Are you in the middle of rebuilding your engine or replacing the head gaskets on your Subaru and the valves look less then perfect? Drop them off at your local machine shop for a check out and you will quickly find the cost to rebuild your Subaru Cylinder heads can be anywhere from $500.00-$1200.00, Wow! What if I told you for less than the price of one machine shop valve job you could have all the tooling to do them yourself at home with professional results? With a little bit of patience and a positive attitude you can start repairing the Intake & Exhaust Valves in your Subaru, and since you will own all the tooling now you can do it anytime you like, help out a friend, family member or even make a little extra money on the side. Being able to properly cut valves and valve seats are one those valuable life skills you will sure be glad to have picked up! And the best part about it: It's really not hard at all.
Below is a small list of things of things you will need to become a Professional Subaru Valve Jobber.
DON'T BE SCARED YOU CAN DO THIS!
Digital Micrometer.
Carb Cleaner
Sand Blaster in a Bucket (Optional)
Fine Wallnut Shell Media
Not all of these things you will need depending on how you go about the task at hand. For example: When repairing multiple Subaru cylinder heads in a row i am generally pressed for time and instead of refacing all of my intake and exhaust valves I will opt to just purchase brand new valves (because they are cheap) I save time by not refacing them and I get a bit of additional insurance knowing that no material has been removed so it has a better ability to withstand high temps and transfer heat. I know there is a debate out there about having to machine brand new valves to make absolutely sure they are true and blah blah blah, I have done my own investigation on this issue and the majority of the machine shops out there say that it is 2021, the robots cutting the machines are better these days, etc etc. Besides all of that, the layout fluid will tell you the story before they have a permanent home. If you get one that is not going to seal properly because its distorted to a degree and you do not have the valve refacer tool you will have to purchase a new valve and more than likely it will seal no problem. It may be an inconvenience but then again going the new valve method route will save you $400.00 on not having to purchase the Gizmatic. I Personally have a Quickway SVS2 for my valve refacing but more and more these days I have been putting new valves in as it saves me tons of time.
I Will not be going into full detail in this article step by step on how to cut your valves. I am just going to explain the basics and let you know that if this is something that you would like to get into that A. It does not cost all that much to do it yourself to get pro results & B. To give show you the resources needed and where to find them if you want to accomplish this task.
Before you get started cutting the seats and or valves in your cylinder heads you are going to have to disassemble them. If equipped, remove the rocker assembly, the cam plates and the cams. Set them aside in a safe place where they will not be harmed ; damage the cam plate(s) and you can kiss your cylinder head goodbye as they are married together from the factory with a line hone and are not interchangeable. If you are working on a 2006-2012 2.5 Subaru with ACVS/VVT be sure to unclip the hold down springs for the ACVS rocker arms as there are 6 oil galley pistons and 4 springs that are located in the rocker body and arms that can fall out of place and out of the assembly if you are not careful. It is not a problem if they fall out, but would pose a problem if they were forgotten during install. The small pistons are meant to direct oil flow to the appropriate camshaft rocker arm during cam "advance" or "lift" change. If you are working on any Subaru cylinder heads with buckets or the newer FA/FB style Subaru engines with mini buckets on the valve stem be sure to keep those in place as they are responsible for your valve clearance. Not that it's going to matter much as we are going to cut the seats and tweak all the values around and will need to correct that afterwards.
After you have the rocker arms/buckets, cam plates and cam's out of the picture it is time to remove the valves from the cylinder heads. Get the appropriate valve spring compressor tool set up and in place. Slowly press down on the spring until the valve keepers are out of the top locking plate. Remove the keepers with your magnet. Slowly decompress the spring and remove the tool. ou shouldn't need to worry about the valve falling out as the Subaru valve stem seals usually holds it in place until you get an extra hand to pull it out of there. Set all the keepers, keeper locking plates and springs aside, it is always best to keep them to their related counterparts but if you get them mixed up somehow it is not the end of the world as all of the springs, keepers and locking plates are all interchangeable. The Intake & Exhaust Springs are Painted torward the top show what the upright position should be.
Once you have all of the Subaru Intake & Exhaust Valves out, set them aside. It is now time to remove the intake valve stem seals and the exhaust valve stem seals.
Remove the seals with a plyers or a valve stem seal remover tool and, throw them in the garbage. Underneath the valve stem seals will be a spring base plate that sits remove that as well and set it aside.
Your Cylinder Heads should be down to bare castings by now and at this point before you more any further you are going to need to clean things up a bit. This is where having a sandblaster with the walnut media can be especially effective. Walnut media does not leave the best finish to your cylinder heads as many pro machine shops use glass bead. I do not care how nice of a finish glass bead leaves I will not put that type of media anywhere near an internal engine part because using it comes with the risk of blowing up an engine no matter how much you jet blast, hot tank, ultrasonic clean there is always a chance one little grain of glass will blow up a $5000-$10,000 Engine. Walnut Media is safe, i do not have to worry about it ruining a valve guide on accident or getting trapped in an oil galley for later engine destruction. If you use a media blaster concentrate your efforts on the dish and the chamber area as right now we are focused on getting the carbon out of the way.
One of the best reasons to use a media blaster to clean up your cylinder heads is that it makes quick work of the combustion chamber. It does the best job at revealing any cracks that lie by spark plug holes or in between valve seats. If you do not have a sand blaster clean up the chambers the best you can with some carb cleaner and a nylon brush and follow up with your mini bench grinder with the carbon steel wire wheel, again focus on getting the valve seats carbon free. When your done rinse everything down and blow everything out. *** If you used water to clean or rinse make sure to follow up with some type of rust inhibitor (eg: wd40, pam, etc) as flash rust can form very quickly.
**** DO NOT USE ANY TYPE OF DEGREASER ON ALUMINUM CYLINDER HEADS FOR AN EXTENDED PERIOD OF TIME ( MORE THAN 3 MIN ) AS IT WILL CAUSE A FORM OF ANODIZING THAT WILL LEAVE THE SURFACE DULL AND ROUGH *** THIS IS ESPECIALLY IMPORTANT WHEN ANY DEGREASER AGENT HAS MADE CONTACT WITH THE CAM BEARING SURFACES ****
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