Zetec Build

So I've mentioned previously that I'm working on building an engine to put into my Focus. I got the block back from the machine shop a week and a half ago and put it back on the stand. I realized after I had it back that I'm going to need to cut a little bit out of the windage tray to provide adequate clearance for ARP main studs. I was going to take the whole thing back to the shop and have him do all the cutting. But I've decided that this is a project that I'm working on and its certainly not difficult to notch the windage tray with a dremel and a carbide bit. It doesn't have to be pretty, its going to be buried deep within the bowels of the engine and its not going to compromise the integrity of the tray. I just need to blow the metal shavings out of it and wash it a few times.

Anyhow, it got me thinking how I've kind of lost sight of the original intent of the build. Its pretty easy to invest cubic dollars into an engine to get a certain power in return. However, its kind of like being a sheep and following the leader around. You're never going to get beyond a certain point unless you step up and try something new. So that's what I'm going to do!

The biggest undertaking is going to be to port and polish the head. Reading online, there are all sorts of warnings against attempting this yourself. Apparently, the majority of head builders have a Ph.D in Fluid Dynamics [maybe the OEMs do, but I'm pretty sure the aftermarket guys just have a lot of experience]. Its certainly not something to be undertaken lightly, but this is a "project"; I'm doing this to learn something. The path is fraught with peril (I like that phrase), as cylinder heads are full of oil and coolant passages; one slip with the cutter and you're liable to end up with a 30lb paperweight. Good thing Zetec heads are fairly cheap (and I'm working on a spare head to begin with)! I have yet to look really closely at what I need to do to the head, but I think my biggest focus will be on the point where the ports enter/exit the head. It seems as though there is quite a bit of meat there and most of the oil/coolant passage ways go through the inner portion of the head. The biggest thing is that if you get your ports too big, your air flow goes up, but your air velocity drops and leads to uneven distribution of atomized fuel in the combustion chamber (as well as losing some exhaust scavenging on the other side). Zetec heads are notorious for their poor flow characteristics, so it shouldn't take too much to get a noticable improvement.

If I thought I knew nothing of building an engine, I certainly know even less about the intricacies of cylinder heads, what with disassembling them (the easy part) and 3 angle valve jobs. Some of the simpler stuff, like cam timing and clearancing is pretty straightforward. However, I'm really looking forward to getting my hands dirty and doing what I did as a kid. If I wanted something back then and didn't have the money for it, I either saved until I could afford it or I researched the project and made it for myself.