Project: Fix Until I Can Afford The Rebuild

[sabretooth]

As posted in the other thread, here are a few more pics of the car. Here's how the engine bay is looking at the moment:



I'll be ordering a replacement headgasket and valve stem seal today. I'm going to take a valve from the MX-5 motor and use that.

[sabretooth]

There's the valve I pulled out of the motor. I have to mod the homemade valve spring compressor, but didn't use it for removing this valve. The compressor fit perfectly, but the slot where you stick a tool in (such as tweezers) to grab the collet isn't long enough. So I'll be lengthening the groove by about 2-3cm. Later tonight I'll also pull the dodgy valves from the original MX-5 motor just to gawk at the damage. I removed that valve with the \"hammer and socket\" method - stick a spark plug socket on top of the valve cap thing (remove the lifter first!) and then hit it with a hammer until the collets dislodge and release the cap.

[sabretooth]

Here begin the chronicles of my engine head disassembly and reassembly.

Pulling things apart

So I sat down (on the floor) to see what I needed to do. With both the MX-5 and Familia heads in front of me, I began work. Firstly, I wanted to give spectral's custom valve spring compressor tool a try so that I could remove some valves. Unfortunately, the 2cm slot he cut in the tool wasn't long enough - unexpectedly, it was far from long enough. With pliers, a file and a saw (and no vice - gah), I managed to hack at the tube and extend the length of the slot to span half the length of the tube.

Because the cylinder that the melted valve was in (number 3) must have become pretty hot, I decided that replacing both exhaust valves in cylinder 3 would be the way to go. I grabbed the valve spring compressor and attached it to the head. It hooked in and was compressing the valve nicely - and with it I managed to wind the spring down enough to expose the collet. It took a fair bit of turning, but I eventually managed to do it. This method is a bit of a pain because you have to mount the compressor, wind it down, dislodge the collets, retrieve the collets and then wind it all back up again. So, on suggestion of my girlfriend's dad, I got out a spark plug socket, short extension and a hammer. I removed the hydraulic lifters, put the spark plug socket on the top of the valve spring retainer and gave the extension a few hits with a hammer. A few whacks later the collets sprung out of their positions and the valve spring retainer was freed.

I also used this method on the MX-5 motor to pull one of the old damaged valves and two good ones - the old melted valve was pulled for curiousity's sake, and the good valves are going into the Familia motor.

And, the head with the valves removed:



While waiting for parts, I needed something to do. Seeing as I didn't need to touch the intake side of the head, on went the intake camshaft.



Cleaning up the valves

Next, I began work on the valves. I bought a steel wire brush and with a spray of some degreaser I managed to clean a lot of crap off of the valves. Some of it was extremely stubborn though - I don't have any strong solvents I can use so I just left the valve faces as is. I did manage to get most of the carbon off of the valve stems though. I also gave the rear of the valves a good clean to make sure that the seal would be as tight as can be expected without lapping. Technically, I should have gotten valve grinding paste and used that - but this is my temporary motor, so it doesn't have to be a 100% job. I won't skip this part for my built MX-5 motor though.

[sabretooth]

The valve stem seals were the next to be replaced. Earlier that day I picked myself up some needle nose pliers. With these, I reached down into the valve stems, grabbed the old seals and yanked them off. The top parts of the stem seals where the little circular spring goes around were pretty stiff - but they're meant to at least be a little soft. They're actually very similar in design to the rear main seal - they're a circular ring of viton around which a circular spring wraps to keep a tight seal on whatever happens to be moving around on the other side of the viton. In this case a valve, and in the case of the rear main seal, it's the back of the crank.




So, off came the old valve stem seals, and on went the new ones. My Haynes service manual said that the seals are different for the exhaust and intake valves, but neither saboteur nor I could tell any difference with the seals I had. General advice was to sit the stem seal on, put a 10mm socket over the end of the seal (as per the below pic) and push it until it is felt to 'click' into place. Unfortunately for me, I couldn't feel a click on either one of the valve stem seals and so I tapped the stem seals in place with a hammer for peace of mind.




Next came the really tough part. This is an absolute bitch of a job with the tools I had, and saboteur will be able to attest to the difficulty - valve assembly reassembly. Now that I had replaced the tired valve stem seals, we reinserted the newly cleaned valves and popped the valve spring and its retainer back in. Then, on went the valve spring compressor. Because I was using the compressor and was working on the concrete (as opposed to a bench), I wasn’t able to have the head sitting upright. I ended up having to sit with the exhaust ports facing upwards. After a few tries to see if we had the VSC slot length long enough we managed to get it to a fairly workable position. But this is where the sh*t started.

What you’re meant to do is with some tweezers or other similar tool is grab a collet, stick some oil on it to make it stick to the top of the valve stem, and then put it on while the valve spring is compressed. Given the confines of the homemade zero cost tool, it was –extremely- difficult to get the collets onto the top of the valves. What I did was magnetise a screwdriver and get a small Allen key to assist in holding the collet in place. With the screwdriver magnetised, the collet would either stick to the valve spring compressor (due to the magnetic force going through it), when I finally get the bugger in the right place on the valve stem, it’d still want to stick to the screwdriver and not the valve! This is where the Allen key came in – once I had the collet in place with the screwdriver, I stuck the Allen key in there to hold the collet in place while I removed the screwdriver. So I’d have to say - definitely make sure that you have large enough slots to work in. Also, I can almost guarantee that you’ll drop the collets, so have a magnet handy so that you can pick them up.

[sabretooth]

Also, make sure that no children are about, because you’re also likely to swear while doing this.


So, 2hrs later. Yep. That’s two hours, and the little bastards are on. I then slowly wound back the valve spring compressor, and the valve retainer raised up around the collets and locked them into place. That was ONE valve done. I then did the next and now that I had the “screwdriver plus allen key” technique down, I did the next one within about 20min or so. With the right tools I reckon I can probably get it down to a fine art – this fortunately can wait until I do the MX-5 motor rebuild – because I can tell you I’m in no hurry to go through that again!

With both valves now done, in went the hydraulic lifters and then on with the camshaft caps. If you look closely at the caps, they’re actually arrowed and numbered, so you won’t get the orientation or ordering wrong. The arrows are all meant to point to the camshaft sprocket, and the caps are ordered from 1 to 5, with #1 being closest to the camshaft sprocket also. Those went on.

Next I did some more cleaning of the tops of the pistons and the block surface. I got the scraper out and carefully removed what carbon I could from the tops of the pistons – oil I had poured in during the week actually softened the carbon a bit, so I was able to clean things up with a bit more ease.

Also, my headgaskets arrived while I was in Sydney on Wednesday, so the engine can go back together now! Tonight I’m going to be giving the head’s surface a final clean and check it for warping. If it’s all fine, then it’s going to go back together and then everything else bolted back on. This morning I also picked up a tap wrench, die nut and some new HT bolts – with those I’ll be replacing the appropriate dump pipe nuts, bolts and bolts that are holding the turbocharger on. The ones that I have at the moment look like they’re about ready to snap.

[sabretooth]

The above posts were written on Friday morning. but only posted Sat night/Sunday morning.

Friday night was where the interesting stuff began. With a paint scraper at the ready, I commenced work cleaning both the head, the pistons (to an extent) and the block's mating surface. While there was a lot of discolouration from gasket material, no sane amount of scraping was able to get most of it off - the surface felt perfectly smooth to touch, so I ended up leaving it imperfect. Short of machining, I don't think there was any humanly way to get the surface any better! With the valves reassembled, I then replaced the lifters and then the exhaust camshaft. Reasonable progress was finally being made. The headgaskets that I purchased are pictured below - they're not the same - I believe one is Mazda OEM and the other from ACL. I can't say for sure though. For the curious, they're triple layer steel - that's how they are from the factory.



Numerous other bits and pieces were also done. I purchased an valve tap wrench (to complement my M8x1.25 tap) and M8x1.25 die nut. These things are magic - I've lost count of the number of threads I've cleaned up since getting it. When redoing the turbo and manifold, the turbo got the treatment - I highly recommend getting some taps and die nuts! Corrosion, thermal expansion, various sealants (such as maniseal) tend to block up threads, so running a tap through them tends to clean them out nicely.

With the help of saboteur a ton more work was done today. After a bit of headscratching and misjudged attempts at installing the head, we got it on and bolted down - a few twiddles of the torque wrench on the headbolts later and that was installed. A bunch of other accessories were also installed - I didn't bother keeping documentation or pictures of the process, as you pretty much get to see it in my old engine swap project thread posts. Needless to say, a lot of work was done and saboteur seems to have learnt a lot in the process, which is great.

As it stands, there remain only a few more things to reinstall - the dump pipe, intake manifold bracket, a bit of a cleanup and then the test firing. I expect that to take up to an hour.

And once that's done - here's hoping there's enough juice in the battery to fire er over.

[SileNceR]

While there was a lot of discolouration from gasket material, no sane amount of scraping was able to get most of it off - the surface felt perfectly smooth to touch, so I ended up leaving it imperfect. Short of machining, I don't think there was any humanly way to get the surface any better!

Theres some sort of air powered tool that runs little sandpaper style discs (or wire brush ones) about 1.5" in diameter that cleans up heads/blocks awesomely, I used one of these on the AU motor in the shed for the EA turbo project, looked like it had been machined when I'd finished

[JBT]

A Dremel might do the trick too.

[sabretooth]

The dremel was in Ipswich at the time. Not the most convenient, unfortunately. I think I'll have to get the high pressure water thingy though - there are a few stains on the concrete now as I didn't expect so much crap to come off of the parts I was doing

[jules]

Use an oil stone dude!


Jules

[CT]

Great write up Geoff, keep it coming.