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Messing around with some intake porting...

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Nikkormat View Drop Down
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    Posted: Jun/18/2017 at 9:59pm
I've been messing around porting a stock 70 390 intake for this "budget" 401 I've been building. With 4 hours of work the ports have really opened up. What are your critiques of my work on these ports?

Unported side:

Ported side:
74 Cherokee S - 401, Quadratrac, Th400, 416k Miles and Counting
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Post Options Post Options   Thanks (0) Thanks(0)   Quote mixed up Quote  Post ReplyReply Direct Link To This Post Posted: Jun/19/2017 at 1:28am
there looking good are you using the gasket as a template I know when I ported my torqer I opened up the ports quit a lot also look at the water ports on the heads and intake there's lot of room for improvements there
69 amx 290 auto
65 220 290 4spd
80 ford fairmont
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Ken_Parkman Quote  Post ReplyReply Direct Link To This Post Posted: Jun/19/2017 at 7:12am
What is the casting number on the intake?
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Nikkormat Quote  Post ReplyReply Direct Link To This Post Posted: Jun/19/2017 at 10:49am
3185532C, same as a rebel machine intake however this has individual throttle bores on the carb flange instead of the tow ovals like a true rebel machine intake. Is does however have the same larger runners of the rebel machine intake as is visible up near the cast in firing order cast into the intake. The "pocket" between the carb flange and the firing order area is noticably smaller.
74 Cherokee S - 401, Quadratrac, Th400, 416k Miles and Counting
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Ken_Parkman Quote  Post ReplyReply Direct Link To This Post Posted: Jun/19/2017 at 10:13pm
The 5532 is a very good intake, shockingly good actually. The problem with a dual plane is you cannot really do much with a gasket match as you cannot reach the rest of the port to bring up the CSA all the way through. One thing that will help is take the sharp edges off the bottom of the plenum barrels where it transitions into the runners. Those edges really disrupt the flow. There were 2 Machine intakes, the first being the 5532 casting with the plenum machined into a open split (which you can do), and the later 3199762 casting which had a cast split plenum with nice cast radii into the runners.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Nikkormat Quote  Post ReplyReply Direct Link To This Post Posted: Jun/19/2017 at 10:33pm
The carb flange is the next stop!

There was a lot of material in the top of the ports that I've been able to remove. I think most of the gains will be seen there. Most of the runners have about 3/32 of material on the walls. The bottom plane runners had more like 1/4" of material on the "elbow" on the ceiling of the port. Most of the work has been bringing that in to match the profile on the outside of the manifold.

Whatever happens, it'll beat the crap out of my offy dualport on my other 401! And even it revs to six grand quite nicely...
74 Cherokee S - 401, Quadratrac, Th400, 416k Miles and Counting
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Dbouzas Quote  Post ReplyReply Direct Link To This Post Posted: Jun/21/2017 at 3:02pm
https://www.youtube.com/watch?v=2UfZXXrrPTk

here's a video of single and dual plane intakes, to help decide which can be better for different applications
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