Is it worth it to Port heads

[bobel]

Just wondering what have been people’s experience with Porting the heads on the FA20?

I know the heads flow pretty well as standard, and I’ve heard the castings are quiet thin and would not hold up to an aggressive Porting?

I see some have gone +1mm on exhaust valves but can porting help on the exhaust ports as I had not planned on changing the valves.

My goals is to rev to 8.5k with HKS supercharger on a fully built motor, with beehive springs but wondering if I should perform port aswell?

[churchx]

For revving it high you'll be hit by oiling system limitations imho. I doubt engine will last long with 8.5K redline.

[Clutch Dog]

thats actually the exact correct answer

to even go further, the heads are already pretty extremely ported

what you need to do is flow match the heads to the exhaust and intake and change out the cams and valve springs so itll rev to that higher rpm, and most importantly check out the oiling system. its the biggest limitation

Ive read about cavitation at high rpms on stock engines. even an oil cooler cant help that

[humfrz]

Originally Posted by bobel

Just wondering what have been people’s experience with Porting the heads on the FA20?

I know the heads flow pretty well as standard, and I’ve heard the castings are quiet thin and would not hold up to an aggressive Porting?

I see some have gone +1mm on exhaust valves but can porting help on the exhaust ports as I had not planned on changing the valves.

My goals is to rev to 8.5k with HKS supercharger on a fully built motor, with beehive springs but wondering if I should perform port aswell?

Hello bobel -

As I recall, we have had this conversation before on this forum. You may wish to do a search and find that thread for some background information.

My recollection is that porting the heads on this engine isn't really worth the time and effort -


humfrz

[bobel]

Thanks for the response folks

I agree on the oiling modifications, I will be installing racer x sump, killer b pickup, Reimax oil pump, and performing a host of modifications to the oil galleries (similar to the oil starvation thread) and if needed I’ll add an accumulator too.

Thanks I’ll have a search for the previous thread, was hoping for some experiences from anyone who has tried it too if your out there?

Cheers

Bobel

[churchx]

I don't think that just listed oiling mods will suffice. At very least i'd think of dry sump / independent oil pump and alike things. And even then.. afaik element tuning tried to build 8.5-9K engine, but resulting engines lasted few races at most.
You already decided to went forced induction. Turn up a bit boost for decided power goals (or as SC, smaller pulley). Modifying engine for reliable much higher redline imho will be something ten times harder and more expensive. If you are set on high rev as main goal, i'd rather think of swap, eg. 11K rpm synergy V8.

[bobel]

Ye it’s a valid point, and there are not many running the FA20 at high revs over a long period. My intention is to build to support higher revs but i’ll not be going there without first monitoring the oil pressures and seeing how the engine is holding as it’s tuned, if it can realistically only support 7.5k reliably then that’s where i’ll end up I guess, i’m not looking for huge power and to be honest i’m not sure how the HKS charger will hold up anyway as they have questionable reliability. Either ways it’s a little bit of experimentation and hopefully I learn something I can share with the community.

However would love a Synergy V8 swap but it’s just crazy money, I can build an FA20 myself for a fraction of the cost, as i’ve Priced up both as there is a Synergie V8 BRZ in a shop about 150miles from me and i’ve done the costings even with them selling me their current engine second hand.

Thanks again

Bobel

[solidsnake11]

I rev to 8000rpm daily. I did a clean up of the ports and smoothed the bowls. Was going to put in larger valves but didn't want to wait on the cutters to ship from india.

Motor has el cheapo eagle rods, je pistons, oil mods and extra large turbo.

Definatly get 14 plus heads with longer valves, revised rockers and different pivots or retrofit 13s.

Crawford reved to 9000rpm and tracked there car. Larger valves, valve springs, stock crank and i think stock block with oil mods.

[Captain Snooze]

"Element Tuning has discovered that the majority of the gains from the Subaru head are attributed to the valve size itself and not the intake and exhaust ports."


http://elementtuning.com/competition...r-wrx-fa20dit/

[Grady]

Yes it is worth it to port the heads! are you going to get another 10HP.... NO! Some times that .2HP will win a race!

[Drifter X]

Originally Posted by churchx

I don't think that just listed oiling mods will suffice. At very least i'd think of dry sump / independent oil pump and alike things. And even then.. afaik element tuning tried to build 8.5-9K engine, but resulting engines lasted few races at most.
You already decided to went forced induction. Turn up a bit boost for decided power goals (or as SC, smaller pulley). Modifying engine for reliable much higher redline imho will be something ten times harder and more expensive. If you are set on high rev as main goal, i'd rather think of swap, eg. 11K rpm synergy V8.

I had no idea what the Synergy V8 was until you sir. Thank you!

[Lantanafrs2]

Originally Posted by Grady

Yes it is worth it to port the heads! are you going to get another 10HP.... NO! Some times that .2HP will win a race!

Do it wrong and you can lose 10 horsepower

[x808drifter]

Originally Posted by Lantanafrs2

Do it wrong and you can lose all the horsepower

FTFY

[solidsnake11]

Originally Posted by Lantanafrs2

Do it wrong and you can lose 10 horsepower

And all your coolant.