Dec 4

Project time

adventure, blahblahblah Add Comment (1)

Now that it has begun snowing up here, I haven’t ridden the motorcycle much. I hope to still be able to on the days that is is clear to save some gas, but for the last 2 weeks I have been driving the Mustang back and forth to work. At about 12-15 miles to the gallon, with 40 miles to drive each day, it gets pricey. So, I have a nefarious plan.

The Mustang has always been cold blooded. That is to say, it really does not like cold mornings. I recall as a kid really cold mornings when it would almost drain the battery trying to get it to start and stay running. I eventually adjusted the choke and fast idle and it tried harder to stay running, but it was still really funny. It would start up, sit and rev at high idle just fine until you kicked it down, then as soon as you put it in gear, it would start sputtering and bucking.

I’ve thought about why this is the case long and hard, and I’m pretty sure what is going on is due to several issues. The first was the points and condensor style ignition system. I replaced that with a Duraspark II electronic ignition system a few years back. This was a pretty easy change, as Ford started using the Duraspark II in ’78 or so on the 400 ‘Modified’, which was a 351 Cleveland block with a 400 crank in it. I simply bought the parts at Autozone for about $60, plus $5 of junkyard wires, and instant upgrade. Now, it always starts in the morning, but it is still sputtering.

The root issue here is fuel atomization. The intake manifold is cast iron, and takes a while to warm up. The car had two systems in place when it was new to help out with this. The first was a baffle over the exhaust header, and a vacuum door in the air inlet runner. When the engine air temp was below a certain amount, it redirected the inlet from being down and in front, to pulling air over the manifold. This gave you pre-heated air, which helped atomize the fuel. The second thing in place was under the carb, under the intake manifold, a passage had been created that allowed hot exhaust gas from each cylinder head to flow, heating up the intake and by extension, the intake air and fuel. Now, many years later, this passage is choked off with carbon. The baffle on the manifold is gone as well, so neither system is doing me any good, leading to the horrible mornings until the intake finally warms up.

The other trick with the Cleveland, which is different than most engines, is that there is no water passages in the intake manifold, so the intake has to warm up via conduction from the heads, a slow process. The net-net of it all is that I’m not running well until I am about 5 miles into my commute, each way.

So, the nefarious plan. I had planned on building up a motor for my Jeep and fuel injecting it with MegaSquirt. That project is on hold, but I do have a complete MegaSquirt on the shelf, and that started me thinking. You see, MegaSquirt is an ‘open source’ style electronic fuel injection computer. You build the board your self, program it however you like, and then tune your engine with a laptop and some software. There is a large community of people using MegaSquirt, and folks have used it on everything from lawnmowers to race cars. As such, I’ve decided to ditch the carb, and go EFI on the Mustang.

I bought another cast iron intake manifold of the original kind off ebay for $1 (and $23.90 shipping). I have a 2V Cleveland, so intakes are a tad harder to find, as everyone seems to want the 4V, which will not work with my heads anyway. The plan is that once I get the intake in, I will put it in the CNC and drill it for injectors. I will then need to make some fuel rails and plumb it up. Next step is to dig up some injectors, which Brian says he has a handle on a bunch, for free. I’ll need to install a fuel pump and re-do the fuel lines to handle the higher pressure, as well as a return line. Next, I will need to adapt a late model Mustang throttle body to the intake manifold. Brian gave me his throttle body off his old engine, and it is really close to being a bolt on. One adapter plate and I am there. Then, I need to install a ‘H’ pipe in the exhaust, and bung in an O2 sensor. Finally, wire it all up, and… fuel injection!

Of course, this will take a lot of fabrication, but the way I plan to do it, I can work on it slowly and test a lot of things before committing to putting it on the car, so that will be nice.

Regardless, I’ll update with progress. Right now I am firmly into the research stage. I need to build the MegaSquirt up at some point, and my intake will be here soon. Should be fun!

-Steve