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View Full Version : Mid section exhaust port sizes.



madgadget
09-04-2014, 05:49 PM
My SST120/XR2 powerhead has larger exhaust ports than my 79' v6 mid section does. This image shows what I mean:

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You can see the carbon around the edge of the ports where the ports look small (this is just a mid for sale, that I use as an example)

This has to be damaging to power I'd have thought? Since 1/5th of the gasses hit a solid face and will cause turbulence. I just wondered what year/age midsection etc has the right size ports? I have a 91 135 black max and also a XRi EFI, but I think both of those also have the smaller ports?

Would love to know what is the best option here.

Eagle One
09-04-2014, 08:36 PM
yep the 150's are rectagular the 200's are square. You can either change the top plate to a 150 style or take a die grinder and a base gasket and match it. common thing.