The "Good" Engine

We left the last post having just dropped my 2nd engine out of the MX6 having had trouble with the initial engine having a few low compression figures on the cylinders that weren't firing. I had tested the engine in the MX6 and had slightly lower figures but they were all consistent so it was a decent place to start from.

With the engine all painted up and attached with all the necessary ancillaries, it was ready to go back in. I've had the engine in and out so much I decided on this lovely sunny day that I would do it myself and hopefully be ready in time to enjoy the rest of summer. Only issue is I'm still "recovering" from my surgery so probably get a slap on the wrist by the doctors for this. I'll take it easy. Promise.

Nearly there on this photo. Nice and easy to get back in. See. About time something started going right...

Whoops. Spoke to soon. Struggling to get the gearbox and engine to mate up properly. This would be much easier with someone not under doctors orders to help wiggle the engine about. Too late to turn back now! Thankfully it didn't take much to get done properly.

Another standard "engine back in" photo opportunity. Sooooo much space in front of the engine. Nicely bringing the weight back

Thought it was also a good time to put my new aluminium radiator on to help deal with the extra heat this thing may produce. Not that I currently have a working temp sensor to use....eitherway, looks nice. Rad, fan and shroud from a '92-'00 Honda Civic, cost about £60 delivered. Bargain compared to the GBS one at over £300!! Only thing I need to do is some fixing brackets. Easy that. 4x 1.5mm mild steel flat bar, 8 holes, bolt up and job done!



So, with that back in, I guess I should fire it up and test Jez's theory on the new firing order.

[insert video of it backfiring through the throttle bodies and not starting - use your imagination on this one, camera wasn't running]

As you can hopefully see from your imagined video, it didn't work. It wouldn't even start. Maybe the infallible Jez has finally been beaten! Back to my original firing order from Stoneleigh.

[insert second imaginary video of backfiring and not starting]

Yep now I'm confused. I mean, it backfired less but still would not start. Double checked leads vs Stoneleigh. Nope, still the same. What is going on here?! One thing mentioned at Stoneleigh was timing. Was that correct. I'd double checked once home and both the mechanical timing and also the microsquirt timing was all spot on as it should. As this had given me consistent compression test results, I'd assumed this was also fine (having also ran no issues prior to being removed).

Anyway, sanity check as a starting point.......oh whats this? These two red circles should overlay. With the crank in the correct position, the cams are miles off!



As seen here as well. Both sides a fair distance out.


Don't ask me how. I do not know. Belt tension is fine, so is the tensioner. I've not even had the front cover off until now! Something jumped somewhere.....











Anyway, grabbed my Haynes manual and double checked I wasn't going mad, reset the timing and away we go. Luckily Mazda like their non-interference engines so cranking this one didn't do any damage to the valves.

Partly due to keeping a known firing order that had the engine running but mostly due to the fact the ignition leads hadn't been touched, I fired it up. On the button. Like it had never been sat at all. These Mazda engines are awesome. Well...they would be if they fired on all cylinders. Alas I was still on 3 cylinders.

Time to see if the timing had been ruining Jez's theory...new firing order in....fired into life! Lots of smoke and burning from the cylinders originally vacant of combustion! We have a winner! Jez saves the day.....again. All 6 cylinders now reporting for duty!

Well, it would be rude not to test it.....just ignore all the smoke. Its no Prius.

And, for the first time since the engine swap, making it home under its own power! You'll want your volume up for this! It would now rev so so much cleaner. What used to be thought as a bad tune, turned out to be half an engine being dragged along. I think its on par with the first ever drive in the Zero to be quite honest. Can't wait to have it tuned properly and running sweet.

Well then. With that sorted, looks like I'll be going on my way soon! Next show, Coventry Motofest, its on my doorstep so should have no problems at least rolling down the road!