installing a miata CAS onto an FE3N
 

My quest to make a shaft extender to use an unmodified miata cas onto an FE3N. I searched and didn't come up with anything so i immediately assume it's a bad idea but can't see why yet. I'm going to be putting 3 fe3s mated to b2600 trans into my truck and into two of my friends cars within the next year. All will be running megasquirt and since i run into weird problems and come here for help id like to keep the MS as close to MX5 as possible.

The actual adapter it's quite simple as i have access to a lathe at work.it will be a one peice aluminum shaft with disc that would replace the "T" on the CAS. It would be pinned into place Just like the "T" and directly index onto the peg on the fe's cam.


https://www.miataturbo.net/attachmen...ine=1439410243

https://www.miataturbo.net/attachmen...ine=1439410243





Idea

<p>Sounds cool. If it was balanced and everything I bet it would work.</p><p>@yank, @m2cupcar are the local FE3 guys. @concealer404 too.</p>

Isn't there already a workaround for this?

I like the idea, though.

Why not just run the OE fe3 CAS? The megasquirt picks it up just fine. Its also low profile so you'll have a bunch of room between the sensor and firewall.

i want to use the miata one for both the crank/cam signals. i already have a MS1 that im going to upgrade to an MS2 and would like to not have to change the board for different crank/cam inputs.

im using the sportage fe3n but im using the B2600 clutch/flywheel/trans which doesnt have the crank pick ups on the flywheel. i think it will be simpler for me to use it instead of making a pickup on the crank pulley.

i talked to 18PSI earlier about possible variation in the signal if the tolerances are too loose but im pretty sure i can make it zero clearance.

You need an FE3 distributor. Move the Miata CAS guts to the dis body. Then either rekey the disk for correct offset OR if the engine management is capable, determine your offset and adjust accordingly. I've done both successfully.

i was just looking for an FE3N dizzy but they look like they use a BP style slot in the cam. the sportage cam is not slotted, it just has that pin sticking out and thats it. Will i need an exhaust cam out of a genuine mazda FE with the aluminum oil pan?

:doh: - missed that part. Yeah- you need the Mazda FE3 exhaust cam. I would disregard the oil pan ID method since mine had a steel pan and gold cam cover with the FE3N cams and the lower (catalyst) compression. Offhand I can't remember what the other cams are - but the FE3N is second most desirable. And the bottom to avoid is strictly aimed at fuel economy.

This probably the largest collection of FE3 owners: https://www.facebook.com/fedohc?fref=ts

You can also find FE3 parts for sale at mx6.com

I think your adapter idea would work IF you sleeved it over the cam end so you could pin it the same as the Miata CAS drive. If just using the pin, then you'd need to attached it like a cam gear IMO - which is probably more of challenge.

My intake cam is a FE3N but the exhaust is a K013. It's going to slide inside the cam instead of over it. I suck at drawing but heres a better idea of what I'm planning.

https://www.miataturbo.net/attachmen...ine=1439480114

Is the adapter fastened to the cam end, or are you relying on the CAS to keep the adapter engaged in the cam end? My (non-engineer) gut says to keep it OE so you have the adapter fastened to the cam as if it was THE cam end.

Im going to make it a tight fit and rely on the cas. If i had a way to secure the cam into my lathe i would make it a pressed fit and machine it as one piece.

get better at paint:

https://www.miataturbo.net/attachmen...1&d=1439484966

Hahaha awesome 3d rendering. That's what I'm going for.

Edit: maybe if i put a spring inside the adapter that will push against the cas and keep it seated into the cam it will be a little added security.

Yeah that's my only problem with this extension idea - if for whatever reason the cas was to move or shift or something, during 7,000 rpm, during a power shift (because let's face it, this thing is gonna get raped like a redheaded bastard stepchild, racing every single car in Sacramento :giggle: ), then you'd be in for a bad time.

My issue is the CAS is not design to press against anything. The key floats on the pin in the CAS and floats in the CAS slot. It looks like the adapter penetrates the cam end? Can you not drill the cam and adapter for a pin through both- similar to the CAS pin for the key?

yeah see, this is why I'm nervous about his idea. if the part was not designed to have pressure on it, there's some potential for falilure.

A threaded hole into the cam with a bolt holding the adapter might work though. (better be seriously balanced though)

The cam will only to 3500rpm

Lol that's still enough speed to break stuff should that piece come off
Also leave you stranded on side of road as the mercedes you just smoked drives away :giggle:

I'd do it and not think twice...

















...smoke you in my mercedes that is.


the cam is held onto the head, is it not? no way it could move.

Ill try to finish it after work and post the finished product

https://www.miataturbo.net/attachmen...ine=1439501489