I used to polish glass. I know what a proper surface is, and a few passes of 150 grit don't get you there. Glass is not a perfect plane, and 150 grit leaves DEEP scratches that themselves are deeper than the .02mm surface prep spec. And even if it is perfectly "flat" it may not be truelly parallel plane to the crank centerline/ Perpendicular to the bore.
Glad it's working for you. But If I told my customers I was gonna use sandpaper to refinsh their heads, they would run....rightly.
I remember when you "developed" this method and YOU YOURSELF titled the thread "post apocalyptic" machine techniques. Now it's a totally normal professional accepetable method that others should trust paying you thousands of $ to do to their cars?
And I took the Cams off of an 05 Baja Turbo just last week. Proper tools.....no Problem.
Not all Subarus use Viton seals either. Many non-turbos use black Buna-n seals.
And many of my customers cars have been apart and screwed off by others, so I have to double check and re-do shoddy work all The time. Cheap-o cranks seals, timing belts sets, HGs seen it all.
My head surfacing works wonderfully. I've checked flatness and parallel with a machinist straight edge and height gauge and both are well within spec. It's not an issue nor is surface finish. The paper is not 150 grit after multiple passes. It cuts fast at first then shears down to a fine grit and gives a very nice finish. And again it's MOST important to consider that I've been doing this over a decade and not one head gasket job has EVER failed. You claim my method is wrong though you have no experience with it nor any evidence that it doesn't work. Only speculation and an irrational belief that because it's an arcane method it can't possibly work. If you want to disassemble all the SOHC heads so they can be milled go right ahead. It's a pain in the butt for no benefit to the job in my experienced opinion. I have a customer making 380 AWHP on EJ205 heads surfaced with my method. A fuel system issue caused an injector to clog and he detonated the engine - cylinder pressure was high enough to blow out the 257 cylinder wall like Elmer Fudd's shotgun. The head gaskets did not blow even with enough cylinder pressure to break the block casting on a semi closed deck. It split the iron cylinder liner down 3/4".
All Subarus since 2000 have Viton cam seals unless someone changed them. Subaru superseded the seals on the 90's cars to the Viton seals.
Sometimes the sprocket bolts come off. Sometimes they break all your tools, and the sprocket, and you have to destroy the bolts. That's why the dealer stocks them by the dozen. If you haven't experienced that, then you haven't done very many 02+ dual cam models.
Yes I've seen it all as well. x5 what you have seen I'm sure. Remember I'm running 5 bays simultaneously so I see 5x as many cars on an average day. I'm also pushing all this stuff to the limit and beyond. You have no idea what goes into making a 257 live at 600 HP. There are things that matter a LOT more than the method used for head resurfacing.
Edited by GeneralDisorder, 26 November 2017 - 03:33 PM.