| THE MG |
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 | |  | February 1, 2011 - I've been working on gauges recently.
The parts just arrived to mate my mechanical oil pressure gauge to the engine. The biggest problem was how to deal with the usual oddball British flare fittings. After doing some measuring, I was able to sidestep the problem by cutting the flare off and using a 1/8" compression fitting. It's a perfect fit. That goes to an AN -3 flare, then it's all just off-the-shelf race stuff. I still have to get behind the dash to make sure the connection to the gauge is tight, then we'll see how it works!
The coolant gauge has been more of a hassle. The one for the engine computer works fine so I can monitor things that way, but the dash gauge reads really low. At 180F, it's just come off the C peg. After some putzing around with the gauge and checking wiring, it looks as if the culprit is the temperature sender in the head. The GM part measures 3800 ohms at 63F and about 150 ohms at 185F. A parts-store piece I also have on hand is the same at 63 and 200 at 185F.
The MG sender apparently measures about 800 ohms at 68F and 33 at 190F. So I need to find one that's somewhere in that ballpark. It doesn't have to be perfect, just close enough that the gauge stays near the middle at normal operating temperature. I'll stop by NAPA tonight and see what I can find.
entry 547 - tags: gauges | | |  | February 1, 2011 - My little science fair project.
I started by stopping off at NAPA on the way home and going through their Big Book Of Temperature Sensors. Not all of the sensors had information about their resistances, but I was able to pick out a few likely suspects out of the catalog. Two of them were in stock, so I brought them home to test.
First, I used the multimeter to check the resistance between the body of the sender and the stud. The MG part apparently reads 800-830 ohms. NAPA sensor 6046 read 631, sensor 6178 was 273.
Then I boiled some water and risked my tender fingertips by dipping the sensor in it while I measured the resistance. The cooking thermometer told me the actual temperature of the water. At 195F, sensor 6046 read 48 ohms and 6178 read 31. Apparently the MG one should be 31-35 at 190F.
So, 6046 will be fairly close when the car is cold, but read a bit low when hot. However, it's also changing quickly in the normal operating range. 6178 will probably read right about C when cold, and should be pretty close when hot. I'll give them both a try in the car and see how they behave for real, but at least I know what to expect!
entry 548 - tags: science!, cooling | | |  | February 3, 2011 - I swapped in the 6178 sender today, and it does sit just above C when cold.
That's fine, it shows the gauge is alive! I wasn't able to run the engine to see how it behaves at 180F or so, but I already have a pretty good idea. So that's good.
I couldn't run the engine because I'd mis-measured the length of the AN -3 line I needed. Either that or the length included a fairly large radius 90 degree section that was on one end. Anyhow, the end result was a high-pressure oil system that isn't sealed up. Of course, as can be expected with AN fittings, there are none to be found in town anywhere. So I've had to order another one in from Summit Racing. Argh.
I've taken on a new project, as you can see here. It's being documented on the Flyin' Miata site even though it's one of my own. Why? Because some of the FM fans might enjoy it, and it is a Miata. It's not going to be a long one, but it is going to involve a bit of bodywork and a repaint for a friend. It'll be my practice run for the MG.
entry 549 - tags: other cars, gauges | | |  | February 5, 2011 - The right front flare has been bothering me.
It's at a slightly different angle than the left side. Now, asymmetry isn't a big deal. But the other one works better! So I decided to try to fix it. I cut out my extension piece that molds the flare into the fender, reshaped the flare and cut a new one. After quite a bit of careful positioning, trimming, hammering and prying...it somehow shifted back into the original shape. Well, not exactly. But not quite what I wanted.
Argh. I can use filler to shape it the same as the other side, but it would be about 1/4" thick in the deepest point. I'll see what I can do with yet more steel.
entry 550 - tags: flares, body | | |  | February 5, 2011 - After the frustration of the flare not following orders, I decided to work on something that I know I can do.
The MG interior is made of the biggest collection of little weird bits and pieces, with carpet chunks screwed into bodywork and various vinyl-covered panels all over the place. Of course, the vinyl panels are simply a piece of cardboard underneath, and when they get wet they warp badly. That's an untouched one in the upper right of the photo.
We have a bunch of replacement panels from the UK. But I don't think it includes these kick panels, down in the footwell. More importantly, I've modified both footwells so even pristine pieces would need to be modified.
They're obviously not original because they're biscuit color, and the GT didn't come in biscuit as far as I can tell. They're not spray painted either, thank goodness.
I peeled the vinyl and some decomposing black foam off the backing board. I then modified the original board to make sure it fit properly. Once that was sorted out, I squashed it as flat as I could and traced it on to a piece of MDF. I cut that out (it's at the bottom left) then used some spray adhesive to glue the vinyl on to the board.
entry 551 - tags: interior, vinyl | | |  | February 5, 2011 - Here's the end result, just ahead of the door panel.
It's not perfect, but for a little bit of work it's an enormous improvement. You can see how wobbly the door card is by comparison.
entry 552 - tags: interior, vinyl | | |  | February 5, 2011 - I also spent some time on a passenger footrest.
The engine computer is at the end of the footwell and it really is the best place to rest your feet. Well, not the best place, but the easiest. So I built this panel to cover it up.
It's a royal pain to install, with one bracket that needs to be bolted to both the footrest and the floor. But it's pretty solid and it'll do the job. Now I just have to cut a piece of carpet to fit it.
entry 553 - tags: interior, footrest | | |  | February 6, 2011 - So, how hard would it be to reshape that front fender flare?
Well, here's what the patch would look like. Can I meld that in smoothly? I don't know. I'll give it a shot. But first, I need to buy some more steel!
entry 554 - tags: body, flares, fender | | | February 13, 2011 - We have a full complement of gauges!
It took a few tries to get the correct length of line for the oil pressure gauge, but it's in. I haven't run it up to full temperature yet but there were no leaks upon initial startup.
The car's been kept in the garage for the last couple of weeks due to cold weather, snow and race tires. The temperature's supposed to be nice this week, so it might come out for some extra exercise.
The Miata is coming along. I'm into the bodywork now. I cannot wait to shoot paint, it's so much more rewarding!
entry 555 - tags: gauges | | |  | February 15, 2011 - The Big List keeps getting shorter!
Unfortunately, the coolant gauge has to go back on it. It reads way to high, settling right on the H at normal operating temperature. I'll try the other one, and if that doesn't work I'll add a parallel resistor to the GM sensor. Easy enough to sort out.
I had the car out today in some unseasonably warm temperatures. Man, this is a fun little critter.
entry 556 - tags: gauges | | | February 20, 2011 - The other coolant sender is better, but not right.
It reads right between N and H during normal operating temperatures. I'll deal with that soon. Right now, I'm spending most of my time doing the body prep on the Miata. It'll get painted next week, then I'll start on the bodywork for the MG.
entry 557 - tags: body, gauges | | |  | March 13, 2011 - The Miata is painted, so it's time to turn to the black beast.
I learned a lot doing that car. The experience from it will definitely help with the MG.
So this means it's time for bodywork. I started with the left flares, mostly because they're most easily accessible with the MG in its current parking space. This is going to take a while to get the shape just right, that's for sure. But it's kind of relaxing work.
Why did the hood turn green? Because the black one didn't fit right at the front corners. I was actually afraid the nose of the car had sagged when it was all cut up. But just to be sure before I started taking extreme measures to fix it, I pulled the hood off the green parts car. Problem solved. And laying the black hood on the parts car showed the same fitment problem. So it's not the car. The weird thing is that, looking at old pictures of the car, the hood used to fit perfectly. I'm wondering if it got bent when there were a couple of protruding bolts on the new grille. I wouldn't have forced it hard enough for that, but it's the only explanation I can come up with. Still, I have a good replacement so there's no concern.
entry 558 - tags: hood, bodywork | | |  | March 15, 2011 - The car getting a lot uglier in a hurry.
Since I don't know for sure yet if I'll use the Special Tuning airdam - the nose does look a little unbalanced right now - I'm going to paint both it and the lower section together. And of course, all the lights and chrome has to come off. Poor thing.
I also removed the headers so they could be milled flat. I figure the car won't be going anywhere for a while, and the flanges are a bit warped from the welding heat. I can remove them without even lifting the car! Try that on a Camaro. Or a Miata or stock MG, for that matter. I got lucky.
entry 559 - tags: header, bodywork | | |  | March 23, 2011 - Sanding, sanding, sanding.
I've stripped all of the badges, bumpers, lights and handles off the outside of the car. I may still see if I can get the trim off the windows etc, but the car's looking pretty barren right now. And I'm sanding.
It's pretty relaxing work. The flares are blending well into the body but I know the upcoming shiny black paint is going to highlight even the smallest imperfection. I'm also finding the body's not quite flat at the moment, so I'm trying to sort that out as much as I can. Apply filler, sand filler. Apply filler, sand filler. There is much sanding in my future.
entry 560 - tags: sanding, body | | |  | April 5, 2011 - The sanding work continues.
I'm learning quickly and I think the final result will be good. The left front corner is almost perfect, and the left rear is also good. With how the car is parked, it's harder to get to the right side so it's lagging behind! I have picked up a couple of air-powered sanders that should accelerate progress somewhat - they've proven themselves to be very effective while cleaning up the burned paint on the roof.
One thing I learned from painting the Miata is that errors that appear catastrophic when the car is fresh out of the paint booth and sitting under the fluorescent lights disappear when the car starts to get used. But I'm still going for a good job.
entry 561 - tags: paint | | |  | April 5, 2011 - I played around with shaping the right front fender flare using body filler, but I just couldn't get a good shape without resorting to 1/4" or more of the stuff.
And that's too much. So I cut it up again and added a new metal patch. This is my third attempt on this side to get a shape I want, and I think this one's going to be the right one. Even without any fine-tuning, it's just about bang-on and should blend in nicely.
entry 562 - tags: flares, body | | |  | April 5, 2011 - After the welds were ground down, I put a skim coat of filler over that troublesome right front.
Much better. The profile of the flare is nice and smooth, without a halfway "step" that I had before. This coat is a little on the thick side but it's easier to sand down than build it up again later. Most of the filler will go away and I expect to see big patches of bare metal when I'm done. I feel good about this.
entry 563 - tags: flares, body | | | May 10, 2011 - Another rest for the MG.
I took a trip to visit family, then trucked a couple of thousand miles to Road Atlanta for the vintage races. Meanwhile, the poor car waited. Until tonight! I used my new air powered D/A sander to quickly put the final shape on those front fenders. Not only was it a lot faster, I got a nicer finish than when I'd been doing it by hand. I feel like I'm actually making progress now. I'll do the rears in the next day or two, then shoot the car with a layer of primer in preparation for more exciting sanding!
entry 564 - tags: paint | | |  | May 14, 2011 - Let's hear it for power tools!
My air-powered sanders have made a big difference, and the car is looking particularly disreputable but feeling much smoother now. The flares are almost complete and I'm just working on other small spots of the car now. Progress!
entry 565 - tags: Bodywork | | |  | May 14, 2011 - You can see how much paint is on this poor car.
The original aqua is obvious here, as is the skim coat of filler that covers the whole car under the black. Someone put some real effort into that black paint job, I have to admit.
In this shot, I'm feathering the edges of the paint to get it as smooth as I can and fix some small shaping problems. Sorry about the quality of the pictures, I left my good camera at work so I decided to set the website up to take uploads from an iPad or iPhone. The camera on the former is nothing to get excited about, but it beats no picture at all.
entry 566 - tags: bodywork | | |
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