I'm new here and hoping someone can confirm or disprove my dimensions. Long story short is I run a CNC machine shop and rarely do Mazda work but someone mistakenly took on a job that I would have turned down. So here we are and I intend to make good on accepting the job.

The customer sent a waterjet flange for me to get dimensions from. Upon probing the flange I determined it was either cut on the world's worst waterjet or was drawn by a school child. One of the exhaust ports is almost and 1/8" off to the side of the bolt hole line. I do know that the 2 bolt holes and the exhaust port centers are supposed to be co-linear. So right off the bat that draws suspicion to any dimension taken from the flange.

So between a 13B flange, the internet and what looks like round metric numbers, I came up with what I believe it should be. Note one wire-frame is the pipe side with receiver groves and the other wire-frame is the engine side.

Thanks in advance for any help you can offer.

 

i'm not sure what the customer wants, but i would imagine the exhaust ports should be the same size?

also it says the dimensions are in inches, but they aren't unless this is a really big engine

 

It was just a quick drawing I threw together rather than using a cocktail napkin. The two wire-frames are not the same scale either despite the drawing being labeled as 1:5. But I digress, the dimensions called out are in mm. Also the exhaust ports are all the same size, a closer look at the drawing will reveal the larger dimension being a receiver grove for pipe.

 

instead of those x-bar cutouts between the port openings, it seems to me you're better off getting that top edge of the flange as far away from radiating exhaust heat into the aluminum lower intake manifold as possible: