Skydawg

long story, but I need a stock LS3 reluctor wheel attached to a stock LS3 crank pulley; it has to be precisely aligned with the stock internal reluctor wheel (cylinder 1 TDC aligned). also need a mount fabricated for stock crank position sensor to read the external wheel. Can anyone recommend someone that can fab this and test it to assure it works correctly?

G Atsma

If doing so, be sure to key the crank pulley to the crank to keep accurate time. Normally it is only pressed on with no position reference.

Skydawg

The stock ls pulley is keyed, I think I could just figure out position of the internal reluctor wheel in relation to the keyed pulley shaft and match 2nd wheel to that.

G Atsma

If I may ask, what us the 2nd reluctor going to be used for?

Skydawg

Back up second ecm.

MY_2K_Z

iTrader: (1)

The stock balancer is not keyed

G Atsma

See posts #2 and #3

G Atsma

Do you mean YOUR pulley is keyed, or ALL pulleys are keyed? If you mean ALL are keyed, that is not so. They are pressed on without a key.

MY_2K_Z

iTrader: (1)

See post 6, just kidding but yes I saw your posts but I was just reiterating that the stock pulley is not keyed from the factory

64post

iTrader: (5)

The aftermarket cranks have dual key way, never saw a stock one come with 2 key ways.

LLLosingit

iTrader: (4)

To get the pair to match 100% you'll have to make the external pickup adjustable and figure out a way to time them, It shouldn't be that hard. Won't you also need to do the same with the cam sensor and so on? I can't see any reason to ever need a second backup ecu.

Skydawg

I have 2 ecm's for redundancy, but they currently share same crank sensor which is a critical component and single potential point of failure....simply put, if the CKS signal fails, engine also does regardless of how many ecm's I have. Because I'm using stock GM E67 ECMs I need to use a stock reluctor wheel, or other compatible 58x steel wheel, so couldn't use aftermarket external trigger kits.
My idea was simply key the pulley and shaft at 12 o'clock position (or mark both shaft and pulley otherwise) when #1 TDC then match internal reluctor position with external reluctor position and somehow secure to back of crank pulley so both reluctors positioned identically. Then fab a mount for sensor which can be positioned anywhere along the radius (at least in theory ).

As far as CMS, I don't see any reason to modify that, but could always disconnect or unable it in calibration/tune to back up ecm and it would simply run on wasted spark operation.

My local machine shop or fabricator does not understand the LS3 enough to want to really do this so looking for other fabricators with capability to do it. Any suggestions for such a fabricator?

G Atsma

What sort of application is this being used for? NORMALLY CKS's don't fail that often, nor do ECM's. Is this a severe-use application?

MY_2K_Z

iTrader: (1)

Or an airplane? Seriously though what could possibly need 2 ecus? I've never had one fail?

Skydawg

It's an airplane and wanted a redundant system. Any one have recommendation for pulley fabricator?

Joystick

Holley has a number of them, but you need to change the damper, you can’t bolt anything to a stock damper.
https://www.holley.com/products/igni.../parts/556-109

Joystick

Thought you guys had magnetos. What kind of A/C is it for?

G Atsma

They do, but they are starting to come out of the Dark Ages.
Don't say this too loud, but lots of homebuilt and certified A/C are using EFI too. Baby steps.....

FormulaBoat

iTrader: (1)

Cool project. I like stuff like this. I installed dual pick up coils in the distributor of my boat, and had switchable ignition coils, mounted 2 HEI modules to a liquid cooled aluminum block of metal.

Most engines will run with either a failed crank or cam sensor (either, not both), as long as it happens once the engines starts and obtains synchronization between the two. It may not develop full power, but should run. It will not start with a failed sensor, or re-start with a failed sensor though.

But, if you wanted to, could you just machine the other side of the block to accept a sensor 180 degrees off? Then do the same with the cam sensor?

Skydawg

Thanks for input. I'm using a GM E67 ECM and engine shuts down when I fail the crank sensor even with operating cam sensor. I can not find a method in tune to keep engine running without crank sensor.

I also couldn't see an easy way to modify the block for 2nd sensor to use existing reluctor. Open and grateful for any/all suggestions. Thanks again.