[scalla]

I’m in the middle of throwing in a rebuilt 3.2 SOHC longblock. Slowly. I work on it 5 minutes at a time. Anyway, I recently came across a thread here where it was mentioned that early and later SOHC crankshafts are not compatible due to the change in ignition types (waste-spark to coil-on-plug). That all makes sense, but how can I tell if the engine I have from Engineworld is the one for my early system (93 Trooper)? Everything has swapped over so far, including the crank sensor. But the valve covers were slightly different, a few different mounting points compared to the ones on the original engine. Is there an indicator I can look for? Did I miss read and any year SOHC block will work? I’d hate to start over, but I’d hate more to get it completely reassembled before learning any bad news.

 

[Ed Mc.]

IIRC it's the number of notches on the crankshaft trigger ring for the ignition system crank sensor. The info I have says the early crankshafts ('92-'95) have 6 notches. And the trigger ring on these is cast integral with the crank.

'96-'97 3.2's, I'm pretty sure I remember Jerry Lemond saying that they have more notches on the trigger ring and are not compatible with the early ign system. The trigger ring is pressed-on.

So check the notches on your "new" engine's crankshaft trigger wheel, if the wheel has 6, you should be Good To Go. Beyond that, I'll defer to the 6VD1 experts! 😸

 

[scalla]

Thanks. That is the info I am looking for. This is going to be one nervous tooth count.

 

[scalla]

Thanks Ed Mc for the guidance. I count 6. Well technically the cylinder 1 TDC notch is a double gap, but that's how the system locates itself. Posting some pictures here in case anyone else needs to ever clear this up. Not sure what the coil-on-plug crankshaft pulse wheel looks like. But this is what the early style waste-spark (3 coil packs mounted on the ignition module) pulse wheel looks like.

First turn the crankshaft to the cylinder 1 top dead center (TDC) position by aligning the notch in the crank pulley/balancer with the zero on the timing belt cover.

Then remove your crankshaft position sensor and look for gaps in the pulse wheel when still at the zero position. Unless something is seriously wrong, you should have a double gap here. The double gap allows the system to tell the difference between cylinder 1 TDC, and all the other points in the rotation.

As you rotate the crankshaft 360 degrees back to zero (cylinder 1 TDC) you will count 5 single gaps like this.

In total you will have 6 points on the pulse wheel that excite the crank sensor. One of those points is a double gap, five of those points a single gap. Hope this helps.

 

[Buster28]

96 and newer use a 58x timing system, the 58 tooth reluctor causes the Crankshaft Position Sensor (CKP) to produce 58 pulses per revolution.