Follow along as I build a high performance 914 engine
Modifying Engine Tin
Well, after too long a hiatus, I finally got to spend a little bit of time on my engine over the 4th of July weekend. I mocked up one side of the engine (cylinders 1 & 2) - first putting the crank and cam in the case halves, then grinding my cylinder shims a little bit for proper clearance around the head studs:
After sliding my cylinders in place and setting one of the new heads on top, I was able to put the "engine tin" - the metal shrouding that directs air over the cylinders and head - in place to see how it would fit:
My new heads have the spark plug locations modified, so I will have to "move" the original spark plug access holes. To mark where the location should be, I was able to put a Sharpie marker in the spark plug hole to mark the tin:
Here I've marked up both locations (see my little cross hairs?):
After using a center punch, I was able to drill holes with a step-drill (which works great for sheetmetal, by the way). Probably most people would use a hole saw for this step, but I don't have one that size - but do have a knock-out punch that is the right size.
A knock-out punch is a little die and anvil set with a bolt going through. First you make the holes in your sheetmetal the right size for the bolt (3/4" in this case), then you slide the one piece over the bolt, put the bolt through the hole, and finally, thread the other part onto the bolt. After a little turning, you have a clean, round hole!
Both holes are made in their new locations:
And now it's time to weld up the old holes! I used the knockout slugs from the new holes and some random washers I had laying around.
|All pictures and text copyright 2008|