GSC FA20 Intake/Exhaust Valves
 

With the recent release of their valve spring kits for the FA20, they have now released both intake and SuperAlloy exhaust valves. These will only work on the 2013's since the 2014's have longer valve stems and will be released soon. These are a higher flowing valve then OEM with better materials to help prevent valve distortion at the face. Less distortion allows for better sealing under extreme conditions and more consistent performance. Chrome polished, one piece stems, and swirl polished heads that avoid any flaking off of the valve head under extreme heat.

Super Alloy exhaust valves:
Head size (mm) 29 and 30 available
Total length (mm) 95.15

Intake valves
Head size (mm) 35 and 36 available
Total length (mm) 103.25

PM me for pricing :thumbsup:

Anyone know the motivation for the change in valve heights from '13 to '14?

Do you know what the difference in length is or if it's possible to update to the new valves? Was anything else changed in the head?

Unfortunately I don't know the size difference yet. I can try to reach out to GSC to try and get some more detail.

No pics?

Sorry, they have not been released yet:(

Its quite possible they decided a longer stem would support stiffer springs, hinting at those who boost the motor wont have to worry about it? Thats my best guess.

It could also put the rocker at a different angle making it harder or easier to dislodge at high rpm.

What year is Phil's 86?

Phil's failure was due to the pin coming out. But that's exactly the line of thinking I was on. I don't know the answer to your question though.

The rocker arms. The 2014 rockers "dome" or where the hydraulic lifter seats, it seats deeper into the rocker.
Thats about from 4.74mm versus 5.31mm plus/minus.
If these are fitted in a 2013 the clearances will be too great to buy them, find them at subaru. After calculating the shim, it came to a 3.45mm or so to flll in. And then the shaftcams.

The shaftcams on 2014 has to have either taller heel on the camshaft lobes to add additional material to fill the space between the roller and the camshaft lobe and set the clearances. The 2013 lobe from nose to heel is about 40.31mm plus/minus.

For now im retuning the rocker arms and shim with the rockers i have.

So if the lenght of the valve stem is not enough then the camshaft lobe might be slightly taller. If the lenght is enough then a slight variation in timig is in question, however, i place the chance that is a taller lobe and not timing. As the rest timing chain, timing gear sprockets are the same. In addition to this, the cariers, and lifters fits on and are same too.

That i'm aware if there is a valve train kit and a dual spring kit for 2014 is a harder one to get. At least from the search. Now for the 2013 there are a couple of options available, easier. At least from what it seems.

Photos couldn't be uploaded

The difference is the valve length and the rocker. I switched one of my heads from short to long. One more thing, the extra length is past the keeper towards the rocker. Not so sure why they have two different valve spring kits.

So the goal was to get them riding deeper in the rocker?

I think both the pivot and the valve are deeper.