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Add crank and cam pos sensors to BB (for Megasquirt)?
#1306943
09/19/12 06:50 PM
09/19/12 06:50 PM
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Joined: Jul 2007
Posts: 531
Virginia
JimG
OP
mopar
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OP
mopar
Joined: Jul 2007
Posts: 531
Virginia
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Well, I've now bought enough hardware that I'm comitted to a Magasquirt installation.
I have a 3.57 with the MS3X board. I'd really like to do sequential injection with Chevy LS coil-near-plug sequential ignition. To do this, I'll need a crank position sensor and and cam position sensor.
The crank sensor seems easy enough: just buy the proper diameter 36-1 trigger wheel and adapt it and the sensor to the harmonic balacer/front of the engine. That I can handle.
The cam sensor looks like it'll be the challenge. I could use a lean burn distributor for cam positioning only, but then I'd have distributor with no ignition wires bolted to the front of the engine. I'll save that as the drop-dead option. Somehow imbedding a magnet into the upper timing chain sprocket and installing a sensor through the timing cover crossed my mind, but I'm not sure my fabrication skills are up to the task.
So here we are. I'm open to ideas.
Thanks,
Jim
Last edited by JimG; 09/21/12 11:14 AM.
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Re: Add crank and cam pos sensors to BB (for Megasquirt)?
[Re: JimG]
#1306944
09/19/12 07:55 PM
09/19/12 07:55 PM
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Joined: Dec 2006
Posts: 240
Shingle Springs Ca
haddixj
enthusiast
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enthusiast
Joined: Dec 2006
Posts: 240
Shingle Springs Ca
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I have a aquatintance who has done this same thing to a bbm. Ill see if he is ok with giving out his email.
70 duster 25.1E,73 barracuda, 70 gran coupe, 71 cuda
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Re: Add crank and cam pos sensors to BB (for Megasquirt)?
[Re: haddixj]
#1306945
09/19/12 08:40 PM
09/19/12 08:40 PM
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Joined: Jul 2007
Posts: 531
Virginia
JimG
OP
mopar
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OP
mopar
Joined: Jul 2007
Posts: 531
Virginia
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Re: Add crank and cam pos sensors to BB (for Megasquirt)?
[Re: JimG]
#1306946
09/19/12 09:06 PM
09/19/12 09:06 PM
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Joined: Dec 2003
Posts: 22,695
Bitopia
jcc
If you can't dazzle em with diamonds..
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If you can't dazzle em with diamonds..
Joined: Dec 2003
Posts: 22,695
Bitopia
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Quote:
I could also cheat and fabricate a second trigger wheel with 2 teeth, and somehow attach it to the crank snout. Then I'd have no way to compensate for timing chain stretch, so that seems like a cheesy plan as well. Somehow imbedding a magnet into the upper timing chain sprocket and installing a sensor through the timing cover crossed my mind, but I'm not sure my fabrication skills are up to the task.
This more of a bump then an answer, but I don't think timing chain stretch is an issue period, its mainly for reference to start the timing sequence, and I don't believe to two tooth wheel solution works, period. I sure others will elaborate. i like the magnet imbedded in the chain sprocket though. 
Reality check, that half the population is smarter then 50% of the people and it's a constantly contested fact.
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Re: Add crank and cam pos sensors to BB (for Megasquirt)?
[Re: JimG]
#1306949
09/19/12 10:22 PM
09/19/12 10:22 PM
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Joined: Jan 2004
Posts: 27,347
Today? Who Knows?
1_WILD_RT
Management Trainee
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Management Trainee
Joined: Jan 2004
Posts: 27,347
Today? Who Knows?
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Your gonna have to plug the dist. hole somehow & it's gonna have to be set up to control axial thrust on the oil pump driveshaft... So take lesson from Ford & create a stubby housing to mount a cam sensor...
"The Armies of our ancestors were lucky, in that they were not trailed by a second army of pencil pushers."
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Re: Add crank and cam pos sensors to BB (for Megasquirt)?
[Re: 1_WILD_RT]
#1306950
09/20/12 11:08 AM
09/20/12 11:08 AM
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Joined: Jul 2007
Posts: 531
Virginia
JimG
OP
mopar
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OP
mopar
Joined: Jul 2007
Posts: 531
Virginia
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1 Wild RT:
I had already envisioned something like that when I was thinking this through, I just had no idea that it already existed. Thanks for posting.
Do you know what it fits? I need to find out if they're plentiful in junkyards. It might be possible to graft the top of this thing onto the bottom of a Mopar distributor.
Thanks,
Jim
ETA: Google is my friend! It looks like these things are common on late 90's 5.0 Ford Exploders and Mountaineers.
Last edited by JimG; 09/20/12 12:27 PM.
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Re: Add crank and cam pos sensors to BB (for Megasquirt)?
[Re: astjp2]
#1306951
09/20/12 12:02 PM
09/20/12 12:02 PM
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Joined: Feb 2003
Posts: 21,318
Manitoba, Canada
DaytonaTurbo
Too Many Posts
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Too Many Posts
Joined: Feb 2003
Posts: 21,318
Manitoba, Canada
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Quote:
A dual sync distributor will keep you from modifing things like balancers and timing covers. Tim
Yes that would work, but the OP specifically said he wanted to run coil on plug and not have a dummy distributor sitting around. I suggest just forgetting the COP setup and running a distributor. It will save you all this fabrication work and headache and I don't think will have any measurable difference in performance vs the COP system you are envisioning.
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Re: Add crank and cam pos sensors to BB (for Megasquirt)?
[Re: DaytonaTurbo]
#1306953
09/20/12 12:25 PM
09/20/12 12:25 PM
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Joined: Jul 2007
Posts: 531
Virginia
JimG
OP
mopar
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OP
mopar
Joined: Jul 2007
Posts: 531
Virginia
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Quote:
I suggest just forgetting the COP setup and running a distributor. It will save you all this fabrication work and headache and I don't think will have any measurable difference in performance vs the COP system you are envisioning.
Yes, I'm considering doing just that - getting it going in "fuel only" mode (with the existing ignition system) at first, then looking at integrating the ignition later.
The downside to running the existing ignition system is that I see no way get the equivalent of ported vacuum to keep the vacuum advance working as it does today. But, with all the fuel only systems available today, someone has probably come up with a workaround that I haven't stumbled onto yet.
One other startup option is to run COP in wasted spark mode and to run the fuel in batch fire rather than sequential - both possible without a cam sensor.
Thanks,
Jim
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Re: Add crank and cam pos sensors to BB (for Megasquirt)?
[Re: astjp2]
#1306955
09/20/12 12:34 PM
09/20/12 12:34 PM
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Joined: Jul 2007
Posts: 531
Virginia
JimG
OP
mopar
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OP
mopar
Joined: Jul 2007
Posts: 531
Virginia
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Quote:
Fastman EFI has already done the big block conversion to COP, it uses a dual sync distributor without a cap and rotor. It acts as a cam and crank sensor in one. He has pics of it in his hemi book if I remember correctly. Tim
Good to know, thanks Tim!
I was unaware of this, and also thought you were referring to a "standard" dual sync distributor.
I'll definitely check it out.
Jim
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Re: Add crank and cam pos sensors to BB (for Megasquirt)?
[Re: JimG]
#1306956
09/20/12 12:44 PM
09/20/12 12:44 PM
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Joined: Jan 2004
Posts: 27,347
Today? Who Knows?
1_WILD_RT
Management Trainee
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Management Trainee
Joined: Jan 2004
Posts: 27,347
Today? Who Knows?
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Ford also used a setup like that on 3.8 & 4.2 V6 engines, there are many ways to do what you want, personally I like the idea of a very minimal sensor housing, it would look cleaner...
"The Armies of our ancestors were lucky, in that they were not trailed by a second army of pencil pushers."
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Re: Add crank and cam pos sensors to BB (for Megasquirt)?
[Re: 1_WILD_RT]
#1306957
09/20/12 12:54 PM
09/20/12 12:54 PM
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Joined: Jun 2003
Posts: 21,397
It's a dry heat
gtx6970
Too Many Posts
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Too Many Posts
Joined: Jun 2003
Posts: 21,397
It's a dry heat
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EFI late model 4.0 Jeeps had a cam sensor where the dist USED to be (no idea if the OD the base is the same as LA or B motors ) Looks like this http://www.ebay.com/itm/Wrangler-Grand-C...9e5&vxp=mtrmight be able to adapt something over , or at least use it to design off of They have a crank sensor positioned on the back of the block that reads crank position off the windows on the flywheel
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Re: Add crank and cam pos sensors to BB (for Megasquirt)?
[Re: JimG]
#1306958
09/20/12 01:49 PM
09/20/12 01:49 PM
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Joined: Apr 2003
Posts: 12,229
Looking for a way out of Middl...
IMGTX
I Live Here
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I Live Here
Joined: Apr 2003
Posts: 12,229
Looking for a way out of Middl...
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Can you just convert a small block Magnum distributor's trigger wheel to a Big block and use that? Of so a little time and epoxy can make a cover to replace the cap. Save $ Maintain stock easy to find parts. Keeps the distributor to oil pump shaft in place. Just curious 
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Re: Add crank and cam pos sensors to BB (for Megasquirt)?
[Re: JimG]
#1306959
09/20/12 02:25 PM
09/20/12 02:25 PM
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Joined: Feb 2003
Posts: 21,318
Manitoba, Canada
DaytonaTurbo
Too Many Posts
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Too Many Posts
Joined: Feb 2003
Posts: 21,318
Manitoba, Canada
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Quote:
Quote:
I suggest just forgetting the COP setup and running a distributor. It will save you all this fabrication work and headache and I don't think will have any measurable difference in performance vs the COP system you are envisioning.
Yes, I'm considering doing just that - getting it going in "fuel only" mode (with the existing ignition system) at first, then looking at integrating the ignition later.
The downside to running the existing ignition system is that I see no way get the equivalent of ported vacuum to keep the vacuum advance working as it does today. But, with all the fuel only systems available today, someone has probably come up with a workaround that I haven't stumbled onto yet.
One other startup option is to run COP in wasted spark mode and to run the fuel in batch fire rather than sequential - both possible without a cam sensor.
Thanks,
Jim
Megasquirt can control ignition timing without doing COP. Take a lean burn distributor or a stock electronic ign distributor(with the advance locked out) and throw it on. Megasquirt can control your entire ignition timing curve. From the outside it will look stock - distributor, wires, etc, but it's all computer controlled. That's why I say I don't think you will see any difference between this and COP. Generally I would not suggest going through all the work to go EFI just to leave a mechanical/vacuum distributor there.
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Re: Add crank and cam pos sensors to BB (for Megasquirt)?
[Re: JimG]
#1306962
09/21/12 11:45 AM
09/21/12 11:45 AM
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Joined: Dec 2010
Posts: 208
Norrland, Sweden
Swedcharger67
enthusiast
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enthusiast
Joined: Dec 2010
Posts: 208
Norrland, Sweden
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Jim, stick to your original idea with a crank sensor and tooth wheel, you don't want the bad precision from a distributor signal. The cam sensor on the other hand can be something simple like was suggested above. I have the same idea as you, if you know where I can get the good coils at a reasonable price, pm me... Martin 
Martin, 67 Charger, 512 cui, E85, MegaSquirt MS3X sequential ignition & injection
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