Miata motor/trans as a standalone in another vehicle

Hi everyone, this is my first post on this site.

I've read a bit here but really haven't seen what I was looking for.

I'm starting a project that is similar to the new Morgan Three Wheeler, reverse trike. In the M3W they use a new S&S 2L motor mated through a compensator like Harley uses in their primary drive to a MX-5 5spd trans. They then run it to the rear final drive which is a 90 degree bevel box made by Quaife.

I'm thinking of using a "B" Harley motor or just scrapping the V-Twin and using the Miata motor in its place still coupled to the 5spd. I have a Honda 1800 GW rear final drive that I'll be using as a 90 degree box and from its output run a belt back to a Harley 16"x5" aluminum wheel.

Here's the new M3W

Here's one of their inline 4cyl classics

http://pic80.picturetrail.com/VOL846/863774/24555049/409480465.jpg

So after all that, my question is this...

How can I run a Miata motor as a standalone system? I know that with LS GM motors people have abbreviated engine harnesses that allow this very easily. Does anyone make such a harness for the Miata?

Can I adapt an intake and run a carb, but then what do I do with the ignition? I know they use a crank trigger system, but it may be a lot easier than I think it is.

So can anyone give me some direction where to look?

Thanks.

If any of you would like to see my interests as a gearhead, take a look at my signature Picture Trail link. I've been a bike rider all my life which puts my bike riding day are just over 50 years. I've raced snowmobiles in Michigan in my late teens, had a marina with my parents where I was the mechanic and built dune buggies as well as several full on streetrods. My last streetrod was a '40 Willys coupe with a blown 392 Chrysler hemi putting out 654 hp.

I digress.

Thanks in advance for what I hope will be some direction in my project.

I'm thinking my picture links will not show up as I'm used to to insert pictures and I'm not familiar with the type on this forum. You can just copy and paste the Picture Trail links and see them in my albums.

Dan

Welcome! My first thought to your project would be to use all motorcycle parts from something that's shaft drive, but since the Miata is the darling of this place, you won't find much resistance with that as a swap! I think the Miata harness is pretty straight forward. My Miata doesn't have power locks or windows, or even power steering.

RossD wrote: Welcome! My first thought to your project would be to use all motorcycle parts from something that's shaft drive, but since the Miata is the darling of this place, you won't find much resistance with that as a swap! I think the Miata harness is pretty straight forward. My Miata doesn't have power locks or windows, or even power steering.

Ross, thanks.

I was hoping for a bit more information about using the Miata motor with minimal wiring, kind of what would be needed to put the motor on a dyno and run it.

I understand that some of the 1.6L motors had a two piece intake manifold. This may be somewhat easy to make up an upper plenum to run a two barrel or small four barrel carb.

The ignition being a crank trigger system is hard to hook up without some wiring of sorts. So if there is a guide to removing wires from the engine wiring harness on a Miata, I would be interested in buying that.

I know on LS motors there's enough information out here on what wires are not needed etc and when done, they are pretty bare on the wiring actually needed to run and manage the motor.

The wiring of my project car is of no issue to me, but the motor management system is.

Maybe the above widens my question and makes other options seem more available.

Thanks again Ross and maybe others can offer other bits of wisdom...

The CAS (crank angle sensor) on a Miata is actually driven off the camshaft. The Miata used the CAS because a conventional distributor will not fit in the limited space.

The 1.8 engine in an Escort GT is the same basic engine as the Miata and it has a conventional distributor, but unfortunately the distributor has a solid shaft and no centrifugal/vacuum advance.

You could easily adapt an old school distributor from a VW /Fiat/ or other small four cylinder to fit a Miata engine. You may have to fool around with the weights and springs to get the right curve but it is very do-able.

Megajolt is also another option. It is a programmable ignition computer that would allow you to use an Aspire / Festiva/ Escort GT distributor on the Miata engine.

fujioko wrote: The CAS (crank angle sensor) on a Miata is actually driven off the camshaft. The Miata used the CAS because a conventional distributor will not fit in the limited space. The 1.8 engine in an Escort GT is the same basic engine as the Miata and it has a conventional distributor, but unfortunately the distributor has a solid shaft and no centrifugal/vacuum advance. You could easily adapt an old school distributor from a VW /Fiat/ or other small four cylinder to fit a Miata engine. You may have to fool around with the weights and springs to get the right curve but it is very do-able. Megajolt is also another option. It is a programmable ignition computer that would allow you to use an Aspire / Festiva/ Escort GT distributor on the Miata engine.

I see on ebay that there are "some" distributors for the older 1.6L that have vacuum advance pots on them. I think that one of these may work for me, correct?

I'm not sure I want to go the route with twin side draughts, but maybe make up a manifold to use one of the GM Weber progressive 2bll carbs from possibly a 1.6L Chevette or some other 1.7L or 1.8L earlier car. I see quite a few from the larger Vega/Astre etc that are probably a bit too large for me. I'm not going to be racing this, but want good throttle response and low to mid torque. I know, keep the fuel injection, but I do want to keep this simple with the least amount of wiring as possible.

Thanks again guys for the input.

Have a great weekend.

Dan

What does a Miata weigh vs a Harley, CX 500 et al weigh?

Do you want all that out front? That kit weighs what, 800 lbs? Now cantilever a Miata in front of the axle. Oy.

Are you looking for a cool reproduction to go for ice cream in or are you trying to blister as many tires in a summer as possible? A Miata driveline in a Catterham 7 is fine, but you're talking vintage motorcycle project.

What's your goal, where do you want to be when all the time and money is spent?

Dan

Dan_Lockwood wrote:

fujioko wrote: The CAS (crank angle sensor) on a Miata is actually driven off the camshaft. The Miata used the CAS because a conventional distributor will not fit in the limited space. The 1.8 engine in an Escort GT is the same basic engine as the Miata and it has a conventional distributor, but unfortunately the distributor has a solid shaft and no centrifugal/vacuum advance. You could easily adapt an old school distributor from a VW /Fiat/ or other small four cylinder to fit a Miata engine. You may have to fool around with the weights and springs to get the right curve but it is very do-able. Megajolt is also another option. It is a programmable ignition computer that would allow you to use an Aspire / Festiva/ Escort GT distributor on the Miata engine.

I see on ebay that there are "some" distributors for the older 1.6L that have vacuum advance pots on them. I think that one of these may work for me, correct? I'm not sure I want to go the route with twin side draughts, but maybe make up a manifold to use one of the GM Weber progressive 2bll carbs from possibly a 1.6L Chevette or some other 1.7L or 1.8L earlier car. I see quite a few from the larger Vega/Astre etc that are probably a bit too large for me. I'm not going to be racing this, but want good throttle response and low to mid torque. I know, keep the fuel injection, but I do want to keep this simple with the least amount of wiring as possible. Thanks again guys for the input. Have a great weekend. Dan

Thanks for the comments.

I've been traveling for work of late and have not had a chance to reply back.

With the Miata 1.6L or 1.8L, it would be positioned similarly to a T-Bucket with the front of the motor behind the front axle line.

This project planning is morphing from one thought to another.

I have a front set of control arms from a wire wheel MGB. I was planning on independent front suspension using and modifying the MGB setup, but then it morphed into a Speedway Motors 6" dropped solid axle setup and either using different wheel bearings or modifying the Ford style kingpin spindles to allow the MGB wire wheel splined hubs to mount up. The project has to have wire spoke wheels...

The stock front/rear weight ratio of a Morgan Three Wheeler is 69/39. Imagine this is comparable to what I ended up with on my '40 Willys coupe with a blown Chrysler 392 up front. Man those motors are a huge weight to have up front.

So I've been looking a lot about the distributor for a Miata 1.6L or 1.8L motor. I can get a distributor from eBay that has vacuum advance on it and using the pickup wires to feed back into a MSD 6AL, I think that would work. Any other suggestions on the spark concerns? I'm really into uncharted water for me on this motor. I'm more old school with carbs and distributors that you can see turning. Don't get me wrong, I love the new tech of fuel injection and crank trigger spark, but I'm just not versed on it and would need to study up on it more.

As far as intake goes, I'm still thinking I can waterjet a manifold engine plate and then build up a tube type plenum coming back into a mount for a Holley/Weber progressive two barrel for a similar sized motor.

This will NOT be a performance ride, but a slow cruising fun driving cycle/car. It will remain a two seater and the body will pick up a pair of doors for easier entry and exit. Wheel base is going to be around 100" and front track will be in the range of 60". Front tires will be 18" 4.00", probably side car tread as they tend to be a more flat contact patch rather than motorcycle rounded surface tires. I have the rear wheel now, a late model HD 16"x5" and will be running a 186/55-16 all weather tire. I also have the rear rotor and caliper from the HD. A fully loaded touring HD is going to be about the same weight, within a couple hundred pounds of my project cycle/car. I could upgrade the rear caliper to the newer HD Brembo 4-piston one, but time will tell there. I will also be running Wilwood 4-piston calipers up front. My pedal combo will be Wilwood with two masters for the brake and one for the clutch. Bore sizes are yet to be determined. Unless someone here knows the bore of a stock Miata clutch master???

So from a chassis standpoint, I'll probably make up a rectangular tube dual longitudinal main frame rails with appropriate cross bracing. It will also have uprights that tight in and go from side to side for body attachment as well as a frame about the dash area for steering mounting etc.

Sorry for rambling here, but my mind just keeps going and I cannot shut my fingers up...

Now one last comment totally reverse of some of my above motor conversion statements, how hard would it be if I had ALL of the wiring harness from a Miata, ECM included, to run a standalone Miata motor in a minimalist setup like I described? I know in the LS genre, they're are sites that tell exactly what is needed and not needed along with wiring colors to strip a wiring harness of the unnecessary components etc. I know that the market for the LS conversions far exceed about any other swap today and the Miata motor swap is usually to take out the motor and swap in something else, but does anyone know how to strip down a Miata wiring harness to run like I need?

Thanks again for taking the time to read my ramblings.

Have a great weekend to all!