A recent thread on stripped headbolts reminded me of this thought...

 

Has anybody ever sectioned an EA82(T) head to see what's in there?

 

This activity, both potentially fun and melancholy, might prove useful to the extemists in our midst. You know, the ones that want to port their heads, or look for tap points for cooling or oil enhancements.

 

Or for dealing with stripped headbolts. Is there enough material around the headbolt holes to open them up to accept 12mm fasteners (preferably *studs*) in some common thread? How about 13MM?

 

C'mon! Might be fun!!!

 

And, since I figure anybody that has read this far is almost as sick as I am, has anybody tried having their cracked heads "plugged"? This is a fairly common practice in the rest of the Japanese engine world, but I haven't even seen a disparaging comment yet. Any horror stories?

i do not have any spare ea82t heads... but i do have a metal bandsaw...

Bah! I just scrapped my cracked heads off my old GL-10 last week after sitting around for 2 years, figures that someone would come up with a use for them after I scrap em. Not a bad idea at all, sure some of the Gurus on here could come up with some ideas after doing that, and extra cooling for the turbo heads couldn't hurt at all.

thats a good idea. I don't have any turbo stuff though.

actually now that i think about it

the "better" way to do it instead of merely cutting one if half would be to make 10-20 "slices" out of it so all the port work could be inspected on slive by slice basis

Multiple slices is what I had intended. Sectioning, as in a biological sectioning. Might have to remove things like valve seats/guides.

 

Anybody with an EA82T can make all the cracked heads they want if they try hard enough! I have a few (none my direct doing), but I am still hoping for the "plugging fairy" to tell me it is OK to fix them.

 

Pat

I have a set each of SPFI and MPFI(non-turbo) heads here. One head bad in both sets. Had thoughts of sectioning both of the bad heads to see what it would take to make one more good MPFI head. Just haven't gotten around to it yet.

I am realitively fresh in the subaru flat 4 realm but, I do know a thing or two about vw's and porsches. thicker head studs will have a tendency to snap the larger in diameter you go. the best studs for those applications are a large end tapered in the middle. This gives you the holding power of more thread contact, but lets the head studs expand and contract more evenly.

I haven't done it.....but I'm not above it!

 

I sawed the front of my car off to pull the engine:brow:

(20 minutes flat!) including tires, struts, tranny!

 

SAW IT!

Glenn

82 SubaruHummer---with easyoutengine!

01 Forester---don't even think about it! :-p

I have a set of gen1 EA82T heads that are shot, if anyone wants them to cut apart they are yours! I can give them to JAson in Portland on Sunday if anyone wants to pick them up at his house, as I leave for Wyoming on Monday or Tuedsay..

Jaws Dawg, I haven't heard of Subarus snapping head bolts, but then again it doesn't mean they don't or aren't near the limit of doing so. Stripped threads in the block do seem to be pretty common.

 

The only real experience that I have had with head studs in cars was my old Triumph, which had studs thick as my finger and reaching down near the mains. Engine was cast-iron/cast-iron so differential expansion wasn't such a big deal. Head-torquedown was like 120Ft/Lbs. (came from a diesel design...).

 

Anyway, unlike the aircooled flat-4/-6, the Subaru headbolt (or potential stud) just thread into the cylinder deck; much shorter, perhaps less diff. expansion issues. Were the a-c engined studs snapping from expansion problems axially or radially (i.e along length or across diameter)? I would say that studs thicker on the threaded ends would probably be a good idea (and look cool!) but I don't know how available they are.

 

Just my 2 cents (US; Can about 3 cents?)

I'm not sure, but I think EA81 head studs are teh same thread pitch. Also if you've ever threaded a head bolt into the block with the head off, they thread in quite a bit (several inches) into the aluminum block. I'm not sure why the EA82 uses bolts rather than studs, other than for clearance issues. I'm not sure if you could use studs on an EA82 but if you could it would be perty bad arse. I know ARP offers head stud kits, maybe you can order some that are metric????