Strangely Posted May 17, 2005 Share Posted May 17, 2005 [Also posted to the Sevens list.] I buzzed my engine after fluffing a gear change from 4th to 5th. I think the revs went somewhere over 8,000 rpm (the engine's not normally revved over about 7200 - standard bottom end with 633(?) cams, Lotus Sport 135 head with Jenvey DTH TBs). Now it's making a nasty tappy valvey noise, here: www.strangely.org/tmp/engine.mp3 (The recording makes it sound worse because the noise-canceling microphone that I used did a good job of filtering out the rest of the engine noise.) There are more crackles and pops than normal when I drive it, and I think it's down on power (but no slower because I rarely get chance to use all of the power on my commute, so perhaps I'm going just as quickly by using more throttle?). Bent valve? And recommendations for people who know their K stuff near Reading, and are likely to be able to take a look and hopefully fix it on Wednesday or Thursday? Otherwise I'll start phoning the usual suspects, starting of course with DVA but he's bound to be booked up, and it's a long way to drive a poorly engine. I'd be happy enough if somebody could (truthfully) tell me "yes, there's a problem but you won't damage the engine any more by driving it, so go off to Scotland and fix it when you get back". I'm currently a bit depressed. I'm really looking forward to Haggis, but so is my brother who's coming as my passenger, and I really don't want to let him down. :-( I'm going into the garage to fix some niggley little problems just in case the tour's still on for me... Jason. Link to comment Share on other sites More sharing options...
Trevor Newman Posted May 17, 2005 Share Posted May 17, 2005 sounds expensive Link to comment Share on other sites More sharing options...
Adam Posted May 17, 2005 Share Posted May 17, 2005 Jason This might turn out to be a case of the blind leading the partially sighted, but ... Apart from taking the head off, you could check the cam to tappet gap in case one of the tappets has "lost" oil. Do a search and you find some info on this .... Or could the cam belt have slipped a tooth?? Think I saw the photos on how to check the cam timing on your site. Maybe a good idea to check? Sorry I cant be of any more help .... Edited by - Adam on 17 May 2005 23:01:51 Link to comment Share on other sites More sharing options...
philwaters Posted May 17, 2005 Share Posted May 17, 2005 Assuming you changed down from 4th to 3rd, you'd get the following resultant revs with your diff and gearbox - can you remember what you happened to change gear at? Change @ Gives: 7200 9144 6500 8255 6000 7620 5500 6985 from here Could be a broken valve spring or follower? Phil Waters Edited by - philwaters on 17 May 2005 23:09:25 Link to comment Share on other sites More sharing options...
Strangely Posted May 17, 2005 Author Share Posted May 17, 2005 I changed up from 4th to 5th, fluffed the change, and whilst in neutral I stomped the throttle in the same way I would have done if I hadn't been an 🙆🏻 ☹️. So I've no idea what it revved to... Link to comment Share on other sites More sharing options...
philwaters Posted May 17, 2005 Share Posted May 17, 2005 Arr, I see. Then wouldn't the rev limiter have kicked in? Phil Waters Link to comment Share on other sites More sharing options...
Strangely Posted May 17, 2005 Author Share Posted May 17, 2005 wouldn't the rev limiter have kicked in? Not quickly enough, or it wouldn't have got anywhere near 8k rpm. Link to comment Share on other sites More sharing options...
thinfourth Posted May 18, 2005 Share Posted May 18, 2005 Go to halfords at lunch time and get a compression tester this is your first move. Do a compression test you will find out from here how but easy enough whip the plugs out and stick gauge in each plug hole and spin the engine on the starter WITH THE THROTTLE FULL and record the results on each unit. Post the results here and the wise ones will tell you but basically you are looking for variation. The happy handle made me do it Link to comment Share on other sites More sharing options...
Strangely Posted May 18, 2005 Author Share Posted May 18, 2005 Update: Max ever revs, according to Emerald: 7456 Compression test shows (in bar): 1: 16.5 2: 16.7 3: 16.5 4: 15.8 rising to 16.8 with 1 teaspoon of oil down the bore They seem very high compared to the Haynes recommended minimum pressure of 10 bar. The maximum difference between cylinders is quoted at 1.5 bar, so in theory that 15.8 should be OK?! I'm just waiting for the exhaust to cool down so that I can move the Apollo tank and remove the front cover to check whether the cam timing has changed. Link to comment Share on other sites More sharing options...
WILL FLY Posted May 18, 2005 Share Posted May 18, 2005 Jason 16 bar is normal for a K series, mine had 16, 5, 16, 16 and 100% leak on no 2 comapred with 8% on the other cylinders that we measured. If the engine is just very tappety could it be air in the oil in your followers ? if you only revved to 7450 then I can't see you breaking anything. The oil making the compression figure rises just means worn rings I think. You'll need a compressor to do a leakdown test. Roy. See willfly.net for more info. If you don't spin you ain't trying Happiness is knowing you have just a tad too much power Link to comment Share on other sites More sharing options...
Strangely Posted May 18, 2005 Author Share Posted May 18, 2005 Roy, thanks for that. It doesn't sound like I remember air in the followers sounding. (I used to get that a lot on my old engine before I fitted the Apollo.) Link to comment Share on other sites More sharing options...
WILL FLY Posted May 18, 2005 Share Posted May 18, 2005 Jason Speak to DVA If he thinks its just the head, I have a standard head that you can borrow if you come round tonight. Roy. See willfly.net for more info. If you don't spin you ain't trying Happiness is knowing you have just a tad too much power Link to comment Share on other sites More sharing options...
stevefoster Posted May 18, 2005 Share Posted May 18, 2005 Bummer. It sound pretty much ok on Monday evening. If it's getting rapidly worse I would think it could go terminal pretty soon. Dropped or snapped off valve or totally compressed tappet. Compressed tappet would not be too bad. Roy's offer of a head would be the quickest way if you can find someone to do the work. Hants (North) and Berkshire Area club site here My racing info site here Link to comment Share on other sites More sharing options...
Strangely Posted May 18, 2005 Author Share Posted May 18, 2005 I've checked the cam timing, but I'm not sure whether it's OK or not. The clearest way of showing it is: Crank lined up (confirmed with a mirror to eliminate paralax): http://www.strangely.org/tmp/crank1.jpg Pulleys out by ~ 0.5 tooth: http://www.strangely.org/tmp/pulleys1.jpg It could be down to the fact that when DVA timed them he used true TDC (measure on a piston) rather than the mark on the cover. It maybe / sorta looks like the vernier may have slipped? Not really sure about that though. http://www.strangely.org/tmp/pulley-slip.jpg Link to comment Share on other sites More sharing options...
WILL FLY Posted May 18, 2005 Share Posted May 18, 2005 Your crank is at 90 deg BEFORE TDC there. You need to line up the mark on the rear of the pulley with the TDC mark which is with the group of marks on the cam belt cover at sort of 10 o'clock on the pulley. see here Roy. See willfly.net for more info. If you don't spin you ain't trying Happiness is knowing you have just a tad too much power Link to comment Share on other sites More sharing options...
Strangely Posted May 18, 2005 Author Share Posted May 18, 2005 Bugger. It's not going to make any real difference though, is it? Won't it just mean that the lines on the opposite sides of the pulleys will line up? Link to comment Share on other sites More sharing options...
Myles Posted May 18, 2005 Share Posted May 18, 2005 😳 As usual. Project Scope-Creep is live... Alcester Racing 7's Equipe - 🙆🏻™ Alcester-Racing-Sevens.com Edited by - Myles on 18 May 2005 15:18:22 Link to comment Share on other sites More sharing options...
Strangely Posted May 18, 2005 Author Share Posted May 18, 2005 DVA says that you're wrong, Roy . 90 deg BTDC is what I needed. Half a tooth out is fine. Next check is to see if any of the followers are squidgey, and the cam cover has to come off for that... Link to comment Share on other sites More sharing options...
WILL FLY Posted May 18, 2005 Share Posted May 18, 2005 Ok, I bow to superior knowledge, I thought you were trying to check the timing not get the pistons in a safe position. What's Dave's verdict on the noise ? Roy See willfly.net for more info. If you don't spin you ain't trying Happiness is knowing you have just a tad too much power Link to comment Share on other sites More sharing options...
Strangely Posted May 18, 2005 Author Share Posted May 18, 2005 When I talked to DVA I didn't make good enough notes ☹️. Can anybody please confirm (at which point) I need to check for a gap between followers and cam lobes (e.g. pushing against the valve or not)? Link to comment Share on other sites More sharing options...
Allen Payne Posted May 18, 2005 Share Posted May 18, 2005 I'm sure it would be with the lobe facing up away from the follower. Link to comment Share on other sites More sharing options...
Strangely Posted May 18, 2005 Author Share Posted May 18, 2005 The hopefully final, anticlimactic update... Phil came round this evening. Immediately reckoned that the noise was the injectors and perfectly normal. Checked a few other things over and then drove over to Phil's to a) try to provoke the real problem, b) collect appropriate tools if a) happened. Car was fine - top form, in fact. Here's my theory / excuse for being an arse: there really was a problem on Tuesday, possibly aerated followers, probably unrelated to me buzzing the engine (because that happened on Monday, and both Phil and Steve heard it then, and thought it sounded OK). Wednesday, start engine, all geared up to hear a poorly engine, and I either do hear the remnants of aerated followers, or I hear the injectors and make up the rest. Spend the rest of the day pissing about and wasting peoples' time. After I left Phil's place I went for a vigorous blat, on the basis that I'd rather blow the engine up down here rather than in Scotland. It didn't miss a beat. So the plan is to drive it to work and back home tomorrow (total ~50 miles). If it's OK then drive up to Scotland. If not then quickly hire a cheap hatchback, and drive up to Scotland. Thanks to everybody who helped today, both on the various lists, and off. It was very much appreciated, since I didn't feel comfortable taking a "problem" K-series to anybody local. Cheery, Jason. Link to comment Share on other sites More sharing options...
stevefoster Posted May 19, 2005 Share Posted May 19, 2005 Phil mentioned the data logging in the ECU showing not too high RPM so hopefully it was not buzzed. - Never hurry a T9! Hants (North) and Berkshire Area club site here My racing info site here Link to comment Share on other sites More sharing options...
Tony Whitley Posted May 19, 2005 Share Posted May 19, 2005 If you want to hear what a noisy injector sounds like I can bring my car over... I presume your recording was at tickover? I'd say the ticks are more frequent than with my car. (Assuming my MEMS and your Emerald both do only one injection per revolution. Plus I have only one noisy injector.) Link to comment Share on other sites More sharing options...
Strangely Posted May 19, 2005 Author Share Posted May 19, 2005 Tony, yes it was recorded at idle. I think the MEMS (EU2, non VVC) uses batched injection, so it fires twice per rev. I think the Emerald is the same. My idle might be higher than yours, and as you say I might have more than 1 noisy injector. Link to comment Share on other sites More sharing options...
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