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Author
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Topic: would it be worth home porting/polishing stock 351W heads?
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Dubz
Gearhead Posts: 2005
From: Manitoba Canada
Registered: Oct 2002
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posted 10-01-2003 07:14 PM
 
Next spring i was planning on having my heads pulled off the engine, and getting them milled. I now have a air compressor and die grider, so wondered if it would be worth cleaning up some of the casting flash on the heads, just to help flow for now until i can get new aftermarket heads.Worth it or waste of time??
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69stanger
Journeyman Posts: 77
From: Northridge, CA
Registered: Aug 2002
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posted 10-01-2003 09:35 PM
well if there already off might as well get rid of the exhaust hump and casting flaws.
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CHIPSBAD67
Gearhead Posts: 396
From: LOU,KY;USA
Registered: Sep 2003
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posted 10-01-2003 10:40 PM
be sure and do your grinding first, then machine shop work. dont wanna nick a new valve seat. ------------------
306, 4speed, 4.11's....best 1/8 mile 7.58 at 92mph with 1.72 60ft. PUMP GAS/NO ADDERS/STREET TIRES
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JCQuinn@work
Gearhead Posts: 998
From: Lakewood, CO, USA
Registered: Jun 2001
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posted 10-02-2003 10:13 AM
Most of the easy gains from porting are found in the bowl area just under the valve. You will find a ridge where the seat cutters intersect with the cast port. Smooth out that area by removing the ridge with a carbide cutter and clean it up with a cartridge roll. The other big gain is narrow the intake guide boss by removing as much material as you are comfortable with from both sides. Cut down the front and rear of the giude boss also but the sides give the most gain.On the exhaust port do the same ridge removal where the cutter intersected the casting and try to contour the port roof into a constant radius through the guide area. It does not help flow to lower the port floor on eother the intake or exhaust. Both will respond well to raising the roof but do not exceed the size of the gaskets you are using. The exhaust port like a "D" shape with the top of the port the rounded part. Don't spend much time on the curve around the pushrod, just try to make a smooth radius. You won't gain much flow there. Enjoy
John
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