Recommend a crank sensor???

[djb25]

Hi everyone,

I'm converting a 1977 911s with a 2.7l flat-six. I'm using an ms3/MSX.

Right now I'm near startup for fuel only, but intend to add a crank and cam sensor shortly.

What I need is a recommendation for a reliable crank angle sensor. I intend to use either a 36-1 or 60-2 wheel.

I've searched and I'm coming up empty - a few hints here and there, but no clear part numbers.

If more info is needed, just let me know.

Thanks!

[elutionsdesign]

I've used a Ford Escort 1.9 L crank sensor for a bunch of projects, not all of them auto related. They are inexpensive and readily available in just about every auto parts store in the US. Just ask for a 90's one, make up a year, I usually use 95.

http://www.oreillyauto.com/site/c/searc ... &make=Ford

[DaveEFI]

I'd check with an MS supplier in your country - if it's the US, DIYautotune is the obvious one. There may well be someone who can supply a trigger wheel, sensor and mounting bracket for your engine. Or they will supply just a VR or Hall sensor known to be fine with MS, and the connector to go with it.

In the UK, there is a company called Trigger Wheels who specialise in those and brackets and sensors.

[Matt Cramer]

We sell this sensor:

http://www.diyautotune.com/catalog/hall ... p-479.html

And a line of trigger wheels that adapt to most engines with some fabrication.

http://www.diyautotune.com/catalog/trig ... -c-48.html

The sensor works great - we've tested it with our trigger wheels up to 21,000 RPM with no problems.

If you were looking for something more bolt on, the only place I'm aware of selling bolt on trigger wheels for this motor is Clewitt Engineering. I don't have any experience with their triggers.

[Healey3000]

Hi everyone,

I'm converting a 1977 911s with a 2.7l flat-six. I'm using an ms3/MSX.

Right now I'm near startup for fuel only, but intend to add a crank and cam sensor shortly.

What I need is a recommendation for a reliable crank angle sensor. I intend to use either a 36-1 or 60-2 wheel.

I've searched and I'm coming up empty - a few hints here and there, but no clear part numbers.

If more info is needed, just let me know.

Thanks!

VR or Hall effect? If Hall, the Hamlin 55505 is a good one at a very reasonable price.

[djb25]

Thanks for the info, everyone, and sorry I took so long to respond.

It was my first post so I had to wait for approval. I must have missed the notification email.

So... there are a few companies (Clewett is one) that sell a bolt-on setup for the 911 flat six.

However, since I'm starting from scratch, I thought I would go with the most reliable option available. Unfortunately, I've been having some difficulty figuring out what that would be. I've read through the manual, and although it provides some useful information, it doesn't provide a good compare/contrast between options.

I've also done a bit of searching, and there seems to be a lot of conflicting info out there.

So... what are the advantages of a VR sensor over a Hall sensor? What about compared to a "gear tooth sensor"?

It seems like the "gear tooth sensor" is a good option, but the manual says that they don't work with missing tooth wheels, but then says that DIYAutotune sells one that works "ok" with missing tooth wheels. I don't want something that works "ok" - I want something that "works." I see a lot of posts about "sync loss" and I really would like to avoid those issues, if possible.

If someone could even point me towards a good compare/contrast of various sensors, that would be great.

[Matt Cramer]

By "works OK", our Hall effect sensor will follow one of our 36-1 wheels up to 21,000 RPM with no loss of sync. We're fans of understatement here.

[elaw]

So... what are the advantages of a VR sensor over a Hall sensor? What about compared to a "gear tooth sensor"?

VR sensors have two distinct advantages over Hall sensors:

1) They don't require power. Hall sensors require a source of clean +5 (usually, and obtainable from the Megasquirt) or +12 (less common) voltage.

2) The tweaking sometimes needed to get them to work can be a character-building exercise. Fiddling with adjustment pots inside the Megasquirt, adding different combinations of resistors to deal with issues at low or high RPM, etc.

I'd recommend using a Hall sensor.

Joking aside, the most common reason for using a VR sensor is that it came with your engine. If you're starting from scratch, other than the minor one-time inconvenience of finding and connecting a power source, a Hall sensor is usually the quickest path to success.

[DaveEFI]

VR sensors are a pretty reliable device - just basically a coil of wire. It's unusual for a decent quality one ever to fail. Hall effect are electronic, and generally are less reliable.
A VR sensor requires more sophistication in the electronics following it to covert a varying amplitude sine wave into pulses the processor can read.
A Hall effect produces pulses direct.

Hall is the obvious choice for lack of initial problems. I'd just make sure it is easy to change in event of a failure - and perhaps have a spare.