Outfront Motorsports Closed Deck Block


It’s been a while since my last update and figured now was the time. When the car came back it arrived with a check engine code for a 2nd cylinder misfire. It wouldn’t go away so I took it to PSI and had them check it out. Combined with the CEL, low compression in cylinder 2, there were bubbles in the coolant and a bit of white smoke in the exhaust when getting on boost. The diagnosis was a failed headgasket. Ugh. The last thing I wanted to see.

I pulled the engine, did a leakdown test, and it was also indicative of unhealthy motor, despite everything looking clean. The pistons were good, cylinders were great (still had a great cross hatch too), rings looked fine, and no cracks. I thought “hey lets just replace the rings and call it a day”. We went to re-hone it and the piston cylinders were out of round. I’m betting Rallispec used stock case halves and didn’t bore it themselves, which means Subaru doesn’t use torque plates when boring the case halves. Lame.

So I’ve been taking my time thinking through what I want to do with the car and how I wanted to proceed. After a bit of time and research, I came across a new block strengthening treatment that is meant to be nearly indestructible with high boost. A few people over at NASIOC have been stress testing these blocks with great success, pushing the 800whp on these new blocks. I was sold and put one on order. Outfront Motorsport’s closed deck subaru block is a beautiful solution with 10 years experience behind it. The machining looks impeccable! Hoping this is a better long term solution to running a high boost Subie!

PS – Outfront also sells a custom headgasket made by JE, since after decking the block again you lose about a 1/2mm in deck surface, so a standard head gasket wouldn’t be adequate.

PPS – Lets see what 30psi feels like now? :)