Rotor Housing?

[C. Ludwig]

Working on putting a new motor together. I'm wondering what the difference is between front and rear housings. They've always been visually identical to me and know guys interchange them. Just curious what the difference is.

------------------
Chris Ludwig
08 ITS RX7 CenDiv

[noresull]

The front one has the mounting points for the front cover and water pump/thermostat housing and the threads for the tension bolts. The rear has none of the above mentioned provisions and the tension bolt holes aren't threaded.

[C. Ludwig]

Rotor housings?

------------------
Chris Ludwig
08 ITS RX7 CenDiv

[noresull]

Sorry, I was thinking the end housings. Please disregard my pointless ramblings! http://Forums.ImprovedTouring.com/it/tongue.gif

[moto62]

Chris. The F&R rotor housings are the same except for the position of the egr ports below the exhaust ports. The front housing has the port to the left of the exh port and the rear housing has the port to the right. None of this matters on a race engine because the egr ports are usually plugged with epoxy and are blocked off by the header flange anyway so the housings can be used at either front or rear.
Ray

[C. Ludwig]

Thanks! That's what I needed to know.

------------------
Chris Ludwig
08 ITS RX7 CenDiv

[Rx7Carl]

Actually that only applies to early housings where the EGR comes out the rotor housing itself. Later housings go up thru the intermediate plate and out under the primary ports. Those later housings are interchangable.

Cheers