MG Sports Cars

The injector bench is coming along. With luck I'll be ready to get the parts for the framework tomorrow. The toggle arms are done and there is only a little machine work left before assembling the shaft. It looks like it should work as expected and at about 26" wide will be pretty compact for a bench that will test 8 injectors simultaneously. I've just about decided to include a small cabinet in the design behind the graduated cylinder area that can be used for storage of hoses, cords, or whatever. And I need to see if I can find some sort of electrically triggered stopwatch timer, that would be a real handy thing, especially if it has a large readout.

Jim

Jim, I wish I had half of your fabrication skills! Nice work. Can't wait to see and hear the finished product.

Thanks Chris, I'm pretty eager to drive it myself.

Jim

Jim, I thought I heard that some injector strategies include a small partial shot of fuel while the intake valve is closed. The balance of the fuel in injected when the valve gets opened. I can imagine some reasons why this is done but I'm no expert so I'd only be speculating.

I suppose that would vaporize the first shot which might help economy. Probably worth playing with if you have sequential injection. It wouldn't affect max power so much since the injectors would probably be near full saturation anyway, meaning it's on nearly continuous anyway.

Jim

I've been sorting things out on the transmission controller and so far progress is good but I am relying on others to provide essential parts and information, which always causes me a little unease. The first part of board assembly is done but before I can test it I need a few upgrade parts for the tuning laptop which are on their way. I have contacted the manufacturer of the wiring harness connector that fits the transmission and requested some samples which should allow me to complete the wiring, and I have contacted the engineering department of Aisin's transmission division and hope to get the information needed to properly drive the shifting solenoids. There may also be some chance that they have a stand alone controller. I expect to speak with an applications or controls engineer in a couple days.

The injector bench has hit a snag, leaky seals on the toggle arms, but I have a new design that I think may solve the problem and will try that as soon as it warms up a little. Basically the idea is to back a hard teflon seal with a soft but resiliant one to maintain contact. If that idea does not succeed it may be time to go with external plumbing. But that is a project which will be drawn out a little anyway as the controls are developed. Right now I'm thinking about installing the spare MegaSquirt controller as an injector driver, which would allow very precise control of testing parameters as well as a datalog of the actual test itself, and with that the program could easily accumulate the injector pulses and output the expected quantity of fuel, allowing me to at least get a general idea of what the delivery curve looks like for a given injector. Then later on it might be possible to use a load cell to measure actual outputs, and at that point it becomes an auto-test routine that outputs an accurate delivery curve for each injector, making injector matching super accurate.

But that's going to take awhile.

Jim

Jim, As far a s seals on the toggle arms, perhaps a chevron lip design might work ? Chevron seals,(shape of the Chevron gas station sign), are available in teflon and other materials. These have the potential, to adjust for wear and seal drag. Cheers, roverman.

Jim is that somehting you are thinking about using a linear actuator on?

[www.firgelliauto.com]

Um... not really Gary but I'm sure they could be useful for other things. Chevron seals aren't a bad idea, might keep them in mind for the next go around. If so it'll probably be something complex to machine though.

Jim

You know they have a feed back circuit for the linear actuators to control position.

Yes, and that could be very handy for some things. Drive by wire controls come to mind, and for throttle control where not much force is needed something like that might be suitable. It also might work for something like the hood opening mechanism where quick reaction is not a concern. If however, both quick reaction and substantil power are required there are probably better options. Worst part though, is that they look pretty clunky and we're not used to seeing things like that on automobiles. Good for door glass and such where they are hidden.

Jim

I haven't posted for awhile because first, sorting out the control electronics is not very sexy and second it took me quite a while to resolve to make the parts required for the injector bench. But today I gun-drilled a new shaft that when finished I believe will work the way I want, and I have ordered the MS-3 upgrade for the controller as well as having completed the circuit assignments for the MegaShift, all of which represents significant progress.

I've been stuck on that injector bench. I really didn't want to make the new shaft which will have independent pistons, multiple seals and springs for the 8 rockers. But today the first of the difficult operations is now complete and it is on the mill for the piston bores to be cut. A person might wonder if it is worth the effort, but being able to map out the injector delivery at part throttle can make all the difference in how the engine runs. The conventional approach would be to simply buy a new set of matched injectors. But this overlooks the vast supply of used injectors which are quite serviceable, but need to be matched in order to give optimum performance, and which are available at bargain prices. And since I'm basically such a cheap @#$%& this idea appeals to me even though I have to work my butt off to make it work. In short, I get a certain amount of enjoyment out of being able to make things that are unique, and I'm well past the point of feeling I have to sell my creations. It's more a matter of what I want the most.

Jim

Back again finally. I ended up punting on the injectors after all that and bought a new set of 42's. the injector bench is put away and will stay there until after the car is running and I have time to mess with it again. For now I'm back to the old plan of trying to do at least one task each day to move things along. I have the coil packs and plug wires back on, sorted out a few of the wiring harness connectors, and have made the surge tank for the cooling system. At the moment I am enlarging my anodizing setup to 5 gallon buckets so I can do the tank and maybe the pulleys. I bought some Burgundy dye from Caswell for those parts. So far I have been very pleased with the Caswell dyes, we'll see how this one comes out in a few days after the lye I ordered comes in. Anodizing current for the tank will be about 8 amps so I've had to beef up my electrical setup as well but will still be using a 12v battery to supply the current. If all goes well there, I'm actually considering anodizing the wheels. That would take a custom tank of course. And the tires would have to come back off so ... maybe.

I've not done a blessed thing on the transmission controller. Have to work back up to it I guess. But one of these days. In the meantime I'm not too far away from being able to start the engine. All of the pieces are built, and it's mostly just a matter of installing lines, connecting wiring, and things like that. All the little details that tend to drive you mad towards the end.

I'll try to post a photo of the surge tank after it's been anodized.

Jim

Such cool stuff! I'd really like to put together an anodizing system.

It's not hard. The most difficult part is deciphering all of the gobbledegook and art specific tecnospeak into plain english. Once you get past that you discover that the process itself and the chemicals used are really quite simple and easily accomplished. You do however need to be rather particular about a few things.

First, the amp loading of the surface area at around 30 mA per square inch (.030A.) which means you have to calculate the area. A little fudging is allowable but since it affects process time more accurate is better. All factors affect process time.

Bath temperature, 73 degrees F is ideal and some way of holding it within a couple degrees is really helpful. Hotter or colder gives you badly formed cells that will not hold the dye well. I use the utility sink as a water bath for the tank and use bubblers for circulation inside and out.

Acid mix of 1:1 battery acid to distilled water is a well regarded concentration of sulfuric. Up to now I've been using 2:1 but will go to the lower conc. with the larger tanks, this will undoubtedly extend the process time, perhaps doubling it from the 75 min I was running.

Cleanliness is next to godliness. Any fingerprints will not anodize. Ultrasonics are your friends but caustics can be too.

Some sort of resistor is needed to set the voltage to the neighborhood of 4-5vdc. Calculate your amp load and maintain it, and it will change as the process progresses, requiring a higher voltage.

Check part growth. Half a thousandth is about all you can expect to gain. Beyond that point you just eat the part.

Dye at 140* F for as long as you like. Quench in boiling water to seal the dye in, wipe down with clean rags, and wax. If it takes the color it is anodized.

That's about all there is to it except setting up the tanks. Hard anodizing however, is a bit more complicated.

Jim

Quote:

It's not hard. The most difficult part is deciphering all of the gobbledegook and art specific tecnospeak into plain english.

Tech Session!!!

Tech session could happen Carl.

While waiting for supplies I put the car back on the lift and tidied up a few items. One was the front brace for the mini starter. This is the same starter we used on the MG-Roadmaster and we've had some issues with breakage so I decided to go ahead and make a brace before it became a problem. Here is what I came up with: (sorry for the bad focus, I accidentally had the camera set for distance work)



As you can see it is sort of shiny. I started out looking for a suitable piece of steel but the only thing the right size was a piece of stainless and I thought, "Oh well, at least I won't have to paint it." And as it got closer and closer to being finished I thought, "Well, a little grinding would get the sharp edges off." And the next thing you know I had Racoon Fever.



It used to be that I was way more concerned with making the car run and handle its best and was only mildly concerned with appearance, but about six months back all that sort of changed somehow. Well you know, it's true that I do enjoy making automotive jewelry and I guess about the only excuse I have for something that will rarely if ever be seen is that I managed to get overrun by the Racoon Brotherhood.

Jim

OK, here is the surge tank I promised.







I thought it came out pretty good, though it is far from flawless. Still, I'm thinking it isn't bad for a first try and I learned some very important things in the process. In particular, welds are almost always going to show up if you look for them even under the best of conditions. But more importantly, the filler rod you use can and will make all the difference in the world. I used 5356 and 4043. In fact, I used some of each on this piece. I still have to determine which rod did what but one of them blended in very well, while the other did not anodize at all, creating instead a sort of brown oxide layer of some sort. If you look closely you can see it in the photos. Luckily this blends in reasonably well with the burgundy dye and is mostly in less visible spots so I decided I could live with it, but on something like, well, the scoop for example, it would mean that trying to anodize the part would be a big mistake.

I think the 5356 filler is the good one but more testing and/or research can confirm that, and I do need to know because I've used the 5356 on almost all my welds up to now.

Anyway guys, Bling, Bling! Here's to all you Racoon Brothers. Enjoy!

Jim

I never cease to be impressed with your work.....

That's an extraordinary part! Sure fits the hole nicely, doesn't it. The luster you achieved is very attractive. Are there tricks to getting extra shine? Do you polish the bare aluminum before you anodize it?

I can see how a guy might get totally carried away. There's a lot of aluminum in that engine bay...