Author Topic: Porting Small block heads  (Read 802 times)

Offline asm74

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Porting Small block heads
« on: July 31, 2008 - 11:43:57 PM »
Im trying my hand at porting my old 73 318 heads.  So far I have the ports gasket matched pretty well, but I can't seem to get down into the runners as far as most others that I've seen, my grinder tips just don't reach.  I've tried the dremel, still too fat to get down in there, and I even borrowed a friends flex shaft, which even if it did fit (which it doesn't...) would be really hard to control.

On big block heads I imagine this is not so much a problem with the larger ports, but what is the secret tool for small block ports?

Thanks! 
 
73 Challenger




Offline 71chally416

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Re: Porting Small block heads
« Reply #1 on: August 01, 2008 - 12:31:57 AM »
I have several extended reach air die grinders similar to this. You can get them from Northern tool or Harbour Freight. Using a dremel tool to try to port cast iron heads is about like using a push mower to cut the grass at the Augusta golf course.  :D
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Offline Jacksboys

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Re: Porting Small block heads
« Reply #2 on: August 01, 2008 - 12:44:12 AM »
 :popcorn:
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Offline Chryco Psycho

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Re: Porting Small block heads
« Reply #3 on: August 01, 2008 - 03:01:38 AM »
I use long shaft carbide cutters with 3-4" shafts

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Offline 422STROKER

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Re: Porting Small block heads
« Reply #4 on: August 01, 2008 - 05:17:52 PM »
I use long shaft carbide cutters with 3-4" shafts

This is what I used, got one from Summit.  Also got a sanding roll kit too.  Used just a straight Air grinder.

Tom :2thumbs:
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Offline asm74

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Re: Porting Small block heads
« Reply #5 on: August 01, 2008 - 11:40:41 PM »
Thanks for all the replies.  I picked up an extended length grinder today, and some cartridge rolls.  Seems like it will work, as long as the mandrel is long enough.  The shaft still doesn't fit into the port (but the chuck does).


Update:

I tried out one of the sanding rolls on the mandrel that came with it.  I test fit it and it looked like it was going to do the job.  Hooray! 

Then I turned it on, and the sanding roll and half the mandrel came flying off!!!! darn thing snapped in two inside the intake runner!!!!
maybe I didn't have the roll snug high enough, but shouldn't those things be a bit stronger?   It came from harbor freight in vallejo, i'll see if I can return it.

 :banghead:
« Last Edit: August 02, 2008 - 12:02:09 AM by asm74 »
73 Challenger

Offline LAA66

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Re: Porting Small block heads
« Reply #6 on: August 01, 2008 - 11:59:17 PM »
 Mines a 70, 340 so not sure if this is relevant. I just trimmed the push rod bulges a little and matched the port openings to the manifold. That was about as far as I could get or feel comfortable with the power tools. Also sanded the casting flaws and rough spots I could reach by hand. :2cents: