cam sensor tech, questions cam in block,, not ohc

[Stich496]

after not sleeping for a few days,, between wakes, I was pondering things..
being the type that does things all or nothing, I looked over a few cam sensors at work.
cause if I try efi I want synquental(sp) but not be forced into a newer block..
have yet to see a newer cam that have the part that triggers the sensor..
on a v8 how many triggers are on the cam.. is it one fly'n magnet to let the ecu know where the cam is, or is there one every 90 degrees, 180 degrees, every 45 degrees..
or are there differences depending on engine. or are they all running the same amount of triggers.. to inform the ecu.. or is it like a crank missing tooth wheel??

got an idea in my head for a set up but can seem to figure out.. what triggers the sensor, and how many are on the cam..
don't know the correct wording, to get a good hit on google.. for info..
thanks..

[SpiderGearsMan]

the cam sensor on 5.7 r and other old vortec chevrolets is the distributor CMP sensor - the trigger for spark is a crank sensor CKP sensor

[Thumpin455]

I was going to say what Spidey said. Been dealing with that on a 99 Blazer with a 4.3

[Barry Donovan]

I'd be confused too.


if cam is half time, the ecm can use the crank...
this "cam sensor" stuff for variable valve something?

if the cylinder is set to be firing.. I am willing to guess both valves are closed.

there is your cam position.

[TheSilverBuick]

A cam sensor only really needs on tooth on it to reference TDC or openning of the Intake valve on #1. Conversely there isn't anything stopping there being a full trigger wheel on it with a single missing tooth to give the same reference.

The Buick Grand National used a distributor replacement for a cam sensor since it had coil packs and the gear is pretty much locked to the cam unlike the play in a timing chain.

[CTX-SLPR]

A cam sensor only really needs on tooth on it to reference TDC or openning of the Intake valve on #1. Conversely there isn't anything stopping there being a full trigger wheel on it with a single missing tooth to give the same reference.

The Buick Grand National used a distributor replacement for a cam sensor since it had coil packs and the gear is pretty much locked to the cam unlike the play in a timing chain.

The cam sensor is simply a refference to which of the two 360deg rotations the #1 is part of. Most of the timing fuctions (ignition or injector) are calculated off of the crank sensor and the cam just tells the computer, in relation to the #1, intake or power stroke. In the Buick V6's this is done by a hall effect sensor that trips every 360deg of cam rotation (720 crank). The 3800 has a magnet in the cam timing chain sprocket and the LC2 has a stub of a distributor that drives the oil pump and has a metal sheild that blocks the magnetic feild of the magnet in the cap from the sensor across from it till the window for the timing pulse.

What kind of motor are you trying to put this on?

[fabricatordave]

it is called dual sync distributer google it

[dieselgeek]

Mark, when or if its time to do your EFI system, you'll be able to home-make a cam sensor out of an old distributor if you need to do it cheap/free. You only need the "tooth" to pass a sensor one time per engine cycle (once per 720 degrees or two rotations of the crankshaft). This means a single tooth on a distributor trigger wheel is all you need.

Personally, I wouldn't recommend sequential EFI because it's a heluva lot of complexity and unless you're developing the engine on an engine dyno, and are satisfied with the .01% gains it'll get you, it's just a lot of hassle for little or no extra value.

But if you're doing it just for fun - GO FOR IT!

[Stich496]

it's for fun.. and for after I get through step 1, batch fire..
it not be an engine I'll be looking to get the last 1% of power out of.. just one to learn on..
more than likely what ever ends up in the truck next.. it'll be an engine that if I blow it up, no harm no fowl..

[Stich496]

What kind of motor are you trying to put this on?

bbc 496 dart pro 1 heads ,, yadda yadda yadda

[CTX-SLPR]

bbc 496 dart pro 1 heads ,, yadda yadda yadda

Past the BBC part is doesn't really mater anymore. There are factory (and aftermarket) versions that will support what you're after.

[Stich496]

what I'm after is to learn by doing,, doctors say no two jobs,,, no working around the clock.. been doing that for um way way to long,, and when I'm better, and health i'll be going stir crazy with all this time on my hands,, so.. why not jump in both feet, waters fine, I hope..