4G63T Head Oil Port Modification
This is a simple and effective mod done to the oil port from block to head.
I have found out a restriction can occur when excessive milling of the head has been done.
Resulting in low/poor oil flow through the cylinder head that can cause lifter tic, cam tower gaulding, and in some cases on turbo engines that feed the turbo oil from a port on the head, to cause the turbo to fail.
Appox mod time with head of engine is 2 mins.
Stock oil port….
Take a die grinder with an aluminum burr and grind and chamfer the oil port, while staying inside the gasket-sealing ring. (I find a ¾ base tree burr works best)
So the end result looks like this.
I prefer this to be done before the head is resurfaced.
I hope you find this useful.