Thartje

Had the intercoolers and heat exchange setup but didn't have anything setup for a water reservoir or a pump. Although I never tried it, I figured the spare tire was no longer of any use to me as I had larger front brake calipers. Also, the rear wheel wouldn't fit in the trunk at all if I had a flat in the back... so I decided to sacrifice the spare wheel space for the reservoir 😂😂 (This provided a further good decision as I changed the bolt pattern and the spare wont work anyways) Decided to use amazon boxes as a unit of measurement to avoid having to use the metric system. It seemed to give pretty much max capacity and still keeping the hood from opening/closing without the hinge contacting. Water volume was was important aspect of the intercooling setup but also needed water flow. As I was moving to a stand alone ECU I figured I could easily setup a PWM pump for maximum flow. Decided to pickup a Pierburg water pump which I immediately painted to look like a Duracell battery 🤦‍♂️😂 (The color scheme looked cooler in my mind) This thing would require some heavy duty wiring and a 40 amp relay, certainly had to flow to keep the water moving. In the same week of making this poor pain scheme choice I decided to paint my wastegate solenoid... which also came out looking like a 9v Duracell 🤦‍♂️😂 At least they are relatively well hidden from view. Although I had what felt like a lot of odd jobs to do on the Esprit after the engine was together I still had one major one to tackle with the Renault UN1 transaxle. I had rebuilt an engine before but this was going to be new territory for me. Fortunately there is a very detailed YouTube video series from someone rebuilding a UN1 for a DeLorean. The head mounted camera view and what feels like over accentuated body movement make it so you can only watch it in about 45 second spurts, but its extremely detailed on going through a UN1 rebuild. I went with the GTO Engineering kit for mine. They seemed to be pretty well tested and were in some of the GT40 replica cars using Ford V8s. Lesson learned, if I ever did this again I would go with the Ford spline option on the rebuild kit and open up a wider range of clutch options. Really limited to AP, Helix or Clutchmaster for a ground up clutch option with the original Renault splines. Other than being a single piece input shaft the GTO upgrade also has a much more robust 5th gear. Sadly, still not supported on the back but hopefully sufficient to hold more power. It is certainly a lot thicker and does not have the deep channel after the 5th gear splines. First gear is also straight cut for strength and should give an impressive whine. 😁 Rebuild process was honestly very easy, but I did take a lot of pictures coming apart so I knew how they went back together. I picked up some decent heavy duty snap ring plyers and a gear puller from Harbor Freight to make the job easier. Was really able to knock this out in an afternoon, not too bad of a job. I also picked up a Quaife limited slip differential, figured I might as well do it right if I was pulling it all apart. I had installed a similar worm gear/spur gear unit in another high horsepower car and it really did make a difference. I didn't get much seat time in the Esprit before it shit the bed but looking forward to seeing how this thing does 😬

Yeah at high RPM because its a flat plane crank, really gets that super car sound! Unfortunately because of the cast manifolds... not so much at low RPM lol

Finally got a good dyno run out of my Esprit after working out a few issues. This was a 2.5 year rebuild and a lot has changed on the car but everything done was to keep the car OEM+. Same 918 V8 Esprit engine and Renault UN1 with modifications and improvements. If you you're interested in the build I keep an IG going for the car at https://www.instagram.com/bespoke_esprit/ or a build log (that I started late) in the forums here. Managed to hit 630tq and 630hp on 22psi Dyno graph below. As you can see, clutch gave up at 4200 RPM. I didn't expect the build to make this much torque, horsepower is about where expected but only had the clutched spec'd for mid to high 500tq. Potential for over 630tq / hp is certainly there once I find a clutch that will handle it. Will have to test it again once that is sourced and can crank the boost up a little more too Dyno video is not of the 630hp run, was a day or so earlier while tuning but about the same boost setting when tracking down a little ignition issue.

So if you read the first post I mentioned this is more of a look back on a build that was already pretty far under way. So as of current the Esprit is actually running now but not fully drivable. Still going through the process of being tuned on the dyno. Video below is just a short clip of it idling. I will keep updating this thread as I have time with the progress and changes I made through the build. May be able to share some lessons and regrets now that its running also 😂 Once I had a solid plan for the shifter I needed to start working on running new oil lines though the tunnel. Would be a lot easier to accomplish this with the shifter out of the way. I decided to move everything over the AN lines for the oil hoses. They are slightly smaller OD but near identical ID for the oil flow. Also, in Arizona and even if the car is garage kept rubber never seems to last as long. With some searching I was able to track down some adapters for the oil coolers from BSP to AN, I believe through Racetronix or Pegasus. I finally had the oil coolers mounter too at this point and had no issues with the extra fan shrouds and fans fitting. Plan was to have these controlled by the ECU based on oil temps at the ending, so didn't take any time to add temp sensors into the fittings/coolers themselves. I was also focusing on intake temps still at this part of the build not just oil temps. The Intercooler / chargecooler setup was done really well and quite compact but that also brought in the issue of cold side parts being close to the hot side part. (really this is a huge issue in the Esprit v8 even in the original design) I do believe the cerakote will help here but really not the end all of extreme heat management. I did pick up some DI fiberglass & gold protective sleeves to add a barrier to the charge pipe, also started looking into turbo blankets at this point too as they seemed to be an option to really cut down the heat soak from the turbos. As you can see from the compressor outlet below the compressed air passes right under the turbine housing.

I was nearing the transmission rebuild in my project timeline. One of the original must haves on my project rebuild was going to be a 1998+ direct shifter assembly, so was sort of getting down to the wire on having this. The 1997 and prior shifter is a bit of a turd. It has a translator in the shifter assembly itself then another one in the back tail housing. Shifting isn't a very fun experience to say the least. Just didn't feel very connected, not that it was exactly hard to find gears, but it just wasn't crip and mechanical. The assembly itself has a lot of slop in it even after tightening up any loose bolts. If you really want to know more about the difference LEW has a pretty good amount of detail. http://www.lotusespritworld.com/EGuides/ETechnical/Gearshift.html I had almost purchased a 1998+ shifter at the start of the rebuild but missed out on the opportunity, was headed to a family funeral and not really a good time to be working out car part transactions 😂. I had also been in contact with a vendor who had been developing a replica 1998+ Esprit shifter for some time, but over the 10+ months of contact it didn't seem to be coming to fruition. So, sort of like the intercooler situation... left to figure out a solution. Obtaining the 1998+ transmission tail housing was simple enough. Seems JAE had a bunch of those. Sort of question the labeling they use though... not sure is abbreviated or just Joe Sulka's sense of humor 🤔🤣 The rest of the brackets and retainers I was able to source also, cant remember if it was all JAE or if I had to pick some piece up from SJ Shifter assembly itself caused a need to get creative and doing some web research. There are a lot of after market shifter assemblies out there. Some were certainly more compact than others, which is the main need for the Esprit's setup. Found there were some fancy billet setups that were nice and compact for $600. In the end, I settled for a $30 option from some old JDM car. 🤣I believe I doubled the cost of the shifter eventually with rebuild components and the whole thing was as tight as a drum. Mounting plate was made with some spare steel and it was pretty much good to go.... minus a little bit of cutting. Overall cant complain with how this turned out, functional 98+shifter assembly and a much shorter shifter throw. Direct link shifts that feel very crisp. Side to side is a little heavy but may go back and sort that out at some point. Also had to make a reverse lockout later on in the build. Was a pretty simple addition, just a gate and a spring.

It was good to have the engine rotating assembly, heads, cam & belts done but really had a lot left to do before the engine was ready to be installed or started. Laundry list included wiring harness, interior LED lighting, gear shift assembly, interior carpets, transmission rebuild, turbo oiling, ignition system, engine sensors, intercooler plumbing, pump and reservoir... the list could really go on. One thing I wanted to address was the coil packs since I was already focused on the engine. I knew I wanted to get away from the cavalier coil packs and the wasted spark setup. Goal was to be able to have a wider plug cap for a smoother idle and still avoid spark blowout at high boost. My first though was LS coil packs since they are relatively bullet proof and reasonably sized. The work fine on my boosted LS setup but that's only 16psi... turns out their output is only about 30 mJ so not the greatest. I looked into doing the Nissan VQ / R35 plug on coil setup, hoping I could figure a way to mount them under the plug cover. Ultimately was concerned about fitment and they were much better than the LS coil packs at 45-50mJ. I decided to mock up a box based on the online dimensions of the IGN1A coil packs. These things put out over 100mJ and will allow for plenty of gap and spark duration. Should be able to get a smooth idle and still have spark if I push the boost 😬 From the online dimensions it looked as though I could still figure a way to fit 8 of them under the intake plenum.🤷‍♂️I ordered 8 to find out when they arrived the online dimensions or my box making skills were not accurate. Not too far off but made the fitment a little more entertaining While I waited for my coil packs to show up I got to work on replacing the interior lights with LEDs since I had most of the interior pulled apart already. I quickly found how brittle the gauges had become when removing the incandescent lights from the back! pretty much each one of them broke in some way while doing this, or had previously been cracked. The faces were all fine but the while housings really did not hold up well. I wasn't really in the mood to spend $1000 on new gauges for the car so each one came out and went through JB Weld surgery. Sort of ugly on the back but cant tell the difference on the faces. Fixing the gauges though did get me wondering about the boost gauge. I anticipated having to replace it as I would be dialing the boost up beyond 1bar, which was the limit of the original gauge. I didn't really want a one off, aftermarket, looking boost gauge in the car as the goal of this project was keeping the car looking OEM, or maybe OEM plus. I pulled apart the boost gauge and it seemed relatively simple inside, I got to wondering... maybe doubling the resister would work? 🤷‍♂️ Who know, electronics aren't my thing... so I called Caerbont and I was able to order a new gauge in the OEM style but a 2 bar boost limit. Threw the pieces of this one in a zip lock bag, just incase 😂 Replacing all of the lights in the dash with LED bulbs wasn't too much of a task and seems to have evened up the illumination of the instruments and center AC controls. Not sure if I would take the time to do it if I had no other reason to pull the dash and center console apart. I wasn't able to find a way to safely pull the buttons apart, so those were left as incandescent bulbs. Was pretty please that I found a way to get the turn signal to work with an LED however, despite the polarity issues. PXL_20221115_012458122-1920.mp4

Through hard work and the use of child labor I was able to get the engine assembled relatively quickly. Taking care of the cam belts however was another story. I've never dealt with installing cam belts before so was really getting into new territory, especially with having to index the cam pullies on new cam shafts at the same time. I understood the concept of what I needed to get done and luckily had the workshop manual available too. I did find that Harbor Freight sells a Lotus Esprit 918 cam pully tensioner... they just package it as an "adjustable pin wrench". 🤷‍♂️ The part that really gave me a lot of trouble was the indexing the cam pulleys however! I must have tried 5 or 6 times to do it as the book says. I believe it was Gonzalo who eventually clued me in that the workshop manual doesn't give the best directions with the 5lb ft of torque on the cam bolts. Issues I was running into was the cam pulleys were not being allowed to drag at all, which was resulting in them not indexing correctly. Can sort of see the issue occurring in the photo below with the teeth and belt getting out of sync. Essentially causing the belt to over tighten then jump. Once I attempted it finger tight cam bolts I was able to knock it out in one try. Used the android Spectroid app to test the tension and had it where it needed to be. So, if you ever have to index new cam pulleys on the Lotus 918 V8, don't follow the manual for the initial torque spec. All said and done it came out alright. Still a lot of planning ang prep to go before the engine can be completely put together or go into the car. Still had a transmission to rebuild also! One big step closer though. Also managed to find these as I was finishing up the engine assembly. ARP exhaust manifold studs. A few of mine had been broken off in the head so I had the machine ship sort them out when they did the valve job. ARP part number was 400-8022.

I was surprised when I saw the time/distance in the book 😂 I didn't realize they had it different for other markets. Would be interesting to know what drove that decision.

They were more ambitious with the longevity of their cam belts in '97 it seems @mike_sekinger

The handbook from the car says 102k miles or 8 years. I don't think I would let it go that long though 😬

All cleaned up and back together. Waiting to go to the tuner in a couple of weeks for the first start up hopefully 😶 this is the cleanest my Esprit has been in 2.5 years of collecting dust while I rebuilt it 😂

The machine shop had a pretty quick turn time on getting the block ready for me. Received the block back with all the main bearing clearances at .0015". While the block was away I took the time to Cerakote the cylinder heads titanium to match the block, which looked pretty good against the yellow for the valve covers and intake. Once the bearing clearances were confirmed getting the rotating assembly in was a pretty quick process. I really didn't stop for too many photos of this as the new liner install did require the heads to be bolted on in short order. I did still have the original head gaskets so I made use of those for the initial sealing bolt down of the heads. I went with Threebond for the liner sealant. It seemed like the best option as it has some give for thermal expansion, also its pretty resistant to anything it should be coming into contact with. It was pretty nice to see the engine block and heads assembled finally with the rotating assembly inside. Felt like a long time coming. Snapped a couple pics with my Arizona Lowtus plate to mark the occasion then popped the heads back off after a day or so of the sealant curing. Still had a little work to do with planning out the valley cover. I wasn't going to be reusing the original coil packs, I'm not sure of the output from the GM cavalier coil packs but I'm pretty sure they didn't have high boost in mind 😂 Also it seemed like a good time to move the knock sensor as I would have the option to run two with the new ECU. Having two stacked in the middle wasn't going to be as much of an improvement as having one closer to or on each cylinder head. Starting with a clean base for a valley cover seemed like the best option to start with at this point. Took the time to key the intermediate shaft while the engine was out also. Made a jig out of a heavy duty washer I had laying around and went together pretty easily. Ended up using a 1/4" steel pin from the local hardware store. Seems to be a pretty sensible common mod on these engines. Especially with the devastating consequences if these pulleys come loose and rotate freely 😂

I'm of zero help on the light probably but I really dig the gold wheels and stripe 😁❤️🤣 Have always wondered if I would want a stripe on mine if I ever had it repainted 🤔 I would think its an issue with a switch though on the light. I believe it is hidden down with the handbrake on my 97 from when I pulled the carpet on mine.

Its the general use blue loctite. I did it on mine, not sure if the concern is the race rotating in the housing. Figured it couldn't hurt anything

We do have exceptionally good taste in color choices 🧐🤔😂

Another internal coating I did was on the side skirts of the pistons. I considered going the Cerakote Micro slick route with them as it really does seem to have a lot of the benefits I would be after in a skirt coating. I eventually came across a pretty interesting option of having them powder coated with an abradable graphite coating. The idea behind it is a thick coating (compared to the 0.00025" thickness of Micro slick) to reduce the piston to wall clearance while holding in a layer of oil. This does create a very tight fitting piston but the coating is worn down during the initial break in process until a perfect fit is achieved. This should result in improved VE and a smoother/quieter engine. This isn't anything new and has been around for 10+ years, company I used to do it was Line2Line coatings but seems as though there are several options out there. Have to say I was pretty happy with their process, timeline and tech taking the time to answer all my question. It's a little tricky to really complete comparison tests on internal engine stuff but there seems to be enough testing and information out there to support that this will work just fine as a skirt coating and does improve efficiency. Not going to be disappointed at only $35 a piston. I actually thought I was ready to start building at this point but came across another issue with that probably contributed to the initial engine failure 😑. I didn't stop to take photos at this part of the process but started to spec out the main bearing clearances. I have to say I realized at this point why the new billet crank I had previous bought through JAE came with the price tag that it did. Not only did it look fantastic but every measurement on it was bang on to spec and each main bearing journal was identical. I tried every which way to measure something different than 2.5578" and couldn't do it. This thing was very precisely made. That being said I was pretty bummed to measure my main bearing clearances at the following (#1 0.0006", #2 0.0003", #3 0.0007", #4 0.0002" #5 -0.0003") 😂 I did at this point take the time to measure the original crank and found the clearances to be in the upper end of the range and completely off the chart for #1 at this point. I had never actually taken the time to check as I knew I wouldn't be using the same crank. None of the original crank journals were close and had a range of 0.0018". The original crank bearing clearances were as follows (#1 0.004"😬 , #2 0.0021", #3 0.0023", #4 0.0023" #5 0.0024") Not sure if #1 was opened up by garbage from #8 rod failure or was causing low oil pressure that resulted in #8 rod failure as i don't know the original engine build measurements. No signs of bearing damage on the mains though from the tear down. As the initial piston rings were gapped at 2MM each I'm not sure if they were actually measuring anything on the previous rebuild. Well, Since the engine block was going off for a line hone regardless I decided to order ARP bottom end studs and at least make another improvement in the process. This gave me some time to continue on making parts pretty while I waited for the machine shop to do their part also. A lot of parts that hopefully wont be seen to often but I figured it was down to details to make everything tie in together nicely. Cleaning and powder coating washers and bolts. If installed with a little care this actually does work with minimal damage to the bolts. I usually use a blue shop rag on the final torque just to avoid metal/metal on the socket. Also decided to go with the Cerakote titanium color on the turbo compressor housings. Decided it would look nicer than having the whole thing gold and tie into the Cerakote titanium color of the intercoolers and charge piping. Hoping this might help keep IATs down from WOT temp spikes in the exhaust manifold, but either way it came out looking nice 😁 One thing I was able to start on while the engine block was away at the machine shop was the piston rings. I had managed to gather all the necessary tools for that job 😂

Well with mockup completed I had to get everything back out at this point and store it nicely away in the dining room so it didn't get dirty in the garage. At least its easy to remove the engine when you can lift the empty block and transmission out by hand thought 😂 I wasn't quite ready to rebuild at this point. Still had a few things bothering me. One of them being the throttle body being a bit of an eyesore. It would be ideal to have it Cerakoted to match the intercooler and transmission bell housing it was sitting above. Also the return springs on them were pretty ugly with black paint flaking off them. This isn't really a part that's overly visible but the more I looked at it in the parts pile the more it bothered me 😬 Disassembly on it wasn't too difficult but a little nerve wracking knowing it probably a pita to find a replacement. Sand blasting it with the throttle blades in probably wasn't going to be a good plan however as the minor sand particles would never get back out. The cerakoted surface of the throttle body stack really cleaned it up overall from the bare aluminum. I powder coated the return springs gold to tie it into the rest of the theme of the car. Not exactly noticeable when its mounted but I felt like it was a minor detail that really cleaned it up. I don't expect the cerakote to have any impact on intake temps, really just to tie in the color and makes it a little easier to keep clean. I also took the time to Cerakote the engine block around this time. Probably a little premature but I was I was curious how it would turn out. The block is too big to fit in the sandblaster but I was able to thoroughly clean it in the ultrasonic cleaner. Getting it masked off and ready for paint was a little time consuming but worth it in the end. Pro tip for anyone who who has a bunch of RTV to clean off their block, magic erasers work amazingly well to do this. You can usually find them under the kitchen sink or wherever your wife keeps cleaning supplies. 🤷‍♂️😂 They do come apart as you clean with them so as you can see, but they do make short work of sealant. Just make sure to air blast and tapped holes/ports to clean it out. PXL_20220801_004307299-1920.mp4 And one last thing I discovered at this point in the rebuild. It's not a bad idea to remove, clean, inspect your oil squirters. Especially after catastrophic bearing failure. This one I ended up replacing as no amount of cleaning would get it to flow nicely. As you can see from the comparison, the first squirter under the faucet is a bad one (conveniently labeled Bad) and the second one gives a nice jet out of each end when under the tap. PXL_20220807_000137559~2-1920.mp4

I think its case by case. Blocks not going to damage easily and the important sealing is really on the cylinder liners. The head gasket has some crush to it so it also. If you had to have material taken off the deck of the block then you would have to account for it in the liners too. I had the surface of my heads prepped, nothing significant. Would not have any impact on the cylinder liners. I just asked Westwood to make mine 0.003" taller when I ordered them. Didn't change the cost or anything.

I went with 6 piston because they look sexy. My Esprit had the Brembo brakes. You wont stop any shorter going from 4 to 6. Brake fade on track events would really be the reason to upgrade, and there are other things you can do first. Brake air ducting, dot 5.1 or racing brake fluid

Thank you Kent! Hope to actually have it running in the next few week so I will probably make a new post when I do but will continue this one looking back on the rebuild. That is good to hear! I've had the manifold on my turbo LS car jot-hot coated for about that long and they have held up also , however I've probably put less than 10k miles on it during that time 😂

Looks like a perfect fit when its illuminated. If it really does bother you though Caerbont will make you a custom gauge to match the look of the others. Took several months wait time but came out looking pretty good. Original on the left and custom on the right. Cost was not much more than a standard replacement. I believe it was $75 extra maybe.

From my experience those gauges fall to pieces when you remove them. The plastic doesn't age well. Might be worth running a vacuum line and a mechanical gauge.

I started on some interior projects along with continuing the fuel system once I had the intercoolers sorted out. I had some random wires in the car that I needed to figure out what they did... which lead me to finding more issues that were fortunately easy to resolve. The previous owner had "wired" in a switch to turn on the radiator fans at any time. Not a terrible idea if done correctly. It was really just a switch that would ground the relay to trigger the fans. however the execution left me scratching my head. The thick ground wire was run to the brake boosted with a 10amp fuse in line... no idea why. I found this additional wire months ago but had no clue of its purpose. Was able to just remove it and clean the front up a little more. The switch was located in the tray under the radio. Most of the wires were held in place with electrical tape 🤦‍♂️Either way, this whole setup got yanked out as it will be a lot easier to control the fans from the ECU based on engine temp, oil temp and movement speed instead of a switch. While I was poking around in the front though I did come across this little issue what was one of the contributing factors to the heater not working in the car. Appears the controls are operated by a wire, and in this case it broke. This seems like a bad design and I expect it to break again. I've reattached it but if anyone has a suggestion for a permanent fix I'm interested. My next improvement project was to complete the fuel system. I had the fuel rails knocked, pressure regulator, and lines in/out sorted for the engine bay. Really was down to sorting out the fuel pump themselves. Going for really twice the power and I needed larger pumps. I opted for a pair of Walbro 450 pumps as they should deliver sufficient fuel and they wont be as demanding on the amp load. This being said, inspecting the wiring on the current pump setup and it wasn't sufficient and appeared to be a potential fire hazard already 😂 So scrapped most of it and got to work. It is nice that the Esprit already had two fuel pumps from the factory but the feed line was certainly small. So really decided to repurpose the holes on the fuel hat for different used. The original wiring hole became the site of the new feed line and the port for the tank pressure sensor was repurposed to be used for wiring. Not planning on having this sensor connected to the new ECU. It wasn't the prettiest thing I've made but should deliver the amount of fuel necessary for 700hp. I was also able to find a nice home for my summit fuel filter in the original spot on top of the RH gas tank.

I would look into TXL wiring if you're going to be replacing any major part of the loom. It's a thinner shielding but higher heat resistance and very flexible. Just makes the job easier and more tidy. Might have to hunt around for the colors but a lot of options on Amazon. 20 or 22awg would be good though, not sure what that is in those fancy mm² sizes though 😂