VR Sensor & Trigger Wheel Mounting Information Discrepancy

EDIS and Megajolt installation related topics. Be sure to review the <a href="http://www.autosportlabs.net/MJLJ_V4_vehicle_installation_guide">Vehicle installation guide</a>

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Pantera
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Joined: Sun Aug 01, 2004 6:40 am

VR Sensor & Trigger Wheel Mounting Information Discrepancy

Post by Pantera »

I hope that someone can clear up a discrepancy in the way that various sources say that the VR Sensor should be mounted in relation to the missing tooth on a 36 tooth EDIS trigger wheel. At the outset let me clarify that what I am asking for are Ford's intended EDIS design parameters.

BrentP states, in this web-site: "With the Engine at TDC, the sensor should be positioned 'N' degrees before the missing tooth. Make sure you take into account the rotation of the engine- clockwise or counterclockwise when determining your sensor mounting".

However, in another web-site ( http://www.dainst.com/info/edis/edis.html ) the author states: "On all EDIS installations, the missing tooth of the wheel is directly opposite (180 degrees) the VR sensor when the engine is at the above TDC value ('N' degrees). This means your crank wheel needs to be aligned on the damper such that when the engine is 'N' degrees BTDC, the missing tooth is located 180 degrees away from the VR sensor".

You understand my confusion. I'm hoping that someone can clarify this matter for me.


KITT
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Joined: Thu Aug 26, 2004 6:53 pm

My understanding

Post by KITT »

I was told by a fairly well known engine builder that the way to do it is such (assuming EDIS 4):

1) fix VR sensor to where ever's most convienant. Doesn't matter where.
2) find TDC of the engine
3) rotate engine until it's 90 degrees BTDC
4) align missing tooth with VR senor
5) fix toothed wheel in place

I will add I've not actally fixed mine in place yet, but will do this this weekend.

Matt

Luca Lagonigro
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Joined: Sun Feb 29, 2004 9:23 pm

Sounds good to me, at least t

Post by Luca Lagonigro »

Sounds good to me, at least this is what I was intended to do for my insallation.

Pantera
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Joined: Sun Aug 01, 2004 6:40 am

My Understanding - is BrentP Wrong ?

Post by Pantera »

KITT, so what you're saying is our moderator, BrentP, is wrong in his VRS - trigger wheel mounting instructions. (BrentP, please comment...)

Your description, although 180 degrees different, is consistant with the second description in my posting of yesterday:

"On all EDIS installations, the missing tooth of the wheel is directly opposite (180 degrees) the VR sensor when the engine is at the above TDC value ('N' degrees). This means your crank wheel needs to be aligned on the damper such that when the engine is 'N' degrees BTDC, the missing tooth is located 180 degrees away from the VR sensor".

With a waste spark system, such as EDIS, this 180 degree difference won't cause a problem as the two plugs that get ignited at the same time, fire 180 degrees apart.

KITT
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Joined: Thu Aug 26, 2004 6:53 pm

Same as Brent's

Post by KITT »

Nope, read my description again. It's the same as Brent's. The missing tooth is pointing to the sensor when the engine is 90 degrees BTDC.

I think it does matter which way you do it because even through it's a waisted spark setup it'll fire 180 degrees out (unless you connect your HT leads up differently).

regards

Matt
PS bloody confusing isn't it!

Paratime
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Joined: Sat Apr 17, 2004 12:47 am

Third Degree

Post by Paratime »

Both Brent's and Kitt's mounting instructions result in the sensor being mounted in the same place, in relation to the wheel. Just two different ways to describe it.

The confusion about the instructions from "dainst.com" is the statement they make:

"On all engines the complementary coils are connected to the cylinders that are 180 degrees apart in the firing order"


That is 180 degrees of camshaft rotation. Cam rotates once per firing order. BUT... The crank rotates TWICE, or 720 degrees. Complimentary cylinders are 360 crank degrees apart in the firing order.

Since distributorless ignitions have no input from the cam, all our degree measurements should be in crank degrees.

Now the confusing part. Both 4 and 8 cylinder cars have a set of cylinders that are 180 crank degrees opposite another set of cylinders.

Example: firing order 1,3,4,2 If cylinders 1 fires at TDC, so will cylinder 4. They are a pair. Cylinders 3 and 2 will fire at BDC, or 180 crank degrees from the other pair.

SO... both installation systems will work, one will just require the coil packs to be renumbered as to which cylinder they connect to. However, this is not the case with V6 engines.
Therefore, one of the guys running a V6 setup will have to give the final answer as to whether the missing tooth should align with the sensor, or be opposite it.

Wow, that made my head hurt.

Josh_b
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Joined: Sun Feb 29, 2004 9:23 pm

it confused me for a while!

Post by Josh_b »

the way i did it was to mount the wheel so the middle of the missing tooth was TDC, then i mounted my sensor 90deg from it (edis4)

rondefly
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Joined: Wed Apr 21, 2004 1:59 am

it confused me for a while also

Post by rondefly »

Josh, doing it the way you did would it matter if the sensor was 90 degrees BTDC or ATDC on edis4?. I am getting confused on the TDC location of before or after. On a clockwise engine I assume BTDC would be at 3 o'clock and not 9 o'clock if the TDC is straight up.

Ron Triano

Pantera
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Joined: Sun Aug 01, 2004 6:40 am

This is where the confusion arises from.

Post by Pantera »

KITT, your installation instructions and Brent's installation instructions ARE DIFFERENT. Ron picked-up on this too.

Using Brent's method, the VRS would be "N" degrees BEFORE the missing tooth on the trigger wheel. Using KITT's method, the VRS would be "N" degrees AFTER the missing tooth.

This is the source of my confusion. An EDIS-4 installation will work either way (which only adds to everyone's confusion) as moving the VRS by 180 degrees from it's design location has no effect, but an EDIS-6, 8 or 10 installation definitely won't work both ways. As my application is EDIS-8, the correct answer to this question is critical.

Paratime
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Joined: Sat Apr 17, 2004 12:47 am

Before and After

Post by Paratime »

No, Kitt's method has the sensor 90 degrees Before TDC as well.

Brent's- Put Engine TDC, put sensor 90 degrees before missing tooth.

That means that when you rotate the engine backwards 90 degrees (90BTC), the missing tooth and sensor are lined up.

Kitt's- Put engine at 90BTC and line up sensor and tooth.

Same thing.
The web-site http://www.dainst.com/info/edis/edis.html is different.

Pantera
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Joined: Sun Aug 01, 2004 6:40 am

Re: Before and After

Post by Pantera »

Paratime, you stated:

"Brent's- Put Engine TDC, put sensor 90 degrees before missing tooth.
That means that when you rotate the engine backwards 90 degrees (90BTC), the missing tooth and sensor are lined up."

I think you're wrong. If you are looking at the front of the engine, the missing tooth and TDC would be at 12:00. The VRS (according to Brent) should be "N" degrees BTDC (which would put it at 9:00 assuming an EDIS-4 setup). If you rotate the engine to "N" degrees BTDC, you are moving the trigger wheel clockwise, which moves the missing tooth further away from the VRS, not closer.

brentp
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Pantera, I think you have it

Post by brentp »

Pantera, I think you have it correct- I may have mine set up opposite of the instructions on http://www.dainst.com/info/edis/edis.html . It coincidentally works correctly due to the nature of the EDIS-4 modules.

I'd like to see an EDIS-4 installation that has it installed according to the above instructions.

Brent
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Paratime
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Joined: Sat Apr 17, 2004 12:47 am

Clock Watchers

Post by Paratime »

Does the engine normally run clockwise, or counter clockwise, when viewed from the front?

rondefly
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Joined: Wed Apr 21, 2004 1:59 am

clock watchers also

Post by rondefly »

This is my confusion also. with a clockwise engine is BTDC clockwise or counterwise? i would assume it is counterwise. but Brent said clockwise.

Ron Triano

KITT
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Joined: Thu Aug 26, 2004 6:53 pm

Clockwise

Post by KITT »

My engine (a Ford 2lt Pinto) spins clockwise when looking at the front pulley. I believe pretty much all engines, except Hondas, spin this way.

I fitted my toothed wheel yesterday using the method I described and it works great. I'm very certain that the way Brent's described it is the same as mine. Best thing is to stop talking about it and do it! Worst case you get the timing 180 degrees out and you have to move the toothed wheel or sensor round.

cheers

Matt

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