Cam Position Sensor for small block Buick (& Rover)

[BritishV8]

I've got my 1962 Buick 215 running well with MS3-Pro in batch-fire mode, and next I want to upgrade to sequential injection with crank-fired multi-coil ignition. So, I needed a cam position sensor. Based on tips from two of my BritishV8 friends, Jim Blackwood and Bill Jacobson (no relation), I purchased a Ford Taurus/Windstar V6 cam position sensor and the oil pump drive mechanism it mounts on. $30/used (shipping included) via eBay.

FordCamPositionSensor.jpg

I also purchased an old Buick 350 V8 distributor. $20/used (shipping included) via eBay. Any model small block Buick distributor would have worked, because all I needed it for was its drive gear, plus it was convenient to take measurements off of it.

My very good friends Scott and Doug McRoberts - of McRoberts Machine here in Longmont Colorado - get credit for all the skilled work that went into making this project happen. I heartily recommend their shop to anyone! We decided to make a new housing from scratch. I picked up two oilite bushings from a local hardware store. They're 1/2"ID, 3/4"OD, and 1" long. We pressed those into the new housing. We reworked the Ford shaft as follows: first we cut it off just above the hole Ford used to mount their drive gear. Then we turned the shaft to just over half inch diameter and reamed the oilite bushings to match. The shaft then needed to be turned to a slightly smaller diameter at the bottom end to mate to the Buick drive gear. We drilled a new hole for the retaining split-pin and milled flats onto the shaft's end for the Buick oil pump drive.

Here are two snapshots of the results:

Buick-V8-Cam-Position-Sensor.jpg

Buick-V8-Cam-Position-Sensor-Installed.jpg

This is how the resulting part looks as installed on my Buick 215. It would fit the other Buick small blocks too. Rover 3.5/3.9/4.2 V8s could use a similar solution; they're just a little different in terms of drive gear and oil pump drive.

[TheSilverBuick]

Do Grand National cam sensors work in the Rover V8's? They fit un-modified into the small block Buick and just require a gear swap for the big Buick. They are larger than what you have there though, that is a nice piece of engineering there.

[BritishV8]

Rover has a different gear than small block Buick (including Buick 215.)

Wow. I wasn't even aware of that Grand National sensor! That might have saved me a bunch of work. On the other hand my sensor does sit lower, and that's going to be a major advantage because I've been working to fill the space where the distributor used to go. Here's a quick preview snapshot. I'll start another thread when I'm a little closer to done.

Preview-IgnitionCoilBracket.jpg

[TheSilverBuick]

Nice. I'm halfway through a distributorless conversion on my 455 Buick. I'm looking at getting a GN sensor when I'm confident I can get rid of the HEI cap (which currently houses my cam sensor). I have a few spacial issues at the moment though that I plan to work through tomorrow.

[Ollie8974]

Yes, The Buick GN's use a cam sensor similar to the Ford sensor. I like the construction of the Ford sensor over the GN
sensor. The Ford sensor features a machined one piece shaft and shutter wheel. Where as the GN sensor uses an machined
shaft with a stamped shutter wheel secured with a screw.
The GN sensor is not any higher than the Ford sensor.
I would be interested in one of these sensors for a traditional Pontiac engine.

[Healey3000]

We decided to make a new housing from scratch. I picked up two oilite bushings from a local hardware store. They're 1/2"ID, 3/4"OD, and 1" long. We pressed those into the new housing. We reworked the Ford shaft as follows: first we cut it off just above the hole Ford used to mount their drive gear. Then we turned the shaft to just over half inch diameter and reamed the oilite bushings to match. The shaft then needed to be turned to a slightly smaller diameter at the bottom end to mate to the Buick drive gear. We drilled a new hole for the retaining split-pin and milled flats onto the shaft's end for the Buick oil pump drive.

Hi,

I'm contemplating something very similar for my AH3000. Would you mind sharing the dimensioned drawing of the upper end, where the sensor mounts, as well as the vane chamber? Ford used Hall Effect sensors on the 97 Explorer on what looks like an identical housing. Curious why you opted to go with the VR style.

Thanks.

[BritishV8]

I didn't keep the napkin sketches, so to make a drawing of the finished part I'd have to take everything apart. If you need dimensions I suppose I could grab the old Ford part out of my aluminum recycling bin. As for VR vs. Hall... I ended up using a Hall sensor after all. Here's another snapshot and a caption I posted in my build diary:

The Ford shaft was cut in diameter and length. We milled flats onto its end to drive a Buick oil
pump. Note how it has a "half moon wheel" at the top instead of one with one or more narrow
teeth. The sensor at right came with it; it's a VR (variable reluctance) 2-wire sensor. I prefer
to instead use the Hall effect 3-wire sensor at left. This particular Airtex Wells sensor (part#
5S1283) is an improved version of a Hall effect sensor Ford used in the 1990s. It features an
over-molded magnet instead of one that can shake loose. The functional advantage of a Hall
effect sensor in combination with a half moon wheel is quicker starts. MS3-Pro can "poll" cam
position when the crank sensor detects a missing tooth and immediately sync ignition timing.

Seems to be shaking out okay. I've been driving the car this month, and have probably put over 500 miles on the sensor so far.

[Ollie8974]

I have CAD drawings.
This is for a traditional Pontiac engine.

REVISED ASSEMBLY.jpg

[Healey3000]

I have CAD drawings.
This is for a traditional Pontiac engine.

REVISED ASSEMBLY.jpg

Thanks for the drawing. It may require as much machining as the design I'm contemplating (attached images). It has two machined pieces plus a shaft that integrates the drive key and the slot for the sensor. Instead of bushings, I have two bearings, an oil seal and a Hamlin 55505 Hall sensor. Bearings, seal and shaft stock are available from McMaster at reasonable prices; of course, you can get the same for a lot less elsewhere. The Hamlin sensor is about $12 at Mouser.

[Healey3000]

If you need dimensions I suppose I could grab the old Ford part out of my aluminum recycling bin.

Hi,

Please don't take the trouble to pull the part and take measurements. If you had a drawing at hand it would have been easy enough. Nice looking installation, glad it runs well.

Thanks.