Moparts Tech Archive

Motor General

Porting

I have my reasons for what I say but if you insist here's an exciting picture of a stock 360 bowl with 1.88 intake

Now that you are feeling confident & have grinder in hand ( dangerous weapon with some ), you carefully grind away this excess metal to this point

Carefully blend to the 60 degree cut, to a measurement of about .160 inch in width with the carbide cutter, which you can see with the vernier here, blend off the sharpness with a 40 grit roller & final finish with a finer grade, make sure the 60 degree cut & bowl meeting point is smooth with no ledge or sharpness or else it will cause the air flow to be rough passing the valve, once you have finished blending the width of the 60 degree cut as shown with the venier should be about .130 inch

Here's a shot showing the 45 degree cut, which is about 0.040 wide, be very careful not to damage this area while working in the port, if you look carefully enough you can see the 60 degree cut outline

After a bit of goofing around maybe it will look something like this, it's a 318 bowl but I thought it looks pretty..LOL !

Further note, don't get adventurous with the short turn, just take the excess metal away VERY carefully & get a nice even smooth conture of the short turn, using sanding rollers

FastOne

Just looking at this stock 360 port again, you can see at the base of the guide there's a tail or hump of casting that swings to the right, it's quite generous in thickness as is the guide boss itself, taking metal from these areas helps, you can take that hump right out flush with the roof but on the opposite end intake port that has the short head bolt, you could get daylight through the roof near the guide because the bolt seat on top of the runner is cut quite deep, so it will probably be best to leave some of that hump there & play safe, I make a metal plug for mine & use a longer head bolt, then tack a dab of cast iron weld on the plug, though you could probably use a thicker washer & pack epoxy around it, if you wanted to go that far that is.

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