Originally Posted by sen2two

I knew the twin dizzy had more bolts than all the newer motors. But it's actually only by one tension bolt. Which is fine since it's right about where I would put my PP anyways. So It would become obsolete anyways.

But one thing I wasnt ready for, two of the tension bolt holes do NOT line up properly. One just below the spark plug area, and one just below the exhaust port. If I look through, only about half of each hole is visible.





Here's a pic to point out the areas:










On a side not, the twin dizzy tension bolts are much thinner also. The twin dizzy tension bolts are just under 7mm, and the 13b tension bolt I measured was around 9.4mm. But the thread and pitch at the end is the same. Obviously much less thread, but none the less the same.

Originally Posted by Tommy12a

How did you get around this? I'm building a 6port 12a but have used early twin dissy housings and have come into the same trouble

Originally Posted by sen2two

I never did it. I decided on using a newer 12a motor. I put this motor away for a "one day" project and hung the twin dizzy front cover on the wall because it looks so damn cool.

Originally Posted by Tommy12a

Ok i think I'm going to just not run the two bolts that don't align and fill the holes with epoxy steel. Hope she holds up

Originally Posted by WJM ROTARIES

The holes that don't line up you can drill to suit the plates [irons ] I have fitted 12A rx7 plates on to a 10A rx3 motor and used a single dist electronic unit as well. Plus don't use the wasted bolts get some rx7 bolts ,the wasted ones don't hold tension as well and tension bolts to 30ft lbs not 22 which mazda recommend