Shockwave
Registered User
I had bought a used early blower last year to use for porting and rebuilding. I installed all new front snout bearings and new rear case needle bearings from Tbird88.
Click on pics for full size pictures.
I did a conservative port on the rear inlet. I was looking to move the opening up into the rotor centerline. I took about .200 out of the top of the opening, but I ported in an angle to match the case floor.
<a href="http://www.jerrytbirdsc.com/m90/full/Dscn0004.jpg"><img src="http://www.jerrytbirdsc.com/m90/Dscn0004.jpg" width="240" height="180" border="0"></a>
There is a lot of material available to work with on the inside unlike the rear where you need a sealing surface. This should increase the volume of air available to the rotors.
<a href="http://www.jerrytbirdsc.com/m90/full/Dscn0002.jpg"><img src="http://www.jerrytbirdsc.com/m90/Dscn0002.jpg" width="240" height="180" border="0"></a>
I didn't go crazy on the outlet side either. The triangle outlet is about a half an inch wider than stock and a little longer. It looks about right to me.
<a href="http://www.jerrytbirdsc.com/m90/full/Dscn0008.jpg"><img src="http://www.jerrytbirdsc.com/m90/Dscn0008.jpg" width="240" height="180" border="0"></a>
Here are a couple of side-by-side shots of a stock blower and my ported one.
<a href="http://www.jerrytbirdsc.com/m90/full/Dscn0006.jpg"><img src="http://www.jerrytbirdsc.com/m90/Dscn0006.jpg" width="240" height="180" border="0"></a>
<a href="http://www.jerrytbirdsc.com/m90/full/Dscn0007.jpg"><img src="http://www.jerrytbirdsc.com/m90/Dscn0007.jpg" width="240" height="180" border="0"></a>
I also port matched the inlet plenum to match. The factory original was smaller than the blower opening to start with, so this should really be beneficial.
<a href="http://www.jerrytbirdsc.com/m90/full/Dscn0009.jpg"><img src="http://www.jerrytbirdsc.com/m90/Dscn0009.jpg" width="240" height="180" border="0"></a>
Click on pics for full size pictures.
I did a conservative port on the rear inlet. I was looking to move the opening up into the rotor centerline. I took about .200 out of the top of the opening, but I ported in an angle to match the case floor.
<a href="http://www.jerrytbirdsc.com/m90/full/Dscn0004.jpg"><img src="http://www.jerrytbirdsc.com/m90/Dscn0004.jpg" width="240" height="180" border="0"></a>
There is a lot of material available to work with on the inside unlike the rear where you need a sealing surface. This should increase the volume of air available to the rotors.
<a href="http://www.jerrytbirdsc.com/m90/full/Dscn0002.jpg"><img src="http://www.jerrytbirdsc.com/m90/Dscn0002.jpg" width="240" height="180" border="0"></a>
I didn't go crazy on the outlet side either. The triangle outlet is about a half an inch wider than stock and a little longer. It looks about right to me.
<a href="http://www.jerrytbirdsc.com/m90/full/Dscn0008.jpg"><img src="http://www.jerrytbirdsc.com/m90/Dscn0008.jpg" width="240" height="180" border="0"></a>
Here are a couple of side-by-side shots of a stock blower and my ported one.
<a href="http://www.jerrytbirdsc.com/m90/full/Dscn0006.jpg"><img src="http://www.jerrytbirdsc.com/m90/Dscn0006.jpg" width="240" height="180" border="0"></a>
<a href="http://www.jerrytbirdsc.com/m90/full/Dscn0007.jpg"><img src="http://www.jerrytbirdsc.com/m90/Dscn0007.jpg" width="240" height="180" border="0"></a>
I also port matched the inlet plenum to match. The factory original was smaller than the blower opening to start with, so this should really be beneficial.
<a href="http://www.jerrytbirdsc.com/m90/full/Dscn0009.jpg"><img src="http://www.jerrytbirdsc.com/m90/Dscn0009.jpg" width="240" height="180" border="0"></a>