janas19 Posted October 27, 2016 Author Share Posted October 27, 2016 What makes the STi gaskets superior? Quote Link to comment Share on other sites More sharing options...
86BRATMAN Posted October 27, 2016 Share Posted October 27, 2016 They're multi layer steel, the stock ej251 gaskets are single layer and are prone to failure in the form of leaking coolant and oil along the bottom of the head/block seam. I've done somewhere in the neighborhood of 75 head gasket jobs on the ej251/3 engines using the 04-06 sti gasket and never had a repeat failure, which is still an issue with the oem replacement ej251 gaskets. Quote Link to comment Share on other sites More sharing options...
janas19 Posted October 27, 2016 Author Share Posted October 27, 2016 (edited) Seems like the EJ25D heads on the EJ251 block would be a nice little NA setup if you drop it in an early year 5MT. I'll think about doing this if I can find a deal on those heads. However, my gut feeling is it would be cheaper to just get the whole EJ251 longblock from a Pull-a-Part and just use the Delta 220 regrinds. Edited October 27, 2016 by janas19 Quote Link to comment Share on other sites More sharing options...
86BRATMAN Posted October 27, 2016 Share Posted October 27, 2016 If you can find a pick a part with both a 25d and a 251 you could make the hybrid there. Pay longblock price for it and pit it together with new gaskets and such afterwards. Just make sure you keep the dohc head bolts with the heads, sohc head bolts are longer. Quote Link to comment Share on other sites More sharing options...
janas19 Posted October 27, 2016 Author Share Posted October 27, 2016 Bahahaha. Build a hybrid in the junkyard ground? I love it! LOL Dude, you get a gold star. This is genius! Quote Link to comment Share on other sites More sharing options...
janas19 Posted October 27, 2016 Author Share Posted October 27, 2016 So I didn't know this but there are factory hybrids. The 98 2.5RS has the Phase II block and DOHC heads. Rumor is the 98-99 Outbacks also have the hybrid engine: I was recently informed of this fluke by the folks a Colorado Component Rebuilders who do nothing but rebuild EJ's all day long. For some reason the '98 and '99 Outbacks got the phase II shortblocks but continued to use the DOHC heads... Can anyone confirm? Quote Link to comment Share on other sites More sharing options...
Numbchux Posted October 27, 2016 Share Posted October 27, 2016 Sort of... After engine #2213362 (manufacture date sometime in 03/98, which would primarily be '99s, maybe a few '98s), the OE catalog shows the #5 thrust bearing. The '99 SUS I had, definitely had a phase 2 style timing belt tensioner. But, all '97+ 25Ds show the same part number for pistons and all 25Ds with the same head gaskets. Which is why the compression isn't higher. Quote Link to comment Share on other sites More sharing options...
matt167 Posted October 27, 2016 Share Posted October 27, 2016 Bahahaha. Build a hybrid in the junkyard ground? I love it! LOL Dude, you get a gold star. This is genius! It's more common than you might think.. Find an old work van and set up shop in the back. Quote Link to comment Share on other sites More sharing options...
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