Crank Position Sensor?

[packman]

If an engine has a distributor; why would you need a crank position sensor? Noticed the points for the CPS on the back of the stock damper on for my '96 351W.

Packman

[sly]

Timing advance IIRC.

[gadget73]

Can also be used to drive the injectors, the ignition, or feed the ECM info about misfires. The distributor typically also has a position sensor, so indirectly it can measure slop in the timing chain by comparing the two.

[merc91]

For true sequential ignition and injection the crank sensor accuratly directly measures crank/piston position and the cam/distributer sensor reads when each cylinder is on the compression stroke to fire.
There is quite a bit of room for error by the time the dist/cam sensor gets the reading of where the crank postition is, which I can see by logging my ms3 readings with both the cam and crank position sensors in parallel.

[His Royal Ghostliness]

What I wanna know is where can one actually find a crank position sensor on a '96 351W? There were only two applications that used that engine in that model year, F-series trucks and E-series vans, both of which have a fuel delivery system that might as well be comparable to that godforsaken CFI disasterpiece, I mean the thing is actually dumber than the standard SEFI the earlier 302 cars came standard with... Certainly do not need a crank position sensor there, so maybe the particular engine in question somehow got a leftover piece during assembly? OR it's been replaced already, and that's the only thing that whoever did the work had access to at the time.

[packman]

Makes sense with the timing chain theory and more input. I guess by '96, the F-series trucks were getting more advanced (despite having E7 heads on a 351W) before they started with the mod engines. I probably should look up when the push rods were stricken from the truck line.

Packman

[gadget73]

F150 may have had the CPS, the F250 I don't think did. They were still rocking EEC-IV in 97 at least. The light duty stuff was OBD2 in 96, but the HD stuff didn't have to comply until some later date.

[merc91]

E7's on a 351 lol... Whoever made that call at for should be locked up

[sly]

E7's on a 351 lol... Whoever made that call at for should be locked up

+1

[His Royal Ghostliness]

The fawk's wrong with E7s on a 351? What should they have run, especially in the entire decade preceding the GT40s? You speed freaks gotta remember that not everyone wants to turn at 4k to make power, good torque off idle is more useful for the standard 351 applications and the E7s do quite alright there IMHO.

I do wonder what a 351 with GT40s and a nice RV-style cam will do tho, but ah well, no such truck to play with yet.

[sly]

I do wonder what a 351 with GT40s and a nice RV-style cam will do tho, but ah well, no such truck to play with yet.

This is exactly the combo I was thinking should have been. Would be nice to see what that would do off-idle.

[merc91]

There's allot wrong with running e7's on a 351. Lets remember even in the 60's/70's they approached 1hp/ci.
My gt40p's on the 302 make gobs of tq off idle thanks to all/any cams with good lobe seperation. Pass e-tests/25mpg cruising, daily driven and tows regularly.

Saving money for ford by sticking barely acceptable 302 heads on the 351's is almost criminal is all i'mma sayin... It's not like they had no idea a realm beyond e7 could exist lol.

[His Royal Ghostliness]

You're looking at it the wrong way, you want performance when Ford's real goal was just good enough to make the sale and get the job done. Gotta remember who bought these engines - mostly fleet operators, and also those individuals who couldn't afford to or simply had no real need to step up to a big block or a diesel. In the world of fleet use, you absolutely do not want to give the common steering wheel holder anything they can easily damage or do damage with - these dumb shits will run foot on the floor loaded to the gills day in and day out if they know they can get away with it, and back in those days getting away with it was easy enough. Matter of fact some of the first things smart diesel fleet owners used to do upon taking delivery of a new truck was turn the fuel down - this way the assholes could stand upright on the throttle without risking burning holes in the pistons. With an EFI gasser such power limitations are not very easy to accomplish tho, remember even U-haul had to resort to using mere 3-speed automatics in an attempt to keep people from speeding and wrecking the trucks. So even if Ford could develop the GT40 heads earlier, there was no real reason for them to do so just cause there was no real demand for high-performance 351s. Also the engine platform was running on borrowed time with the mod engines already in development, from a bean-counter's point of view there is little sense in developing new heads for an engine that is soon to be out of production anyways - in which case R&D cost would have to be passed onto the consumer, who if they knew any better would then choose the 300 as their base fleet engine as it's practically idiot-proof and at that point the savings would be more than sufficient to offset the performance loss as compared to the new hi-po 351. Actually given how well the 4.6 was doing already, I am somewhat surprised Ford decided to breathe some new life into the 302s with the GT40 and then the GT40P heads...

[merc91]

Assuming everyone who drives an e7 351 is an "asshole" driving a company vehicle and can't handle a whopping 290+hp to get 5000-10,000lbs around with functioning traffic isn't much of an argument for e7's on 351's. Why not throw an e7 302 or even a 4 banger in them... That'd be even "safer". The reason they gotta hold the pedal to the floor is because they are driving piles of crap with e7 headed 351's.

Not saying they should have put afr 225's and a 4000-8000rpm massive duration cam in the things. But come on. People buy a 351 vehicle beacuse they need it. And they got ripped off. Later gator

[gadget73]

I think the reason they kept th 302 around for a while longer was to stuff it in the Exploder. I believe after the models that could be had with a 302 ended production, it got bigger enough to take the fat-ass modular motor. The old Windsor is rather more compact, and even still it just about fit in the Explorer.


At the marina i worked at, we had an '87 F250HD with a 4V 351, last year for the carbonator. That thing was the most gutless piece of shit I've ever driven. I ran it home once, and I had to beat the snot out of it just to get on and maintain highway speeds. It was dead empty too. It was miserable enough with a load on it that I simply left it in 4L for dragging things around the yard. It struggled otherwise. Not sure what heads it had, but if they weren't e7 it was probably something comparable. They had the nerve to call that thing a 351-HO too.