eeyoreish 837 Posted February 3, 2019 Author Report Share Posted February 3, 2019 I had the alternator bearings changed while it was off so probably eliminates that. They didn't feel quite right and I thought (along with the knackered tensioner bearing) the alternator might be contributing to my mystery whine. Cam journals worn? What's the answer there if that's the problem? As far as I can see there are no replaceable camshaft bearings. Quote Not worth starting anything now... Link to post Share on other sites
Sparky 2,749 Posted February 3, 2019 Report Share Posted February 3, 2019 Not necessarily an issue worth looking at. First off, get that tension checked! With the right tools, you can adjust the tensioner without any dismantling. Quote British Fart to Florida, Nude to New York, Dunce to Denmark, Numpty to Newfoundland. And Shitfaced Silly Sod to Sweden. Link to post Share on other sites
eeyoreish 837 Posted February 3, 2019 Author Report Share Posted February 3, 2019 Yes, I'll have another look at the tension next weekend. If that doesn't change anything maybe I should try swapping a pulley off the TE engine to see if it makes any difference. It's a HC engine too and as far as I can see from Deroure it will be the same pulley. Quote Not worth starting anything now... Link to post Share on other sites
snowrx 140 Posted February 4, 2019 Report Share Posted February 4, 2019 Looks like all ended well despite much worry, but if one was to revisit the oil pump gasket issue: You can dry assemble the pump housing over the rotor/annulus with a piece of Plastigage (don't know UK equivalent brand, a deformable plastic rod used to measure small clearances) and check the pump end float just like you would fitting crank bearings. Then you can make an informed decision on gasket thickness, or grind the pump housing face to reduce end float. What would sell on these forums would be if someone found a similar diameter (OEM?) rotor set that was taller and made a pump housing (or doweled spacer) to fit it. The powdered metal innards could be had affordably, but a custom housing would drive up the cost. Said housing could feature a threaded port to prime the pump and oil galleys! Quote Link to post Share on other sites
peteyg 317 Posted February 4, 2019 Report Share Posted February 4, 2019 @eeyoreish more than happy to have a look Neil, but not sure i'll be of much use. You're welcome to borrow my Krikit gauge which I've found perfectly good for tensioning the cambelt. Pete 1 Quote Pete '79 S2 LEW Miss September 2009 Link to post Share on other sites
eeyoreish 837 Posted February 4, 2019 Author Report Share Posted February 4, 2019 Thanks Pete. Based on the advice here so far I need to investigate the belt tension first. Do you think I’d be able to get access to get the gauge on the belt with the engine in? If so then yes, borrowing it would be a great help. Quote Not worth starting anything now... Link to post Share on other sites
Sparky 2,749 Posted February 4, 2019 Report Share Posted February 4, 2019 The Krikit gauge is very small. You absolutely must use it correctly! It's easy to get a bad reading. Quote British Fart to Florida, Nude to New York, Dunce to Denmark, Numpty to Newfoundland. And Shitfaced Silly Sod to Sweden. Link to post Share on other sites
peteyg 317 Posted February 4, 2019 Report Share Posted February 4, 2019 1 hour ago, Sparky said: The Krikit gauge is very small. You absolutely must use it correctly! It's easy to get a bad reading. You are right @Sparky but I'm on my 3rd Krikit- tensioned cambelt and so far so good (and that's not because the previous 2 snapped!). @eeyoreish We can certainly give it a go Neil. I only need to get to the long bit of belt at the top and it should give you a ballpark to work from. PM me and we'll sort a time. Pete 1 Quote Pete '79 S2 LEW Miss September 2009 Link to post Share on other sites
910Esprit 502 Posted February 4, 2019 Report Share Posted February 4, 2019 If you are on a round profile tooth, why not just do it by frequency? (endorsed by Lotus) The twist 'method' is nothing more than an informal check for an experienced mechanic. 1 Quote Link to post Share on other sites
Sparky 2,749 Posted February 4, 2019 Report Share Posted February 4, 2019 Yup, I do all mine on frequency now. Quote British Fart to Florida, Nude to New York, Dunce to Denmark, Numpty to Newfoundland. And Shitfaced Silly Sod to Sweden. Link to post Share on other sites
Clive59 109 Posted February 4, 2019 Report Share Posted February 4, 2019 1 hour ago, 910Esprit said: If you are on a round profile tooth, why not just do it by frequency? I thought it was valid for trapezoidal teeth too? The Gates Carbon Drive app works really well. Quote Link to post Share on other sites
910Esprit 502 Posted February 4, 2019 Report Share Posted February 4, 2019 Yeah I agree. I use 'Carbon Drive' on my trap belt. (I actually had a Lotus Burroughs gauge, but sold it when 'frequency' came more device accessible....) However, Lotus explicitly recommended frequency for the round tooth profile, but I don't think they ever did for Trap profile, so I always think its a bit more of 'use it at your own risk' Quote Link to post Share on other sites
Clive59 109 Posted February 4, 2019 Report Share Posted February 4, 2019 I saw an old post of yours and Geert, which was interesting. is 114Hz still what you set your trap belt to? And assume that +/-10% gives plenty of latitude? I checked mine and it seems to run fine around 110Hz, any more and I got some whine. Quote Link to post Share on other sites
910Esprit 502 Posted February 5, 2019 Report Share Posted February 5, 2019 I agree Clive, I run mine at about 107-108Hz Quote Link to post Share on other sites
eeyoreish 837 Posted February 5, 2019 Author Report Share Posted February 5, 2019 So how exactly are people measuring frequency of the round toothed belt? I've never done it so interested to know how it's done and what app etc to use. I have an iPhone if that's a suitable 'tool'? Quote Not worth starting anything now... Link to post Share on other sites
910Esprit 502 Posted February 5, 2019 Report Share Posted February 5, 2019 (edited) Download Gates Carbon Drive app to your phone (assuming its available on IOS) If not, there will be many other instrument tuning apps that display frequency. Rotate the crankshaft until the engine is at 30degrees BTDC (important). Cold engine of course . Then hit (a sharp tap) the cambelt between the aux pulley and the inlet pulley with something suitable, I use the handle of a large screwdriver, its not too important as long as its suitably weighted and could not damage the belt. Simply read the frequency from the phone that is being held in reasonably close proximity to the belt being struck. Adjust as required then recheck.... Edited February 5, 2019 by 910Esprit 1 Quote Link to post Share on other sites
eeyoreish 837 Posted February 5, 2019 Author Report Share Posted February 5, 2019 Thanks, sounds simple enough! So I'm rotating the engine clockwise as normal and not backing it off anti-clockwise at all? Do I drop/bounce the screwdriver handle on the belt or just give it a short, sharp tap? Quote Not worth starting anything now... Link to post Share on other sites
910Esprit 502 Posted February 5, 2019 Report Share Posted February 5, 2019 Its super simple, I can't understand why anyone faffs around with gauges anymore, they always seem more inconsistent to me. Rotate engine in 'normal' direction until 30 degrees btdc, The advice is not to rotate these engines backwards, although I suspect that instruction originates from models with the semi-automatic tensioner (not yours). You'll get a feeling for it, its a brisk tap, but with a solid object with enough weight to get a reading. As you will see, the readings will be pretty consistent however you approach it Quote Link to post Share on other sites
Clive59 109 Posted February 5, 2019 Report Share Posted February 5, 2019 I find just plucking the belt by hand works fine, as long as you have finger nails I guess. The Carbon Drive software seems very good at picking up even short plucks. I suspect it has a very sharp filter around the desired frequency range. Quote Link to post Share on other sites
fjmuurling 64 Posted February 6, 2019 Report Share Posted February 6, 2019 Frequency measuring should be done 30 BTDC with the timing dots on the inlet and exhaust cam pulleys pointing to each other, but not aligned. The chargecooler pump impeller will be damaged if you turn the engine backwards. Even if you turn the engine a little bit backwards (tempting to do when you overshoot the 30BTDC mark) will alter the tension of the belt between the pulleys and screwing up your measurements. See the attached sheet from Lotus. (substitute Clavis Gauge for Phone app, Tuneit! etc). sn_ef_p18a.pdf Quote Esprit Freak Link to post Share on other sites
jonwat 379 Posted February 6, 2019 Report Share Posted February 6, 2019 10 hours ago, 910Esprit said: The advice is not to rotate these engines backwards, although I suspect that instruction originates from models with the semi-automatic tensioner And mechanical charge cooler pumps. Quote Cheers, John W http://jonwatkins.co.uk Link to post Share on other sites
Gold FFM johnpwalsh 1,316 Posted February 6, 2019 Gold FFM Report Share Posted February 6, 2019 Anyone got a link to the app. Original technophobe here. Running a Samsung J7. Quote Link to post Share on other sites
Bibs 10,827 Posted February 6, 2019 Report Share Posted February 6, 2019 https://play.google.com/store/apps/details?id=com.gates.carbondrivecalculator Quote 88 Esprit NA, 89 Esprit Turbo SE, Evora, Evora S, Evora IPS, Evora S IPS, Evora S IPS SR, Evora 400, Elise S1, Elise S1 111s, Evora GT410 Sport Evora NA For forum issues, please contact the Moderators. I will aim to respond to emails/PM's Mon-Fri 9-6 GMT. Link to post Share on other sites
Clive59 109 Posted February 6, 2019 Report Share Posted February 6, 2019 John, if you go into the Play Store app on your phone, you can get it there. If you haven't used Play Store before, do so. It has all sorts of good stuff(and lots of crap of course). If you just search the apps on your phone you will find it. 1 Quote Link to post Share on other sites
eeyoreish 837 Posted February 8, 2019 Author Report Share Posted February 8, 2019 What frequency is recommended for the round toothed belt on the HC? Quote Not worth starting anything now... Link to post Share on other sites
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