Bazzman Posted December 8, 2022 Report Share Posted December 8, 2022 Just wondering if this scope is normal or is trigger 2 odd? For some reason in my mind I would've thought they would all be the same length as the teeth are all same size. If it is O.K any ideas on cam pulse window sync tooth? Currently at 1 with 50 degree swing, starts and runs fine every time but to me it is very close to a cam tooth on either stroke having a chance of being in the window. Trigger escort.llgx Quote Link to comment Share on other sites More sharing options...
Adamw Posted December 8, 2022 Report Share Posted December 8, 2022 That is not one I have seen before, what is the engine? Using cam level sync on tooth 30 would allow the cam to move about 60deg advance without getting into trouble. Quote Link to comment Share on other sites More sharing options...
Bazzman Posted December 8, 2022 Author Report Share Posted December 8, 2022 It's essentially a mazda 3/ford duratec vvt cam with 6 teeth all over the place but using the 36-1 crank pulley Quote Link to comment Share on other sites More sharing options...
Bazzman Posted December 8, 2022 Author Report Share Posted December 8, 2022 Quote Link to comment Share on other sites More sharing options...
Adamw Posted December 8, 2022 Report Share Posted December 8, 2022 The cam sensor in these engines output a signal that inverts at a certain RPM - often somewhere around idle speed. When they do invert one edge (falling I think)remains accurate but the rising edge moves. Somewhere either side of that inversion RPM you see the this odd effect with the variable tooth widths due to one edge moving around. They normally have a 36-2-2-2 crank wheel on this engine and we have a dedicated trigger mode for them to take care of this. I suspect the dedicated trigger mode probably uses an edge count type sync strategy (for example it will check if it saw 4 cam edges or 2 cam edges between 2 points in the last crank revolution). I dont think cam level or cam window sync with a generic 36-1 is going to be a reliable option in this case. Why the change of crank wheel? Can you change back to OEM? If you do have trigger issues, possibly grinding a tooth or 2 off the cam to get a bit more wiggle room for a cam window sync would be another option. Quote Link to comment Share on other sites More sharing options...
Bazzman Posted December 8, 2022 Author Report Share Posted December 8, 2022 Factory pulley is a big heavy damper pulley with no keyway and too large of a diameter poly v for the revs intended in this application. Bugger is all I can say, Surprising that Kent cams doesn't change the cam wheel to suit being it is a dedicated vvt cam intended for competition. If I took off the 2 teeth circled in red then it would leave a decent window to use the green tooth as the cam tooth to be picked up right? Quote Link to comment Share on other sites More sharing options...
Bazzman Posted December 9, 2022 Author Report Share Posted December 9, 2022 Can the vvt still function 100% with as little as 1 can tooth? Obviously not as mazda 3 but with the cam angle test it could work itself out Quote Link to comment Share on other sites More sharing options...
Adamw Posted December 10, 2022 Report Share Posted December 10, 2022 I would want at least 2 teeth for VVT. One of the early BMW's has a single long tooth on a VVT cam, we use both the rising and falling edge on that to get more regular position updates but even then its control is never as good as other engines with more teeth. 2JZ has 3 teeth and that works well. Quote Link to comment Share on other sites More sharing options...
Bazzman Posted December 10, 2022 Author Report Share Posted December 10, 2022 I think I'll take 2 teeth off, just have no idea what 2 will be best, definitely the one that comes close to interfering in the sync area, but the second not so sure. It's it better for the ecu to have more teeth on one crank rotation to the other or as long as they're in different orientation it will work this out relatively easily. I'm thinking just remove one of each of the 2 close pairs. Quote Link to comment Share on other sites More sharing options...
Adamw Posted December 11, 2022 Report Share Posted December 11, 2022 I think the 2 teeth you have marked in red above would be fine. Or take off the 3 pins you havent marked which would make it into a 4-1 pattern which is common on cams. Quote Link to comment Share on other sites More sharing options...
Bazzman Posted December 11, 2022 Author Report Share Posted December 11, 2022 I really appreciate the help, I'm amazed you offer the help and set up you give at no charge, I did a bit of logging and checking today, the vvt only got to 34 degrees, I then had a good look at another cam phaser I had on my bench and it only moves 17degrees, this is good news as at full advance the falling edge of the cam tooth I was worried may come into the sync window does not, and not by quite a way, so I think I'm going to be safe there. I guess the vvt tables that appear when you select the mazda 3 vvt setup are very generic as the go to 50 degrees of advance which the mazda vvt phaser can not achieve. Is there an easy way to take these tables and change to suit as a start point for tuning or is it best to just wait till it's on the dyno and start from zeros. Thanks again for being a legend Quote Link to comment Share on other sites More sharing options...
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