30 Apr 2014

Removed the slip-lock connector that was slipping instead of locking, which feeds MAP from the throttle body to a distribution block, then on to the wastegates. It was going to be replaced with a barbed fitting, but after it was removed it became clear why it was slipping. The first picture shows the fitting with the hose in position. The blue collar is pushed toward the fitting to retract internal barbs that retain the hose, allowing removal. The second picture shows the barbs… only that fitting is the replacement part. The third picture is of the removed fitting… no barbs! So where’d they go?! They either got pulled out along with the hose and fell off, or sucked into the intake manifold. Let’s hope that they got pulled out…

In other news, as proof that global warming is happening, it’s in the mid-90s today, so doing the above was about the extent of the garage work. I don’t ever remember a Santa Ana (hot desert winds) happening in April; they usually happen in October or so.

Lastly, I think I’ve mentioned how care is needed when the front cover is tilted up so that wind doesn’t blow it shut… well that finally happened while I was distracted, working on the car last weekend on the side of the road. It put two nice scratchs in the edges of the paneling, right where the locking pins slide down outside the bodywork instead of dropping straight into the holes. Oh well, it builds character.

26 Apr 2014

Well that could have been fun…

Driving over to see mom, I briefly got on it in traffic and started smelling gasoline. That in itself isn’t terrible, since in open top cars, there are always all sorts of smells from other cars and the surrounding (I had smelled some pretty nice barbeques along the way). About that same time though, the car started running odd… uh oh, not good. The thought of 90 psi fuel spraying around meant finding a field to land in in a hurry, so with a couple of right turns I ended up in a quiet parking lot, perfect for field repairs. With a full set of tools always on board there wasn’t any concern about being stuck, though depending where the problem was located it might take a while to access it. Hit the battery kill just in case – no point in going up with a bang – then removed the engine cover and started looking around. Yup, the fuel smell was definitely coming from my car, and I could see it puddled at the bottom of the engine tray.

There just aren’t that many connections in the high pressure fuel circuit. The hose from the outlet of the high pressure pump to the filter, that one was dry. From the filter to the fuel rail… wet, huh. Then checked the hose at the other end of the fuel rail,connecting the engine to the fuel pressure regulator on the fire wall, also wet… huh, again. Both were slightly loose, and with the latter, I could understand it if I’d forgotten to tighten it after doing last weeks repairs. The former, at the outlet of the filter, was a bit more strange. Maybe I bumped it while installing the heat exchanger? Maybe, but why didn’t I smell gas earlier on then, from either of them, and why was it running oddly (idle speed fluctuating between 500 – 2000 rpm). Hmmm, vacuum leak?

Yes indeed. I’m using very high pressure “press and click” connectors here and there for several vacuum lines. The reason is that turbo and supercharged engines can have a fair bit of positive pressure in what are normally vacuum lines – in my case as much as 11 psi. Because of that, the hoses try to pop themselves off whatever they’re plugged onto, but this type of connector shouldn’t have been able to unplug. They are 3000 psi connectors used on paintball markers, where the hose is pushed into a collar which locks it in place, though this one didn’t seem to want to play any longer. Thinking it through, with the hose popping off, two things happen: the fuel pressure regulator loses its pressure reference, so fuel pressure goes to maximum – part of the reason for the leaks it seems. Also, with a vacuum leak, the idle was high, so the ECU was attempting to correct for it and making it worse. So the weeping hoses were tightened and the hose plugged back in, and I kept the car below boost during the rest of the trip so the hose wouldn’t pop off again.

23 Apr 2014

Spent all day Sunday getting the car back together, installing the updated alternator mount and plumbing the big oil-to-coolant heat exchanger. Took it on a short drive and all was fine, but of course, found a few drops of coolant under the engine compartment – grrr. At least Midlana’s back on the road for now, though it reminds me of the other two changes on the list: bending the steering arms to allow installing unmodified (stronger) rod ends on the steering arms, and swapping in 20% stiffer suspension springs.

13 Apr 2014

Finally, a real, actual, Midlana car post! The new belt tensioner parts on the way, so hopefully that’ll take care of that (note the shiny water pump pulley, which should have tipped me off months ago). Today was spent again removing the intake manifold, in preparation of upgrading the oil/coolant heat exchanger and dealing with the suspect clunking engine mount.

The new heat exchanger is a lot bigger than the previous one, so time was spent moving it around to find the best location, which turned out to be flat on the engine bay floor. The third picture is a top view of the front side of the engine, with the shiny new heat exchanger sitting down at the bottom. It’s not going to be pretty to service since there’s currently no easy way to access it without removing a lot of stuff, note to self about adding access holes in the engine bay floor…

Looking at the front engine mount, it was odd that I’d designed the chassis with so little clearance. It wasn’t until it was removed was it clear that A. Yes it was definitely hitting, and B. The mount is broken, hence the lack of clearance. The mount is an interesting design, with a soft “A-arm” subassembly, bracketed within a rigid box to keep the engine from moving too much. Since it’s broken, and because the rear mount is a stiffer aftermarket unit, the front mount is being left out for now.

In other news, a coworker recently quit her job at out company in order to do something she’s been planning to do for years, hike the Pacific Crest Trail, from the Mexican border to Canada… alone! She started her odyssey last week and is maintaining a daily blog, which I check every morning 🙂 Don’t forget to click on the “Where am I” tab to see a live updated map showing her progress. I’ll admit that I’m living the adventure through her, because if I’d thought of it when I was her age, I might have done it myself.

And a tidbit from some other news, regarding the Malasian airliner search, there’s a cool website that gives live position updates on all world shipping traffic. If you go to marinetraffic.com it’ll show a world map. Zoom in on the Indian ocean west of Australia, then in closer to the smallest of the three purple search areas. Click on the ship icons to show the name, pictures, and you can even click on its path to see where its been recently. It makes the whole search thing suddenly seem a lot more real, with the ship Ocean Shield dutifully and persistently keeping at it.

9 Apr 2014

With the alternator mount fixed and our near nonexistent winter, what better than driving Midlana down the coast, or that was the idea…

Some background is in order:
When I pieced together my engine, I needed a way of mounting the alternator, but no air compressor or power steering pump. The catch was that the various mounting brackets tend to “lean on each other” such that it’s not easy to remove two while keeping one. So I bought an alternator adaptor kit which allows bolting a K20 alternator onto a K24 block. For whatever reason, the tensioner – also needed – had a 6-rib pulley, while the alternator and crank pulley both have 7-rib pulleys. When I fixed the alternator mount and reinstalled the water pump/alternator belt, I couldn’t remember which side of the 7-rib pulleys the 6-rib belt rode on. Eyeballing it, it appeared it needed to go to “this” side, and all was well.

About 15 minutes from home, the little voice in my head said that there was a new noise, “oh yeah, so there is.” In a home built car, you have to listen to the little voice, because it’s trying to watch out for you. The other part of me thought, “meh, it’s nothing, I’ll keep going.” However, I’m old enough now to listen, pulled over, and removed the engine cover, and sure enough, the belt was in the progress of disintegrating. Worse, while doing so it throws off flailing threads which whip around things and grab onto them, just like Indiana Jones’s whip. Fortunately it didn’t grab and rip the hose out of the header tank, which was right there, but it probably would have if I’d kept going.

So I limp the car back home, get a new $26 Gates belt and replace it, offsetting the belt to “that” side. All was well – for about 30 minutes and a lot further from home, sitting at a long red light, when I heard it start breaking up again… huh? Then it made an unhappy noise and the coolant temperature jumped up, uh oh. However, the saving grace was that the electric water pump at the front of the car kept the cooling moving, so there was no overheating. Got it off the road and sure enough, the new belt was torn up as well. I managed to rip off the flailing bits, get it back on the pulleys (it had hopped off) and got it home.

The mystery is why it worked fine for a year, including racing, and now doesn’t. The only thing I can think of is that since there are three pulleys, maybe I got it right on two of the three and not the third? Somewhat related, over the last year I’ve noticed how the water pump pulley (which rides on the backside of the belt) was polished clean right through its anodize coating. It had been in the back of my mind but didn’t seem to be a big enough deal to change. So I went back to the vendor of the alternator and tensioner adaptors, and learned that with the combination of parts I had, there was a small misalignment in the belt path – ah hah. So I’m going to start with a clean slate in order to make things right (reliable), so a new setup was ordered: updated alternator mount, different alternator pulley, updated tensioner design, and a new belt. It’ll be here next week, so this weekend I’ll try to get everything apart – again. It’s probably also time to bite the bullet and also remove enough stuff so that the oil/coolant heat exchanger can be updated as well. If I’d left the engine dead stock like I did on Kimini, I don’t think I’d be having to do all this…