1 00:00:09,125 --> 00:00:09,625 Right. 2 00:00:09,625 --> 00:00:11,333 Following on from our last video. 3 00:00:11,333 --> 00:00:13,458 Now, we've got the head actually on the bench. 4 00:00:13,458 --> 00:00:15,166 We've just checked, we've cleaned the work area. 5 00:00:15,166 --> 00:00:19,333 We've got a tool here we don't use all the time, a valve spring compressor. 6 00:00:19,333 --> 00:00:20,458 Okay, this is a universal one. 7 00:00:20,458 --> 00:00:22,041 There's a couple of different types. 8 00:00:22,041 --> 00:00:24,083 For this one, we can use this one. 9 00:00:24,083 --> 00:00:27,416 So it's fully adjustable and then this section fits 10 00:00:27,416 --> 00:00:30,500 over the heads of the valves and we use that to compress the springs. 11 00:00:30,875 --> 00:00:35,333 This side goes on the valve head itself, and then we can adjust it and use it to push through 12 00:00:35,541 --> 00:00:39,791 It's a bit fiddly, so we just have to be a bit mindful when we're kind of taking it out 13 00:00:39,791 --> 00:00:42,958 that we don't lose any of the components and we keep them in the same order. 14 00:00:44,125 --> 00:00:50,375 I tend to use like a little lid or part of something just to keep the parts together, the collets themselves. 15 00:00:50,750 --> 00:00:53,958 I'll take one valve out now and then I can show you what we mean. 16 00:00:54,458 --> 00:00:59,416 So we're adjusting it on the back and then we clamp ot together to run it through on here. 17 00:00:59,708 --> 00:01:00,916 So we need to tighten it up. 18 00:01:00,916 --> 00:01:03,708 There's a bit of trial and error involved here. 19 00:01:09,958 --> 00:01:13,166 So what we're actually trying to achieve is we're trying to compress the spring. 20 00:01:13,541 --> 00:01:15,541 So then we can remove it. 21 00:01:15,541 --> 00:01:20,166 Small screwdriver handy here, magnetic ones are ideal because then it'll actually catch the components 22 00:01:20,166 --> 00:01:22,875 that were taking off, these are the valve collets. 23 00:01:45,250 --> 00:01:48,250 Right, we can release the spring pressure 24 00:01:48,250 --> 00:01:49,708 and now that one's free. 25 00:01:49,708 --> 00:01:51,875 Okay, so these are the valve collets themselves. 26 00:01:52,250 --> 00:01:55,791 They're tapered and they fit with the groove which sits inside the valve. 27 00:01:56,333 --> 00:01:58,583 Okay. You can't put them in the wrong way round. 28 00:01:58,583 --> 00:01:59,875 They won't physically fit. 29 00:01:59,875 --> 00:02:03,791 But when we do the refitting procedure, we'll just show that they've got to be located 30 00:02:03,791 --> 00:02:06,083 correctly before we can reseat the valve. 31 00:02:06,875 --> 00:02:12,208 Okay, so this valve, then we can remove the spring and the cap okay. 32 00:02:12,208 --> 00:02:14,041 So they come apart separately. 33 00:02:14,041 --> 00:02:17,458 So the spring, there is actually a measurement we can do on that, which will do in a moment 34 00:02:17,458 --> 00:02:21,208 for free length because they've been compressed since the engine was built. 35 00:02:21,583 --> 00:02:24,208 They get hammered up and down thousands of times a minute. 36 00:02:24,458 --> 00:02:28,250 Every time the engine's running, then obviously they do tend to compress 37 00:02:28,250 --> 00:02:31,916 and if they, if they're over compressed, then they won't function properly. 38 00:02:32,125 --> 00:02:35,916 Their job is to close the valve every time the camshaft lifts off 39 00:02:36,291 --> 00:02:38,916 and then to stop the valve from bouncing a high speed. 40 00:02:39,583 --> 00:02:43,458 So the valve itself, we can push it through from the top, we can remove it. 41 00:02:44,416 --> 00:02:46,041 Okay so we just give it wipe over. 42 00:02:47,000 --> 00:02:52,208 So the valve there itself, that groove at the top, that is where you collet fits in. 43 00:02:52,375 --> 00:02:57,208 So when it's assembled, that just sits in there and the two halves, then hold it in place. 44 00:02:57,875 --> 00:02:58,250 Okay. 45 00:02:58,250 --> 00:03:02,625 But as you can see, that's not much to hold a valve that's been hammered up and down by the engine. 46 00:03:03,000 --> 00:03:05,041 So we need to make sure they're located correctly. 47 00:03:05,416 --> 00:03:05,791 Right. 48 00:03:05,791 --> 00:03:06,166 Okay. 49 00:03:06,166 --> 00:03:10,958 So for a valve inspection, we need to check the valve stem to check that it's not bent. 50 00:03:11,250 --> 00:03:14,208 Ok. Quickest way to do that really is to spin it on a flat surface. 51 00:03:14,208 --> 00:03:16,791 We know this bench is okay, so we can let it roll round. 52 00:03:17,333 --> 00:03:22,916 So it rolls, there's no undue wobbles or it's not unsteady as it goes round. 53 00:03:22,916 --> 00:03:26,416 So generally as a good rule of thumb, that should be okay to refit. 54 00:03:26,416 --> 00:03:29,666 We will inspect it more closely when we're grinding them back in. 55 00:03:29,666 --> 00:03:32,375 Ok so the valve seat itself. 56 00:03:32,375 --> 00:03:35,958 That's actually the portion that sits on the head, which we're going to look at in a second. 57 00:03:36,166 --> 00:03:40,541 Any cracks or damage there generally this item is going to be unserviceable, 58 00:03:40,541 --> 00:03:44,250 but I'll be inspecting the head closely just check there's no damage to that. 59 00:03:45,125 --> 00:03:48,791 If you've got a burnt valve seat, it results in poor sealing on that cylinder. 60 00:03:48,791 --> 00:03:51,875 Poor performance, low power or a general misfire. 61 00:03:53,125 --> 00:03:55,625 We've covered testing for that in a compression test. 62 00:03:55,625 --> 00:03:57,666 That was one of the test videos we did earlier. 63 00:03:57,958 --> 00:04:01,333 And this is one of the things we can get via a compression test. 64 00:04:01,875 --> 00:04:03,958 So I'm going to put the valve there for a moment. 65 00:04:03,958 --> 00:04:07,291 We'll keep it out of the way because the head is stripped, we can lay it flat 66 00:04:07,291 --> 00:04:10,583 and then we can have a look at the actual valve seat itself. 67 00:04:10,833 --> 00:04:12,291 So I'll turn it that way. 68 00:04:12,291 --> 00:04:12,625 Okay. 69 00:04:12,625 --> 00:04:15,791 So we can give that quick wipe around 70 00:04:17,000 --> 00:04:17,458 Okay. 71 00:04:17,458 --> 00:04:21,791 So Sparkplug there, obviously the other valves there, some layouts are slightly different. 72 00:04:21,791 --> 00:04:24,875 A lot of engines now have four valves, per cylinder, and not two. 73 00:04:24,875 --> 00:04:27,750 So this is quite a nice, straightforward set up to look at. 74 00:04:28,458 --> 00:04:31,000 Okay, so if we have a look at the valve seat itself, 75 00:04:31,000 --> 00:04:33,750 that's the hardened insert that the valve runs in. 76 00:04:34,041 --> 00:04:36,250 So it just sits flush like that when it's closed. 77 00:04:36,833 --> 00:04:38,958 OK, we can look at the side of this. 78 00:04:38,958 --> 00:04:41,458 It's a nice dull finish, which is generally quite good. 79 00:04:42,250 --> 00:04:44,541 There are a couple of small blemishes. 80 00:04:44,541 --> 00:04:49,166 So if we were refitting these valves, we just grind that in with some light grinding paste 81 00:04:49,416 --> 00:04:53,291 just to reseal the valve and then we can reservice it and use it again. 82 00:04:53,916 --> 00:04:54,291 Okay. 83 00:04:54,291 --> 00:04:56,333 So what we'll do is I'll take another valve out in a minute. 84 00:04:56,333 --> 00:04:58,583 We'll have a look at the rest of the cylinder. 85 00:04:58,583 --> 00:04:58,916 Okay. 86 00:04:58,916 --> 00:05:03,500 We're looking for any cracks from the spark plug or especially cracks between the two valves. 87 00:05:03,958 --> 00:05:08,000 Any loss of sealing between those two and gases can escape 88 00:05:08,000 --> 00:05:12,041 from one side of the cylinders to the other, and then we'll end up with poor performance. 89 00:05:12,416 --> 00:05:13,666 And then that's a case of 90 00:05:14,625 --> 00:05:15,208 they're not 91 00:05:15,208 --> 00:05:20,333 generally repairable if you've got a crack in the cylinder head, unfortunately, that's time for a new unit. 92 00:05:20,333 --> 00:05:23,125 Because there is no way of permanently repairing them. 93 00:05:24,500 --> 00:05:26,958 Okay, so what we do is we set the heads aside for a moment. 94 00:05:27,250 --> 00:05:29,708 We'll just measure the valve spring length. 95 00:05:30,333 --> 00:05:33,416 You can use a steel ruler, straight edge or a micrometer, 96 00:05:33,416 --> 00:05:36,208 depending We've got nice flat bench, so we can use that. 97 00:05:36,666 --> 00:05:38,875 And what we do is we take a measurement for that 98 00:05:41,041 --> 00:05:44,833 and then we can compare it to the settings in your workshop manual. 99 00:05:45,208 --> 00:05:50,208 If it's overly compressed or very close to the limit, I would say for the cost of a set of valve springs 100 00:05:50,375 --> 00:05:55,625 it's worth replacing them just to ensure that your engine's running kind of the optimum setting. 101 00:05:56,041 --> 00:06:00,375 So a lot of engines now use double valve springs, so they'll have a smaller one inside 102 00:06:00,666 --> 00:06:05,291 and that allows you to rev the engines harder because then the valve is less prone to bounce. 103 00:06:06,333 --> 00:06:06,791 Okay. 104 00:06:06,791 --> 00:06:11,750 So what I will do is I'm going to take another valve out this side of the cylinder now, 105 00:06:11,750 --> 00:06:15,583 and then we can inspect that side and then that will conclude this video.