LS engine reluctor / timing wheel

[induction apprentice]

does anyone know of a ls reluctor wheel installation tool available for 8 or 9 bolt crank flange configurations?

Secondly, Can anyone explain the importance of wheel index to me and if the computer would be able to validate tdc off the cam sensor if it see's a relationship error or if the cam crank wheel position is critical on 24 or 58 times wheel and if so how many degrees of installation error is allowed if any etc....

Finally if anyone has had horizontal or radial runout ever cause a running issue?

I am not looking to see how sloppy I can be with it. Just looking for peace of mind with any knowledge to be gained here. Every LS I do I shake in horror until all is done and over with hoping there is no error or problem associated with wheel installation. I'm hoping a discussion will relieve my reluctor anxiety?

[peejay]

The computer does not validate TDC from the cam sensor... the computer assumes the crank wheel is accurately installed. The cam sensor is a "coarse" sensor not used for position determination, but just so the computer is working on the correct half of the firing order when it fires the coils and injectors.

I haven't seen a sloppy timing chain cause errors/no start conditions (if you scope the cam and crank signals, and compare them to known good, you can determine timing chain slop to a remarkable degree of accuracy) but bear in mind that any misalignment of the crankwheel will cause your ignition and injector timing to be off by that many degrees.

[Caprimaniac]

I assume you use Stock LS ECU?

No, I don't know much about that Box, BUT I know alot of the aftermarket ECU's have quite a large window for installation "error"- crank degree- wise.
You set ignition to fixed number of degrees, and then after starting the engine, adjust the setting of TDC point to make actual timing = set timing. Maybe that is an option for ECU- software for the LS box too.... No idea, but some(one) on here knows.

I'd like a reluctor flywheel for my SBF, then less thinking and taking up less Space at the front. Who makes one?

[tjz450]

I'm on my phone, so I don't know yet how to grab a link from another website, but go to LS1tech.com forum-- "Generation IV Internal Engine". Do a search for "Reluctor Wheel Shift". That may get you started. Lance is very knowledgeable.

[tjz450]

Indexing the wheel is the biggest question I had. I installed a wheel without the over priced and patented tool. The inference fit to to crank is low, too low in my opinion. On the parts I measured, anyway. So would never recommend reusing a wheel, new ones are cheap.

[induction apprentice]

Let's say I get a build from another shop and I am supposed to get it running but it has a ignition problem. I want to confirm mechanical positioning of the reluctor wheel?

Can I put the motor on tdc #1 and look through the crank sensor hole to see the wheel notch or something to that effect to confirm it's position without removing the crank?

[peejay]

Crankwheel slip is a not uncommon issue on not only the V8s but also on some of the 3.6s, from what I have seen from tech bulletins.

Since there are no timing marks on the damper (how could there be? no keyway!) all you could really do is put a 2 channel scope on the cam and crank sensors and compare the waveforms with "known good".

If you wanted to get fancier than that, a better way would be a 2 channel scope on the crank sensor and a pressure transducer in one of the cylinders. The pressure transducer WILL tell you where TDC compression is on that cylinder. As much as I would love to have one, I still haven't quite had enough want to justify the expense, although I don't see why I couldn't bung an A/C pressure sensor and an old spark plug together and rig up a 5 volt reference voltage to make it work.... Would be a hell of a lot cheaper than the ready-made offerings cost!

If you didn't have a "known good" to look at (iATN has a lot of waveforms to look at but as it is all user submitted there are gaps) you could make your own reference by first scoping crank sigal vs. the pressure transducer, and then set whatever computer is controlling the engine to fire the plugs at 0 degrees and scope the crank sensor and an ignition probe, then compare the waveforms.

[ijames]

Crankwheel slip is a not uncommon issue on not only the V8s but also on some of the 3.6s, from what I have seen from tech bulletins.

Since there are no timing marks on the damper (how could there be? no keyway!) all you could really do is put a 2 channel scope on the cam and crank sensors and compare the waveforms with "known good".

I'm not any kind of expert on this but couldn't you rig up a pointer to the damper then use a piston stop spark plug and mark the damper with paint as you approach tdc from each direction? Then measure halfway between the marks to get tdc, and use the damper diameter to calculate how far over for the timing at idle and check that with a timing light. The damper shouldn't move just cranking and idling a few times, and you can check it with the stop again afterwards to make sure that it didn't move.

[induction apprentice]

finding tdc and wiping a mark on the dampner is what I am thinking. From there, My question is. Does anyone know where the crankshaft position should be in relation to when the wide notched area on the wheel is lined up with the crank sensor hole. That way I could just look through the hole as a quick reference to know if it is at least within a few degrees?

[tjz450]

Did you find my reference to the posting at LS1 tech? I don't have my notes here, but off the top of my head... you will see the 14th tooth centered in the "window" of the Crank Sensor with #1 cyl at TDC. The 14th T is after the space. CW looking forward. Mark that tooth with paint. In addition, with the flange dowel hole positioned at 12 o'clock check to see if the triangle holes of the TW are at 9 o'clock and 3 o'clock.

[tjz450]

The ECM is looking for the 14th tooth. Lance from PanteraEFI prefers the 13th tooth. The space would be close to the top of the block, very tough to see. HTH.

[induction apprentice]

I did follow up on the link and found it. Thank's everyone.

Very much answers my question and clearly critical information for any of us in the engine trade.

Cheers!