camshaft

[chrispare]

hi I am going to attempt to build a home brew v8 but dont really know how to make a cam any input or anyone willing to machine one for me

[stevehuckss396]

Originally Posted by chrispare hi I am going to attempt to build a home brew v8 but dont really know how to make a cam any input or anyone willing to machine one for me

Here is an article I wrote on the subject.

camarticle

[chrispare]

im sorry I hate to sound dumb but I really dont understand that article can you explane it in any easier tearms.
chris

[stevehuckss396]

Originally Posted by chrispare im sorry I hate to sound dumb but I really dont understand that article can you explane it in any easier tearms. chris

Basically you use a fixture to hold the cam off the center axis of the lathe so when you take a cut, you cut the side off the lobe. Then you rotate the cam in the fixture and cut again. After 40-50 cuts you have a base circle with a bump (lobe) on it.

The chart is used so you know when to cut and when not to. If the table is followed with no errors, all the lobes will end up in the correct place. I have a table layed out for the V8 i'm working on with a 1-8-4-3-6-5-7-2 firing order, clockwise rotation, 280/280 duration. The lift is determined by how deep you cut on the lobes. If your cam is driven gear to gear by the crank, your's will be a CCW and this table will not work for you.

[chrispare]

ok I think I get the process but how do you figure out when to cut what lobe,and for the fixture is there a plan i can get for this.
thanks for your help by the way,your work is inspiring me to go through with this attempt to build this engine(believe it or not it will be my first engine) but that is what this knowelge on this fourm is for right.

chris

[stevehuckss396]

Originally Posted by chrispare ok I think I get the process but how do you figure out when to cut what lobe,and for the fixture is there a plan i can get for this. thanks for your help by the way,your work is inspiring me to go through with this attempt to build this engine(believe it or not it will be my first engine) but that is what this knowelge on this fourm is for right. chris

The fixture is a custom design for each camshaft. There is some help with that in the article.

You have to figure out all the cuts based on what engine you are building, how many cylinder, what direction it will rotate, lift and duration, ect. , ect.


Have you visited HMEM?

Home Model Engine Machinest web site is a wealth of information for the model engine builder.

May I suggest you start with a V-twin and then try a V-4 before going for the V8. It will help alot with learning how everything works and how to make all the parts.