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'91 Esprit Turbo SE is our school shop project


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Okay, after a long period of car detailing (mostly big 4x4 trucks) the automotives shop has returned to a bit more Lotus-related work.

The cylinder head was washed in solvent and lovingly disassembled. That process, once again, convincing me that my vintage Mac Tools valve spring compressor cannot be bettered. All aspects of the head checked out really well . . . . longitudinal and transverse "warp" was far less than what we could measure (under 1.5 thou of an inch). The head's mating surface was flawless, all the manifold surfaces were nick-free and the whole thing looked either new or recently machined. I think that head had been put on the block and the engine had never ran (even for a minute). Good thing because of all the missing oil gallery plugs.

The stainless valves are also new . . . still wet with assembly lube. All the guides look like new brass (perhaps a bronze alloy?) and they are also perfect in spec. Strangely, a stiff solvent-resistant grease was applied to the top of the valve keepers (likely to hold the valve shims in place). This grease was brilliant red in colour and resisted being washed away with brake cleaner, electrical contact cleaner, acetone, varsol, etc., etc. No idea what it was but after two days of soaking in our solvent tank we picked it clean with a brass brush and fine screwdrivers. Could this have been some version of red rubber grease?

The head was mated to the block this evening (after school). The kids rather liked how it appeared that I "talked" to the cylinder head as I worked on it. Just simple stuff like the "1,2,3,4" you say to yourself as you torque the head stud nuts in stages. They tell me I also clearly said "good baby . . . sit tight" as the cylinder head slid down the head studs and seated to the roll pins on the block. Teaching really is part entertainment when you think about it.

We stopped soon after that. It appears I now need 1/8" British taper thread pipe plugs for the threaded holes above each exhaust port as mine have distorted hexes. Anyone have a Canadian source? We also will need a single thicker-than-standard cam thrust washer. I doubt it, but does anyone have a spare one of those? One cam measured to 2.5 thou play, the other showed 7 or 8 thou. I believe the manual claims 5 thou to be the acceptable max (sorry, I left the manual at school today). Considering we also had time (after school) to drive downtown and completely rid Walmart of its $5-a-gallon motor oil -which was on sale-, I have to conclude that today was a rather good day. By-the-way, we use that for "regular car" oil changes.

AP

Edited by andrewp1989
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Serge, I will be back to Edmonton for the May 23 weekend (for certain).

Since the snow has left Edmonton, I have visited for some really intensive wrecking yard visits . . . things like pulling an entire SAAB 2.3 litre engine using only hand tools, a 6' long webbing sling, plus two sets of hands and a 2"X4" beam. It rained pretty intensely that Saturday as well so I had a great time in the evening cleaning every single socket, extension and wrench for a return visit on Sunday morning. I was there April 30-May 1st for (believe it or not) some Chevy Aveo pieces and, again, May 7-8th for the SAAB 9000 block. We required both up at school in Fort Mac. The second time you spend 5.5 hours (straight) at a wrecking yard you sort of get a better understanding of when to pause for food or water, how to organize your tools so you don't lose too many in the mud, and/or ensure you pace yourself so the job gets done with minimal risk to crushing fingers or related skin abrasions. Buck's Auto Wreckers is my choice for these outings.

Tonight (after school) we set out to measure all the key corner points of the '91 Esprit's frame and rear suspension. One student was wildly keen on helping. That took much longer than expected, plus the shop was baking warm by 5:00 PM. We used a sheet of paper atop some plywood and leveled this with cedar cabinet shims so it was parallel to the frame's base (the shop floor tilts a bit). We then marked the key pivot points using a plumb bob. I haven't yet done the trig with the kids, but I expect that the frame is wholly straight but the rear right frame "ear" holding the lower link will be bent (perhaps as much as 5 degrees). For certain all the rear suspension pieces measured 100% perfectly the same L-side to R-side. I think a few suspension bits have been replaced (there is less oxidation on the RR bolt's cadmium plating and "fresher" looking/feeling RR link bushings). I should mention the RR rim is known to have sustained a good whack, bending it 2.5 mm off of true. The deformation and flange abrasion suggests the car spun (?) and managed to strike an unlikely-to-move object on the inside of the RR rim (deforming that region of the wheel outward) while sparing all other rim surfaces. When collected, the car's RR wheel sat "off" (easily seen to be toed and cambered in). I guess what can I expect with a $4200 Esprit? Some extra shims were added to the RR radius arm by some previous owner.

Importantly, there is a reason why I have collected seven sets of Steven's Esprit rims over the years. Not only was it to lovingly clean them, strip the paint, hand sand them, weld over any nicks and chips, file the repaired area to perfection using tiny rifler files and then spend a fortune powder-painted them . . . but, now, I can tell my wife that it was a smart idea to have those spares because this car needs a straight set of rims (just pick a set you like the most). In case you are wondering, she didn't buy that argument.

AP

Edited by andrewp1989
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LOL,

Yup, they don't understand much about cars and our point of view on them! I can't imagine your situation with 3 of them! Esprit's that is! Not wives! I look forward to seeing you when you get back.

Serge

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Serge:

Yes, I have three Esprits . . . and one (and only one) wife. Her input this morning around breakfast is she "doesn't tolerate the Esprits so much as resenting them". I will call you when I visit the Edmonton house next.

AP

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As for the frame alignment on the '91 Esprit turbo SE, I can confidently say we measured this "till the cows came home" between 1:30 and 6:00 PM last Friday. We also did this Wednesday night . . . just to get skilled on the procedure.

The frame is straight, but the mounting "ear" for the RR lower link is bent. The bend works out to be 1.65 degree (forward) -according to my math-. The distal link bushing center lies exactly 1.25 cm forward of the RL's and 0.9 cm inward of the RL's. We plan on correcting this by machining a thick solid steel tube 1.75" in length and welding this to a solid rod exactly the length off lower link. That (new) rod will have a machined taper point which will act as a reference point to gauge how much bend the ears will require.

After some discussion with the welding instructor at the school, we decided to mark the longitudinal and transverse frames axes (measured using the rear suspension shock mount holes) directly onto the concrete floor. Be aware that the car is sitting on axle stands. The old RR lower link point-of-contact-with-the-floor and the new point (when the ears are bent similar to the RL-side) will be marked on the floor. The ears will be warmed with an acetylene torch until orange, the taper point rod quickly installed (using thick/wide washers and a bolt with a nut) and the reference tip of the rod will be used as the lever arm to pull the ears into proper orientation. Rapid rewarming of the ears might be needed. It is expected that a solid reference piece would allow the thin base of the ears to we warmed far more that what should be transferred to the rod. The link will be "tied in place" as the ears cool to limit/prevent spring back. Much talk was made to quench the steel ears with a mist of water (or should we use oil?) immediately after the dull orange is lost via air chilling. This will be done to only the outer ear surfaces. Once cold, that portion of steel frame will be wire brushed, spray painted with a galvanic primer (likely three times), and then covered with an asphalt coating. Strong ventilation will be provided as the original galvanic coating burns off.

I welcome any comments that might improve this repair procedure. We likely will wait 1-2 weeks until attempting this repair. Note that buying a new frame (though an ideal solution) isn't really an option for this car.

AP

Edited by andrewp1989
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Today, after class was over, the '91 car's intake camshaft biscuit shim clearances were measured.

Since the "rebuilt" head was previously serviced by an individual unfamiliar with Lotus cars, I decided to start with an identical set of similar shims (each 99 thou of an inch thick). All the intake valves ended up needing remarkably thick shims. In order to get the 6 thou desired gap, the thinnest shim is 111 thou and the thickest shim is 115 thousands of an inch thick. My -said to be huge- collection of Esprit valve shims caps at 109 thou, so I guess I'll be mail-order shopping for new valve shims. In case you were wondering, the car came with wildly off intake valve clearances. They ranged from 9 thou to 15 thousands of an inch. Tomorrow we do the exhaust camshaft.

Just for comparison purposes, my far higher mileage 1989 Esprit came with nearly perfect valve clearances. I guess I was simply "over due" for this extra work.

AP

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I decided to use Victoria British (aka "Vicky Brit") for the valve shims; they sell them for the Triumph TR-7. All the traditional Lotus suppliers -that I am familiar with- aren't open on a Sunday, but Vicky Brit sure answered their phone quickly. On Saturday, I first tried the local independent SAAB shop in Edmonton. He wanted $5.00 per shim (used). Vicky Brit charged $2.95 a shim (new) for most sizes. As expected, I grossly over bought shims. I think I pretty much cleared out VB's stock of 111, 112, 113, 114, 115, 116 and 121 (thou) sizes. The 121's are for wet sanding to some in-between size that I fear I might need someday.

In other news, the engine's exhaust cam clearances all measured up well. Contained shims were 88 to 95 (thou). Only one valve would benefit from a different shim one thousand's of an inch thinner . . . the rest were perfect. Beyond that, I have a lot of spare shims in the more typical 85 to 108 (thou) sizes.

Question. Has anyone ever tried a motorcycle case sealant in replacement of the Lotus-spec red Loctite case sealant for the 910 cam boxes? The motorcycle sealant is both flexible and withstands high temperatures (such as those found in air-cooled bike engines). It might be a better long-term solution. The red Loctite seems to always heat check and then drip (pour?) oil on most 910's I have stripped for rebuilding. It was patchy and heat-checked on this '91 engine, yet I do not think this engine ever ran after its last rebuild. Odd.

AP

Edited by andrewp1989
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I do. Add .001-.002in to your shim measurements when checking or confirming them before the final assembly.

DanR

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Hi Andrew,

Keep up the good work, you make me want to go back to school!

I just did a cam housing job on mine and I had the same question, there just have to be something better (read more op to date) to seal the housings.

Is it that everybody sticks (good choice of words) to the product? I don't know ziltch about motorcycles, if there is a good product out there, your class is a good place to experiment...

I guess part of the reason why this stuff is still around is nobody wants to chance it, I know I didn't even if I know I'll have to do it again in the near future. Smoke thru the louvers is not so hot!

Good luck with the bending and eventual quenching.

Luc

Something I learned about cars or planes, it all works until it doesn't anymore...sometime there is no way around it!

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Thank you (all) for the recent input.

We are setting up -to weld together- the reference arm for the RR suspension lower link. I think we will try that repair this coming Friday. To be honest, I am a bit worried about this operation. It is sort of a "make or break" major fix that could decide on the fate of this car.

As for the motorcycle case sealant, I am familiar with SUDCO Three Bond Adhesive case sealant/liquid gasket. Part number TB1104. It is an opaque white liquid that is really sticky (when wet) but remains highly elastic (when dry). It is also a small fortune per tube . . . I have seen it go for $60 to $90 tube in the early 1990's. Never has an engine case leaked using that product on any SuperBike 750 engine that I worked on (two decades ago I was a mechanic/engine builder for some Kawasaki pro privateers). In Canada, I have found that it is a difficult product to locate. Motorcycle speed shops occasionally sell it.

No new repair work on the Lotus (other than me cleaning/polishing turbocharger parts) till the valve shims arrive from UPS.

AP

Can anyone sell me a new (or good used) exhaust manifold? Look around the garage folks . . . someone has to be more of a collector than me.

Post '88 (or so) turbo with an internal wastegate. New manifolds are pricey, to say the least.

AP

Edited by andrewp1989
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  • 2 weeks later...

Okay, we warmed the RR lower link's ears and bent them straight. It is quite a relief just to write that statement.

It was a lengthy process; started ~5:00 PM and finishing it at 10:30 PM. The reference tool had to be fabricated and then tested. I am not proud to say it failed the first bending test (weakness at the weld connecting the threaded rod to the machined bushing). A second one was made out of thicker rod and the weld adjusted for more penetration. Two rounds of welding/grinding ensured that any slag was removed and new weld material was then built up over every weld-fissure. The 2nd one easily passed the bend test. A 1.75" (long) threaded insert was pushed into the bushing and two bolts/wide washers retained the reference tool to the lower link's ears.

With the aid of a plumb bob, a reference grid was scratched onto the concrete floor and the pencil-point tip of the manufactured tool was recorded on the floor (using an awl). All that was needed was to measure a new point 13 mm behind and 3 mm swung to the right of that point. The trig told me this. This was marked with a black sharpie pen. Just to be sure, we again measured the frame. It measured perfectly straight longitudinally and transversely . . . but the RR link axis lay displaced forward and inward.

The school's Welding/Fabrication instructor (Mr. Adam Taggart) lay underneath the car while I ensured the car didn't catch fire (although this sounds funny . . . it isn't all that humorous when you are working on your car). Oxygen and acetylene fuel and a brazing tip could warmed one half of the boxed-in ears, but this side would cool before the opposite side glowed orange. After 1/2 and hour we switched to a richer acetylene mixture and a cutting torch head (without using the oxygen blast). This wider flame could warm both ears. An immense amount of time was required to heat that frame. Everyone involved (including the spectators) were surprised just how much heating was needed to warm the ear mounts to orange. Once this was reached, the tool was gently pulled to the new index mark and this was held as the ears cooled. By that time I was pretty close to flash-blind, so spectators assisted in telling me how close I was to the new point. Using an discarded Spray-9 bottle, a water mist created a surface hardening. We limited this to 30 seconds. The rest of the frame cooled for over an hour as I cleaned up the tools and shop floor. Legally we had to wait for 1 hour due to fire risk (this is a school policy).

Based on all measured marks there was no spring-back whatsoever. I believe we are now at a point less than +/- 0.5 mm of perfection. Any error = the width of our drawn reference lines. Although it might not sound all too impressive, this is a major step forward in the rebuilding of that car. The engine/transmission/rear suspension can now begin to be returned. I am now confident (hopeful?) the car will be road-worthy this time next school year. By-the-way, a new exhaust manifold was ordered. I am choosing not to tell my wife how much that part cost.

AP

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We began refinishing the heated/straightened area today. After 15 minutes of wire-brushing, another student takes over with 10 minutes of hand sanding using 60 grit paper. I do not know if it helps with a better finish, but I offer another 10 minutes of detail sanding using a finer grit . . . I think mostly for Zen-like "effect". The spray-on zinc coating matches the frame in terms of texture, but not colour. It is quite a bit lighter. Three lights coats were applied; they dry almost instantly. After that I decided to mist the patch with rubberized underbody spray (satin black) to darken it.

Well, underbody spray doesn't mist . . . it spits. Now, the stippled salt and pepper combo is neither the correct colour or texture but pretty much every student in the shop likes it a lot. So I have decided to leave it as is. I have found one or two surface rust spots elsewhere on the frame (one closest to the exhaust manifold and another due to the RR spring nicking the frame). Those areas will be touched up tomorrow.

The rest of the rear suspension pieces will be powder-painted gloss black -likely this summer while in Edmonton. I have a spare set of SJ (purple) poly bushings to add to these. I also bought some new Renault Fuego front wheel bearings = Esprit rear wheel bearings from "Canada Eh" Auto Parts (highly, highly recommend this web site to all the Canadian Lotus folks . . . just be sure to know your cross reference info). The hubs only required wire brushing to clean them up. I have decided not to use the yellow adjustable Spax shocks (I am saving those for the '89). Instead, I will use some nearly-new blue Armstrong(?) shocks bought years ago on eBay. I have new springs as well from that same eBay buy. These were advertized to be off of a 1991 with less than 10,000 miles on it and said to be replaced with V8 items.

AP

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Guest WausauLotus

I am throughly enjoying reading your on-going story of the re-store. I too went to my local technical college for offering a learning experience with helping in "re-hab/re-building/re-storing" my 84 S3 engine and they turned me down saying that these students would probably never see an S3 turbo again so they would not accept the challenge. What an opportunity they will be missing.

Keep up the good work.................... ..With my wife having been a 5th grade teacher for 30 years,I am totally enthusiased that you have found a "subject" that turns the students on!!!!!!!!!!!!!

Dave

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The frame re-spray is, for now, done. We have now touched up all the small bits and I'm really pleased with the final look. Progressively more rubberized undercoating was applied so it is a darker repair than what I left it as last evening. I think that I'll let it harden for a few days more and then mat clear-coat all of it. My thought is the clear-coat will offer a greater level of rust protection.

During the final touch-ups I noticed one thing that seems odd to me. At the back end of the frame there are orange plugs that cap round steel tubing . . . these lie slightly inward of the upper shock mounting points. There are two of them (one L and one R). I measured their elevation and although they are nearly exact (L = 548.1 mm, where as R = 550.0 mm up off the ground), I wonder if this is something to worry about? Is a difference of less than 2 mm an issue here?

I am up here in Fort McMurray, Alberta while my other Esprits are hiding 500 km south in Edmonton. So I cannot easily compare between similar cars. One big question I have is the two round frame tubes have vastly different gaps between the trunk floor. The L side has an inch plus between the tube top and the inside crest of the fiberglass wheel well. The R side lies absolutely flush with the trunk floor. Both locals have body bolts really close by and each bolt possesses a similar 1/4" spacer washer between the frame and the body. There appears to be no damage to the fiberglass body around either body bolt. No stress cracking is evident anywhere near these points . . . even on the R-hand side.

Question: Is the R side frame tube too close to the body when the tube contacts the trunk floor underside? If the answer is yes, then I guess this indicates a far more severe amount of rear frame damage than I first thought.

Can anyone help me out with this comparison? Many thanks.

AP

Edited by andrewp1989
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  • 2 months later...

Special thanks go out to Mr. Scott Lawrence (of Edmonton). The frame tube lies pretty much perfectly as it should. The R side tube is -on his unmolested car- less than 0.1 mm below the fiberglass trunk floor. So my '91 shop car's frame (which just contacts the trunk floor) is pretty much where it is suppose to be.

Quite a relief.

AP

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  • 1 month later...

Okay, a "new" problem has just appeared. The wiper is acting weird.

With the ignition on, when the wiper switch is activated (at any speed) the wiper sweeps . . . however it cannot be turned off via the switch. Similarly there is only one speed (slow); the wiper switch shows no ability to change this. To turn off the wiper the key must be pulled out. This parks the wiper in any position on the glass; it down NOT park itself at the base of the screen. I first thought some of the wiring was out of position on the signal switches . . . but according to the manual wiring diagram they are all perfect. I also replaced the 6-pin wipe/wash delay module (a GM relay #90069864) which hides under the dash, but no improvement.

With the key on, I get 12 volts from the following three wires:

1) green (pin location 53A)

2) light green/black (pin location W)

3) orange/brown (pin location 53E)

Upon activating the wiper that GM relay buzzes wildly for about 1-2 seconds. I am in the process of stripping the loom and checking each wire independently. Anyone have any better ideas?

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Andrew, you should be posting these problems in the correct technical areas really my friend. You'll get more people reading, and therefore responding and it will be more useful for future owners to be able to find, diagnose and fix similar problems.

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. 

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Hi Andrew,

Bibs is correct, this is the first I've seen of this thread & it's been running for 6 months. :thumbdown:

This grease was brilliant red in colour and resisted being washed away with brake cleaner, electrical contact cleaner, acetone, varsol, etc., etc. No idea what it was

That sounds like cam lube which is often used when engines are rebuilt, normally spread over the cam lobes & tappets not inside the them.

Great project though, if only we'd had these sort of lessons when I was in school, maybe I'd ended up working in F1 like I always dreamed of. :thumbsup:

Cheers,

John W

http://jonwatkins.co.uk

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Many thanks for the input. That is some seriously weird red cam lube . . . who might have made it?

I should mention that I did post a request for help about the wiper wiring problem about 2-3 days BEFORE I mentioned it here in this portion of the forum. It was posted under "Esprit/Steven's Body Technical Room/Interior Exterior Lights Glass Alarms ICE HAVC". I hope I got that right.

Only because I did not get any feedback there (and, to date, have yet to get a reply there) I posted it here.

AP

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  • 2 weeks later...

Okay, the wiper works now well.

It appears that it did not like the replacement GM relay (#90069864) but, rather, preferred a Bosch one from a Volkswagen. Let's just say that pretty much EVERY damaged VW at both self-serve Edmonton auto wreckers donated its #19 relay to me. Good thing VW relay boxes are easy to access. I think I collected 28 replacements.

If you need one, just e-mail me.

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  • 2 months later...


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