2.2's, did you know....

[njdrsubaru]

... that 2.2's engines 97 and up are an interference engine? i thought it was only the 2.5's. yikessssss

hehe

[shazapple]

*runs to check timing belt*

Where did you get this info?

[njdrsubaru]

i got it here

http://www.ultimatesubaru.net/forum/sho ... hp?t=55321 (http://www.ultimatesubaru.net/forum/showthread.php?t=55321)

[njdrsubaru]

apparently 95 and 96 non inteference are the same and then 97 and 98 inteference are the same and lastly 99 is a different inteference engine, hmmmmmmmmmmmmm :shock: :roll: :!:

[Manarius]

In 97, they shaved a bit off the top of the heads in order to gain a compression boost making the car interference. I had the same issues when I was looking at a 97 Legacy a while ago.

[Wiscon_Mark]

yeah, i knew that. The valves can overextend. Not a big deal unless you do something stupid. The synchros don't really allow you to throw it into 2nd or 1st at an excessive speed.

[dropdfocus]

Yeah, a buddy tried to put a '97-'98 valve train in his '99 2.5GT and it had issues with smacking the bottom of the valves. DOH!! He didn't believe me when I told him there was a reason the '99 motor is excluded from being listed a lot of times when looking for aftermarket internals.

'95-'96 should be the Stage 1 motor and then it switched to the Stage 2 after that.

[subyluvr2212]

In 97, they shaved a bit off the top of the heads in order to gain a compression boost making the car interference.

Nope, the other way. The crown of the piston is shaped differently. That's what changed the compression.

As best I know, EVERY Subaru engine from 97-up is interference.

[Manarius]

Nope, the other way. The crown of the piston is shaped differently. That's what changed the compression.

As best I know, EVERY Subaru engine from 97-up is interference.
My mistake. I knew they did something with the pistons. I think I was reading though, SoA says the engine is non-interference. I'll have to find that letter from SoA saying it isn't.

[subyluvr2212]

Well, here's the EndWrench article that is my source of info. The compression change is circled in red...
http://www.thawa.net/gallery/albums/album47/EndWrench.thumb.jpg (http://www.thawa.net/gallery/albums/album47/EndWrench.jpg)

[Manarius]

Yeah..that's where the dispute is...SoA seems to be in denial :P

[tjpete04]

What exactly does a interference engine mean?

[Wiscon_Mark]

It means, that if you push the car beyond what it can handle (ie: seriously redlining it), then the pistons/valves (or both) will overextend, and hit each other or something else, completely destroying the engine.

[subyluvr2212]

It means, that if you push the car beyond what it can handle (ie: seriously redlining it), then the pistons/valves (or both) will overextend, and hit each other or something else, completely destroying the engine.

Well, that's a possibility, most likely if you're overrevving a tuned engine that doesn't have any valvetrain work to it. But in our case, that rarely happens.

In 999 out of 1000 cases, the timing belt/chain either has to be off, or it has to break. What happens then is the crank will keep going because the wheels are still spinning it, but the cams will just stop completely. So any valves that are stuck open when the cams stop will hit the pistons since they will keep moving.

Or in the case of valve-valve interference, the chances of both cams stopping in the exact same position relative to each other is practically nonexistant. Therefore, when the cams move independently of each other, the valves will hit each other.

[losdiosdeverde86]

... that 2.2's engines 97 and up are an interference engine? i thought it was only the 2.5's. yikessssss

hehe

i'm kinda suprised a lot of you guys didn't know that

[Sarra]

Interferance means that if you break the timing belt andt he camshafts aren't turning anymore, the piston will "interfear" with your valves.

1987 Maxima is an interferance engine. :p Friends timing belt broke, had to have some work done on it.

[subyluvr2212]

Interferance means that if you break the timing belt andt he camshafts aren't turning anymore, the piston will "interfear" with your valves.

But if you read my last post, you'd know that this isn't the only type of interference ;)

[Sarra]

Interferance means that if you break the timing belt andt he camshafts aren't turning anymore, the piston will "interfear" with your valves.

But if you read my last post, you'd know that this isn't the only type of interference ;)

Interferance is also when my neighbor's cordless phone destroys my wireless internet signal. :(

[Superu264]

Interferance is also when my neighbor's cordless phone destroys my wireless internet signal. :(

+1