Great idea.

I have for a long time been keen to build a long conrod, destroked, big bore (100-102mm), sleeved, closed deck with 75mm stroke (EJ207 crank) engine.

High boost + big revs = big grin!

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[SIGPIC][/SIGPIC]

So Ive got the heads off today.

Just looks like the valves have just failed. There is no sign of PTV contact on any of the other three pistons.
Both valves have failed in exactly the same place just before it widens out to the head.
There's no sign of Det or anything heat related.

So pissed off about this one as I have gone to great lengths to make sure it didn't happen again.
proper valves double springs, hardened steel retainers, a conservative 7800rpm rev limit and 1.1mm gaskets.

Really really pissed off this time.

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605whp
Quarter Mile in 10.9 seconds @ 135mph /217kph
0-100 kph 3.2 seconds

Bummer Daz...especially after all your diligent work...but a rebuild is always an opportunity! Good luck...

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No Subarus currently owned

Hows the bore?

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Balls.

Wow those valves have been having a party in there.

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New Foz Build http://ozfoz.com/forum/viewtopic.php?f=12&t=43042

Wow. Interesting the point that the valves broke at. I always pictured them braking at the end where the collet/retainer connects.

Do you think it could be related to the double springs? Have you had a chance to individually measure the spring pressure of those springs vs the rest?

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Doing it for all the wagons out there

Thanks to Leigh from Deshele performance we've come to the conclusion it's valve to valve contact that's done it. I've always thought the engine was slightly noisier after my drag strip visit but until now just though I was imagining things.

Something Leigh said (without knowing about the noisier engine) has confirmed my suspicions. We think it's valve float when hitting the limiter that's done it.

On the drag strip I hit the limiter in 4th at 135mph about 10 meteres before the line. I think this has been the point where the inlet and exhaust valves have hit each other and bent slightly. Then they've just fatigued over time.

I'm not going to buy supertech again. I've read a few posts by some quite serious engine builders who have switched to Ferrea valves as they tend to just bend rather than break.

I'm also going to raise the limiter from 7800rpm to 8500rpm. That will get me across the line without limiter bashing. It's not the rpm that's done this it's the float when the limiter kicks in.

Block is possibly salvageable, bottom end looks to be good too apart from the pistons of course. Ill know for sure when i split the block later.

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605whp
Quarter Mile in 10.9 seconds @ 135mph /217kph
0-100 kph 3.2 seconds

I really hate seeing things like that but knowing you, you'll always come back bigger and better. The workmanship you apply to all your builds is always top notch.

Can't wait to see what combo you end up with next. Also when you do end up putting the long motor together, do it like the old times with lots of pics and details.

Good luck Daz

Yeah, If the block is goosed I'm going to do an EJ22T build. I've built them for other people just never for myself. They are supposed to be just awesome and better than the EJ25 option because it revs so well.

If I do that I'll document the whole build from start to finish.

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605whp
Quarter Mile in 10.9 seconds @ 135mph /217kph
0-100 kph 3.2 seconds

Ever considered an ej25 block with ej207 crank and custom longer rods? Short stroke of a 207 and even taller rod/stroke ratio than that of a 207 with a bit more displacemnt aswell. Will rev like crazy and still with enough displacemnt to keep you smiling. Once you have either sleeved or CDB the ej25 then its not such a bad setup. Especially if finding a good condition ej22 block thats un-mollested is becoming more difficult.

You mentioned doing ej22 stroker. Once you put the 79mm crank in an ej22 your moving away from the short crank that gives it its good revving qualities in the first place. And still end up with the same displacement as a de-stroked 25.

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Doing it for all the wagons out there