting of the surfaces)

I'm mistaken then, thanks for posting up that info - it makes sense tbh.

[Gabbastard]

I love it when randoms on teh forum have greater knowledge than the actual manufacturers.