Oil Mod

[Dan-K]

Has anyone ever drilled a hole in the 12 o'clock oil galley plug to enhance timing gear oiling ?

[RustyPile]

You see those 2 large holes on each side of that plug?? That's how oil gets to the timing chain.. No need to drill holes in those plugs and risk loosing pressurized oil to the cam bearings and crankshaft.

[Ziegelsteinfaust]

Originally Posted by RustyPile

You see those 2 large holes on each side of that plug?? That's how oil gets to the timing chain.. No need to drill holes in those plugs and risk loosing pressurized oil to the cam bearings and crankshaft.

This.

The splash or residual oil from the valve covers and valve train os enough to properly lubricate the chain.

The only time that maybe even needed is if you were to restricting oil to the top end because your running a solid cam.. So you could keep more for for the crank, and rods. But I have run solid cams with restrictors in several and had no detrimental issues with chain life.

[Grounded63]

Never drilled the press/staked in cups. But, I've drilled a few of the
threaded in plugs.

If you were going to drill it. It should be done, before its installed. Iirc its usually the right hand one that is drilled.

[HO455]

I believe it's a modification done for engines that are used for racing. High G forces can cause the normal splash lubrication of the chain to be inadequate. To make up for that lack of oil folks drill a hole to provide lubrication and to cool the chain. It's just not needed on the majority SBCs.