Timing on newly forged motor!
 

Hey guys! So I just rebuilt my motor and have been having a hell of a time getting the timing right. I took the CAS off and twisted it past the adjuster and the car runs great, however I know that this is only a temporary fix. I know there is a way to count the belt teeth or something to double check the timing.
Thanks!
Chase
Forged on Manley rods and 8.8:1 supertech pistons!!! Ready for a turbo!
https://www.miataturbo.net/attachmen...ine=1374090021
https://www.miataturbo.net/attachmen...ine=1374090021

19 teeth between marks looks good. Does everything line up otherwise? The main crank notch, and then the upper two. It's impossible to tell at the angle this picture was taken.

From this angle looks like exhaust is a tooph off. But that could be the angle of the dangle.

Also no coolant re-route no ready for trubo.

Hmmm ok, the yellow notch on the crank is top dead center right? I can take more pictures however I was hoping I did not have to remove the crank pulley.

coolant reroute is on my list to do also :)

https://www.miataturbo.net/attachmen...ine=1374091088

Make sure the cam marks line up correctly like this.

I honestly was not aware that you could set the timing without pulling the crank pulley to see the "notch" on the timing belt cog.

However, i'll let others help you out on that.

https://www.miataturbo.net/attachmen...ine=1374091604
Ok I may just pull the crank pulley, but im almost posotive I got it right the cams are perfectly horizontal as well.

Got the crew pulling the crank off. I'll keep you guys updated!!
Thanks!

Maybe.

Crank pulleys have been know to deteriorate and slip.

Crank gears aren't always on mark either. Keyways deteriorate and there's even been one instance from a member this year where the the Woodruff key sheared, which means the crank gear wasn't aligned with the crankshaft (he had a supercharger though -- more stress).

Easy way to tell if you can rely on the crank pulley mark is to stick your dipstick into the #1 spark plug hole. You should reach TDC when indicated by the crank pulley mark. Otherwise, something else is off as described above.

Crew? You let someone else work on your Miata?

You want the little marks on the teeth of the cam gears to lign up with the back cover

Read here...is about the same as your 1.6.

Yeah I stole it from Revlimiter...what of it?

NB Miata timing belt change — revlimiter.net

https://www.miataturbo.net/attachmen...ine=1374093720

My crew is just my two friends who are helping me out today haha. Thank you Mica I'm working on it now!

Exactly, I'd just time it off the cog the timing belt goes around. It has a notch you can line up perfectly and go from there.

https://www.miataturbo.net/attachmen...ine=1374095100

https://www.miataturbo.net/attachmen...ine=1374095100

hmmmm

The E and the I are aligned with the backplate its just hard to get a good picture.

Hard to tell in the pics, but as long as they are aligned you look good to go. 19 teeth between the top marks is right.

What was the problem with the motor? What ECU, injectors, etc ?

The motor will not turn over if the CAS is on the adjuster, if I remove the CAS from the adjuster and spin it 90 degrees it will fire up and run great. It is a fresh motor with Manley rods, 8.8:1 pistons, and everything replaced haha kind of depressing being so close...

On a megasquirt? Try messing with the trigger angle is megasquirt settings until it starts, then time it from there.

Hmmm . . . .

90° out.

Hmmm . . . .

Might we have the spark plug wires connected to the wrong coils?

Hmmm . . . .

Injectors would have to be wrong too. Something in the ECU settings is 90* off.

and if they line up that perfectly it tends to me it's not correct, as the intake cam in that case would be off at least 1 tooth.

cliffs: the OP's timing is correct and shouldn't be touched.

??

Unless he's switched to sequential injection, the injectors just run off duty cycle and aren't timed to the engine.

?!?!?!

The injectors are absolutely timed to the engine, regardless of whether batch or sequential operation is in use.

That said, the firing angle of the injectors is almost totally inconsequential. Outside of idle, you'd be hard-pressed to identify a 90° change in injector timing.


Assuming the OP is using a Megasquirt (I don't remember that question being directly answered), I can pretty much guarantee that the coils are reversed. This is easy to do, especially on the NAs, because the build documentation that most everyone follows is reversed, which gets cancelled out by the fact that the default CAS settings which DIY specifies are ALSO reversed.


Put the CAS back where it belongs, flip the plug wires between the two coils, and the engine will start.

So, that's two votes. Anyone else? :party:

Time for a threadjack!

I just want to make sure my understanding is correct.

First, as you correctly pointed out, we don't know what OP's setup is. However, in one picture it looks like he has stock coils, so I assumed that he was running wasted spark and batch fire.

My understanding of batch fire is that multiple injector are fired at the same time for a certain pulse-width duration under ECU control. The timing of the batch fire signal does not necessarily correspond to an intake valve being open (and, in fact, could only have this relationship for one injector of the batch). I'll certainly defer to your knowledge on this -- you've looked at MS signals on a scope, I haven't. Just trying to make sure I have a correct understanding.

You are correct that multiple injectors are fired simultaneously in batch-fire mode.

It would be incorrect, however, to posit that the injector firings are not timed to the engine. There is an absolute phase-relationship between the injector firings and the engine rotation. The timing is (somewhat) optimized to correlate with the intake cycles of the paired cylinders, albeit with one valve opening 180° after the other (as opposed to 360°, as would be the case is the injectors and coils were paired similarly.)

This is the reason that the injectors are paired differently from the coils. It never made sense to me until I actually looked at the scope traces and overlaid the TDC positions, and then it clicked. The injectors are paired on cylinders which fire adjacent to one another.

So, a bastardized sequential approximation. Interesting.

yes thats why I posted a better picture of the actual marks on the tooth that is supposed to lighn up cam cover.

M.net...what else can I say.

Right, which is why the MS's default batch-mode puzzles me so very greatly.

Every two-channel inline 4 I've ever seen has been paired like the Miata, with 1/3 and 2/4. And yet the batch-injection mode on ALL Megasquirts (1, 2 and 3) fires each of the two injector banks a minimum of TWICE per engine cycle, and there's no way to work around this. As a result, it is completely impossible to correctly align the injection angle on a 1.6 Miata using a traditional MS. (1.8 owners can work around this by pairing their injector 1/4 and 1/2 to match the firing order.)

With the MS3X/Pro, you can work around this by lying to the ECU and telling it to run 4 channel sequential, but connecting only to two of the injector lines. (I can't remember which two align correctly at the moment), and thus match the OEM config.

Or you can re-wire the car for sequential. :)

words that are over my head because I don't want to think:

The Miata wiring was the original source of the "MS2/Extra 2.x semi sequential settings" which is now called sequenced batch fire in MS3.

This allows a repeatable sequence but allows "2 sq alt"

It is called "Injector Sequence" on the Advanced menu.

The "start" value will be set to 0 or 1. The "mask" allows a form of rudimentary injector timing.

What it does is force the batch fire fuel to align on a particular cylinder for more repeatable results.

It's still wrong (relative to OEM wiring on a vehicle originally built with two-channel injection on an inline 4) because 2 squirts per cycle.

That is the very heart of the problem.

The 2 squirts thing is fine if you're downgrading a car originally wired for full-sequential (so long as you know to wire it "incorrectly" relative to OEM) and you also don't mind that you're doubling your injector dead-time and thus throwing away fuel resolution.

full-sequential like a boss over here.

Yup. Re-wired my '90 for full-sequential as well.

I just find it odd that the owner of a '90-'93 Miata (or any car originally delivered with 2 channel injection) cannot properly phase their injectors on a Megasquirt which also has two injector channels, simply because the damned software cannot be made to understand the concept of ONE SQUIRT PER CYCLE.

It sounds like the MS designers originally thought that the fuel injectors were wired together the same way as the wasted-spark coils. If that were the case, then two squirts per cycle could be aligned so one of the squirts was phased to the intake valve being opened on each cylinder. Alas, it's not the case. But what if you changed the fuel injector connectors around to align with the ignition system?

I look at it this way because dinosaur:
1. Better than a carburetor.
2. Better than throttle-body injection.
3. I like how my car runs, or at least I did before Joe illuminated me. Ignorance WAS bliss.

Can I have a dinosaur smiley?

The original MS design had no ignition controls at all. It was intended to be used with throttle-body-injection and a distributor, as an upgrade for carbureted American V8s using the same TBI hardware which was common in the 80s.

Everything which came after that, included wasted-spark ignition, was a hack added on afterwards.


https://www.miataturbo.net/attachmen...ine=1374265989

I need to MS my Fury.

LOL at the dino.

Yeah, that's pretty much what it was designed for originally. Megasquirt didn't have ignition control of any kind in the original design, hence the name. The ECU that we now know as "Megasquirt" was more properly called "MegaSquirt-n-Spark" back then, as it was a mod which allowed for one channel of ignition control (still required a distributor, but timing was placed under computer control rather than being purely mechanical.)



They're actually a decent company. I've bought a lot of little stuff from them- HLAs, timing belt kits, etc.

You get this thing working yet?

Hey guys sorry I'll update in case anyone else has this problem, my problem was that the CAS was flipped 180 degrees.... on the back of the motor there is two holes for the CAS adjustment screw, but you only use one. Thank you guys for your help!

wait, wut?!

There are two threaded holes on the back of the head, the machine shop put the CAS adjustment on the wrong side essentially flipping it

ohhhh i get it. So the tab was basically pointing towards the driver side, not the passenger?


I was going to say, the CAS can only go into the cam one way.

Yep exactly what happened! I was so concerned about the cam timing I forgot something so simple. I didn't even think about checking it because I assumed the machine shop put it back on right after hot tanking the head haha....