Datsun / Mazda /Nissan / Ford Frankenstein motor

[antus]

The 4 cylinder looms are pretty stand alone and easy to pull out almost in their entirety. What sort of CAS is the one you are using? Grab sensors like coolant and manifold air temp (leave them on the loom). If the seller isnt charging too much and just sells you the lot for a flat fee grab the map sensor too. You wont need it for your conversion but its nice to power the loom and computer up before you install in the car and see sain readings of room temp from the sensors and ~ 100kpa from the map, less if you suck on a hose to create vacuum. The commodore CAS is useless, and only grab coil if your planning to setup the american trigger system and run a D1927a or LX345 coil pack module. I looked in to this the other day for a new project and those modules have gotten rarer and more expensive though, so Im currently thinking a VL400 ignition module will be better and provide more CAS options.

[reuby_tuesday]

What sort of CAS is the one you are using?

The CAS is the standard mazda B6/BP unit that bolts into the back of the head, on the intake cam from memory. Ignore that this image shows it on the exhaust side, (and blanked off) its just a later BP (1.8l) head, but they are essentially the same. The hole is same size, just on the other side.
I'll blank off the dizzy hole in the datsun block.

Mazda BP head

99head4W.jpg (52.55 KiB) Viewed 6454 times

So, the shopping list,

4 cyclinder cars - take the whole loom and anything connected to it. Im on the look out for an N13 pulsar now. If I can buy a complete car, pilfer as required, and then sell the wreck again will be the way forward.
VN dunny dores - not much it seems, just the ECU and as much loom as possible from under the dash - hack it out. I've got access to 3 x VX V6 cars for nix. Ill go and steal the coil packs for Justin (just in case). That might be a job for today. I'm at work, so I'm sure the boss wont mind me visiting the training yard. Ill tell him i'm prepping for training on Tuesday!

The Standard MX5 intake uses a MAF sensor, so should be able to utilize that hopefully. Else, bolt on a universal TB and screw in a MAP sensor.

For the coil packs, I was planning on using a wasted spark coil pack system from a silvia or similar car, but open to options on this. individual coils or a coil on plug option is also viable - Perhaps i can fish out on old oil filled coil from my stash

[Charlescrown]

Your correct with the knock sensor. No you don't need it. They are designed to work at a noise frequency generated when the engine pings and is relative to the bore size. The filter is designed to match the dimensions. "festy" has made adjustable knock sensor boards but I haven't had anything to do with them. Have a look in the for sale section of this forum. I just fit the V6 and find they do work and I don't get any false knock recording but are they sensitive enough I don't know. What I can say is they detect knock and I tune it out with the timing map. Most turbo engines don't last if the engine pings. Kabang.
You will need a 2 or 3 bar map sensor if you use an 808 and 12P not a maf.
Also grab the ignition module from the dissy along with the coil it will depend which way you go with the ignition.

[antus]

Yep, because its not an after market computer you need to provide delco compatible signals. MAF is out, MAP is good. If you use a universal TB try and get one with support for a GM IAC. You wont be able to make it idle at the same revs over different temperature conditions without it, and you wont get the fine rpm control without it. What signal comes out of that CAS? Its unlikely you'll be able to use it. The Delco CAS or Distributor controls the spark, and there is a propriety interface. If you use a reluctor distributor the module on the pulsar distributor will provide the delco compatible interface, and the rotor sends the spark to the right cylinder. If you have the American 4cyl D1927a module with commodore V6 coils the module provides the interface and controls which pack is firing and you need to fabricate a wheel with the right trigger pattern. If you get a VL400 ignition module it supports some common trigger patterns and you can get use an off the shelf trigger wheel.

See this thread
viewtopic.php?f=15&t=128&p=1428

And
viewtopic.php?f=11&t=2913

[reuby_tuesday]

righto.

As Im sure you find often, newbies trip up at every corner. Thanks for the heads up.

MAF is out, MAP is good

Im on the lookout for an N13 pulsar to raid including the MAP sensor.
As it seems the Mazda TB wont be any good as you mention about the idle control, then the MAF goes anyways.

If you use a universal TB try and get one with support for a GM IAC. You wont be able to make it idle at the same revs over different temperature conditions without it, and you wont get the fine rpm control without it.

For the TB, if i grab a commodore unit will that suffice? Ive got 3 x VX wrecks in various states to pilfer from.

What signal comes out of that CAS? Its unlikely you'll be able to use it. The Delco CAS or Distributor controls the spark, and there is a propriety interface.

I wanted to stick with the standard mazda CAS as its neat and is a factory part that is easy and reliable. My project is enough of a Frankenstein without using custom parts if i can avoid it.

Mazda CAS

cas_wires.JPG (21.92 KiB) Viewed 6432 times

This is image showing the wiring for the Mzada CAS. Its a 4 wire setup like you mention the Delco needs. What specifically does the delco need as such? Does the above diagram offer any cluse as to what the mazda outputs?
I can post over at the Mazda forums to ask for their technical advice.

ECU sensor layout

ecu_sensor_2.jpg (70.45 KiB) Viewed 6432 times

This image shows the back of the head with the CAS in place for reference

If you get a VL400 ignition module it supports some common trigger patterns

Reading the thread about the VL400 modules, that may be the way to go. Seems like the goods to use with the 808.

[Charlescrown]

While it's ok to use the std map sensor initially save yourself some time and get a 2 or 3 bar sensor. Be careful as eBay sellers have lots of crap ones. It's just that if you run the turbo straight up you can't go into boost without the 2 or 3 bar map meaning if you start tuning with the std one you will have to do it all over again. If you have downloaded 12P I can post up my (unfinished after 8 years) bin file. I am currently running 18 psi boost but it might be a real good starting point. I am not familiar with your CAS so can't comment. Maybe you can post a wiring diagram or more info.

[antus]

The cas is not going to be compatible. The delco modules have a fat +12v for coils, +12v for signals and grounds. Then the 4 wire interface is + and - (high and low) for a 5v square wave for RPM and one called EST and called Bypass. The module provides its own spark trigger below a programmable RPM (450 from factory) to get the engine moving. Then above this rpm the ECM sets the bypass signal and sends the variable spark trigger out the EST line. This signal is the same for 4, 6 and 8 cylinder, commodore or american hall effect, and distributor reluctor. The different ignition modules themselves convert the differing input signals in to this '4 wire' (2+1+1, not counting power) signals. If the mazda is runinng coilpacks there is very little chance you'll be able to use it but if it has a distributor then a signal similar to a sine or square wave might be able to feed that in to the pulsar ignition module. Getting the reference angle can be a pain (and wear out your starter) but you can ground the diagnostic mode pin on the ecm and you'll get a static 10 degrees of timing. If its close enough to start on whatever degrees you get from the ignition module (not programmable), then you can realtime the ecm reference until you can observe it idling at 10 degrees and your set.

the tl;dr of that is unless its a distributor, plan to set up your own trigger. There are a couple of threads where this has been done, and there is a lot of info the first thread I linked above.

The commodore TB will be OK. Once you have the fuel and spark dialed in there are some other settings to take in to account the amount of air dumped in when you open such a large TB on an engine like that and the enrichment/enleanment is in milliseconds of fuel so will probably need tweaking too. But that will come much later.

[reuby_tuesday]

Poo Poo on the CAS being no good. its such a nice and clean option. Still thats the way it is.

I have an electronic dizzy from an N12 pulsar with the E15 motor. That can swap into the datsun block dizzy hole with only a cog gear change.
At the very least that will get the ignition sorted and working, and I can look at cleaner options later.

The FJ20 CAS slots into the same hole, as well as early 80s VW hall effect dizzys, and a few other random units that happen to be the right dimensions.

I'm not sure what type of dizzy the E15 unit is, hopefully it ticks the boxes.

As for the TB, i didn't think about it being to big. Ill get one I spose to start, and look for a smaller unit that is similar size to the MX5 one and compatible with the Delco.
Ill also look at the MX5 unit and see if that outputs the right signals - after removing the MAF if that possible.
I spose a TB of a smaller 4 cylinder like the Pulsar would be a better start. There is a N14 available to me as well. I might go raid the TB off that, but that would use the nissan BCM.
Its looking more and more like I need to buy a complete (or at least a front cut) N13 pulsar so that I can raid as necessary without going back and forth to the wreckers

Thanks again for the advice guys. This is why i prefer to use forums for this kind of thing and not Facebook. Crackbook may have killed off many forums, but its just not the way forward for the serious person. Great for piontless chatter, not so good for technical conversations.

[vlad01]

Why not make up a crank trigger and use the programmable module? way better than a dizzy or cam driven CAS. More accurate and not subject to jittering as anything reading the valve train side does.

[reuby_tuesday]

Why not make up a crank trigger and use the programmable module? way better than a dizzy or cam driven CAS. More accurate and not subject to jittering as anything reading the valve train side does.

Ill have a look at this in more detail once I have the motor together (hoping for that to be my January project)

I do have constraints everywhere with this project that without photos are hard to describe. Space in every direction is at a premium. (ill add photos as they become available - and some already available in other forums that I'm linked with)
The motor itself is an amalgam of parts from so many places that have little to nothing to do with the car its going in - its what makes it such an exciting project. My everyday work is very uninteresting / unfulfilling, like many, and this is the side project that keeps me sane.

I already have lost space in front of the motor as the drive for the DOHC is an add-on pulley on the crank - the usual place where you might fit a 36:1 trigger wheel or similar.
I am loathe to add anything else here as I have to fit in a radiator and hopefully a FMIC in there too! Air-con is out, as much as I would love the luxury.

So whilst a crank trigger may be the best option from a signal stability viewpoint, a CAS or distributor that is located where space is more available may have to be the best trade-off. I'm not locked into one decision as such. Anything is an option, but if a CAS or dizzy can provide a signal that is suitable (maybe not perfect) then that's probably the best option for this project - Not sure yet. We will see.

Thanks again team. Everyone here has already either answered questions for me, or predicted issues that Ill hit and answered up front.

Just collecting the right parts is proving more complex that I initially thought.