EVO X - VIII motor comparison details
#1
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EVO X - VIII motor comparison details
First let's look at the rods. As you can see the EVO X rod looks much stronger. Physically it's larger in width and thickness across the beam. The X rods have rod bolts instead of studs, meaning you can upgrade to ARP or other aftermarket bolts easily. The big end is narrower but also larger in diameter than a VIII/IX. The narrower bearing width has less surface area to distribute the load but the larger diameter should help a little. The larger diameter will increase bearing surface speed which can be an issue at very high engine RPM (oil shear issues) but also means the rod journals on the crank are larger and thus stronger.
Stock VIII rod width vs. EVO X rod width
You can see the X rod is almost 3mm wider.
Next with have rod beam thickness
The X rod is about 2mm thicker
Here is shot of the rods side by side
You can see the new X rod has rod bolts rather than studs and nuts like the VIII and IX. This makes upgrading to aftermarket rod bolts very easy.
Stock VIII rod width vs. EVO X rod width
You can see the X rod is almost 3mm wider.
Next with have rod beam thickness
The X rod is about 2mm thicker
Here is shot of the rods side by side
You can see the new X rod has rod bolts rather than studs and nuts like the VIII and IX. This makes upgrading to aftermarket rod bolts very easy.
#5
awesome, but what about the block? I think that's where the most concern is right about now. Hey, here's a great comparison: since the sti is a semi closed deck, aluminum block, how about comparing the two to see which one is stronger/better reinforced? That would be a great comparison.
#10
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I would guess the block has to be a bit tougher given that its running 24psi from factory at the largest load point. If we are going to compare stock to stock, then that would mean no ARP studs / bolts etc and then do the boost comparison. Then I think you would find that the new motor is quite a bit stronger in this area. However, add studs etc, its all unknown.
#12
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I would guess the block has to be a bit tougher given that its running 24psi from factory at the largest load point. If we are going to compare stock to stock, then that would mean no ARP studs / bolts etc and then do the boost comparison. Then I think you would find that the new motor is quite a bit stronger in this area. However, add studs etc, its all unknown.
stock to stock i dont doubt 1 bit the X block is better. Lets see what happens when you throw 40-50psi of boost at it.. Nothing more aggravating then sleeve issues IMO..
#13
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Apology accepted ;p
This is definitely going to be an interesting ride. Its very exciting to have a new motor with unknown attributes. We all knew what we could or couldnt do with the 4G63, and now we get to start that roller coaster ride all over again!!
Thanks to AMS for sharing so openly!
This is definitely going to be an interesting ride. Its very exciting to have a new motor with unknown attributes. We all knew what we could or couldnt do with the 4G63, and now we get to start that roller coaster ride all over again!!
Thanks to AMS for sharing so openly!