00:00 |
- The tools required for accurately degreeing a camshaft are relatively simple and they definitely don't need to break the bank.
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00:07 |
The first tool you're going to need is a degree wheel, which is simply a large diameter aluminium disk with 360 individual degree markings on it.
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00:16 |
We're going to be using this to read the cam timing events and hence it's a critical component.
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00:22 |
These degree wheels are available from a number of suppliers and the one we're using is from Moroso.
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00:28 |
They're also available in a range of different diameters and it's actually an advantage to use a larger diameter degree wheel since this has the effect of providing finer resolution since there's going to be a greater distance between the degree markings at the outside edge of the wheel.
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00:45 |
In order to read the numbers off the degree wheel, we'll also need a pointer that attaches to the engine block.
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00:51 |
This can be as simple as a piece of welding wire or similar, that's bolted to the block temporarily and then bent into location.
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00:58 |
To help improve the accuracy of reading the degree markings we want to use a thin piece of wire or alternatively you can sharpen the end to a point.
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01:08 |
Next we're going to need a way of measuring the cam or valve opening and this can be done with a dial gauge.
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01:14 |
These gauges use a small plunger which turns the dial and hence we can accurately read the amount of valve or cam lift.
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01:21 |
These dial gauges can be purchased in metric or imperial scales, so it's up to your preference as to which you choose.
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01:29 |
You'll often find that the camshaft specs are given in imperial units, so despite us using the metric system here in New Zealand, I'll still often use an imperial dial gauge.
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01:40 |
You also need to make sure the dial gauge has sufficient travel to suit the valve lift that you need to measure.
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01:47 |
Some dial gauges for example only have a range of perhaps 0 to 10 millimetres, so these will be of little use if you have 12.5 millimetres of valve lift.
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01:56 |
Dial gauges can also be used for a range of tasks in the engine building field and hence are a pretty universal design.
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02:04 |
For our purposes for measuring valve lift, we'll also need an extension that screws into the base of the dial gauge and allows us to access down into the cylinder head to locate the dial gauge onto the valve spring retainer or the bucket.
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02:18 |
We'll also need a way of attaching the dial gauge to the engine or cylinder head, and this can be achieved with a magnetic base.
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02:25 |
These use a strong magnet and a variety of adjustable arms to allow the dial gauge to be accurately located and orientated as required.
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02:33 |
Since a lot of the cylinder heads we're likely to deal with are alloy and hence not magnetic, I also keep a piece of steel plate in my toolbox with a variety of holes drilled in it that can be temporarily bolted to the head to act as a place to locate the magnetic base.
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02:50 |
In some particular engines such as Honda's VTEC range, you can purchase specific tools for dialling in the cams which bolt into location on the head and include permanently mounted dial indicators.
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03:03 |
While these simplify the process, they aren't essential and the techniques we'll look at shortly will still cross over to these products if you choose to purchase them.
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03:13 |
Next we're going to need some way of limiting the piston travel when we go through the process of finding true top dead centre.
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03:20 |
This can be done with a couple of different tools including a positive piston stop that screws down the spark plug hole to limit piston travel or if we're finding true TDC with the cylinder head removed, this can be done with a plate that bolts across the top of the engine block and has an adjustable stopper that screws down against he crown of the piston.
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