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 Post Posted: Thu Apr 21, 2011 1:54 pm 
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Got some questions about the finish on a head or intake runner. My heads were CNC ported by Cboggs @ RFD a few years back but NOT fully finished with a squirrel dick, ie, sandpaper roll. That machined finish left little lines all around the inside of the ports. If memory serves, and I can't remember where I read this, these lines are NOT suppose to be negatives with either air flow or fuel distribution. Having said that, is there really a need to use a squirrel dick on any intake or port work other than for cosmetic type stuff? What I mean is like Slowpoke says about fishing lures, ie, they are designed to catch FISHERMEN, not so much fish and yes, that slick squirrel dick finish LOOKS good, but is it really worth anything from a performance standpoint?

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 Post Posted: Thu Apr 21, 2011 5:20 pm 
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Ken,

I have flowed cnc ported heads before and after I smoothed them down with the cartridge roll and found no worth while gains. I've tried this on 3 or 4 sets of heads, now I don't waste my time on it.

Don

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 Post Posted: Thu Apr 21, 2011 6:26 pm 
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want-a-be wrote:
Ken,

I have flowed cnc ported heads before and after I smoothed them down with the cartridge roll and found no worth while gains. I've tried this on 3 or 4 sets of heads, now I don't waste my time on it.

Don


That's what I kinda figured Don. I've redone the old Dart intake with the funnel adapter for the 1050 carb by opening up the plenum about a half inch all around and was wondering if it would be worth while to "make it pretty". I guess not then, hey! ;-)

Did some porting on the old Dart intake lately. Here are the before and after results on the carburetor side. The other end is yet to come.

Here it is as it was when I got it back from Curtis.

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Here is what it looks like on that end now and I did hit it with a squirrel dick just for the hell of it. =;

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Still have some work to do on the head port ends.

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 Post Posted: Thu Apr 21, 2011 7:45 pm 
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Good lookin plenum Ken. Have you ever considered extending the runners farther into the plenum? Worth the time everytime I've done it.

Don

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 Post Posted: Thu Apr 21, 2011 8:50 pm 
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want-a-be wrote:
Good lookin plenum Ken. Have you ever considered extending the runners farther into the plenum? Worth the time every time I've done it.

Don


Would you care to elaborate on that a little??? :-k From what I've been told, most times shorter is better?? That Edelbrock Victor Glidden intake I have has runners that are about 4.5 inches long?? Then too, it's not working all that well about now. I'll admit though that I'm not through tweaking on it either.

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 Post Posted: Fri Apr 22, 2011 8:40 am 
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As you are looking into the plenum there. See the runner dividers? I've seen some pretty good increases in both the torque and HP numbers by welding extensions onto them. I usually use 1/4" aluminum cut a little different then what is in this pic.

Damn I hate trying to post pix on your forum [-( [-o< I know I know...use some link to post the pix and do it from there. Thing is though I don't use that kind of stuff. ](*,)

So here is the link to the forum I got the pic from.

http://speedtalk.com/forum/viewtopic.ph ... ght=plenum

Don

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 Post Posted: Fri Apr 22, 2011 11:27 am 
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What I did to this intake is similar to what another member (regal racer I think and there's pics posted on that one too) did to another type SBC intake that netted him some pretty decent reductions in ET along with gained MPH.

I've got data from running this intake for the first 2 years but the bad thing about that is that within a month or so the engine will come out of the Camaro on it's way into the dragster I bought last month. That will render that old info pretty much useless for a comparison.

From what I've seen so far I'd bet that engine goes in the dragster with that sheetmetal intake on it as numbers I got first time out show I'm way down on power from last fall and I'm pretty sure that jet changes won't get all that back. We were scheduled to go to Roxboro this evening but the weather has gone in the tank again so I guess we won't get out until next week. I've got a good bit of data from Roxboro so after a test there I'll know more about where I'm am.

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 Post Posted: Fri Apr 22, 2011 11:32 am 
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Wrong, it was BarryW that did that intake mod. Here is a link to that thread with pics.

viewtopic.php?f=9&t=7598

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 Post Posted: Fri Apr 22, 2011 7:21 pm 
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 Post Posted: Mon Apr 25, 2011 9:51 pm 
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Normally..the "real" use of a cartridge roll is to verify that everything is straight and flat. Of course...it can be used to make things pretty...if you want to spend money on looks instead of speed.

If the program is good and the cnc machine is tight.... the finish it gives is perfectly good. Don't waste your time with the rolls...


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 Post Posted: Tue Apr 26, 2011 9:08 pm 
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I gotta wonder if there are a lot of squirrels running around Virginia looking for thier missing johnsons. Thanks for making me laugh that hard.

As to the question. I don't think you need to pretty things up to improve anything.


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