Vacation Day Progress - Subaru heads

Post date: Dec 23, 2015 8:35:14 PM

I took Tuesday off and except for one meeting I puttered around the house and yard. Its still bizarrely warm. Got up to around 50 today.

1. When I was dozing Sunday I took the opportunity to shove around and pile higher, some old logs that are left over from originally clearing the land for the house. I took the chainsaw out today and started bucking them up into manageable pieces to either burn or truck off. Saw is running very nicely since I adjusted the high speed mixture a bit more rich.

2. I decided to investigate the heads from the second Subaru 2.5L engine because the heads from the first engine are pretty shot. The valves are in terrible shape, one is slightly deformed (from cylinder 2 which was missing terrible), and the valve seats are terrible too. The second engine's heads were supposedly replaced with used ones not too long ago but when I got the car, the cylinders were full of coolant. I suspect that the heads were not cleaned properly, or maybe were warped, and therefore the head gaskets, which these engines are known to be finicky about, didn't last long. The gaskets they used look like the new fancy multi-layer steel with Vitron coating. I'm hoping that the heads aren't cracked. My strategy is to clean them up, pull the valves, check for warpage, sand flat (using the flat glass method), and then pressure test the cooling passages using a thick piece of plexiglass and rubber to seal all the openings except one, and use a pressure gauge to measure leakage. The method I've see online is to pressure the head and submerge it in water and look for bubbles.

3. About the time I got the first head cleaned up and washed with kerosene and then hot water, it started to rain pretty hard. I escaped inside to play some World of Tanks and then did the second head, cleaning it up with the hose in the rain. Here's they are after sanding with 150 grit to near perfect flatness ( < .001" ) and a shot of what the sandpaper looked like afterwards. (notice how nice the valve seat look? I haven't touched them up with grinding compound yet!) I also priced out felpro MMS head, valve stem, valve cover, intake and exhaust gaskets at Rock Auto. $150 for everything needed. Not bad when a pair of MMS Felpro head gaskets locally got for over $100 all by themselves!