I have both a b17a and b18a flywheel in my garage, and when straightening things up I noticed they were slightly different, upon further inspection I noticed more differences.
I’m just a bit confused because of this old post: http://www.g2ic.com/forums/showthread.php?s=&threadid=12997 In which the weight of the b17a flywheel as 19lbs, which is supposed to be the same as the b18a flywheel.
Also, i’ve seen the weight of the non-R b series flywheels posted as 18lbs, not 19lbs. And the R flywheel being either 14lbs or 15lbs, both numbers seem to be posted quite often.
Well, here is some info I found. The b18a flywheel I have is off of my 91 b18a1. The b17a flywheel I have is off of a 92 b17a that I bought awhile back. The owner had put a jdm b18c into his car, so there is a small chance that the flywheel is atually a jdm b18c flywheel if he for some reason decided to swap them? But chances are its a b17a flywheel. Another thing that makes me thing its a b17a flywheel is the fact that from the front it looks the same as another b17a flywheel that i have that I KNOW is from a b17a.
The b18a flywheel I have weighed in at 19lbs, the b17a flywheel weighed in at 17.5lbs (note, the weights may not be exact due to the fact that I used a cheap scale…I simply mean to show that there is substantial difference in weight).
[size=3]Front of Flywheel[/size]
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Here are the 2 flywheels side by side. They look the same, but if you look closely you can see a difference.
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The red line on the b17a flywheel shows that that portion is all the same height. On the b18a flywheel there is also a red line, this is the same height as the area on the b17a flywheel. However the blue line indicates an area that sits even higher up. Having the metal go higher up means more metal, which means more weight.
[size=3]Back and Back of Flywheel[/size]
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Here it’s quite obvious that the backs of the flywheels are very different.
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The b18a flywheel is much more flat on the back. Whereas it looks like a lot of material has been cut out of the backside of the b17a when compared to the b18a.
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From the side they look almost the same in the pic. They look to be the same thickness. However you’ll notice I marked the b18a flywheel with a little red line. This line is to show that the side of the flywheel is stepped. The part where the line is sticks further out toward the camera than does the rest of the side. The pics below show this too.
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Here its obvious that there is more material on the b18a flywheel. As you can see the material on the back extends nearly as far as the teeth do. But this isn’t seen on the b17a flywheel.
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There is a considerable amount of material on the outer rim of the backside of the flywheel. However less on the b17a. As you can see by the lines I drew the height of the material drops down after about 1cm from the outside of the b17a. However this material extends much further into the center of the flywheel on the b18a.
If anyone has any info about different weights of b series flywheels please post it. And if any of my assumptions about the flywheels is wrong, please correct me.
