Are our engines overhead cam? Are our heads aluminum?

 

No overhead cam and the cylinder head is not aluminum.

 

HUH?
J/K

Thats the beauty of the Cummins in it's simplicity.


-Seeder

 

Aluminum is for beer cans....

 

so with our blocks being cast then, our cam rides right in the journals without bearings?

 

No the cam bearing journals have bearings, but the lobes are just out there with the lifters riding on them.

 

uuuuuhhhh... ok, cast iron block, cylinder head (thank god....) Cam in block, pushrod engine. The camshaft uses friction bearings, much like the rod and main bearings. Main difference being that the rod and main are clam-shell type( 2-piece) and the camshaft bearings are one piece that have a cleat that joins them together.

 

i havent had 1 of the CR's apart. but the industrial 12valve 5.9's only have a cam bearing at the front. the remainder ride on the block material

 

Below is from the 06 Manual.

 

Thats a first for me, what does the machine shop do if its out of spec?

 

The answer from the manual!


REMOVAL
CAMSHAFT BEARINGS
NOTE: Measure the diameter of each bore. If the camshaft bore for the cam bushing is worn beyond the
limit, install a new service bushing. Inspect the rest of the camshaft bores for damage or excessive wear.If
the bores without a bushing are worn beyond the limit, the engine must be removed for machining and
installation of service bushings. If badly worn, replace the cylinder block.

 

Use good oil, check often!!! Wow thats something else right there. It sounds like they sleeve it then, cut it oversize and install a reg. press. bushing. Man id want a good machine shop to do that work! That sucker would have to be true and prefect. Still odd to me a heavy duty engine with loads that these engines were made to handle no having cam bearings? Id like to have one with all 7 ROLLER bearings like Nascar uses!! Cool huh

 

No cam bushings except up front. Thats why you have to install cam bushings usually when you put a cam in expecially a billet cam. My motor had 60,000 miles on it when it blew and the journal where so worn out they need bushings. 750 bucks for a machine shop to do it.

 

Bushing or bearing, doesn't matter really as it's doing the same job. Probably bushed because the bearing material is too soft in that application. My point being is it's not a metal on metal contact. Does anyone know if this bushing is made of brass???

 

Yes they are brass but a stock cummins only has one brass bushing for all the cam journals. The others are metal to metal (not 100 percent sure though). Look at Schied's website, for a billet cam it says cam bushings are neccesary because it will wear out the journals fast. When I put mine in the valve clearence was out of wack because of wear so I had to put bushings in.