How to Degree a Cam: Step 3: Fit Dial Gauge
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Step 3: Fit Dial Gauge
04.14
| 00:00 | - The third step of our process is to fit our dial indicator so that we'll be able to physically measure the valve motion. |
| 00:06 | In this case, we're going to want to fit our dial indicator directly on top of the valve or more specifically, the retainer, so that it's directly measuring the valve motion, this is because our camshaft spec sheet lists our timing events at valve lift as opposed to cam lift. |
| 00:24 | Now in this example, we're going to be using a metric dial indicator. |
| 00:28 | This is simply because our camshaft specifications use metric units. |
| 00:33 | Of course we could always use an imperial dial indicator and simply convert between metric and imperial. |
| 00:40 | But for our example, using a metric dial indicator is going to keep everything nice and clean and simple. |
| 00:47 | Now we also know that because we have 11.25 millimetres maximum valve lift, we're going to need a dial indicator that can measure at least 11.25 millimetres. |
| 00:58 | In this case we're using a Mitutoyo dial indicator that provides 20 millimetres of travel. |
| 01:04 | Our first step now is going to be to fit a steel plate so that we've got somewhere to fit our magnetic base to. |
| 01:12 | In this case I'm just using a simple offcut of steel and I've just drilled a couple of holes in here that allow me to locate this on our cam cap. |
| 01:22 | So we're just going to fit that now. |
| 01:26 | In this case with our Honda B18C, there's really nothing for this particular steel plate to foul on but in some instances we do want to be careful that once we've fitted this plate, it's not going to end up contacting anything on the valve train when we're actually turning the engine over. |
| 01:46 | OK once we've got our steel plate in place and we've got somewhere to locate our magnetic base, we can take our magnetic base and our dial indicator. |
| 01:55 | And in this case in order to get down on top of that retainer, I'm using a 100 millimetre extension that will simply wind into the base of our Mitutoyo dial gauge. |
| 02:07 | Once we've got that fitted, we can locate our magnetic base. |
| 02:10 | And again here all I'm trying to do is locate our dial indicator on the edge of our retainer, we want to be really careful that that's located in a place where it's not going to foul on any of the valve train components. |
| 02:23 | And we also want to be really careful that once we've got this fitted, that it is operating directly in line with our valve. |
| 02:30 | We don't want any angulation on there. |
| 02:32 | Now at the moment also we've got our inlet valve completely closed. |
| 02:36 | So at this point we know that we're going to be opening from here, an additional 11.25 millimetres. |
| 02:42 | So it's important to start with our dial indicator pre loaded so that it's not going to run out of travel as it extends while the valve opens. |
| 02:51 | So I'm just going to go through that process now. |
| 02:59 | So at this point on our smaller dial on our indicator we can see that we've got our dial indicator pre loaded by around about 14 millimetres. |
| 03:07 | So we know that we're going to have plenty of travel there when we turn the engine around and the valve opens. |
| 03:12 | What we're going to do now is we're going to zero our dial indicator. |
| 03:17 | This is important because we want to always have a zero point, when we end up going through the valve motion we wanna make sure that we're coming back to that zero point. |
| 03:26 | So I'm just going to zero our dial indicator. |
| 03:28 | With our dial gauge zeroed, we're now going to turn the engine through one full engine cycle or two complete revolutions of the crankshaft. |
| 03:36 | And there's two reasons we're going to go through this process, first of all we want to be really sure that the extension for our dial indicator isn't going to foul or contact on any of the valve train components during the valve train movement. |
| 03:49 | We also want to make sure that our dial indicator comes back to zero when the valves close again. |
| 03:54 | So let's do that now. |
| 04:07 | OK so now we've got our dial indicator fitted, we know it's zeroed correctly, we can move on with the next step of our process. |
