How To: Resurface (EJ25/Subaru) Heads At Home - Backyard Machining 101

Blown head gaskets? NEVER change a gasket without resurfacing (machining) the heads. Proper preparation is critical to ensure the gasket does not prematurely fail
I do recommend having a professional Machine Shop do this service if theres any doubt in your mind.
As a EX machinist of 7 years, I am showing you a hack that can save money, and more importantly, time.
If you had a composite gasket, and are upgrading to a MLS - Multi Layer Steel-, skipping this is NOT AN OPTION.
Blocks generally stay straight, however I do recommend theroughly cleaning them with a boxcutter/razor blade at the bare minimum. If you have a straight edge, check it with a feeler gauge.
At .003" (3 thousandths) or more, check with your local machine shop/ Haynes/Chilton Repair manual, but block machining very well might be needed.
Thanks for watching!
Dont forget to subscribe!

[@williamhorsley7799]

This dude is unbelievable! Just popped up in my feed and he is 💯 better than any other automotive channels I watch! GREAT VIDEO MY FRIEND 👍 I JUST SUBSCRIBED!😊

[@steinfabgarage]

Thanks for the love!!!!! These comments make me unbelievably happy!

[@symbaleursuline]

That's the coolest KZbin channel I've discovered this year

[@eriksanchez8501]

Please show how to do it in car your content is so in depth and entertaining I’m learning lots for the at home garage worker. My 06 Impreza has signs of head gasket failure so I’m very interested in doing this with out removing the entire engine!!

[@steinfabgarage]

I’d pull it with that car, it can be done, but it’s soooooo tight. The bigger body 10-12 outback/ legacy is the only one I’ll do in car.

[@williamhorsley7799]

Love your videos bro im about to benge watch since im off thursdays and fridays!

[@James-of-all]

This is the most useful and entertaining channel on KZbin

[@mikeblack6953]

Enjoyed watching this, a past machinist for many years. If head touch-up resurfacing with coated abrasives is something you do enough, might be worth picking up a good used Starrett granite inspection plate for a few hundred bucks.

[@steinfabgarage]

I have a machinist straight edge, I’ll look into the Starrett plate! Thank you

[@Eric-xq7ji]

You posted this just days before I start a head-gasket/re-seal job on a 2009 outback ej253. Great timing! If the surfaces don't seem too bad, I may consider this budget method. If they are bad, I'll suck up that machine shop decking cost. Great post! (also your ej25 engine pull video came in handy as a reference!)

[@steinfabgarage]

If there barely blown, this beats waiting for them to be milled. But sometimes a few day break isn’t bad, depends on your situation

[@stephenbrown7167]

Gotta love the 80 grit!

[@luccahagerman525]

usefull and informative: 10/10. cats: 11/10

[@Garage_Beers]

A glass shop always has scrap glass you can get either free or like $5-$10, and will be SUPER flat

[@steinfabgarage]

Great tip!!

[@alexmoloney1560]

I wanna see you do it in the car!

[@steinfabgarage]

Coming soon! Let me go buy another car real quick

[@elesjuan]

I've done something pretty similar with a mazda BP 1.8 head and block and it worked great. Used one of those pneumatic long sanding boards for the block to flatten it enough the MLS gasket sealed fine. A trick I learned for carbon and crud on valves from a grey hair.. use a brass punch and a hammer to strike the stem of the valve (on the cam side) which briefly shocks the valve open/closed helping it seat. Edit: also.. awww kitty...

[@James-of-all]

Bruh, I'd like this video multiple times if I could!

[@dallasmcfadden4897]

I agree 110% with your head resurface method. Also I was was WAS going to nag you about HOW THE HELL a clogged heater core could cause engine overheat (time stamp 1:17). But I stopped, did some research & learned (to my amazement) Subaru (EJ based at least) are designed to run coolant thru heater core 100% while engine is running. ((There exists no control valve to stop the flow in summer etc like in vehicles I'm more familiar with)) So I can see how a clogged core could INDEED cause problems that the design does not tolerate. So I apologize & glad I researched BEFORE "firing off" at you!!.

[@steinfabgarage]

That’s the most amazing thing I’ve ever read. Most the clowns on the internet speak without knowing a thing, which is why I ignore my comments section now. All the Subaru owners who use stop leak are dooming their car for problem after problem. Then they wonder why the headgaskets blow in 50k when the originals lasted 150k This method works 100%, AS LONG AS YOU CLEAN ALL THE METAL OUT AFTER. The same goes for any machining process tho.

[@poptartmcjelly7054]

I've found that dish soap with some water works better than WD-40 at washing the swarf away. With that i've basically been able to just keep grinding endlessly. Also if you're worried about cost, then you can get large sandpaper sheets without the glue and just get a can of spray glue.

[@steinfabgarage]

I’ll give the soap a try next time. I’m not worried about cost, time is critical for me. I started doing this when I would offer 24 hour headgasket/ timing jobs. Most of the time it was for the external oil leak, 1 hr and I’d be putting it back together

[@crazyoilfieldmechanic3195]

This concept is definitely a respectable way to "clean up" an aluminum head as long as you don't sand to much. However it is in no way an effective replacement for having the head surfaced at a machine shop. It's so much better than using those little 2 inch discs on a high speed air grinder that I wouldn't even compare it to that kind of butchering type of clean up.

[@steinfabgarage]

As a 7 year machinist I can tell you, this IS a effective replacement for a machine shop. It pretty hard to sand TOO MUCH. Trust me, we used to mill .020-.030 tho off customer heads all the time. I HIGHLY AGREE with the BUTCHERING done with the 2” discs, we would see them come in “cleaned” by those and often have to have the head welded due to low spots around the fire ring (combustion chamber)

[@crazyoilfieldmechanic3195]

If you worked in a machine shop then you should understand that you have no clue if your sand paper method is keeping the head surface perpendicular to the crank shaft and cam. I doubt as much as .003 difference from one end of the head to the other would cause any valvetrain or bolt alignment issues but your not measuring anything so you don't know if it is off or not. Those tiny 2 cylinder heads are the best case scenario for attempting this in the first place. A 4 cylinder head could easily become off over .005 end to end by trying this.

[@williamhorsley7799]

​@@crazyoilfieldmechanic3195 Y U Hate in on this man? I bet u never did a head job in your entire life!!! U might have GAVE SOME HEAD but mechanicly u probably never did any head gaskets a day in ur life!

[@jacquelinesears1770]

Life long tool maker he is spot on the tile is ok a large piece of steel that looks like it has two sides ground flat would be better

[@invujerry]

Loved the video, I’ve been thinking about doing this for my neon I need to put back together. I’ve seen heads on neons be out .004 that didn’t leak on a turbo race car. But they knew they were running a risk at the time.

[@steinfabgarage]

They headgasket is meant to compensate for flaws, that’s it’s job. But most manuals state that .003 is the limit. . I’ll be trying my skidsteer head this week (4cyl), to date, 3cyl heads (v6) are the largest I have done, so we will see….

[@invujerry]

@@steinfabgarage might be worth it to get a longer slab and sandpaper for a belt sander. I’ve seen people doing v8 heads I just don’t know what they were using at the time.

[@stevenoe6395]

Sweet video i forgot all about that way to do a head been a long time since i did that my son just got a 08 legacy with 116k i think then i found out they have issues like that plus i have found a few on marketplace with bad headgaskets and i need a vehicle i can put rools in like a wagon or suv but something good on gas work isnt so good right now and my 10 f150 has the tranny going out i cant change it wven if i liked the truck lol had heart surgery back on February 1st so trying to get back to working right now on our condo it coufht fire on February 16 on February 7 when my youngest brought me home he totaled my 08 sonata my oldest already did that 3 years ago but was a easy fix lol he had to get a car i havnt been able to get his explorer on the road tet have it filled qith new parts but with everything going on its been undoable lol i would love to see a in care video on getting the heads off would help me out if i decide to get one also looking at a couple older diesel something i can use black diesel in no dpf or what ever its callled lol thanks for the video!!!!!!!!

[@notquitea]

thank you!

[@steinfabgarage]

You're welcome!

[@RicoCantrell]

Good tonknow on that degreaser.

[@steinfabgarage]

Seriously the best 👍🏻

[@Loach461]

... roll that beautiful in-car footage

[@JohnDoe-ml8ru]

Remove the spark plugs first. Also, pressure wash or clean the heads any other way before you do this. I have done this many times when I had no money, it does work. Also, aluminum heads need a much higher grit finish than that, at least 150.

[@steinfabgarage]

Negative, you want a little roughness to hold the gasket. 7 year machinist here, and over 120 (60) cars done like this. Bmw N20 motors are notorious for slipping timing, the updated parts are LASER ETCHED to provide friction and reduce slipping

[@JohnDoe-ml8ru]

@@steinfabgarage Only for Iron blocks/heads with traditional head gaskets. Modern aluminum blocks/heads and MLS head gaskets require at least 150 grit to 180, sometimes more like 220 grit. The RA for aluminum with MLS is 30 to 20, or 180 to 220 grit. Look it up.

[@stephenbrown7167]

Hey mate love your vlogs. What's your take on 2006 EJ20 versus EJ25 with respect to continued head gasket issues. Correct me if I'm wrong.. And I know you will! The EJ20 (non turbo) engines have a better cooling system as there is more water cooling the engine?

[@steinfabgarage]

Here in the US, the only 20’s we got were turbo in the WRX, so I don’t have experience with the NA’s. But even the turbos were open deck VS the 25 semi closed deck. So yes I would say more coolant is good and leads to less head-gasket issues. Also, less power, less issues

[@stephenbrown7167]

@@steinfabgarage Thank you

[@steinfabgarage]

@@stephenbrown7167 thanks for checking out the video. I appreciate all my viewers 🤙🏻

[@leoliu041892]

Does this work for inline 6? Sticking two sandpaper together?

[@steinfabgarage]

I’ve never tried it, to be honest, I’d just take that to a shop

[@shikaivlessing929]

Just out of curiosity why do you use 80 grit sandpaper? Seems like everyone online is using 200-320 grit with this method. Is there any chance 80 grit will leave too rough of a surface?

[@steinfabgarage]

Because 80 leaves the gaskets a surface to “hold” on to. It’s the same theory as why port and polish is good for airflow, but bad for fuel atomization. Sometimes rougher is better

[@dragolfin7]

In car

[@James-of-all]

Aww kitty!

[@steinfabgarage]

She’s New Mexican, so she’s “all sad” 😞

[@Bscully]

Please do a video in the car!

[@steinfabgarage]

Coming soon 😎

[@Bscully]

Could you also please do that budget rebuild video you talked about in a previous video? Love the videos!

[@MADagain]

Why does everyone use 80 or 120 grit for this... wouldn't you want it to be a flatter surface with 1000 grit or something?

[@steinfabgarage]

No, too smooth is bad, you want to “hold” the gasket, please look up “bmw N20 timing slip” the updated bmw parts are LASER ETCHED to provide friction. This is because there’s no key ways on the crank, everything is sandwiched, just like a head gasket. Same concept.

[@Jfjs58-g]

Too bad KZbin doesn’t show the number of dislikes

[@steinfabgarage]

Sounds like I got one from you! Thanks for watching 😉