Heads milled under spec? EJ25D

I just took my heads in to get milled. On the way back i thought "what if they mill them under spec and the pistons hit the heads?" does anyone know what the spec is? what do i do if they mill under spec? can i just mill the piston heads?

Im sure they will be fine they are just taking enough off to make them flat.

Yeah^

 

It's not as if they're taking like like 30mm or something lol

are you sure? both the guy milling the head and the tech i talked to told.me to make absoloutley sure because it was a concern. i know theyre just trying to sell me shit, but its still something reasonably concerning.

also, the guys at the machine shop told me not to use the felpro mls gaskets. they want to sell me other ones, but imo, one gaskets should be just as good as the next

i guess a better question is, how much can they take off before its below spec? how much can they take off before the pistons will touch the heads?

but imo, one gaskets should be just as good as the next

 

this was not true in 1999 when the the first head gaskets started going bad. fel pros would not do the job because they were making the ej25 gaskets just like the ej22 gaskets.

 

today however they have change the design of the head gaskets and they maybe good enough. but subaru gaskets are not more expensive, less than some in fact. the wholesale cost of the subaru gaskets at the dealer is about 75$, gaskets only. online is a little cheaper but you have to pay shipping.

 

so why buy any brand except subaru.?

 

but different folks have different opinions. each to his own.

 

and if the machine shop does not know what the specs are for your head i wouldn't let them touch the heads and go somewhere else. and absolutely not take their advice on head gaskets.

this was not true in 1999 when the the first head gaskets started going bad. fel pros would not do the job because they were making the ej25 gaskets just like the ej22 gaskets.

 

today however they have change the design of the head gaskets and they maybe good enough. but subaru gaskets are not more expensive, less than some in fact. the wholesale cost of the subaru gaskets at the dealer is about 75$, gaskets only. online is a little cheaper but you have to pay shipping.

 

so why buy any brand except subaru.?

 

but different folks have different opinions. each to his own.

 

and if the machine shop does not know what the specs are for your head i wouldn't let them touch the heads and go somewhere else. and absolutely not take their advice on head gaskets.

 

The FelPro gasket set was about $150 shipped. That includes both head gaskets, and all of the gaskets I need after that. It was normally $200 but I used a coupon code and got $50 off plus free shipping. So I could've had JUST the Subaru head gaskets from the dealer for the same price, but I would've ended up paying more for the other gaskets (which some I did need). The FelPro head gaskets are all Multi-Layered Steel and I looked up the torque specs for them on FelPro's website. They SHOULD work fine.

 

My main concern atm is making sure they have a good surface to lay on. I really need to know how much material they can take off before the pistons start to get too familiar with the head... I have faith in these gaskets, but it's all for nothing if the piston knocks into the head and causes irreversible damage.

 

So if the clearance is good, no problem. If it's not, I need to mill the piston heads. Does that sound reasonable?

You can get Cometic MLS head gaskets in custom thickness directly from them for a bit of an upcharge. That would be a solution if they're milled too much. Specs per the FSM are:

 

Warping limit: 0.035 mm (0.0014 in)

Grinding limit: 0.3 mm (0.012 in)

Standard height of cylinder head: 127.5 mm (5.02 in)

and if the machine shop does not know what the specs are for your head i wouldn't let them touch the heads and go somewhere else. and absolutely not take their advice on head gaskets.

 

 

this.

Plus. The phase one engines don't have pistons that come up over the deck. So the only thing you gotta worry about is valves. And the valves do not get THAT close to the pistons that a simple decking would cause problems

 

Plus. Felpro head gaskets. I used them on a motor I didn't get decked and its holding up fine. Over 1000 miles so far.

 

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Plus. The phase one engines don't have pistons that come up over the deck. So the only thing you gotta worry about is valves. And the valves do not get THAT close to the pistons that a simple decking would cause problems

 

Plus. Felpro head gaskets. I used them on a motor I didn't get decked and its holding up fine. Over 1000 miles so far.

 

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Not true the ej25d has pistons that go above the deck, that is the reason for the ungodly thick headgasket. The phase II motors do not go above the deck.

ej25d has pistons that go above the deck, that is the reason for the ungodly thick headgasket. The phase II motors do not go above the deck.

 

This is true. I used a phase1 bottom end in my Impreza. The pistons will enter the headgasket about 0.5mm, OEM gaskets measure close to 1mm. Pistons have a bit of room for valve clearance.

I had that backwards I guess. Woops my bad

 

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Not true the ej25d has pistons that go above the deck, that is the reason for the ungodly thick headgasket. The phase II motors do not go above the deck.

 

This is true. I used a phase1 bottom end in my Impreza. The pistons will enter the headgasket about 0.5mm, OEM gaskets measure close to 1mm. Pistons have a bit of room for valve clearance.

 

So you guys are telling me that the piston could hit the gasket? The guy at the machine shop told me that FelPro's EJ25D MLS gasket is bad because the piston will hit it.

If this IS the case, can I just mill the piston heads down so they don't come above the deck? haha

 

Also, they took 0.004 in off of my heads. If the grinding limit is 0.012, then I'm good right? There's nothing else I have to account for?

Piston hitting the head gasket? The gasket doesnt protrude into the cylinder. You will be ok but why not get the newest oem mls gasket I got mine from subarupartsforyou.

Yeah, just go to the dealer and buy the gaskets from them. Buy a cheap gasket kit off of eBay for $70 to get all of the rubber seals your engine needs and you're good to go with a $140 investment into it...

I got the whole set for $150 shipped. It's about the same price as an OEM MLS gasket set NOT shipped for JUST the head gaskets.

 

@JJay03 I'm pretty sure they were just trying to sell me their gaskets, but I wanted to make sure.

Weird... Gaskets at the dealer are $40 each.

Same here I can get them for 40 each.

Felpros are perfectly fine, I have used them myself with no issues. OEM and felpro are the same type of gasket and for the most part they look identical.

 

Some machine shops refuse to give you a warranty if they use parts supplied by the customer, it is just to cover their a$$. Probably why he was trying to get you to use his gaskets. I would not use anything but the felpros you have or OEM.