BritishV8 Forum

General Category => Engine, Transmission, & Rear Axle assy. => Topic started by: Moderator on June 05, 2013, 03:53:09 AM

Title: Sensing cam position on Buick/Rover V8
Post by: Moderator on June 05, 2013, 03:53:09 AM
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?
Title: Re: Sensing cam position on Buick/Rover V8
Post by: BlownMGB-V8 on June 05, 2013, 09:54:41 AM
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
Title: Re: Sensing cam position on Buick/Rover V8
Post by: MG four six eight on June 05, 2013, 12:24:39 PM
Here ya go Curtis! http://forum.britishv8.org/read.php?6,9814
Title: Re: Sensing cam position on Buick/Rover V8
Post by: Moderator on July 06, 2013, 07:33:43 PM
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.
Title: Re: Sensing cam position on Buick/Rover V8
Post by: mgb260 on July 07, 2013, 02:39:25 PM
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.
Title: Re: Sensing cam position on Buick/Rover V8
Post by: Moderator on July 07, 2013, 03:22:36 PM
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.)
Title: Re: Sensing cam position on Buick/Rover V8
Post by: Moderator on August 28, 2013, 07:09:08 PM
I'm very excited to announce that I now have a Buick V8 cam position sensor!

Here's how it came out:

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

Buick-V8-Cam-Position-Sensor-Installed.jpg
(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.
Title: Re: Sensing cam position on Buick/Rover V8
Post by: BlownMGB-V8 on August 29, 2013, 11:52:09 AM
Very nice. I expect you might sell a few of those if extra parts were made.

Jim
Title: Re: Sensing cam position on Buick/Rover V8
Post by: Rotus8guy on August 29, 2013, 06:52:00 PM
If the price was no more than moderately exorbitant, I'd go for one :-)
Title: Re: Sensing cam position on Buick/Rover V8
Post by: mstemp on August 29, 2013, 10:45:28 PM
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
Title: Re: Sensing cam position on Buick/Rover V8
Post by: Moderator on August 29, 2013, 10:45:48 PM
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.
Title: Re: Sensing cam position on Buick/Rover V8
Post by: Moderator on August 29, 2013, 10:49:59 PM
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.)
Title: Re: Sensing cam position on Buick/Rover V8
Post by: mgb260 on August 29, 2013, 10:58:01 PM
Another work of art, Curtis!
Title: Re: Sensing cam position on Buick/Rover V8
Post by: BlownMGB-V8 on August 30, 2013, 09:53:01 AM
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
Title: Re: Sensing cam position on Buick/Rover V8
Post by: Rotus8guy on August 30, 2013, 12:14:48 PM
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
Title: Re: Sensing cam position on Buick/Rover V8
Post by: quietone on September 26, 2013, 05:39:46 PM
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.
Title: Re: Sensing cam position on Buick/Rover V8
Post by: Moderator on September 27, 2013, 02:24:46 AM
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.
Title: Re: Sensing cam position on Buick/Rover V8
Post by: NCtim on October 08, 2013, 05:45:04 PM
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
Title: Re: Sensing cam position on Buick/Rover V8
Post by: DiDueColpi on October 08, 2013, 06:38:51 PM
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
Title: Re: Sensing cam position on Buick/Rover V8
Post by: DiDueColpi on October 08, 2013, 06:41:18 PM
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
Title: Re: Sensing cam position on Buick/Rover V8
Post by: BlownMGB-V8 on October 09, 2013, 10:11:26 AM
Not sure how Curtis dealt with that issue, on mine I kept the stock bushings and oiling method.

Jim
Title: Re: Sensing cam position on Buick/Rover V8
Post by: NCtim on October 15, 2013, 05:29:52 PM
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
Title: Re: Sensing cam position on Buick/Rover V8
Post by: DiDueColpi on October 15, 2013, 07:53:22 PM
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
Title: Re: Sensing cam position on Buick/Rover V8
Post by: mgb260 on October 16, 2013, 12:05:34 AM
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.
Title: Re: Sensing cam position on Buick/Rover V8
Post by: Eccentric British Guy on July 24, 2014, 06:55:43 PM
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
cam_trigger.jpg

Water jet cut cam sensor wheel on engine
20140417_180030.jpg

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)
Title: Re: Sensing cam position on Buick/Rover V8
Post by: DiDueColpi on July 24, 2014, 10:34:54 PM
Looks fantastic David.
And it's doing the job as intended, can't do much better than that.
Cheers
Fred
Title: Re: Sensing cam position on Buick/Rover V8
Post by: parrisw on November 18, 2014, 09:39:37 PM
I need to do the same thing here. Any of these for sale yet?  Or do I need to make one.  I was just planning on using the crane optical pickup in the distributor as a cam sensor, just fill in all but one slit on the chopper wheel.
Title: Re: Sensing cam position on Buick/Rover V8
Post by: parrisw on November 19, 2014, 12:28:47 AM
Another question.  How are you setting the Sync on the cam sensor?  Like how to index it. Ford uses a tool that goes in place of the sensor when you install it, it indexes it in the correct position.
Title: Re: Sensing cam position on Buick/Rover V8
Post by: parrisw on November 22, 2014, 11:08:26 AM
Anyone? Anyone?  So I got a synchronizer out of a Ford 4.2L V6, it's the 3 wire sensor.  Now just need an old distributor to cut apart.
Title: Re: Sensing cam position on Buick/Rover V8
Post by: Moderator on November 22, 2014, 12:15:43 PM
Well... with a half moon set-up (180 degrees "on" and 180 degrees "off",) you don't have to be very precise. I just eyeballed it. I'm probably within 45 degrees or so!
Title: Re: Sensing cam position on Buick/Rover V8
Post by: parrisw on November 26, 2014, 12:48:11 AM
Wow!!  LOL. That's not very close!!  Ever think of using a Lab Scope?  Dual channel, then line up the waveforms?  So at #1 TDC, you'd want the half moon vane just at the edge of the sensor?
Title: Re: Sensing cam position on Buick/Rover V8
Post by: Moderator on November 27, 2014, 11:42:18 PM
As I understand/recall, MegaSquirt polls my Hall effect (3-wire) cam sensor just once while I'm cranking the engine and immediately after sensing the missing-tooth gap in my 36-1 crank position trigger wheel. It only needs to know whether I'm on the compression stroke or the exhaust stroke. Just after top-dead-center it's got to be one or the other, right? The half moon wheel gives me a whole lot of leeway.

(http://www.britishv8.org/MG/CurtisJacobson/HallEffectSensor.jpg)
(The sensor on the left is a Hall effect sensor. The sensor on the right is a two-wire VR sensor... and that's the kind you don't want to use in combination with a half moon wheel.)
Title: Re: Sensing cam position on Buick/Rover V8
Post by: parrisw on December 07, 2014, 10:38:51 PM
I've got the Hall effect one with three wires.

I've got my sensor all done. Was pretty easy actually.

Pics to come.
Title: Re: Sensing cam position on Buick/Rover V8
Post by: parrisw on December 07, 2014, 10:57:26 PM
Post on my site about building a sensor.

http://www.tr-8.ca/?page_id=132
Title: Re: Sensing cam position on Buick/Rover V8
Post by: donkelly23 on August 02, 2016, 05:08:34 PM
Thank you for all the info.I am going to try the GN cam sensor I was able to buy on a close out sale for about $75
20141215_173214Medium.jpg
Title: Re: Sensing cam position on Buick/Rover V8
Post by: Moderator on August 03, 2016, 06:07:02 AM
Sweet!
Title: Re: Sensing cam position on Buick/Rover V8
Post by: donkelly23 on August 03, 2016, 09:53:31 AM
Curtis, I am in awe of what you, Mr Nichols and Mr Blackwood do.
I am getting help with this from Will Parris and others on the TWOA site for my Wedge.
Most NW people I noticed. Should have done this before I left Seattle for the Beaches of Charleston
Title: Re: Sensing cam position on Buick/Rover V8
Post by: BlownMGB-V8 on August 03, 2016, 11:14:50 AM
Don, that's a nice find on the GN cam sensor. Mind telling where you got it?

Jim
Title: Re: Sensing cam position on Buick/Rover V8
Post by: donkelly23 on August 03, 2016, 11:26:57 AM
Jim, I bought it a least 2 years ago from Rockauto on a closeout.
Just looked at the pic. Took it 12/15/2014
Somebody mentioned it somewhere and I knew in the back of my mind I would MS the car eventually.
It's been sitting in my office closet since then
Title: Re: Sensing cam position on Buick/Rover V8
Post by: BlownMGB-V8 on August 03, 2016, 04:59:53 PM
Got a part number for it anywhere by chance?

Jim
Title: Re: Sensing cam position on Buick/Rover V8
Post by: donkelly23 on August 03, 2016, 05:20:50 PM
Yep, pretty sure it is NLS.
Just use the top number I think
20160803_171800_resized.jpg
Title: Re: Sensing cam position on Buick/Rover V8
Post by: BlownMGB-V8 on August 03, 2016, 07:03:00 PM
Looks like that was an extremely good price. Makes sense of the mods Curtis and I have done. Cheapest I saw was about $175 on ebay (maybe) and prices between $230 and $375 otherwise.

Wonder if they sell just the sensor off the top? Maybe that could be useful. Don, would you be willing to remove the cap and take some pictures of what is inside?

Jim
Title: Re: Sensing cam position on Buick/Rover V8
Post by: MG four six eight on August 03, 2016, 11:27:37 PM
Interesting, I didn't realize that such a part existed. Although it's fairly expensive, it would have been easier then making one.
Looking back, I did enjoy using the lathe to fabricate one up though!

Bill
Title: Re: Sensing cam position on Buick/Rover V8
Post by: donkelly23 on August 04, 2016, 08:58:09 AM
Jim
"Don, would you be willing to remove the cap and take some pictures of what is inside?"
Sure, I'll try to get to it today.

Right now I'm hassling with the lifter preload on my 4.0 motor
Title: Re: Sensing cam position on Buick/Rover V8
Post by: donkelly23 on August 04, 2016, 09:24:16 AM
Looks like a standard Hall effects sensor
20160804_091316_resized.jpg
20160804_091157_resized.jpg
20160804_091201_resized.jpg
Title: Re: Sensing cam position on Buick/Rover V8
Post by: BlownMGB-V8 on August 04, 2016, 10:29:31 AM
Hmm... Could be a photo-diode pair.

Jim
Title: Re: Sensing cam position on Buick/Rover V8
Post by: DiDueColpi on August 04, 2016, 10:33:08 PM
I`m going with Hall Effect for two hundred Jim!

Hold something ferrous, like a screw driver up to the sensor. If it`s magnetic then it`s a Hall effect.
Either way you will need to trim the trigger wheel so that it`s a 180 degree cut out for most systems to recognize it
Still a very useful part at an excellent price.

Live like you mean it.
Fred
Title: Re: Sensing cam position on Buick/Rover V8
Post by: donkelly23 on August 05, 2016, 08:10:06 AM
Fred
"Either way you will need to trim the trigger wheel so that it`s a 180 degree cut out for most systems to recognize it "

English please.
Still new to all these modern dealies.
Title: Re: Sensing cam position on Buick/Rover V8
Post by: TR8Driver on October 08, 2019, 06:34:16 PM
I know this is an old thread, but I'm going to use this same sensor for my Rover V8.  I will have to change the drive gear, and have found that the Buick shaft is slightly thicker than the Rover shaft, so I'm waiting for a 1/2" reamer to open up the drive gear slightly.  I will also have to cut off the end of the Buick shaft, as the TR8 uses a different drive end.

But I wanted to comment on the comment from Fred:

"Either way you will need to trim the trigger wheel so that it`s a 180 degree cut out for most systems to recognize it "

If I want to use this as a single-tooth wheel, I believe it will work as-is, and I can define either rising or falling edge.  If I wanted to use a polled setup, then yes, I think you could widen the window to be 180 degrees.  But from what I'm reading the MegaSquirt manual, the only downside of setting it up as a single-tooth is it might take an extra rotation for the ECU to set sync.
Title: Re: Sensing cam position on Buick/Rover V8
Post by: TR8Driver on November 22, 2019, 06:37:55 PM
Just a note for anyone looking to use this Buick Grand National cam sensor (if you can find one).  It will require a pull-up resistor when using with a MegaSquirt.