STI vs WRX block comparo (pictures)
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From: Hillsboro, OR
Car Info: H6-3.0T+GT35R
Originally posted by Steppin Razor
Yeah baby, keep it coming.
Would someone be kind enough to advise on appx how much an EJ207 short block would run? Also. would that even make sense because one of the real advantages of that motor is the AVCS? Would it be better to just buy the whole thing?
Yeah baby, keep it coming.
Would someone be kind enough to advise on appx how much an EJ207 short block would run? Also. would that even make sense because one of the real advantages of that motor is the AVCS? Would it be better to just buy the whole thing?
The block are very similar, so if you have time, I would just get JE pistons, and some good rods in a 205 block.
Jeff
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Originally posted by Steppin Razor
Nathan: Would you explain what the quench area is for all the n00bs who are reading this and don't know. Perhaps we could have a little "fundamentals of combustion engine building" seesion here.
Nathan: Would you explain what the quench area is for all the n00bs who are reading this and don't know. Perhaps we could have a little "fundamentals of combustion engine building" seesion here.
http://www.google.com/search?q=quenc...UTF-8&oe=UTF-8
Bottom line; it’s a design feature of the combustion chamber that can be called “mechanical octane boost.”
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Posts: 25
From: Hillsboro, OR
Car Info: H6-3.0T+GT35R
Originally posted by Turboxs_Nathan
Jeff,
Did you happen to take pictures of the actual combustion chambers on the heads? How about the intake and exhaust ports?
By the way, those pistons explain a lot about the STI motors, but I’d like to see how the quench area lines up with the STI heads.
-Nathan
Jeff,
Did you happen to take pictures of the actual combustion chambers on the heads? How about the intake and exhaust ports?
By the way, those pistons explain a lot about the STI motors, but I’d like to see how the quench area lines up with the STI heads.
-Nathan
That's a good question. Since the pistons have less dish, but sit a bit lower in the deck (pin in a bit higher), the quench volume is about the same, but the quench shape is different. When we pull Adam's current engine out (soon), I'll get detailed measurements and pictures of the AVCS STI heads vs the regular WRX heads. There may be some other small changes in the head layout that effects the quench area.
If you want to see some mechanical octane in action, go to www.theoldone.com
The second main bearing seat (from the rear) appears to be differant as well. It's also very interesting to hear that the STI has longer rods. I was planning on going with longer rods when I build my motor. With the Rod ratio improvement, the piston speeds will come down a bit, which in turn keeps the combustion chambers cooler. This allows you to run more timing safely, and the motor runs cooler and smoother. I gotta get my hands on one of those cranks now to. Jeff can you measure the STI rod and check to see if there is any difference in deck height?
The second main bearing seat (from the rear) appears to be differant as well. It's also very interesting to hear that the STI has longer rods. I was planning on going with longer rods when I build my motor. With the Rod ratio improvement, the piston speeds will come down a bit, which in turn keeps the combustion chambers cooler. This allows you to run more timing safely, and the motor runs cooler and smoother. I gotta get my hands on one of those cranks now to. Jeff can you measure the STI rod and check to see if there is any difference in deck height?
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Joined: Nov 2002
Posts: 25
From: Hillsboro, OR
Car Info: H6-3.0T+GT35R
Originally posted by DeliciouSpeed
If you want to see some mechanical octane in action, go to www.theoldone.com
The second main bearing seat (from the rear) appears to be differant as well. It's also very interesting to hear that the STI has longer rods. I was planning on going with longer rods when I build my motor. With the Rod ratio improvement, the piston speeds will come down a bit, which in turn keeps the combustion chambers cooler. This allows you to run more timing safely, and the motor runs cooler and smoother. I gotta get my hands on one of those cranks now to. Jeff can you measure the STI rod and check to see if there is any difference in deck height?
If you want to see some mechanical octane in action, go to www.theoldone.com
The second main bearing seat (from the rear) appears to be differant as well. It's also very interesting to hear that the STI has longer rods. I was planning on going with longer rods when I build my motor. With the Rod ratio improvement, the piston speeds will come down a bit, which in turn keeps the combustion chambers cooler. This allows you to run more timing safely, and the motor runs cooler and smoother. I gotta get my hands on one of those cranks now to. Jeff can you measure the STI rod and check to see if there is any difference in deck height?
I don't think the STI Rods are any longer? When I was talking about the change in piston design and pin location, I was refering to the offset of the Pin from the top of the piston. I'll take a double measurement on the rods, but they look to be the same length.. Just beefier, and with different endbolts.
I'll get some more pictures together, along with some good pictures of the heads.
Jeff
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