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Discussion Starter · #1 · (Edited)
I looked around to find a post to answer my question but I couldn't find any. I have a 2015 Subaru Wrx and I'm planning to do a Full Bolt On build on it. The mechanic who's working on it recommends I should get aftermarket head gaskets with ARP head studs but I just want to double check. If I need to, which thickness should I run. I looked at the grimmspeed ones but I'm not sure which thickness to run, let me know if I should get other ones. If I don't need to, should I still run ARP head studs or just leave the stock head studs.
 

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Discussion Starter · #5 ·
Because a mechanic suggesting headgaskets and head studs on the fa20f for bolt ons has zero knowledge of the platform and will blow that engine up the moment they start "tuning".
Ohh, well thank you for the heads up. So will oem head gaskets and oem head studs work fine?
 

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Discussion Starter · #7 ·
Why are the heads off the car?

You'll blow the rods apart before you reach the point you are lifting the heads.

If
I bought the car off the auction and it was in an accident, the head has a piece missing. It's where the front timing cover bolts onto the head. I need it to be change in order to get the car running.
 

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Little Homie
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I bought off the auction and it was in an accident, the head has a piece missing. It's where the front timing cover bolts onto the head. I need it to be change in order to get the car running.
Buddy, if that car got hit hard enough to damage the head, I doubt that engine is good.

God speed but you may be in more than a car with a clean title would have cost.
 

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Discussion Starter · #9 ·
Buddy, if that car got hit hard enough to damage the head, I doubt that engine is good.

God speed but you may be in more than a car with a clean title would have cost.
Damn, um well thanks for letting me know. But I just want to clarify something, will oem head gaskets and head studs be okay for a bolts on build?
 

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Little Homie
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Damn, um well thanks for letting me know. But I just want to clarify something, will oem head gaskets and head studs be okay for a bolts on build?
Yes. As I said. The rods will fail before the head lifts.

You really need to find a Subaru specific shop, one that deals with turbo Subarus. If you impacted a head that hard it can damage the block. At minimum I'd expect it would need machined.

Remember the Subaru engines are split blocks. If you hit it hard enough you can split the case. Doesn't take much and it's a critical issue.
 

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Discussion Starter · #12 ·
Yes. As I said. The rods will fail before the head lifts.

You really need to find a Subaru specific shop, one that deals with turbo Subarus. If you impacted a head that hard it can damage the block. At minimum I'd expect it would need machined.

Remember the Subaru engines are split blocks. If you hit it hard enough you can split the case. Doesn't take much and it's a critical issue.
Thank you for your help, I really hope the case isn't split. I'll look around for Subaru specific shops. Once again, thank you for your help.
 

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Little Homie
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Would it work for a stock block too or just the stage 1 IAG block?
First off.

Why do you think you need aftermarket head studs? Do you forsee boost levels that you fear risk lifting the head? Well you won't have to worry it's an open deck block you'll see no benefit in them as if you are pushing that pressure you'll distort the cylinder wall anyway.
 

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Discussion Starter · #17 ·
First off.

Why do you think you need aftermarket head studs? Do you forsee boost levels that you fear risk lifting the head? Well you won't have to worry it's an open deck block you'll see no benefit in them as if you are pushing that pressure you'll distort the cylinder wall anyway.
Just curious, when would aftermarket head studs be necessary, like horsepower wise.
 

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Little Homie
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Just curious, when would aftermarket head studs be necessary, like horsepower wise.
About the same point you'll be looking at closed deck blocks. So the 450-500whp range. Depending on the dyno. Locally we have a heart breaker so I'd expect probably closer to the 450-475 mark.

There are a lot of builders that recommend a closed block earlier, and it may be warranted, but the only member I know that has entered insane power territory is @WRX-maniac.

Head studs are pretty normal things. They are made to tensile standards and when changing them torque values required change and everything. If you need them, you'll know you need them.
 

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Discussion Starter · #19 ·
About the same point you'll be looking at closed deck blocks. So the 450-500whp range. Depending on the dyno. Locally we have a heart breaker so I'd expect probably closer to the 450-475 mark.

There are a lot of builders that recommend a closed block earlier, and it may be warranted, but the only member I know that has entered insane power territory is @WRX-maniac.

Head studs are pretty normal things. They are made to tensile standards and when changing them torque values required change and everything. If you need them, you'll know you need them.
Good to know, thank for the valuable information. One more thing, what's the difference between open deck and closed deck blocks?
 
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