Hi guys,
I bought a new 1.6 clutch + 1.6 flywheel and installed on during an engine swap I was doing ('05 vvt). Finally got the swap finished started the car, couldn't change gears. Grinded one for a second attempting it. Sucks. Clutch pedal all the way down and the rear wheels are still moving.
New TOB, Pilot Bearing, Exedy Slave & Master. Measured the clutch fork travel under the car and it looks a hair bigger than 0.6". If I'm remembering correctly the master's pushrod is adjusted to the maximum length anyways so I couldn't get more if I tried.
Painstakingly dropped the trans, checked to make sure the clutch disc itself was not backwards, and retorqued everything down. Pressure plate in a pattern twice over to ensure it was torqued to spec ~20 ftlbs. About the only not "new" item in the circuit is the stainless steel clutch line...so maybe I'll change that next.
Any ideas before I give up and just buy a different clutch kit and hope for the best?

 

You've covered the basics, I would never suspect a SS line to cause any issue, I wouldn't bother swapping it. I don't know total throw at the slave cylinder off the top of my head, but .6" sounds about right, but it never hurts to bleed it another time or two.

Brand new clutches often grab a little bit until they're broken in. Is it totally engaged or just dragging a bit? Put the car in 1st with the engine off, push the clutch in, and start it. Does it lurch forward? Is it only a minor amount of brake to keep it from rolling forward? Or does it idle only a little low? If it's one of the first two, it's completely engaged and somethings wrong. If it's just idling a bit low, some clutch break in might help.

What brand is the clutch?

 

^^
Yep, I've been caught out a time or two by just how much bleeding a clutch master and slave can require before they truly work.
So, well worth pouring another bottle through.

 

It's a supermiata clutch. Their customer support has been quick and helpful and I know they make good products, hopefully it ends up being a problem on my end. If I can't get it working they're going to check it out and see if there's something up with it.
The car's still on jack stands, I've mostly been testing with it with the wheels in the air. Clutch down, 5th gear, and the wheels are spinning. Dropping the clutch causes a weird clunk but it might be normal. Based on the resistance I get trying to shift out of / into gears...I want to say it's stuck-stuck. Did some more slave bleeding with a couple different methods, pedal feels the same. Going to measure the clutch fork travel with a ruler and get the real value and if it's close to what I've seen online searching around (15 mm / 0.6"), looks like I'm dropping the trans.

 

This is from Flyin' Miata...

"Many performance clutches (including the ACT and FM clutches) will engage much closer to
the floor than a stock clutch, sometimes to the point of not dis-engaging completely, even
when the pedal is on the floor. Re-adjustment of the clutch pedal height and clutch master
cylinder free-play is almost always required or the car will not go into gear. Really, we mean it.
Please be sure to follow all of these directions before you call us. Even if you've put in dozens of
clutches, humor us- our way works. Here's how to do it:

Start by cracking the nut loose on the larger clutch pedal switch, it's a 17mm. Then unscrew
the switch a few turns, which will raise the resting position of the clutch pedal, giving you
more travel. Next adjust the free-play on the master cylinder pushrod by cracking the 12 mm
locknut loose. Once that nut is loose you should be able to easily turn the pushrod by hand.
You will need to lengthen it to reduce free-play. Turn the rod to lengthen and as soon as you
feel it touch the piston in the master, back off a hair. Get under the car (easiest with two
people) and try to push the slave pushrod back into its bore. If you can push it in, you still
have some free-play. If it won't budge, you have covered the fill/bleed hole from the
reservoir into the master cylinder and need to shorten the rod on the clutch pedal a little. If
you are able to push it in, be sure to pump the clutch pedal a few times to get fluid back into
the slave. You want as little free-play as possible while still allowing the slave pushrod to be
pushed back into its bore. Don't forget to tighten the locknut when you're done and then recheck
that the slave pushrod still goes back into its bore when pushed by hand.

Technical note: Understanding how a master cylinder works may help understand our
adjustment procedure. A properly adjusted master cylinder has the piston just behind the fill
hole from the reservoir. As soon as you step on the pedal, the piston covers this hole and
you start generating pressure in the hydraulics. If you have too much free-play, it means you
are using up part of your pedal travel just getting to the point where the piston passes the
hole, so your clutch may not dis-engage fully. On the other side of the coin, if you adjust out
all of the free-play, you will cover the bleed/fill hole. This does two very bad things. One is
that your clutch fluid can't go back up into the reservoir as it expands with heat. If it can't
bleed into the reservoir, the fluid will build up pressure in the system and try to disengage
the clutch by pushing on the slave cylinder. The second bad thing is this: as you remove
free-play and pass the bleed/fill hole, you are “reducing” clutch travel by moving a smaller
volume of fluid than if you were properly adjusted with the piston resting just behind the fill hole.
This is a common error. “If I tighten it more, I'll get more travel, right?” Wrong."

The only other thing I can think of is the friction plate is in backwards.

 

Raising the clutch pedal seemed to help a hair. I could roughly feel gear engagement but could actually shift gears. ADDING a lot more Freeplay on the pedal and then I could actually shift gears smoothly. I don't understand it. Most videos have you reduce Freeplay just until the pedal is firm and then back off a hair to keep a little Freeplay (which is where mine was). It works and if this means I don't have to drop the trans again, even better. Going to hope this holds up this way. Time to put the hood back on and drive this thing for once since swapping the engine. Appreciate the help guys. I'm still at a loss why this worked but w/e.

 

Great to hear. I saw the quote from Flyin MIata tech notes, and threw a cat to him immediately.
That looked like good advice.
Glad to know it seems it was!

 

That’s a tough one, sounds like you’ve been super thorough, so I feel your frustration. If the clutch disc is installed correctly and the TOB, pilot bearing, and hydraulics are all new, the issue might not be the clutch kit itself but something else in the system

The 0.6” clutch fork travel you measured should be enough in most cases, but if it’s on the low end, it might point to a hydraulic issue. Before replacing the clutch kit, I’d double-check a few things. bleed the clutch system again, even if it seems fine, sometimes air can hide in the lines and mess with travel. If you’re running a stainless steel line, it’s unlikely, but a damaged or kinked line could cause reduced pressure. Swapping it out would at least eliminate that variable.