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Hi ALL!

I've been on the phone with a local Subaru ONLY mechanic asking about my EGR flow problem......he suggested that I replace the Transducer, since it can't be tested. I'm going to! ANYHOW!

I had him on the phone..... I asked about the 2.5 Phase I Head Gasket problem, he came up with another idea for why that I have not yet heard of......he's saying that is a block casting problem. Something about the water jaccket being too thin, not strong enough. The original HG hasn't made strong enough to handle this casting problem,.....that's why they blow! New one on me!

 

STed

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I think that was his way of saying Subaru saved $0.27 per block by reducing the amount of material by casting the material between the water passage and the cylinder wall as thin (weak) as possible. Because it's thin, the gasket has to be thin too, and hence weaker. As long as it lasts past the warranty period it's no big deal.

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Someone on the board recently suggested that Subaru should left the capacity at 2.4 litres after increasing the stroke only. The 2.5 bore is just too big to fit inside the EJ block.

 

I expect they wanted distance the 2.0 and 2.5, so customers won't mind coughing up the extra money.

 

The previous generation BMW 5-series had a 2.5 litre in the "523i", in order to keep a sizeable gap up to the more expensive 2.8 litre "528i".

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About a year and a half ago i was having a conversation with one of the mechanics that I worked with at a Subaru only Shop. At the time he was doing a HG job on a EJ25 phase 1. He told me that the gaskets he was putting in were the second redesign that he's seen in the gaskets that SOA sells.

 

About a month ago we were talking again about headgaskets and he was telling me that basically none of the Subarus that he'd did a headgasket job with those gaskets have come back in with blown headgaskets. So maybe SOA has fixxed the problem, but it'll probably take another year or two to know for sure.

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He told me that the gaskets he was putting in were the second redesign that he's seen in the gaskets that SOA sells.

When I did the headgaskets on our outback the part guy told me the gaskets had been changed six times. I don't know how true it that is.

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I don't think the wall's thickness, or lack thereof, is a direct problem, just the indirect variety.

 

The metal used on the gasket to go around the cylinders is very thin. Unfortunately, this metal becomes part of the cumbustion chamber and takes a tremendous amount of heat and pressure.

 

I am not sure how close the water jacket holes are to the edges of the cylinder walls, but maybe because of that limited surface area, the metal cannot cool sufficiently to keep from cracking and burning.

 

Or, the metal they use is not worth a crap.

 

Do the Turbo models experience this problem? If not, what is the diff??

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Someone on the board recently suggested that Subaru should left the capacity at 2.4 litres after increasing the stroke only. The 2.5 bore is just too big to fit inside the EJ block.

 

I expect they wanted distance the 2.0 and 2.5, so customers won't mind coughing up the extra money.

 

The previous generation BMW 5-series had a 2.5 litre in the "523i", in order to keep a sizeable gap up to the more expensive 2.8 litre "528i".

That was me. I just did a little math and discovered I was mistaken.

 

EJ-25

Bore: 99.5mm

Stroke: 79mm

 

EJ-22

Bore: 97mm

Stroke: 75mm

 

The 97mm bore combined with the 79mm stroke yields 2.335 liters. Axis racing builds an awsome 2.4 that's based on a 2.2 turbo block using a 2.5 crank, but apparently there's some sleeving and proprietary whatnot going on to arrive at the 2.4 liter displacement.

 

http://axispowerracing.net

 

Apologies for the confusion.

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When I did the headgaskets on our outback the part guy told me the gaskets had been changed six times. I don't know how true it that is.
I know of 3 replacement part numbers (in other words, they are on the 4th gasket design) for the Phase I engines. AFAIK, the one I got just over 2 years ago (p/n ends with 610 IIRC) is still the current one. The gasket is a 4 layer affair. The orginal was three layer. I don't know about the others (but they have been superceded anyway).

 

2.25 years and 140,000 km later, my head gaskets are still holding together. Knock wood.

 

Commuter

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