modifying performer intakes

[xjs3667]

well since I had a few guys inquire about my little secret on how to modify the performer intake and the performer rpm intake. I figured I'd share it with the rest of you guys.

This modification will make the performer intake have the same horsepower/  torque curve of the performer rpm. And actually a little better low end torque. It will also make the the performer rpm the same horsepower/ torque curve as the the air gap, and will also give just a little more lower end torque as well.


What you do on both of these intakes is in the center where the carb bolts down, you mill it out 3'' across by 3/4'' down, by using 1'' carb spacer the hp/tq value on the performer will match the air gap also.

I got the idea after looking at the air gaps and how they were milled down like this from factory, it works great and very inexpensive to do, ti is a great way to bring a few more ponies back with out going out and buying a new intake

1st pic is what you start with
2nd pic is measurements and where you mill.
3rd pic is what it looks like all done

I know the 3rd pic is a intake for a 4.3 and the others are sbc but it was the only pic I could find, its what it will look like after you mill it. Like I said not to many people know about this.

[marshall]

Dyno papers please

[betterbeaters]

Dyno papers please

x2

[xjs3667]

Dyno papers please

Sorry I dont have em, I knew someone would ask     they went up in a fire we had at the shop, along with a lot of of other stuff, the whole damn place burned down.   I cant afford to get an engine dynoed, we had one at the shop, but I am going to be milling down a performer here real soon for a sbc that I am going to be building in the near future, so if anyone would like to borrow it and have a engine dynoed with it on before they mill their own, stop on by as long as I get it back and maybe a deposit or something ,

but the shop I worked at was a hypo shop all we did was mess around with and throw it on a dyno all day some stuff worked, some didn,t   but 3/4'' down seemed to be the magic number.

[85cHeavyMetalBogger]

thats interesting,how does it work?

[xjs3667]

if you remember the tv show suck, squeeze, bang, blow. They did an episode on this, from our shop its funny they filmed us and they just repeated everything we didwith tier actors lol, Im trying to find it they had the dyno results.  I'll post the vid when I find it

[xjs3667]

[84silverado]

i think imma do that when i put my new cam in...prolly make a carb spacer too 

[michigan maniac]

Looks like its worth trying !!

[BAD APPLE]

i did something simular to my performer II intake if you put the cab on and open the throttle up all the way you will see where part of the center is still exposed which doesnt alow the air to flow as well it kinda works as a wall that the air has to bounce around, little tip out engine builder gave us was to have it milled out so i took it to work and did it, couldnt tell you if it really made much of a diferance but our engine builder recommended doing it so thats what we did

[J.C.]

Sounds like you mkght as well buy an airgap with a spacer Have the same amount of money into machining unless you got a mill i would think.

[xjs3667]

Sounds like you mkght as well buy an airgap with a spacer Have the same amount of money into machining unless you got a mill i would think.

It shouldn't cost that much to have it milled down, they can do it in one pass  and its fast.  If you have ever ported your own heads, then you should have no problem doing this yourself,  just remember aluminum is soft, and its easy to get carried away with a cutting bit , I do it myself this way, and scribe a line where to stop, I stop just before I get to the line and use a small file to finish it.


one thing I am going to try different with this one is actually make the cross piece thats left on a ^  instead of it being flat might help with the air flow a little idk

[BAD APPLE]

I can do it for free the joys of working in a machine shop

[84silverado]

I can do it for free the joys of working in a machine shop

or the joy of having a bridgeport in the garage

[Rapid Transit]

that performer intake looks familuar... and iam deff gonna take it to work throw it up on the bridge port and mill it down ( also a joy of working in your familys machine shop). Thanks for the tip xjs!

[91 k1500]

this work on bbc intakes too?

[BAD APPLE]

this work on bbc intakes too?

yeah did it on mine

[Eroq]

might as well port & polish the intake too.... knowing edelbrock is rough as hell inside it...

[michigan maniac]

might as well port & polish the intake too.... knowing edelbrock is rough as hell inside it...

I heard they leave them rough so the air fuel will atomize better, and being totally smooth will actually hurt the performance,  



It is popularly held that enlarging the ports to the maximum possible size and applying a mirror finish is what porting is. However that is not so. Some ports may be enlarged to their maximum possible size (in keeping with the highest level of aerodynamic efficiency) but those engines are highly developed very high speed units where the actual size of the ports has become a restriction. Larger ports flow more fuel/air at higher RPM's but sacrifice torque at lower RPM's due to lower fuel/air velocity. A mirror finish of the port does not provide the increase that intuition suggests.In fact, within intake systems, the surface is usually deliberately textured to a degree of uniform roughness to encourage fuel deposited on the port walls to evaporate quickly. A rough surface on selected areas of the port may also alter flow by energizing the boundary layer, which can alter the flow path noticeably, possibly increasing flow. This is similar to what the dimples on a golf ball do. Flow bench testing shows that the difference between a mirror finished intake port and a rough texturedport is typically less than 1%. The difference between a smooth to the touch port and an optically mirrored surface is not measurable by ordinary means. Exhaust ports may be smooth finished because of the dry gas flow and in the interest of minimizing exhaust by-product build-up. A 300 - 400 Grit finish followed by a light buff is generally accepted to be representative of a near optimal finish for exhaust gas ports.

The reason that polished ports are not advantageous from a flow standpoint is that at the interfacebetween the metal wall and the air, the air speed is ZERO (see boundary layer and laminar flow). This is due to the wetting action of the air and indeed all fluids. The first layer of molecules adheres to the wall and does not move significantly. The rest of the flow field must shear past, which develops a velocity profile (or gradient) across the duct. For surface roughness to impact flow appreciably, the high spots must be high enough to protrude into the faster moving air toward the center. Only a very rough surface does this.

[Jthomas]

i got the intake and the mill!