engine and drivetrain Ignorant q: no cam-bearings?!?

[Guest Anonymous]

I just found out the engine I have has no cam bearings. Just

the steel camshaft in the alloy head. Weird. All other engine-

types I've worked on did. Is it worth fitting bearings? Has

anyone done so?

Thanks,

Hugo

[Guest Anonymous]

Cam riding in plain bores is just fine !

No cam bearings, the head casting is align-bored and oil is fed to the journals.

I use an oil restrictor in the gallery which feeds up from the front of the engine block to supply the head.

The size reduction from my restrictor is like going from ~10 mm to 2.5mm (approximate numbers, don't quote me). This limits a lot of the oiling to the head, which prevents oil pooling up there due to the constant high RPM usage it gets.

The point to the above description is that even with the restriction in oil to the head, I found the cam journal bores in the head with no wear after 15 years of hard use. The head had originally been align-bored for a larger journal cam, and the machine marks were still evident on head's enlarged cam journals. That helped validate the use of the restrictor (which was designed to improve oiling on the lower end.)

If you do find wear on a particular spot on the journal bore, or have any indication there is binding with a known "good" cam, I'd suspect the head was warped. OR was warped, then machined flat on the bottom, which stll leaves the cam bores mis-aligned.

[Guest Anonymous]

The only real bearing you could put in there is a needle roller bearing for like more HP.. but there's no need for a cam bearing... alot of DOHC heads don't run a cam bearing.. honestly it's not uncommon... v8 pushrod engines run them because they're usually a cast iron block..

[Guest Anonymous]

(nt)