If it's not really about tuning or wiring. Then it belongs in here.
hey guys, have a question on head gasket water jacket holes. When I bought my cometic MLS gasket it just had pilot holes where the water and oil jacket/galleries go. Except cylinder NO 4 it had all the wholes punched out to the full size.
Now should I be drilling the others out the the same size as the holes in the block and head? Or making them different sizes for any reason? It’s only the metal between the two outer crush plates that I need to drill. The outer crush plates have the right size holes in it already.
This is is on an SR20DET awd engine. East west.
It's quite common to have the holes in the gasket different to the size of the holes in the block, particularly with regard to the water jacket. I'd be inclined to compare the cometic gasket you have to your stock/old gasket and this will be a better reference to what you gasket should look like. From memory there are subtle differences between the FWD and RWD SR20 gaskets too so you want to ensure you have the right one. Here's some further information on the subject - https://www.sr20forum.com/turbo/254887-rwd-fwd-headgasket-fitment.html
Yeah I mean we have a gtir and it has its own gasket. Due to the m12 head bolts instead of m11. I also had no way of comparing because the old gasket was someone else’s work and they didn’t drill the water jacket for cylinder 1 at all and it blew through right there. Which I believe was from the water backing up and boiling in the head. We are about to build another engine for it so I wanted to be sure of this for when I buy another gasket.
Head gaskets are meant to be like that. The smaller holes at the front are to encourage the water to travel to the end of the engine furthermost from the water pump. If you have the same size holes all the way along, the water will take the path of least resistance - i.e. straight up from the water pump and out of the head and back to the radiator, the rear of the engine would get very little water flow.