BritishV8 Forum

I'm just about ready to think about this aspect of electronic ignition.

If you were starting from scratch and designing a cam sensor mechanism, what features would you want?  

Is it feasible to put a trigger wheel right on the camshaft, instead of geared off the cam like a distributor?

You would need a cam gear with either a protrusion or a hole that could be used to trigger the sensor, though a trigger wheel could be made that would work. The sensor could be mounted in the distributor hole or the fuel pump hole.

Because the early style cover still requires an oil pump drive, I cut down a distributor and added a Ford sensor as a cap:
http://forum.britishv8.org/read.php?2,274,page=23

Accurate location is not a requirement, that is provided by the crank sensor. All the ECM needs to know is which rotation the crank is on.

If you use the late cover with the gerotor pump the drive can be eliminated. I doubt that cover has a mount for a mechanical fuel pump, so another location must be found. The distributor location could be redrilled for a sensor. The front may be out due to the water pump, but I would think a location could be found below the pump. Which cam to use is another question that should be considered, since Art has some roller cam blanks based on the later cam.

Jim

Here ya go Curtis! http://forum.britishv8.org/read.php?6,9814

Well... I bought one of those complete Taurus/Windstar style cam positions sensor assemblies from someone on eBay and it arrived today. $30, shipping included. Spotlessly clean and well packaged even. (<a href="http://www.ebay.com/itm/121027160605">Reference</a>.)

Now I'm on the lookout for a suitable Delco-Remy distributor for the lower part. I suppose the Buick V6 distributors would probably work just as well for this purpose as the V8 ones, right?  I don't recall anything about their camshafts having a different gear.

Curtis, I don't know about the V6 cam gear being the same but I know the Buick 350 distributor has been used in the 215/Rover. Pretty common motor used in the 80's. I would buy a rebuilt one from the auto parts store rather than the junk yard.

A-ha! NAPA website shows a remarkably low price too: $58.50 plus $6 core charge: http://www.napaonline.com/Catalog/CatalogItemDetail.aspx?R=NRD481813_0130772398

I have already bid on a used one though. ($10 plus $10 shipping, if no one else bids in the next 3 hours.)

I'm very excited to announce that I now have a Buick V8 cam position sensor!

Here's how it came out:


(New part in center. Cut-down Buick 350 V8 distributor housing on left. Ford Taurus V6 cam sender mount on right.)


(Installed on my Buick 215, but it would fit the other Buick small blocks too.
Rover 3.5/3.9/4.2 V8s could use a similar solution, although they'd require a different drive gear.)

My very good friends Scott and Doug McRoberts - of <a href="http://www.mcrobertsmachine.com/index.htm">McRoberts Machine</a> - get credit for all the skilled work that went into making this development happen. I heartily recommend their shop to anyone! The design is obviously an interpretation of what Bill and Jim have done previously.

It turns out that the only part we needed from the old Buick 350 V8 distributor was its drive gear. Its housing casting was very ugly compared to my old Buick 215 distributor in terms of surface finish, flash, etc. - It just didn't see worth messing with. Instead, we decided to make a new housing from scratch. Then, 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 place. 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 oil pump drive.

Very nice. I expect you might sell a few of those if extra parts were made.

Jim

If the price was no more than moderately exorbitant, I'd go for one :-)

Ok I need to ask a basic question. Why do you need this? To account for chain stretch?
You have the crank sensor for the ignition timing already.......

Thanks

I'm sure my friend Scott would be happy to make more of them.  If there's enough interest, perhaps a group buy could be arranged.

I learned yesterday that Buick created something similar for Grand National. The Buick version can be found on eBay, <a href="http://www.ebay.com/itm/Buick-Grand-National-New-Cam-Sensor-Free-Ship-USA-/231037108186">here</a>. It ain't exactly bargain priced though, and it appears to be about an inch taller.  That would likely be a problem for me. (I'm getting ready to mount something directly above the cam sender... I'll post pictures of the mystery part soon.)  I also have no idea what the Buick sensor's electrical characteristics are. It appears to have a three-pin Weather-Pack connector.

QuoteWhy do you need this?

The crank position sensor gives a precise timing signal, but it doesn't provide the computer with a way to differentiate between the intake stroke and the power stroke (or between the compression stroke and the exhaust stroke.)

Another work of art, Curtis!

It's very nice, and shorter than the one I made from an old 215 distributor, which in my case would have helped as I had to dimple in the bottom of my thermostat neck for clearance (ain't TIG grand?) Of course the stock neck is not in the way like that.

I would guess the GN sensor uses power, ground, and signal. Possibly a Hall sensor.

The MS-3, with discrete individual cylinder control, needs to know when #1 comes up on the compression stroke. Some of the other controllers do too.

Jim

Curtis,
Thanks for the link to that GN sensor. A quick search on that part # finds many choices. OEM replacement parts for as low as $108 shipped. Yours looks nicer, but I cant imagine Scott could do it for less than that.
Cheers,
John

If you need a cam sensor and a shorter engine (almost 5 inches) you can use a Buick 3800 V6 series II front cover and oil pump. It has a sensor that operates by a magnet mounted in the timing gear. You will have to use DIS and do some minor machine work on the nose of the cam. Everything works, but you have to make a little plate to block off an oil mismatch.

Now there's an idea! Looks like GM offered at least 5 different oil filter adapters for those engines, so you can point the filter 5 different directions. That's as far as my research got before I started looking at pics of buick's (eaton) m62 blower. tres fantastique! (I have to sign off now and resume my Paris vacation.) Somebody please post some pics of that s2 cover.

QuoteIf you need a cam sensor and a shorter engine (almost 5 inches) you can use a Buick 3800 V6 series II front cover and oil pump. It has a sensor that operates by a magnet mounted in the timing gear. You will have to use DIS and do some minor machine work on the nose of the cam. Everything works, but you have to make a little plate to block off an oil mismatch.

Has anyone tried this on a distributorless engine such as a Rover GEMS engine?

Tim

I like your cam sensor Curtis. Nicely done.
Have you thought about a method to lube the bushings?
Dried out bearings were the # 1 failure on the Ford sensors.
The very first ones actually had a grease fitting that got deleted later on. You can see the boss for it on the housing.
Just a thought.
Cheers
Fred

Hey Tim,
The GEMS engines had a cam position sensor built right into the timing cover.
No need to do anything. just wire it up.
Cheers
Fred

Not sure how Curtis dealt with that issue, on mine I kept the stock bushings and oiling method.

Jim

Hey Fred,

I was thinking of exploring Larry's idea to shorten the engine by a few inches. Just bouncing ideas around. I wouldn't have to modify the cam because there's not the extra length for the distributor drive gear. How much room would it save? I won't know until I can get to the junk yard and measure. I have to wait until the copperheads and rattlesnakes are down for the winter. I don't do junk yards in nice weather around here. Killed a rattlesnake two weeks ago. Hate those things, yeeesh!

Tim

Hey Tim,
I've got a CUX engine and a GEMS engine sitting here side by side (and no rattlers)
Measured from the water pump pulley flange, the Gems engine is 2.5" shorter.
I don't know about the 3800 covers but I would suspect that they are even shorter to clear a FWD installation.
Sounds like Larry is the guy to talk to about that.
Cheers
Fred

I've never tried the 3800 cover but, you better get all the accessory brackets and use that water pump also as it is serpentine belt. There was a thread here where they used the bottom half 3800 cover and used the gearotor oil pump by modifying the damper and welded to the top stock half for distributor and water pump. Or the uncommon Rover late 3.9/4.2 transitional cover which has gearotor oil pump and distributor hole. I think there is a rare 87-88 Buick V6 cover also but it maybe serpentine drive also, so again you would need all accessory brackets.

Sorry for resurrecting an old thread, but this thread provided a good insight into cam sensors.  I have now completed an installation on my TVR (rover) V8 so thought it worth the time to provide an update.

The concept:  A wheel designed to sit in front of the JP duplex timing sprocket on the cam.  It's balanced by design.  The pin is designed to give a clean signal with the readily available 1gt101dc Hall sensor from Honeywell, fitted in the standard cam sensor location in an intermediate Serpentine timing cover.

CAD drawing of the wheel


Water jet cut cam sensor wheel on engine


The engine is now complete and I'm pleased to say the cam wheel and sensor performed flawlessly from the beginning, and the installation is nice and tidy, even if I did have to hack a corner off the inside of the timing cover.  (It's not there on the later timing covers)