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drdoom

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Everything posted by drdoom

  1. Glyn, I hope you're being exceedingly careful in choosing SS hardware for any stressed application, as most such stuff here in North America is Grade 2, or worse. Shite, in other words. Proper spec for any stressed automotive assembly would be 8.8 or 10.9 rated in Metric, Grades 5 or 8 in Imperial sizes. Best of all for Imperial fasteners would be AN or MIL spec. Regarding crank seal locating one can offer up an appropriately small drill shank at 3 points circumferentially to effectively eyeball concentricity with the crank hub. Cheers
  2. Yes, Neil, not original but quite similar. Cheers
  3. Andy, yes the '94 unit differs but in major terms only where the body air inlet / blower adaptors are concerned. Not surprisingly Lotus kept the majority of casings and flap components consistent over the life of the Esprit with A/C. So it's easy-peasy to exchange the pieces between Giugiaro and Stevens units where the applicable body inlet / blower plenums are correct for the car. Ian, agree with you both suspecting the foam to be some effort at vapor suppression. Agree as well that it's not a good idea in the first place, and good luck to any old sod who fancies servicing any of these bits on a runner without half tearing the car apart.
  4. I am having a go at refreshing the HVAC unit which is to serve in my S2. The car was fitted with A/C from the factory so I have the components all in hand. Given the (ahem) well used state of the old girl, I have also acquired the HVAC unit from a wrecked '94 as a donor. So my first question is what purpose is served by the placement of a sheet of open-cell foam on the interior side (downwind) of the A/C evaporator? I am inside the '94 unit ( 40k miles, by the way, and in good shape visually ) and that foam has largely disintegrated. Steve
  5. Jacques, thanks for sharing your experiences in dialing in a chassis to suit your tastes, however fine the Lotus cars are from new there is room for improvement over OEM Lotus set-up in the cars I've had the joy of driving. I offered the point regarding use of spherical bearings in shocks not as a recommendation, rather it was to illustrate the need to permit free articulation. For a street/track day Lotus I do not advise use of spherical bearings anywhere. I believe the LOTAC components are likely best when they are available for the car in question. Certainly choice of bushings in a Lotus chassis is not to be taken lightly. I'd have added my name to the list of prospects for LOTAC Bilstein/Eibach package by now had this opportunity remained. Absent that I have fortunately long ago acquired spec Konis for the rear, and had a pair of comparably scaled front Konis re-valved for the front when no spec set could be found. Cheers
  6. Several professional mechanics of my acquaintance have informed me that brake related shimmies are no longer thought related to warped rotors, in general, as this does not typically occur. Instead modern pad formulations are designed to transfer a residue onto the rotor surface which increases the friction coefficient, thus increasing force or reducing effort at the pedal. This can be problematic when the residue is deposited unevenly, leaving a patch on one segment of the rotor. This can occur when the car is brought to a halt from high speed with fierce braking and the brakes remain clamped for a time after the car is stationary. Rather than machine turn the rotors the mechanics will machine sand the surfaces back to an even condition. FWIW. Cheers
  7. William, there's no reason to refrain from converting to Dellortos from the Strombergs, other than perverse attachment to originality. The IR form of carburetion exemplified by Dellortos or Webers is optimal for the broadest range of performance. Stiffer cams will in fact trouble the Strombergs more quickly and surely than they would the full IR carb set-ups. If you want to really take the Dellortos to their utmost potential I suggest you examine the work done by American, Keith Franck, logged on his forum, "Sidedraft Central", hosted on Yahoo.
  8. Giniw, I looked through my folders and found nothing of the sort so no URL at this time. There is a printed excerpt from the Koni Racing manual on pages 205 - 206 of race engineer, Carroll Smith's fine book, "Engineer To Win" which covers the topic very well. Lotus was a race car company first and it seems that the superb street cars we play around with reflect the pertinent influences prominently. In plain language Lotus build a car with fine chassis characteristics typical of a better race car - sensitive and communicative steering, quick yet stable chassis behavior born of optimal distribution of masses coupled with deep understanding of suspension articulation effects. Travis, you are correct in saying the single adjustable Konis largely afford adjustment in rebound, not much in bump ( jounce ). I've fitted them to quite a few cars over the years, including Elan and Esprit, and they have been lovely. Lotus turned out a fine handling car with the early Esprits, with dampers decidedly biased to rebound control. No doubt the ride benefitted substantially from the soft bump values, as well. It would seem that Koni Racing advise from a differing point of view, "Bump damping controls the unsprung weight of the vehicle. It controls the upward movement of the suspension as when hitting a bump on track. It should not be used to control the downward movement of the vehicle when it encounters dips. Also it should not be used to control either roll or bottoming. ..." I feel fairly confident to say that tinkering with suspension settings on a Lotus will be well informed by sound practices applicable to non-aero effect racecars. Carroll Smith's fine books, "Prepare to Win", "Tune To Win" and "Engineer To Win" are to be recommended. Cheers Chris, be mindful of hard pivots in place of rubber where complex suspension arcs may be anticipated. Race shocks would have spherical bearings to accommodate angular change while seeking to eliminate bushing deflection, so unless your dampers have some measure of angular compliance in those bushes I'd give the matter some further thought.
  9. The aluminium pieces referred to for use at the rear of Esprit may likely be spacers, in fact. From the earliest cars I believe Lotus used a spacer on one side rear for the sake of balancing ride height, particularly with LHD cars where the engine leans over onto the side where driver's weight is biased. Can't see any value in isolation by use of a metallic spacer, in any case. Observations offered by Travis and Jacques are top-notch and I would advise anyone venturing into suspension tinkering for the first time to read and understand the points made. On damper settings, FWIW, the OEM Armstrongs removed from my S2 exhibit a great bias toward rebound restraint, the jounce rate being remarkably soft by comparison. Koni, always known for fine dampers, published a white paper in which they addressed the basic approach to setting dampers. As I recall the jounce damping is calibrated in terms of adequate restraint of the unsprung mass over uneven road surfaces, so damping the wheel/tyre motion when driven upwards by a sharp-ish impact. The rebound damping was to be set as best compromise between restraint of movement of sprung mass ( i.e. the rest of the car and contents ) versus rate of return motion of the wheel/tyre ( unsprung ) to pavement after the sharper, higher frequency impacts. In summary, enough jounce damping to keep the upward wheel/tyre movement within reasonable limits of response to sharp bumps, and enough rebound damping to keep the overall vehicle from wallowing through the larger, lower frequency motions while maintaining roadholding over rough surfaces by not overly restraining the downward motion of wheel/tyre after a sharp bump. I await the inevitable onslaught of remedial technical instruction from our properly trained fellows, in serenity.
  10. RD Enterprises in Pennsylvania are good people with which to deal. They have had such bits listed recently, as I recall, and have a rather nice website. Search RD Lotus. Cheers
  11. Welcome, Chris. The screeching belt does not bode particularly well for the soundness of your mechanic, but let's hope he's a good guy. As to the airflow through the HVAC system it's basically IN via the vents at the base of the windscreen, then down into the black ABS plenum in the forward luggage area before flowing through the squirrel cage blower into the heart of the system. Any clear plastic hoses running down into the car underside areas are for the purpose of draining away water, either from A/C condensate or from rain or wash water separated in the ABS plenum. Cheers Steve
  12. Hey Mark, Mine is an S2 with A/C and the photos posted in this thread don't correlate with my components. My HVAC main case, which does not look like that posted, is assembled from blown plastic mouldings riveted together, not steel. Also, the pics of boot area plenum cover and blower look to be of the Stevens series. If you want further pics I can post a number which reveal the parts and their locations in the unit, and placement in the dash area. Agree you're very likely looking at a heater core leak, and yes, it will be found to be the point around which all other parts of the car were constructed. A trusted pro mechanic, when offering advice on how to remove the core on my wife's Mustang many years ago, told me to start in the back seat. He wasn't kidding, as I confirmed once all of the console and dash pieces needing removal had been dealt with. It's a long time since I tore out my Esprit kit but it's a large lump tucked well up under the dash and there is NO way you'll get to the core by way of the boot area if your set-up is like mine. Condolences Steve
  13. Christian, The rack is adjustable in terms of mounting position for the purpose of minimizing bump-steer. This is a phenomenon which you should familiarize yourself with in detail unless you turn over assembly of the front end to a capable professional. Bump-steer, in brief, is the measure of how toe changes as the wheel travels through its arc of articulation as dictated by the suspension and steering links. It is generally thought desirable that the toe change only minimally through suspension travel so setting bump-steer is a matter of trial and error positioning of the rack while checking toe settings through wheel travel. A rough outline of how to proceed: 1) - Equip yourself with a means to measure toe - it can be as simple as a trammel bar or as clever as using a laser reflected off a mirror applied to the wheel; 2 - Assemble front end minus springs/dampers, leaving pivot fasteners just short of nipped so as to afford free travel up and down. Set static toe-in to spec in the manual; 3 - Support front of car with a jack under box section ( plate between to distribute load and not damage the chassis ) to facilitate raising/lowering to emulate wheel travel; 4) - Placed sheets of newsprint or similar between floor and tyres to negate resistance to travel owing to scrub; 5) - Measure toe at various points through the full travel of suspension and graph for interpretation. Toe out is less desirable than toe in, generally, but no great measure of either is to be tolerated. Repeat measurements with rack in alternative positions until changes to toe are minimized, then lock the rack in that position. No Lotus should be sent forth after re-work of the steering components without the bump-steer exercise, they're a sublime chassis above all and should be enjoyed accordingly. Bear in mind the aforementioned exercise assumes all suspension and steering links to be in good nick, otherwise there may be confounding inconsistencies in measurements. End of sermon. Cheers
  14. Well lads, so glad I asked, clearly we need more opportunities to share views on managing relationships with the fairer sex. Steve, like you I am flummoxed with my wife's incapacity to grasp the concept of any thermostat. I take it in stride, with a grin, much as I do with other politically fraught matters in these peculiar times. As I've got the whole, bleedin' mess apart on the bench at the moment there's no question of access, rather just whether to make changes for the better. My prior Lotus was a '64 Elan, fully restored with upgrades though the heater remained as original. That worked quite nicely despite being rudimentary. Matters of cooling system capacity for my Esprit will be addressed directly, so with focus on the HVAC specifically I'm inclined to forego the T/stat override on the flow valve thinking it not ultimately helpful to have less direct control of the flow through the heater. My thanks to everyone who posted views and insights on the HVAC system here over time. I'm taking a good look at any likely prospects to improve on known weak points but lack first hand experience as I purchased the old thing in a non-drivable state. Cheers
  15. Thanks, Steve, that's how I figured it to work. I'd further ask how well does it function in practice? I wonder how this compensator might limit one's ability to control the entire range of temperatures, as compared to a non-compensated valve?
  16. Agreed, Roland. I prefer to heel and toe with ball of foot planted securely on the brake, rocking the ankle to blip throttle for gearchanges. Others may prefer alternative approaches but I like the neat measures of throttle possible with my method. Cheers
  17. What does the thermostatic compensator on the heater water flow valve do?
  18. From what I have read, the confusion on ignition timing specs for the Lotus 9xx series engines hinges upon semantics, the limitations of clarity when English is used in more than one way to describe a fact. The consensus seems to be that Lotus intended the printed specs to be understood as follows: 1) - Idle timing when checked with light on running engine to be as described; i.e. 10 degrees as printed means 10 degrees read with the light; 2) - Mechanical advance specs, i.e. 25 degrees all in by 2500 rpm, means what would be seen with the distributor on a machine built for the testing and adjustment of a distributor, figured in crankshaft degrees; 3) - Total timing, not ever helpfully spec'd in the manuals, to be the sum of the idle setting plus the advance added via distributor mechanism(s). So 32 - 36 degrees total for the N/A engines. This concurs with abundant comparable examples found in engine modeling software widely in use today. 4 - One noteworthy real-world case to demonstrate how troublesome has been the Lotus protocol for these specs was when the owner of a G-body Turbo participated in a Road & Track magazine top speed comparison test with other fast exotics, back in the '80's. Owner was vexed by his Esprit's inability to get near to its maximum speed, as declared by Lotus. He thought total timing was to be as what seemed to be spec'd in the manual at 28 degrees. Later was given a non-qualifying run with timing set to the sum of distributor plus idle figures and - voila(!) - the car lit right up, accelerating with gusto to higher than its claimed top speed. The official test outcome would have put the Lotus at the top of the list, if not for the confusion which arose via the peculiar way Lotus chose to describe these timing specs.
  19. I would have applied the grip tape to the brake pedal, left the throttle bare metal. IMO, the go pedal works to good effect when the shoe is free to slide over it, not so much the case where the brakes are concerned. My 2 cents worth. Cheers Steve
  20. Richard, That's a fine looking car you're getting together! I'll attach a photo taken at teardown of my S2, the car fitted at factory with A/C and untouched until gathered up for salvation by yours truly. One forward bulkhead hole is just visible if you follow a line feeding refrigerant to the unit. It's an LHD car, but perhaps instructive in some way. Steve
  21. Darren, I can attest to the validity of the points made by Steve M. in that my S2 has revealed several points of failure to seal out water. It is likely your windscreen sealant does not prevent water from entering via the screws that pierce the body beneath the upper screen, screws which are employed to fasten the wooden strip to which the LED clock and sunvisors are fixed. My strip of wood displayed a measure of mould discolouration, and a mate told me of how his S2, back when nearly new, would slosh water side to side in the visor area when cornering, the resultant drips not found to be pleasant. Further area of concern is around the doorseal flange perimeter of the body. Cracks in the flange gelcoat or in that of the body joint near the door catch will form capillary tracks through which water will migrate to the interior bypassing the otherwise sound seals. This may rot things out, including the firewall plywood, if left damp over time. In summary it's great that your car is used regularly as stated by others but you want to be certain the interior is purged of humidity as much as possible. In my view it's imperative that an Esprit should be stored under some form of shelter but also be afforded some effective method of drying the interior at the same time. Consider placing a small electric heater within the cabin when parked at home with windows slightly opened for circulation in addition to a shelter. A cover is alright enough for the purpose of keeping her clean overnight before a showing but not what's needed for the sort of protection called for here. Cheers Steve
  22. Hey Antonio, Yes, the location for flat washers to which I referred was indeed below component 1, the gearchange mechanism. One must presume the purpose for this to be that Lotus could have no certainty that the chassis closing/mount plate for the gearchange would be entirely flat after the production weld-up. Thus the washers serve to ensure that the mechanism is squarely perched across all 4 corners once bolted in. I was at first rather surprised to find these washers upon teardown but with no doubt I am the first to disassemble it all since the car was first built it can only have been intentional that the washers were so placed. As to your quest for thread specs I hope to have access to my chassis, currently somewhat out of reach in the garage, fairly soon. After the Holidays I must attend to a business matter for a day or two then complete the removal of bitumen undercoat not blasted clear from the engine bay when the shell was sent out for stripping. I have replaced all the bobbins in the course of recent efforts so will be free to fit the chassis up under the shell at long last once that last clean-up is done. Cheers
  23. Steve Don't overlook the matter of thrust bearings as Lotus circulated a Technical Bulletin specifying a minor mod to one of the rearmost main bearing shells for the purpose of improved oiling at the thrust flange of the crank. Cheers Steve
  24. Tony, That's just a brilliant car! Glad you're so enthused. When you've had some time on the road with it could you please report on a couple of points that might shed light on the 2.2 engine and the hardened motor mounts? I'd appreciate your views on NVH in car, plus chassis behavior particularly on/off throttle. Thanks Steve
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