Thanks Lynn,   I am starting to rely on your experienced opinion more
 > and more.  Two questions:  First,  is the timing the same for a 12A
 > and a 13B?   If so, the second question: is there any way I can get a
 > pattern that would locate the port in my housing?
 >
 > I'm glad to hear your recommendation  about keeping the port
 > horizontal and the shaping advice. It makes sense.  Thanks.

 > Jerry Hey

I did make a pattern of that deal last year but it does not look very good
after scanning it in. I will do another and post it for you. As for the
timing, I don't know that one. There is no such thing as a factory 13B
periphery port housing. They are all made up by aftermarket people, or home
builders. The slightly larger displacement would make it a bit less sensitive
to late closing, but I would start with the 12A timing. It works real good. I
mean REAL GOOD. The port in the picture was cut short of the 12A factory port
because it was for an autocross MiniCooper and was going to stay under 8,000
RPM. Well, that was the plan anyway. It was a tight course and the owner
found that he did not have to shift out 1st gear to do the whole thing. It
lasted one weekend. It was a junkyard engine anyway, but it is fondly
remembered by all.
He put a small block in it after the rotary. Duh!!

Lynn E. Hanover

The factory made and sold some 13B P-port housings. The two
on the left in this picture are factory P-ports. The two 
on the right are Racing Beat

Paul Lamar
 
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