Ported Victor 340 and Super Victor

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Earlie A

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Just finished porting the Victor 340 for NC Engine Builder's dyno test. First picture shows the stock intake with a 4150 carb gasket line in Sharpie. There is a lot of metal in the way that needs to be removed. Next picture shows the intake runners with a standard Felpro 1213 gasket line. As can be seen the stock intake runners are quite small, about 2 square inches. The gasket line is about 2.55 square inches. Edelbrock made the Vic 340 with porting in mind as shown in the third picture. The black lines on the roof of the port are on a fairly steep 'ramp' which is quite easily removed. In fact, enlarging the runner only requires blending 1 1/2"-2" deep into the runner. That's a good thing on the Victor 340 because the ports take a sharp turn after about 2" and it's impossible to reach some areas with a burr.

The third picture is an after shot of the inlet after enlarging the opening to the carb gasket line, blending/radiusing the entry to the runners and thinning the dividers. The entire manifold was roughed up with a single cut burr as a last step.

The final picture shows the finished ports, also with a rough burr finish. I chose to grind the ports all the way to the gasket line. I don't know if that's the best method or if leaving a little metal on the pushrod side of the runners would have been better. On ports 1,2,7 and 8 (the 4 outside runners) the air that is following the outside wall runs right into the pushrod bulge.

I thought the Super Victor was finished, but I'm going to go back and thin the runners and rough it up again. More pictures to come.

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Looks very good. I just don’t like how thin the sealing surface is for the carb gasket sealing up. Or is that an optical illusion? Kim
 
oldkimmer said:
Looks very good. I just don’t like how thin the sealing surface is for the carb gasket sealing up. Or is that an optical illusion? Kim
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It looks like he has protective tape over the carb pad.

That’s why it looks like it has too little gasket purchase.
 
Yep. Black Gorilla tape.

Here's a question for you guys who have ported manifolds. The leading edge of the dividers is getting down fairly thin, not knife edge thin but thin for a leading edge. In airfoil (airplane wing) design, the leading edge is rounded and the trailing edge is more knife shaped. I only did this because every one of the pictures I see from some of the well known porters are done this way. It is contrary to what 'makes sense to me'. On the flow bench sharp edges can cause problems, especially in high velocity areas. Velocities in this area of the manifold will be a good bit lower than around the valve, so maybe that helps.

What say you all?
 
It's been a minute since I was in fluid dynamics class, but I would think that a thinner profile would be preferred on the leading edge of the plenum divider. You are trying to divide the air as efficiently as you can, and a thin profile should produce less resistance to flow and subsequent turbulence down the port behind it. Remember that an airfoil or wing has a very different job than the divider, they are producing lift and have to have the longer path on one side. When you look at the tail surfaces that provide directional stability, they are thinner in cross section and more equal length top to bottom.
 
I'm not a porter, but heard Darin Morgan say that what you think that will work aerodynamically doesn't end up working a lot of the time.
 
gzig5 said:
It's been a minute since I was in fluid dynamics class, but I would think that a thinner profile would be preferred on the leading edge of the plenum divider. You are trying to divide the air as efficiently as you can, and a thin profile should produce less resistance to flow and subsequent turbulence down the port behind it. Remember that an airfoil or wing has a very different job than the divider, they are producing lift and have to have the longer path on one side. When you look at the tail surfaces that provide directional stability, they are thinner in cross section and more equal length top to bottom.
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Just thinking out loud here. I agree with you that the thinner leading edge would provide less 'resistance' because of the lesser frontal area. But I do believe a thicker rounded edge would be more forgiving and allow for better flow efficiency if the vane was not accurately aligned with the air flow direction.

A vertical stabilizer on a plane would still be thicker and rounded on the leading edge and sharp on the back, would it not? Unlike a wing the profile would be symmetrical side to side.
 
273 said:
I'm not a porter, but heard Darin Morgan say that what you think that will work aerodynamically doesn't end up working a lot of the time.
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Thinner leading edge needs to be more precise without adverse affects to adjacent cylinder if not perfectly shaped. More rounded leading edge is definitely more forgiving without being exactly what the engine wants. If we could only flow bench at 140+ MPH.
 
Earlie A said:
Just thinking out loud here. I agree with you that the thinner leading edge would provide less 'resistance' because of the lesser frontal area. But I do believe a thicker rounded edge would be more forgiving and allow for better flow efficiency if the vane was not accurately aligned with the air flow direction.
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Very well be more forgiving on alignment with a blunter front end. Makes sense to my feeble mind. Considering the tornado that's going on in the plenum, I'm sure that it is a very dynamic situation in front of every port entrance.
 
Here's the follow up pictures of the ported Super Victor. I didn't take before pictures, just after. I put a little bit more radius on the front of these runners. Width of the leading edge is around 1/8", maybe a little less.

Of the two manifolds, the Super Victor is the easier one to port. The dividers in the plenum are shorter and easier to access. The ports are almost 100% accessible with a 6" burr. Line of sight through each runner is so much better than the Victor 340.

Seems like the plenum volume may be less in the Super Victor. There is also less carb pad thickness, so making the transition/radius from carb to plenum has to occur quicker/tighter. Seems like the Super Vic may benefit from a carb spacer more than the Victor 340???

Super Victor is 1 1/2" taller than the Vic 340. Intake runners at the gasket flange measure 0.950 x 2.150. Different dimensions than the Vic 340, but roughly the same area.

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Looks great!!

“What I would do” is…….
Test both on the first set of heads in the shootout, then use whichever is better for the remaining heads.

My “expectation” is that on that build, the SV should prove superior…….but it’s not a given. That’s why you test.
 
PRH said:
Looks great!!

“What I would do” is…….
Test both on the first set of heads in the shootout, then use whichever is better for the remaining heads.

My “expectation” is that on that build, the SV should prove superior…….but it’s not a given. That’s why you test.
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We gonna need people to start donating gaskets, or money at this rate
 
PBR told me in the one conversation we had (which was specific to intake porting) that he rounded off the leading edges of the dividers. He made them thin, but round. I did the same. Have no back to back testing to verify the validity of one vs the other.
 
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