Started porting today, surprised to see a wide variance in diameter. My manifold had been Extrude Honed some time ago by the prior owner. First picture shows a 35m ball sitting in an IH runner:
Here is the first runner, I need to hit the short turn radius and the 35mm ball should fit through, then lots of cleanup with a flap wheel to try and smooth out the surface.(this will be tough to reach, any advice would be appreciated).
I just picked up a 36.5mm ball and checked the "ported" IHs I bought from Uncle Robin. In some cases the 36.5mm fits in much like yours and some other runners it only goes half way. I borrowed Pete's 35mm and I get a similar variation in runner porting. Think I am going to buy a
36mm foosball and go in steps to 36.5mm. I am also thinking of using a small cyl honing stone and see how that works. Also bought a variable speed control for my electric grinder.
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92 Black Rose/Black ZR-1 #458
92 Aqua/Grey ZR-1 #474 SOLD
84 Xfire Z51SOLD
The 35mm balls that I have(that sounds bad) were labeled on the package..of course Dominic, being Italian,(and I married into a family of Italians) had to prove he had bigger balls than me and found a pair of 36.5mm, (I think it said so on the website).
Corvette Store
Porting; Lessons variance in EH plenum
