Windsor Super Victor – plenums, port forms & finishes Vs flow

[David Vizard]

OK - now I have pointed out how it is necessary flow with the relevant ports open i.e. the one on full draw and the one in overlap it is worthwhile to ask what all produces in the way of extra output. To be honest it has been difficult to put a firm percentage on the numbers likley to be seen. Much hinges on the amount of overlap involved.

Roger Helgesen's research here went a lot deeper than anything I did. He even build a special clear spacer with ports in it so he could see the smoke trace routs and probe the plenum for velocity maps. A lot of time consuming work but as far as the Victor Jnr was concerned it paid off. This Super Victor for my 427 build was the first time in 30 years I was not in a position to hand off a seriously high effort builds intake manifold to RH. (he has been gone two years now) so it was up to me to apply whatever I could remember from all his advice on the subject.

First of lets consider the finish. I have not polished an induction tract since about 1965. It has always been textured to some or other extent. The recent postings on surface finish prompted me to do some flow tests on a sculptured finish as produced by a course carbide burr and an unsteady hand (got the last bit of the equation here well covered).

From the pic below you can see that this intake is no beauty queen. Just a working piece using the surface finishing techniques of RH, Chad and Larry plus a few others with a similar mind set. tests were blow through with a 1050 cfm carb simulator and with 1.2 ports open.


The first test is a combination of a fine cast finish and 60 grit emery to take out the larger casting imperfections. Compare the average flow of this to the cuttered finish which delivered an average of 10 cfm more with only an imperceptible increase in area.

The next test was a full rework including the two adjoining ports that required a sharp edge. All this extra work was confined to the plenum. The ports them selves remained virtually stock area. Just as with cylinder heads preserving or increasing port energy is the way toward a higher specific torque output.Next tine around we will have a look at how the spacer interacts with the carb and manifold.

[David Vizard]

Would this be addressed the same way on SBC? Sharp edge on 7, radius on 5?

Gary,
Precisely!

[David Vizard]

Chad, Charlie, Larry (and whoever else may be viewing)

Forget the grade of skill involved here - what do you think of the results?????????????????????
DV

[Smoke ring]

Looks like some substantial gains David, some responded very well. Does the average gain give a fair prediction of expected power increase from this manifold?

[maxracesoftware]

Chad, Charlie, Larry (and whoever else may be viewing)

Forget the grade of skill involved here - what do you think of the results?????????????????????
DV

good gains !

were the Flow tests with any Carb Spacer(s) or Carb Spacer(s) + Carb bolted on ?

Carb spacers(s) will usually help Flow turn into Runner Roof area
-vs- just Flow coming off the sharp Carb flange in so quick a turn into the Runner's Roof area

[GARY C]

Chad, Charlie, Larry (and whoever else may be viewing)

Forget the grade of skill involved here - what do you think of the results?????????????????????
DV

What are the before and after dyno #'s?

[Boz-Race Engines]

thanks DV, this is a interesting subject, nice results for some fairly basic mods, i have yet to see a increase in power with a smooth finish over a textured finish on a carbed engine so far

[Carnut1]

20170725_063351.jpg

I think the gains are much higher than a simple surface treatment should show! This pic is an enlarged Bill C CNC 289 intake bowl and notice the surface the cutter leaves. I am betting the CNC surface is worth a few cfm and some power over a polished surface. This will always be a problem doing back to back testing because after a surface texture is applied the port is always a bit larger no matter how careful the ported is. This is very interesting to me and actually picks up on some wet flow work I was interested in in the 90's. There is more than one thing to keep in mind, airflow across the surface, fuel flow across the surface, the amount of liquid fuel, the evaporation rate of said fuel, the amount of heat transferred to the fuel and air due to different textures etc! I personally think the better your fuel prep the smaller the gains will be on surface treatment. If you have seen videos of fuel traveling through a plenum or runner the liquid fuel management need lots of work. I am doing a bit of work on my Ported 289 thread now with a very aggressive surface treatment. Thanks, Charlie

[Frankshaft]

I knew it would happen. I have been ditching and dimpling the floor of manifolds for YEARS. So, now, I suppose a certain someone will copy that, and within weeks, he will be credited for doing that. Instead of sanding some stupid diamond, or circle on the floor, my trade mark was the ditching and dimples, something that would actually do something if fuel puddled on the floor.

[Frankshaft]

I generally don't post pics of my work, for numerous reasons,

WP_20170522_22_29_06_Pro.jpg

[Frankshaft]

Mopar SB mopar .

WP_20170515_21_02_02_Pro.jpg

[Carnut1]

I appreciate seeing your work. I like the idea.

[cjperformance]

20170725_063351.jpgI think the gains are much higher than a simple surface treatment should show! This pic is an enlarged Bill C CNC 289 intake bowl and notice the surface the cutter leaves. I am betting the CNC surface is worth a few cfm and some power over a polished surface. This will always be a problem doing back to back testing because after a surface texture is applied the port is always a bit larger no matter how careful the ported is. This is very interesting to me and actually picks up on some wet flow work I was interested in in the 90's. There is more than one thing to keep in mind, airflow across the surface, fuel flow across the surface, the amount of liquid fuel, the evaporation rate of said fuel, the amount of heat transferred to the fuel and air due to different textures etc! I personally think the better your fuel prep the smaller the gains will be on surface treatment. If you have seen videos of fuel traveling through a plenum or runner the liquid fuel management need lots of work. I am doing a bit of work on my Ported 289 thread now with a very aggressive surface treatment. Thanks, Charlie

If concerned about the slight enlargement from the texturing,, try the opposite, texture, test , then smooth out the texture and retest!

[Frankshaft]

Since the cat is out of the bag, there will be documented proof that its my saying, lol, I call that a reverse turtle.

[Amilcar]

That`s about production engine based designs, turns, changes on CSA that will never be seen on max. performance purpose only design.
It`s clearly, not a discussion if it works or not, but how some ways of doing it, works better than another.

Yet, I swear I read around here something like : " if you know what you`re doing, textures are not applied" ...