Crank Position Sensor

matthud

I am using one of the new 2.2L that has the 60-2 crank wheels in a project. I believe is the same setup as the 2.4L uses. Does anyone happen to know what the crank position offset is between the gap in the wheel and TDC power stroke?

si_c1978

gm nearly always use 114deg offset with the 60-2 setup,

im not sure what the british name of your engine is mines z20net its bin strobed up and it runs fine.

love the vette by the way! im not usualy a u.s. car fan! :thumbup:

winstar

I would expect it's the same crank as the Z22YH so Vocky may know as he's just fitted one to his car

si_c1978

more than likely 114 btdc then

exmantaa

And the 114* BTDC is measured on what point (teeth) exactly ?
(middle 1st missing tooth, or what? Also heard about 117deg...)

notsure.gif

si_c1978

yeah that is also what i was also told, however if you are using missing tooth setup like most it will be 114* btdc, i believe 117 would be a rising or falling edge setup.

i had 117* when i went to tipton rollers and it strobed up 3* out. :thumbup:

(incidentaly 3* is half a tooth)

exmantaa

So to clarify this: <u>114° BTDC should be measured on the centre of the 1st missing tooth??</u>

Or what's a bit easier to measure, the centre of the 1st new tooth after the 60-2 gap should be 114°-6°(2nd missing tooth)-6° = 102°btdc?
I have my LSJ engine crank lined up like this and will verify the 102°.

(How did you verify this on the rollers? Just set ignition at 0° advance and strobe the pulley mark? And with 3° (advance/retard?) your 117°btdc set-up lined up exactly with the TDC mark?)

si_c1978

yep middle of first tooth,
someone checked it for me before we put it on the rollers,
it was strobed up to the timing mark on the pulley, i was running 117 but had to set it to 114 before we could continue.
mine is just setup to read first missing tooth (very basic i know!)

si_c1978

aaah i see what your getting at i think, i was supposed to be working :lol: ...... are you running fixed advance?

on ms2 you run 114* + the stated advance on the ignition advance table, which governs itself using a map and rev based table. mines setup quite safe at the bottom with +10* advance and towards the late 20's at high revs. (which is probably a bit hairy!)

exmantaa

I have some US LSJ ecu's (programmable with HP tuners), and to use the available SC maps the 60-2 timing for these need to be set-up according GM specs. There ecu has a special relearn procedure that will sort out small deviations, but the VR sensor must be close to OEM timing.
Have a complete LSJ engine, so can check if this matches the 114* set-up.

Update; getting confused now. Printed a nice degree wheel and put it on my 2.0 LSJ crank:

Zeroed degree wheel on TDC mark => 0*
Rotated LSJ crank clockwise till lined up on centre 1st tooth after 60-2 gap => ₁₁₉* BTDC (??)
Rotated crank further clockwise till TDC mark pulley => 0* check; OK
Checked TDC mark on pulley through plug => highest point on cil 1; OK

**So my 2.0 LSJ engine has the centre of the 1st tooth after 60-2 gap on 119* BTDC, so centre of 1st missing tooth is around 131* BTDC. **
This doesn't make sense with the 114* or 117*BTDC numbers and don't think the 2.0LSJ trigger timing is clocked different than the identical Z20NET or Saab 207 crank... notsure.gif notsure.gif

matthud

It turns out that the US 2.4L LE5 and the 2007+ L61 2.2L that use the 60-2, are actually 72* BTDC on the gap.

si_c1978

most confused! ah well mines ok!
there does appear to be something funky with the many members of this engine family!
just to really confuse things whats the offset for the z22se 7-1 wheel?
i know rik1083 used it.

si_c1978

oh and on aftermarket you can to some extent put any figure you want to in, making this quite a dangerous topic!
we dont want any knackered engines!

exmantaa

Did some digging and for the** Z20LET** (iron VX 2.0-16V lumps) the centre of the 2 missing teeth are at 126* and 120* BTDC, meaning the 1st new tooth after the gap is at 114* BTDC (rotating crank clockwise)

(Edit: The MS manual also states that the VX 60-2 timing is set up at <u>114* for 1st new tooth after the gap</u>)

@Matthud; On US forums I read that the US 2.4L LE5 and the 2007+ L61 2.2L that use the 60-2 timing is 12* off compared to the 2.0 LSJ crank timing. That does not correspond with your 72* BTDC on the gap... notsure.gif

si_c1978

that all makes sense.
good digging! :thumbup: