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tb3033

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About tb3033

  • Rank
    LOTU
  • Birthday 13/07/1975

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  • Name
    ambrose
  • Car
    Turbo Esprit 1985

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  1. Er, GKP yes and yes. It's all about expectations, obviously everyone has a different set and it seems plenty of people have them sufficiently fulfilled by the S3T. That's great, Im happy that people are happy. No doubt the largely joyless experience of Esprit ownership has finally affected my will to continue with it. I strongly suspect that I would have come to the same opinion about the engine eventually, the various meddlings of conmen/incompetents merely increased the rate of convergence. I respect the many owners that plough through the various problems on their cars and for 2yrs I've trod that path but it's now time for me to reconsider. At this point I'm considering the 'end game' and questioning whether I really want to spend another
  2. Thanks Tim, I've decided to pack everything away and leave it alone, maybe until next year unless I get the urge to sell it on as a project in the meantime. The problem I have is that I no longer really respect older turbo esprits from a engineering standpoint. The more I've learnt about engines it comes as no surprise that a non-intercooled, unmanaged, carburettor based, knock sensorless engine with thermal issues is(was) on its second rebuild in less than 65k miles. Couple this to a gearbox that you are afraid to use boisterously and it doesn't really add up to much more than mobile antique. Unfortunately reality never really lived up to my expectations. The only sensible option is to do that Audi V8 conversion but this is way above my comfort zone. An SE engine may be an option I suppose. Anyway, I do wish you the best of luck with your project and that you manage to get some enjoyment from it. Ambrose
  3. Just a warning to those who are tempted to skim the top of their brand new aluminium nikasil coated liners - don't do it. With the block just about acceptably bored and a set of of the later liners in place the tops were some way from spec. The advice from the machinist was to skim the tops to one level with a caveat that the nikasil might chip. And chip it did, though only very slightly on one side. The top of the chip was well above where the rings get to and I would have taken the chance and proceeded with the assembly. The problem was that small bits of very hard nikasil got caught between the cutter and very soft aluminum and have created enormous grooves. In sections the surface resembles a coarse nail file and the possibility of achieving a reliable seal non existant. Towads the end of the year my intention is to replace the whole block plus liners and have (what is left of) the engine rebuilt by a profesional. That way I can at least sell the car and buy a Noble. Ambrose
  4. Just wondered if any of his former customers had managed to get the money they are owed. I've spent
  5. Thanks for the advice. Can't feel an appreciable endfloat so I'll try the parafin + oil + compressed air, wrap it up properly when its done and fit it to the car sometime before summer. A bit uneasy about pulling it apart, though. If it blows up or smokes in use at least it is easy to get to - just about the only thing that is. Ambrose
  6. Good point, I suppose it depends where the dirt is. Just went round and had a look at it again, how much play should there be in the bearing. If I grab the shaft at either end I can waggle it up and down quite a bit, so much so that the vanes on the compressor side just about touch the housing. Is that normal? Ambrose
  7. Hope this helps... Does look a bit odd
  8. Thing is Im not sure what could be down there, although there is a certainly an amount of dog hair?? The shaft spins freely and feels smooth - is that enough to conclude the bearing is clean. Is it worth trying to force engine oil through the oil inlet until it is seen clear from the drain? I'll start as you suggested with paraffin and compressed air. Thanks Ambrose
  9. Hello, Can anyone share their experience of how they cleaned the innards of their turbo. It is currently off the car and has been in less than ideal storage for some months. I'd like to make sure that it is absolutely clean. The unit is a fairly new one fitted less than 10k ago by a PO. Is this a specialist (i.e. TurboTechnics) task or can this be done without disturbing the balanced parts? Thanks Ambrose
  10. What a relief... Hope they/you find the weasel that nicked it and that he be condemned to a lifetime of Nissan Micra (1992 Jizz edition) ownership
  11. OK there were a couple of posts I found very informative on the Yahoo group and Ill post them here, Im sure they won't mind... I see what you mean about the setup Buddsy... I'll be sure to ask about this when the time comes (hopefully soon). I'd advise getting a coffee and optionally at least 2 cigarettes at this point... --------------1ST ENGEL POST ---------------- Re: More Piston & Liner questions for early Esprits. Posted by: "Tim Engel" [email protected] eclat2 Wed Feb 6, 2008 11:00 am (PST) Steve, The original iron liners could still be used if they were bored oversize. However, that would rule out using the Mahle pistons you already have. It's a choice, not an absolute. You can sell your Mahle pistons on eBay and put the proceeds toward new JE .030"-over pistons. A full set to your size spec, complete with wrist pins, circlips and rings will cost under US$1000. Or you can keep the pistons and search for liners that will match them, and will fit in the older '82 block. Fortunately, I've not had to replace any Nikasil liners, so I'm not speaking from experience here. But it's my understanding that the iron and Nikasil are not dimensionally direct-fit replacements for on another. The block was machined to fit one liner style or the other. So, if you are off in search of Nikasil liners for your 1982 block, either make sure you buy liners that will fit, or arrange to have the block machined to accept the new liners. I know nothing about the Omega liners, but Steve at SJ should be able to answer any questions you have. If you elect to keep your existing iron liners but over-bored 0.030", then don't bore them until after the new pistons arrive ! Take the pistons, liners and clearance specs to the machine shop and have them bore & hone the liners to clearance-match each piston individually. Then mark them as sets. Never bore first, then order pistons. Piston/ Liner clearances are loose for iron liners and tight for Nikasil coated aluminum liners. Aluminum expands more than iron as the temperature rises. In order to end up with the desired close running clearance at full operating temperature with iron liners, the clearance must be loose at room temp. However, with Nikasil liners, the difference in expansion rates is nil, and the room temp clearance spec is much tighter. Keep liner material in mind, and use the clearance values that are appropriate for that material. Also note that bore and piston diameters are different for iron and Nikasil engines. Small differences, but different none the less. Mixing and matching parts from standard and Nikasil engines will produce combinations of clearances that are different than quoted in the manual. However, your target clearance will still be the same as quoted for the type of liners you end up using. Am I confusing you? For your Mahle Grade A pistons in stock Iron Liners: 95.205/ 95.219 mm (3.7482/ 3.7488") Mahle A 95.275/ 95.288 mm (3.7510/ 3.7515") Iron A 0.056/ 0.083 mm (0.0022/ 0.00327) Clearance 95.288/ 95.308 mm (3.7515/ 3.7520") Iron B 0.069/ 0.103 mm (0.0027/ 0.00406) Clearance Target Clearances 0.110/ 0.150 mm (0.005/ 0.006") Iron 0.048/ 0.076 mm (0.002/ 0.003") Nikasil Your Mahle Grade A pistons would have been too tight in your standard iron liners if everything was stock... no corrosion/ no honing. How big were the iron bores after honing, and what are the room temperature clearances? Depending upon which clearance spec you were using, there may be more room to hone the liners than you thought. If you go with aftermarket pistons, then be aware that some aluminum pistons are made with internal inserts to control expansion. In that case, the desired clearance with an expansion-controlled piston may be different than quoted above for either liner material with stock Lotus pistons. Know what you're buying and ask the right questions. Use a liner bore and piston diameter to give the clearance required for the liner material and piston type you end up using. You really must coordinate parts and dimensions... it's a must, not a casual option. Liner fit into the cylinder block is also a critical dimension. The liners stick up out above the block deck by a very small margin... that's called the "nip". Proper nip assures the correct crush of the head gasket to produce a tight seal at full operating temperature. It's a critical dimension. As with liners, the different thermal expansion rates of iron and aluminum liners requires different nip dimensions at room temperature to assure a proper head gasket seal at full operating temperature. And just like grading pistons & liners to get the optimal selective fit, liners are 1) selective fit to the cylinder block at the factory (mated as a set), and 2) the nip is set as appropriate for the liner material. The difference between the block depth from deck to liner seat, and the liner length from the top to the shoulder/ step determines how far the top of the liner sticks out of the block (nip). Both dimensions have tolerances too large to control the resulting nip exposure within spec. So production liners and blocks were measured, then matched in sets to produce nip within the desired range. The total nip variation between selective fit liners is within 0.030 mm (0.001") of one another. Liner fitted height above the block deck ("nip") 0.025 / 0.130 mm (0.001 / 0.005") Iron Liner -0.025/ +0.020 mm (-0.001/ +0.002") Nikasil The permissible nip variation between liners is: 0.030 mm (0.001") Reproducing that nip spec with new replacement liners out-of-the-box is a bit of a challenge. It's like shimming valves, where it's nice to have a box full of alternate shims you can use to sneak up on the proper clearance. Except liners are more expensive than shims, and "nobody" other than the factory has a big box of them setting in the corner from which to be selective. And if you have to ship them in from England, it will be a bit inconvenient and expensive to ask for alternatives. Achieving proper nip with a new set of liners may not happen on the first try, and may be a little frustrating. And it may require a machinist who really knows what he's doing, and who can trim the new liners to fit within spec. Pistons Vs Liners... New liners aren't necessarily the easier solution. But if you're up for the challenge, then the coated aluminum liners are clearly superior to the old iron liners. Especially if you wish to play with higher cylinder pressures (compression ratio or boost). If you are going to buy new liners, then have the block depth, liner lengths and current nip exposure accurately measured, using a dial indicator (vernier caliper isn't good enough) at a room temp of 68-72
  12. FWIW Im heading down this exact route with my turbo. They arrived today and I'll be visiting the machine shop sometime next month to get them fitted. One of the engineers in the office muttered something about 'coded' machining? and jig boring? Buddsy - what is the correct/most accurate method to use? As far as compatibility with the LC head, Im hoping it will be better than using iron liners due to their similar thermal expansion coefficients. For much the same reasons the piston-bore clearance is significantly less with this setup so in theory I'll get less piston slap when cold. All good. For those sticking with iron liners (if you can obtain correctly sized ones) and new pistons (Mahle HC or other) I'd urge you to dig into the turboesprit yahoo archive and read some of the Tim Engel posts. Ambrose
  13. Tim, Very pleased to see that you have taken that important first step. Can't agree more with the chap who recommended doing something however small on it / or related to it everyday (aim for borderline obsessive...). The engine expense has to be the largest chunk which is almost done and the rest in my experience is dripping a bit of cash in it each month plus lots of time. I can recommend Mike Taylor (Lotusbits) for bits and for the more difficult jobs. Also collected a substantial pile of weird tools over the past couple of years which are at your disposal. Hopefully when I have managed to complete my house restoration I'll be more available to help (tip:don't run a house and esprit restoration in parallel unless you enjoy uneasy silent dining experiences...) Ambrose
  14. Hi John, Sorry to hear the trouble you are having with your honing efforts. It appears to be a tricky thing to do yourself, although I do wonder whether you may have had better luck with the flexihone thing. Anyway I suspect your supplier will make some effort to check the parts they send now... It may interest you to know that there are MATCHED HC piston liner assemblies (liner,piston,rings,pin) on Ebay direct from Lotus for
  15. John, I assume that you are referring to the Omega forged pistons you obtained from SJ being matched to the liners rather than your original cast pistons. Anyway it sounds to me like you have a path to follow with your honing experiments and a method to measure the results so it should all fine in the end... Incidentally you may find this interesting, http://www.guy-croft.com/viewtopic.php?f=1...it=honing#p5899 and more of the same http://www.guy-croft.com/viewtopic.php?f=1...it=honing#p5318 In fact the whole site is very informative and the chap certainly seems credible. Ambrose
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