Porting Kenne Bell Twin Screws, Good or Bad?

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  1. #1
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    Default Porting Kenne Bell Twin Screws, Good or Bad?

    We obviously cannot force anyone to refrain from “diddling” with our superchargers, but we will not under any circumstances encourage or endorse ANYONE to “port” our products. So, let’s stop this right now, before it gets started and our customers waste a lot of money. First of all, “porting” will void the warranty and can create serious problems for our customers. We do not recommend changing ANYTHING on these superchargers. We perceive that to be our job. The Kenne Bell Twin Screw Superchargers are FAR more complex than porting Eatons, heads or throttle bodies, which are “child’s play” as compared to Twin Screw flow and temperature technology. What’s done to the Eaton’s or Lysholm’s is none of our business. Cast aluminum is rougher with MORE jagged edges than billet. Consider this: Our Twin Screws cannot be accurately tested for temperature, volumetric and adiabatic efficiency on a simple flow bench. Oops! Instead, testing and development requires a special 150HP flow bench with all the necessary monitoring sensors and the rotors SPINNING at 10,000-25,000 rpm UNDER FULL BOOST! Our Twin Screws can’t be accurately tested on a common static flow bench. The Twin Screw is an air compressor and not a “blower.” There IS a difference. One must fully understand the basic principles of the Twin Screw and the relationship between the rotating rotors under pressure and the inlet and outlet plates. For example: We use different CNC machined billet inlet and discharge passages for the various sized superchargers. And there are good reasons why part of the inlet plate opening is BLOCKED OFF and why we actually REDUCE the discharge openings on some models. “Rounding” certain areas will hurt efficiency, not help it. There is a before and after photo of a radiused discharge. Never do this to a KB - NEVER.Then there’s rotor length, helix angle, bore size, etc., etc. and how they affect flow AT DIFFERENT BOOST LEVELS and PRESSURE RATIOS. Simply stated, there is more to the Twin Screw than hogging out and rounding off openings and drilling some extra holes. We are perfectly capable of analyzing our own product modifications. We’ve “been there and done that” already. Our advice. Don’t let anyone screw with your Kenne Bell Twin Screw i.e. “porting” or “rebuilding.” We apologize for being so blunt, but our #1 concern at Kenne Bell remains our customers.

    P.S. No, “the Twin Screw doesn’t move a large volume of air due to a high pitch rotor design.” That is not true. Also, ALL blowers “run hot (hotter) when boosted up” and porting our Twin Screw doesn’t “reduce the heat” and “increase performance” - nor does it “add life” to our Twin Screw. We may all like to think there is some magic undiscovered porting science here, but - the choice is yours.

    Rebuilding? This requires special tools and fixtures. We use different rotor clearance depending on the kit. And your warranty isn’t affected.

    The Kenne Bell is 100% CNC machined billet parts. Who in their right mind is going to have someone grind on these precision flow passages?

    Do you really want someone grinding on your Kenne Bell billet Twin Screw?


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  3. #2
    Premium Member Array Eric Brooks's Avatar
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    Default Re: Porting Kenne Bell Twin Screws, Good or Bad?

    James, after how many miles would you recommend a KB to need a rebuild?

    Thanks
    Eric
    (60,000 miles on a KB)

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    Default Re: Porting Kenne Bell Twin Screws, Good or Bad?

    Quote Originally Posted by Eric Brooks View Post
    James, after how many miles would you recommend a KB to need a rebuild?

    Thanks
    Eric
    (60,000 miles on a KB)
    good question any answers?

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    Default Re: Porting Kenne Bell Twin Screws, Good or Bad?

    Quote Originally Posted by bsfixit View Post
    good question any answers?
    TTTTTTTT

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    Default Re: Porting Kenne Bell Twin Screws, Good or Bad?

    Generally a supercharger will last 80,000-120,000 miles but it just depends on how you use it. Some customers who just race will of course put more stress on it.

    Thank you,
    James

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    Default Re: Porting Kenne Bell Twin Screws, Good or Bad?

    Thanks James.! so how much is a rebuild when that milestone is reached? and what are the signs that the blower is on it's way out?

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    Default Re: Porting Kenne Bell Twin Screws, Good or Bad?

    A rebuild will generally cost about $699 in which we replace all the seal and bearings then clean up the compressor. Normally the seals will go out where you start to lose oil.

    Thank you,
    James

  10. #8
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    Default Re: Porting Kenne Bell Twin Screws, Good or Bad?

    I had my TB off to change the spark plugs on the pass side of the engine.. there was a small amount of oil inside the plenum.. I can see the back of the rotors .. is a small amount of oil there ok it was about a teaspoon of oil ..
    thanks

  11. #9
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    Default Re: Porting Kenne Bell Twin Screws, Good or Bad?

    Generally if it's in the plenum it is blow by from your PCV system. Are you losing oil in the supercharger?

    Thanks,
    James

  12. #10
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    Default Re: Porting Kenne Bell Twin Screws, Good or Bad?

    no no oil loss from the SC thanks James thats what I thought it was ..

  13. #11

    Default Re: Porting Kenne Bell Twin Screws, Good or Bad?

    James did not answer shet.

  14. #12

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    What about gasket matching the manifold ports to match ported heads? Why are the manifolds (for the 2v kits anyways) not gasket matched? I have a big step from the blower port to the gasket and head port. The head port is close to the gasket in size, the KB manifold is not - much smaller. There is a thread below discusing some considerable gains from gasket matching the manifold ports.

    https://www.modularfords.com/showthre...-2.1L-manifold

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