1974 RX-4/929 hybrid-ish.

ewokracing · **Posted:** Sun Dec 02, 2012 8:28 pm

Very close to the finish line!

The head was sitting in my friend's boot/trunk after getting reconditioned. He was meant to come and give me a hand yesterday. Friday night the auto in his Commodore died, so I spent most of yesterday driving, picking up people, dropping them off, picking them up again. After all of that, my mate Steve and I got down to sorting out the head.

We gave the block face a good clean with a sharpening stone, along with all the mating faces - water pump, thermostat housing, the timing cover mounting face. We got rid of all the old gasket remnants and I even managed to scrape off quite a lot of the carbon from the top of the pistons.

In last week's episode, the timing chain tensioner had become jammed, which is why we took the timing cover off. I noticed that the rubber/plastic that pushes against the chain looks like it might be deterorating, so I've made a mental list to buy one for a future VC/MA engine build - if I ever get around to it.

Steve also cursed me when we bolted the tensioner back in, had the timing cover back on, gaskets sealed etc and I realised that part of the cable tie holding the tension in the tensioner was poking out between the block and the timing cover. Off came the cover again... :lol:

To go back a bit, we also noticed that cast onto the block is a U shaped piece of metal that stops the chain all falling down in a heap. Very handy for sort of keeping everything where it's meant to be if you take the head off. Very Mazda like. The keyway on the bottom (crankshaft) and the keyway at the top (camshaft), also line up, so it's easy to tell by eye if you are on the ball, or have things out of sync.

ewokracing · **Posted:** Sun Dec 02, 2012 8:33 pm

He hasn't made an appearance for a while, but the mascot also stepped in for a bit to have a sniff around. Last week he almost marked the tools, so I was keeping a close eye on him.

If I ever build one of these motors up again for track use, I'll go all out and have the head cleaned up further, there's still some rusty reside inside the coolant passages, but it's a lot better than before.

If I can get home early today I'll put the water pump on and the alternator.

ewokracing · **Posted:** Sun Dec 02, 2012 8:39 pm

One of the little traps I uncovered when pulling the head down was to do with the sump.

To get the timing cover off, you need to undo a handful of bolts that hold the sump to the timing cover. One of the bolts isn't actually a bolt. It's a length of threaded bar, with a nut tightened up to the sump. To get it off I had to use the two nuts/two spanners trick and undo the threaded bar. Unfortunately, to get the spanner on the top nut, I had to bend the lip of the sump with a pair of vicegrips.

I'll be replacing the threaded bar with one of the numerous 10mm Mazda bolts I have left over.

timmy201 · **Posted:** Mon Dec 03, 2012 4:33 am

Geez, it almost looks like a mirror image of the TC/UC family (exhaust and intake around the other way)

Do the sprockets and chain not have the timing marks as well?

Also - you've gone far too many pages without a picture of the whole car

by my reckoning since page 8!

ewokracing · **Posted:** Mon Dec 03, 2012 10:45 pm

Hey tim, yeah, I often wonder why the TC/UC/D5 family wasn't just shrunk down from the VA/VB/VC/MA, I'm sure there was a good reason, but then again, they did use screw in wheelstuds. :evil:

The chain has two differently coloured links which is also meant to help you set up the chain once you start taking the chain off the sprockets etc. I didn't look too closely as I didn't take the cam sprocket off, but it's all in the factory engine manual which I had bought years ago for a rainy day.

Whole car picture is coming up soon.

banzaitoyota · **Posted:** Tue Dec 04, 2012 7:55 am

Need an RX4 roof rack?

ewokracing · **Posted:** Tue Dec 04, 2012 8:30 pm

yeah.... but I think shipping one from the US might be a killer.

ewokracing · **Posted:** Sun Dec 09, 2012 12:39 pm

arsehat.

bookmarking for a tale of woe.

banzaitoyota · **Posted:** Sun Dec 09, 2012 7:26 pm

ewokracing wrote:

arsehat.

bookmarking for a tale of woe.

????? Confused

ewokracing · **Posted:** Sun Dec 09, 2012 10:24 pm

Pictures speak a thousand words.

philip · **Posted:** Mon Dec 10, 2012 1:53 am

D'OH!!!!!!!!!!

New bolt or did you use an original?

ewokracing · **Posted:** Mon Dec 10, 2012 3:43 pm

original bolt but they were cleaned up. I think what happened was that some gunk got in the thread inside the rear of the head. I tightened up the bolts for that rear plate*, then tightened them up further the next day to let the sealant form a gasket.

The bolt has only been slightly tight, not enough though and so coolant has leaked out. I've gone to tighten it, the gunk has got stuck in the thread, siezed the bolt thread, then when I've tried to undo it, it's broken the bolt.

Yeah, so it's an engine out job. I didn't do my usual trick of throwing something or swearing profusely but I did come close. Packed up tools, closed bonnet and had some scotch instead. :cry:

* Is that plate for letting coolant expand during winter months?

Oh and I took your advice Phil - I put new hose on that join from the thermo housing to the water pump - the one you pointed out, and yes the hose was starting to fall apart!

ewokracing · **Posted:** Fri Dec 14, 2012 3:24 pm

I have had about 4 hours sleep. Mutliple rescheduling for this weekend. Someone was meant to pickup some of the 1300 rotary parts, that's on hold, someone was meant to come and get some Rover parts, they couldn't pick them up, then nek minute, a guy who rung ages ago about the same Rover parts rung and is 30 mins away. Righto... time for some pics.

We started working at about 8pm. Things did not go smoothly.

First up, draw an outline on the bonnet hinge so we can line it up again easily.

Next up, disconnect everything.

The plan was, unbolt tailshaft, slide tailshaft along on creeper so gearbox oil stays inside gearbox. Didn't happen. Cue gearbox oil going EVERWHERE.

sigh. So much for clean garage.

But. Voila.

Bastard.

Dirty mascot. Little bastard.

Magic begins. Ended up drilling literally the whole bolt out, then running a tap through to clean up the thread. Easy out didnt work.

Bloody phone letting the side down. You can see part of the outside of the bolt wrapped around the tap.

It is 1am by this stage. Time to make a gasket.

All back together.

Motor is back in. Sadly stuff that was powdercoated got scratched, I also did some damage on the firewall when jiggling the engine back in. Having worked for 9 hours, then been at it until 2am, I got sloppy. Bugger. But the engine's back in, when I get the time I'll tighten everything, throw some oil and coolant back in everything and cross fingers.

ewokracing · **Posted:** Tue Dec 18, 2012 4:01 am

Connected all of the coolant lines tonight and filled the radiator. It looks like it's holding. :mrgreen:

timmy201 · **Posted:** Wed Dec 19, 2012 3:57 pm

At least you are still at the stage of taking photos of taking out the engine! Mine became that frequent I didn't bother after a while

I still didn't work out how to keep the gearbox oil in. The one time I put a plug in the spline end it all poured out the gearstick hole when I tilted it to get it out...

Hope you get it back on the road soon though!

philip · **Posted:** Wed Dec 19, 2012 7:23 pm

I'm liking the "moral supports" safety shoes!!!!! :lol:

ewokracing · **Posted:** Wed Dec 19, 2012 10:28 pm

Tim -

Maybe I am kinda glad it ran out of the back of the box then, rather than all through the interior!

I'm still pissed at myself for mashing the firewall. :evil:

Phillip - can't you see, she's showing off her nailpolish.... :lol:

I am actually surprised I didn't get hit with the hammer at her feet that night. Apparently a block and tackle is really noisy at 2am. Who knew?

ewokracing · **Posted:** Sat Dec 22, 2012 7:05 am

buttoned everything up, hit the key. Won't fire up. Checked that the distributor is lined up - it is. Pulled number 1 plug and there is no compression. We suspect that the valve adjustment is up the creek.

ewokracing · **Posted:** Sat Dec 22, 2012 3:59 pm

New boot rubber that has split on the steering:

Also have a nasty feeling that I have lost one of the three bolts that holds the gearshifter in place and that it has fallen into the shifter housing hole in the gearbox. Crap.

ewokracing · **Posted:** Wed Dec 26, 2012 10:42 pm

Bought a new rubber boot. Actually I bought multiple packets of them. Hopefully that's the last one that splits for a while.

Also figured out why it wouldn't start. One of the guys used the gudgeon pin hole as the mark on the drive gear, when in fact there is a tiny little dimple. Lined it all up after a few hours over the last few weeks of head scratching and other things being fixed and it fired up straight away.

I also did the rocker/valve adjustment a the same time, approx .24/.22mm on the cam/rocker. It was crazy tight before after the rebuild.

I just have to replace the boot, fit a new clutch master (on the way from the states), paint a few things to make them look tidy and get this bloody thing registered.

1974 RX-4/929 hybrid-ish.

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