idosubaru Posted April 5, 2011 Share Posted April 5, 2011 Over the years I've asked two Subaru dealers and both said they don't resurface EJ heads. I re-asked the local dealer yesterday when I went in again and they said the same thing again. Given my recent debacle with a machine shop and lack of resources like that around here, I will probably start leaning towards skipping resurfacing ...unless I find somewhere else that can do it. Link to comment Share on other sites More sharing options...
GeneralDisorder Posted April 6, 2011 Share Posted April 6, 2011 Typically it's not needed. I do it because I am usually having stem seals replaced, valves done, etc at the same time..... Ultimately it makes for a better repair I think. Better gasket adhesion - and no possibility of warpage. GD Link to comment Share on other sites More sharing options...
davebugs Posted April 6, 2011 Share Posted April 6, 2011 Gary, I still prefer to have the heads done. But my local dealer doesn't. I check warpage. Occasionally I would have someone who wanted to save an extra hundred so I'd clean them myself. I special ordered a white (the name escapes me - with all the little titties - kinda rubber like) that is the least abrasive. I've seem the dealer use a scotch brite pad on an air drill, die grinder, etc in the parts washer(for lube) and just not get the RPM's up much. Link to comment Share on other sites More sharing options...
subaru360 Posted April 6, 2011 Share Posted April 6, 2011 I don't ever resurface subaru heads. Think about how short they are. If the engine got hot enough to warp a head, I refuse to fix it. You know it'll be back knocking in a few weeks if you do it. The factory finish on the heads is better than anything your typical local machine shop can do as you found out. You need a finish as good as factory to seal the new updated mls gaskets. Link to comment Share on other sites More sharing options...
Fuzpile Posted April 6, 2011 Share Posted April 6, 2011 I come outta nowhere and find this interesting. You can clean your heads all kinds of ways except the mating surface.Or not. the idea of using an abrasive pad or belt sander and stuff is foreign to me. It's not about polishing surfaces, it's about Flatness and squareness from one end to the other. Removing traces of old gasket is accomplised more precisely by proper razor blade and holder with the appropriate solvent(traces of which are removed later) Link to comment Share on other sites More sharing options...
Fuzpile Posted April 6, 2011 Share Posted April 6, 2011 (edited) Once it's clean enough to check you can see certain things with a dead accurate straight edge. One can use Dykem or spotting dye and find high spots and where to concentrate. You have to look at how it's mounted and where it Would bend/warp naturally under certain condition. Don't need bore you except to say I'm not even talking about scraping now. A good mill file is a precision instrument. Filing this way isn't filing thru bars or mishandling the tool on backstroke. There is a way to use the precision flatness of the angled ground teeth to present to the work(head) something which will seriously change the surface without the surface knowing what hit it. That's because it's drawn across it at the proper angle. Edited April 6, 2011 by Fuzpile Link to comment Share on other sites More sharing options...
GeneralDisorder Posted April 6, 2011 Share Posted April 6, 2011 Obviously it must be said that if it's either not-economical, or you have incompetant machinists.... the factory finish is better. But a skilled shop can do a resurface in like 15 minutes or less. They charge me $25 per head to do a hot-tank and resurface on Subaru heads. That adds $50 to the job and they will let me know how the valves look, etc. I typically have them install new stem seals at the same time to avoid oil consumption. As for surface finish - I can get a finish as good as the factory finish with glass, sandpaper, and WD-40. I can get a mirror finish if I want - that's not neccesary though. It's all about the surface finish IMO. I agree that warpage is very rare and is the engine has been overheated that severely it's likely toast. There are cases where I will have heads rebuilt from engines that threw a rod, etc though.... and in the process a resurface needs to done. GD Link to comment Share on other sites More sharing options...
Olnick Posted April 6, 2011 Share Posted April 6, 2011 I can get a finish as good as the factory finish with glass, sandpaper, and WD-40. That fascinates me, GD. How big is the piece of glass you use? What grade(s) of sandpaper? Any "technique" tricks? Link to comment Share on other sites More sharing options...
Fuzpile Posted April 6, 2011 Share Posted April 6, 2011 Compelled to make clear that "fileing" filing" is not what I come out and advocate unless propelled by visual examples of how Not to do it. Life is too short and even chamfers where they shouldn't be increases the compression point at a certain area. Whatever works is ....not what is proposed at either way.Seeing where huge damage is evident by abrasive is different than one applying the straightness of glass and very thin sheet of 3M paper. There is the attention to linearity and that is what is required. At least last i looked. When glass was mentioned as the substrate..the foundation for the media to effect the surface then it's accepted that glass is always flat and straight. but it's not always for you know it's a fluid of a different time than ours and pools over time. Who's to say glass has to be perfect now when it like everything is made somewhere else maybe. Where I'm going with this is a "surface plate" which weren't too expensive once. Yet that goes too, another area where we ain't seen nuttin yet. Link to comment Share on other sites More sharing options...
Gloyale Posted April 6, 2011 Share Posted April 6, 2011 I don't ever resurface subaru heads. Think about how short they are. If the engine got hot enough to warp a head, I refuse to fix it. You know it'll be back knocking in a few weeks if you do it. The factory finish on the heads is better than anything your typical local machine shop can do as you found out. You need a finish as good as factory to seal the new updated mls gaskets. My machinist reports to me that MOST of the subaru heads he does are about .002 off on the lower right corner. Probably a result of the fast cutting, factory machines that produce MILLIONS off these heads. I will skip the machining on a 2.2, but NEVER on a 2.5 And the finish my machinist produces is like glass.........flawless. Maybe I'm just lucky. Link to comment Share on other sites More sharing options...
idosubaru Posted April 22, 2011 Author Share Posted April 22, 2011 thanks guys. i have an unused head in my garage from these guys from two years ago that, if memory serves me correctly, has the really nice finish with light swirling...like i was used to in Maryland. if i ever have time (unlikely) i might take both that old head and this junk one (if it's junk) with me and see what they say. the fact that it was below spec and the valve was nicked with the belt sander was enough for me to shake my head. but i should at least give them a chance to own up. ***is it typically the shops responsibility to mic the heads and see if they're in spec? the 3 different shops i used in Maryland always did, so i just assumed that was normal, maybe i'm wrong? Link to comment Share on other sites More sharing options...
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