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bcwrench · Joined: 21 Apr 2010 Posts: 4

I am getting back into a long term project (3 yrs so far) and wondering if anyone has done testing on the best place to put the knock sensor for the TEC3?

My application is a DART block with 4.125 bore and 3.75 stroke. It runs AFR heads with shaft mounts and a mechanical roller with 0.024 lash. Cam has some aggressive ramps and holds .755 lift. Manifold is Edelbrock Pro flow XT. It uses a Tranzilla manual trans.

Setup is running a ProCharger at 20 PSI (hopefully).

I used a Jerry Dorman stand alone knock indicator back in the early 90's but found it a bit before it's time and had varying results with it.

When I look at the different placements that GM used over the years, this could be a challenge. The setup is going to be a street app so pump is all that is available. For the most part using the sensor may be a long shot but I want to have as much in my corner as I can get.

dkGoodrich dot com · Joined: 18 May 2010 Posts: 159 Location: Frankfort KY

This may not help you as it sounds like you know this, but we always install our knock device at the top of the hottest cylinder via bolt or clamp.

Sounds like you have a real stout setup going, good luck with it!
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bcwrench · Joined: 21 Apr 2010 Posts: 4

DK,

Getting to know which cylinder is going to be the hottest is going to be the trick. To get it hot ya gotta lean on it and herein lays the problem, sort of like the hampster wheel.

I have ruled out the top end of the engine due to the aggressive ramps and large clearance. Due to the extra weight of the DART block I am afraid the drain hole may not be the ticket either but there are many more spots on the block. I was hoping that maybe someone had done some investigation over the years with similar combinations.

stevieturbo · Joined: 29 Aug 2006 Posts: 846 Location: Northern Ireland

With a valvetrain like that, and the supercharger there is going to be a lot of noise.

I wouldnt be hopeful that a knock sensor is going to be able to filter out that noise from actual detonation with great success.

Are you looking to actively use a knock signal, or just to listen manually for detonation ?
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bcwrench · Joined: 21 Apr 2010 Posts: 4

Steve,

At this point it looks like I may have to give up the idea of actively using the sensor, but I will at last see what it will do. I have to run it up on the test stand for a couple of heat soaks for the valve springs so I will hang a scope on it and see what I have.

The stove is for a customer so I am trying to build in as much goof proofing as I can. If the sensor can be factored in I will definitely do so but time will tell.

dkGoodrich dot com · Joined: 18 May 2010 Posts: 159 Location: Frankfort KY

The phormula knock boxes allow you to set thresholds, helps with those cars with a lot of noise in the top end.

Good luck with it!
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http://www.dkGoodrich.com
KY's Fastest Honda's, Acura's & Subaru's
Dyno cell with a 2010 Mustang Load Dyno.

Turboivo · Joined: 09 Mar 2006 Posts: 672 Location: Bulgaria

You need may be to check with J&S Safeguard. It uses knock "windows" for knock listening, so valvetrain noise could be distinguished.

stevieturbo · Joined: 29 Aug 2006 Posts: 846 Location: Northern Ireland

J&S might be your best bet. He might pop along soon to offer some help.

Certainly limiting listening to a certain window of crank rotation for each spark will help isolate possible knock from background noise.
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9.85 @ 144.75mph
202mph standing mile
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bcwrench · Joined: 21 Apr 2010 Posts: 4

Finished all my circuit checks this Saturday, so I will be firing it sometime this week.

I still have the Jerry Dorman setup, so I can mount it in different places and compare with the EMI position.

I expect this thing to make a lot of noise but one never knows, paticularly using aluminum heads. Most of my earlier stuff was Detroit wondermetal.

Since my coil pack is mounted remote of the DFU's I may have problems there before anywhere else.

John at J&S · Joined: 12 Nov 2005 Posts: 270 Location: GARDEN GROVE, CA

Use Delco sensor 10456082 for large bore. It has 3/8x16 threads. Screw it into an unused accessory hole on the end of a cylinder head.

A four channel Vampire could easily be connected. The control wires would tap into the four coil wires on the TEC3.

Six cylinder example here:
http://www.jandssafeguard.com/Instructions/Vampire_Instructions/3chVampireXDI-2.pdf