1997 V8 Lotus Esprit Rebuild (and improvements? 🤷‍♂️)

[Thartje]

At this point in the build I decided it was a good time to order new pistons. Old pistons were serviceable but I wanted to raise the compression a full point to 9:1. I was on the wait list for the pro alloy intercoolers which would bring IATs down, combined with more efficient boost it seems like a good option. Either way though increasing the power will produce more heat. So I started looking for ways to mitigate that issue further. 

I continued with applying cerakote and fully coated the inside and outside of the new exhaust turbine, stuck with the gold to match the exhaust manifolds. I only had one turbine housing and no turbos at this point, I wasn't even sure what I was going to do about the fitment issue still 😂

 

Cerakote has some pretty specific use coatings too that are really designed for harsh environments. One of them being a coating designed for pistons tops to prevent heat soaking into the piston and down into the crank case. Also, less heat into the metal means more heat into the exhaust. Its really EGTs that spin turbos, so I wanted to get more of those. I decided to use the Cerakote piston coating in a less conventional way and coat the exhaust ports, cylinder bows, and valve faces. Cerakote does take some specific prep work however, which meant my cylinder heads were going to have to be tossed in the sand blaster 😬

 

The cerakote piston coating is a dull grey color. Not exactly pretty but the idea here that less heat will soak into the head as it leaves the cylinder. Less carbon should hopefully stick and build up on the cylinder wall as the coating is less porous than the aluminum and relatively smooth.

 

 

Here is the cylinder head getting ready to go back into the sand blaster again to etch the bowls and the coated bowls and valves. The valves were kept in also to protect the valve seats and also needed to be etched for their coating. I did have a valve job done, just in case, after cleaning the heads multiple different ways 😂 This coatings covers about 90% of the bowl after the head is resurfaced as it gets cleared off the quench pad. Basically the same concept as coating the tops of the pistons but in reverse. Heat transfer into the cylinder head and vales will be reduced. More heat will be sent out the exhaust ports. Should reduce carbon build up also.

 

  

 

These are probably minor improvements but looking to get the most output from the engine with the least effort, so efficiency is going to be the key. Keeping any amount of heat out of the cylinder head and putting it through the turbine housing seems like a win.

[drdoom]

Impressively ambitious program here, will be most interesting to see how it all holds up in service.

Cheers

[Thartje]

1 hour ago, drdoom said:

Impressively ambitious program here, will be most interesting to see how it all holds up in service.

Cheers

How it holds up comes down a lot to the application. Need the correct surface texture which is why sand blasting is required. Also the surface has to be completely free of dirt and oil which is where the ultrasonic cleaner plays a big role. Wiping down surfaces with acetone will get them fairly clean but the ultrasonic cleaner really gets everything out. Ceramic coatings are becoming pretty common these days and do hold up. I used some other coatings ill post about later in the build progress that should actually end up with a direct gain to power though.

[Thartje]

Still had some additional coating on the cylinder heads and valves after the bowls and exhaust ports were done. This time on the top side the cam journals. The cam journals were in ok condition but figured it would be a good time to add an additional protective barrier to them with a dry film lubricant, similar to the coating that is used on main and rod bearings. Cerakote makes a dry film lubricant they call Micro slick. Again required sand blasting to texture the metal then painting this stuff it goes on almost as thin as water with a hvlp sprayer. It is very very smooth and gives a thin protective barrier. The coating reduces friction on startup or in a low oil pressure emergency. It actually gets used a lot on firearms here in the US as it reduces friction and holds in a layer of oil. Either way, sounds like a good opportunity to reduce wear and possibly bring down some engine temps... even if only by .005%

a Picture of the head before I sent it back into the sand blaster again. I did everything I could to prevent dust getting in to placed I didn't want it. Ultimately these heads were very thoroughly cleaned before being reassembled. 

  

 

This was a bit of a time consuming process having to mask multiple times to sandblast, clean, and spray but hopefully adds a layer of protection to a set of heads that are not easily available if needing to be replaced. I don't think there is much of any savings on heat here on normal operation. The caps were at lease a little less time consuming to coat. Glad I did it but ultimately if I were to do this again I could coat the cams also as that is the side that sees the friction. 

  

 

 

[Thartje]

Another use for the Cerakote micro slick dry film coating. After coating the valve faces with the piston coating I coated the valve stems. This is where a dry film lubricant can really can make a difference as there will be less friction and heat generated between the valve stem and value guide. This might be a small improvement but there are 32 of them so will add up. Engine oil still still keep the valve stems lubricated, this isn't a replacement for that, but this will aid the process. 

 

  

 

According to a Harbor Freight digital caliper the coating is pretty thin, only about .00025" or less and didn't introduce any clearance issues. Maybe a slightly more snug fit but still moved through the guides just fine.

 

  

 

This was all getting done towards the tail end of March 2022. A lot of the build I was doing with the assumption that I would have a water to air intercooler setup from pro alloy for the car. So pistons had been ordered to bump the compression ratio up to 9:1 and I finally got my hands on a larger turbo to start messing around with. Literally on the exact same day Pro Alloy cancelled the charge cooler group buy on everyone 😑 So was sort of committed to higher compression ratio pistons and at least one larger turbo with zero intercooler coming at this point in the build. Their kit was an appealing option was it was a one stop solution, however was back to the drawing board on intercooling. 

 

 

[Thartje]

Well at this point in the project I knew I needed to have intercoolers built. I wanted to have the intercoolers to look like they were part of the plan and not an afterthought. Also, I wanted it to stick to the plan of not losing any trunk space. So really the only way to do this was to have pretty much everything back in the car that I couldn't later move or adjust to work with the intercoolers. This meant just tossing the empty engine and transmission back into the car and starting to mock things up. I even picked up a pair of BMW intercoolers to mess around with and get the ideas going 😂 Would have been nice it this was a simple fix but ultimately they were pretty ugly anyways 😂

 

 

While I did have some down time waiting for the shop to have availability I started working on another item on the to-do list. I really wanted to move away from the tiny plastic fuel lines and get over to an 8AN fuel system with PTFE hoses. First step was to make fuel rails. Which would require some aluminum welding also so it gave me an opportunity to get familiar with the fabricator for my intercoolers. Picked up some aluminum fuel rail stock and got to work!

Yes, I cut it down with a tile saw because it was available and I'm very lazy sometimes 🤷‍♂️😂

  

 

Got to spend some time with my good buddy and ex Esprit owner Tony Grasso using his drill press for the fuel injector ports. He has a drill press in his workshop which made this job a lot easier. Not pictured here but there is also a specific drill bit to use for this that will drill into the fuel rail but step the hole wider for a fuel injector o-ring. Gives a nice flat seat for the injector also so its not hitting against a taper.

 

 

Fuel rails were fitted with 1000cc injectors to make sure there would be adequate fueling for more boost and higher power goals. They certainly sat a little bit higher but were a snug fit without the intake plenum gasket adding extra height.

  

 

Once they had the 8AN bungs welded on they got a quick coat of Cerakote just to make them a little prettier... even though they are nearly 100% out of sight on the car 🤷‍♂️I did have to file the bungs down just a little to make sure they cleared nicely. That final picture does show unrestrictive these rails will be.

 

    

 

Just as I was about finished with the fuel rail project my intercooler cores arrived and the shop was ready for my car to be dropped off so they could get to work 😁

 

 

 

 

 

[Thartje]

Was without my Esprit for a while as it was towed off to the shop to have intercoolers fabricated. This gave me a little time to plan, finish up other random tasks and, collect parts.

 

In the random tasks department I finally got around to actually cutting the holes for the fans in my oil cooler fan shrouds. Shrouds should really help at low speed and idle when the temps begin to climb. Not the prettiest but functional. The Spal fans pull about 340 CFM each so will be nice to have that all coming through the oil coolers instead of passing around the outside of the fan. Another plan for improving oil temp and engine efficiency was reducing the fiction in the oil pump. Once again found a useful opportunity for the Cerakote Micro Slick. Interest to see how well it holds up as here as unlike the bearings the oil pump is in pretty constant contact. This also seems as though why it could be an area that could see the most benefit if it can live up the the manufacturers claims. I have seen examples where it held up very well in metal on metal situations but not on a surface seeing constant movement like this. 

   

 

Planning was focused on ways to spend more money on this rebuild it felt like 😂 I knew I was going to need to go with a new ECU to make the modification plan and higher horsepower goals work but realized if I was going to be best to start from scratch on an engine wiring harness too. With plans to move away from wasted spark, dropping the saturation injectors, two knock sensors, and updating all the other sensors the nail was really in the coffin when I unwrapped and inspected the wiring harness. There were multiple frayed wires, some poorly rewelded, and even the wires to the fuel pumps looked like they had seen a little too much heat. Not sure if this is common from poor quality wiring or if this car had seen an extra amount of abuse but this wiring harness was a nightmare waiting to happen. So started reading up on engine wiring as this was going to be new territory. 😂

  

 

Also found an opportunity to spend money on new cams! As you can see my cams developed a nice ridge on each journal. The center portion sees less wear as the oil is coming in from the center and flowing to the outside. The oil it squished at the edges so that is where the thin film is. The heads/caps were in ok condition and measured ok on bore. I believe this is a result of the cams being in constant rotation in contaminated oil, essentially grinding themselves away on the metal contamination and slowly adding to the mess also. Either way, I was buying a new set of cams.

 

 

 

Parts continued to show up for the build also. It actually got to a point where my kids now just say "Car parts are here" when they hear a deliver truck 😂 Ordered some blow off valves from Summit. They were going to be hidden and out of the way, so no need for some $300 tuner brand blow off valves. These might be the most pointless thing done in the build but my inner 12 year old wants to hear the PSSSHHHH every time I lift off in boost.

Kinugawa waste gate actuators. Old ones weren't going to work with the new turbo housings and were limited to the springs they ship with. For Chinese parts I'm pretty impressed with the quality of the Kinugawa stuff. Not sure if I would run their turbo cores but their housings and wastegate actuators are well made.

Racetronix fuel pressure regulator arrived, in gold to match the color theme I had going. Was disappointed that their gold was a little more orange than it should be but still looked good.

Also bearings arrived from Calico Coatings. I wasn't quite confident enough to do the coating on the bearings at the time I placed the order. It does actual seem to be similar to the Cerakote but slightly thicker I believe. Either way it will add a nice layer of protection and again hopefully reduce friction, if every so slightly.

 

   

 

And while the car was away to have the intercoolers build my pistons arrived from CP! Nicely built with a custom "Send it" engraved on the back. These had been built to bump the compression ratio from the original 8:1 to 9:1 as there will be lower IATs from the intercoolers and better control of the fueling in each cylinder.  

 

 

And of course when you get new pistons the first thing you have to do is sand blast them 🤷‍♂️

 

 

 

 

[Thartje]

I ordered my pistons bare from CP since I had some different plans for the skirt coatings than what they offered. The top coating I probably isn't a huge difference from what they offered, but since I had all the necessary stuff to coat the pistons I figured I would get the fun of doing it myself. So tossed the pistons in the sand blaster and did a thorough degreasing in the ultrasonic cleaner before applying a coat of cerakote piston coat. I had cerakoted a few parts by now but I was still impressed with how nice and smooth this stuff lays down.  

The ceramic coating on top of the piston should help heat from soaking into the top of the piston itself. This should help with oil temps. The Esprit v8 does have oil squirters to cool the pins and underside of the pistons, so less heat will travel into the oil through that process. Also with the combustion chambers, exhaust ports and valve faces coated the same way this should help direct all the heat out instead of into the engine itself.

I don't believe these coatings would be very effective if only focusing on one part of the engine but from tests done over the years ceramic and dry film coatings can add up to 3%-5% average gains in horsepower and torque. I wont have any way to measure with this build as I'm not in it to do back to back testing lol. I wont have to wonder if I could have pushed a little more power out if I had added coatings though.

 

  

 

While I was finishing up with the piston top coating the intercoolers were getting closer to completion. It wasn't a quick process to have them built as I did want them to look as though they belonged and didn't take away any of the trunk space. So no piping them into the back hatch area or having tanks, hoses, and tubes routed everything. Goal was to make it look OE+ and not over engineered. It took several sessions of brain storming and playing with ideas but this is the rough idea on the final design. Was more than happy with how thy were going to fit, look and function.

 

  

 

[Thartje]

The Esprit made the trip back to my garage from having the intercoolers fabricated. I still had a lot of work to do with the plumbing, tank, pump but I did manage to mount the heat exchanger up front before the intercoolers were built. Can see it in the front of the car while its being towed back home. Found one that fit perfectly and was a double pass setup to improve cooling efficiency. This will restrict airflow over the radiator somewhat but with additional cooling efficiency all around I don't believe it will be an issue. The radiator does already have three Spal fans which are more than enough to pull air through the intercool heat exchanger and radiator.

 

Once I had the car back I figured I would get to work on making the intercooler setup look nice and show worthy before I had to pull everything out to assemble the engine. The blowoff valves are pretty well hidden in this setup but despite that I really didn't want to keep the Summit Racing branding on them. Nothing against summit, just not a fan of their logo 🤷‍♂️Also I wanted to take the time to cerakote the intercoolers themselves and the charge pipes from the turbos. I don't believe there is much benefit to this as far as efficiency goes, but it does make them look nicer and easier to clean. I did decides it would be best to put heat shield sleeves on the charge pipes, but didn't need them for test fitting. Also, decided to take the time to make the T bolt clamps look a little nicer too and power coated the springs gold 😂 I figure its the little details like this that will really tie it all together.

  

  

 

All finished with the rear part of the intercooler setup. I was pretty happy with how clean everything looked once it was installed. I didn't have the water lines installed at this point but even with them connected they are hardly visible when looking into the engine bay. I'm glad I made the decision to keep the pump and reservoir away from the engine bay also. This should help keep the efficiency of the intercoolers up by not heat soaking the coolant and pump before its actually going to work to reduce IATs. I was really digging the look the glacier titanium Cerakote along with the gold accents and yellow, glad I made that decision instead of going silver or way overboard with the gold.

 

 

[Thartje]

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.

 

 

 

 

 

[99ESPRIT]

Amazing work Tom!!        Kent

[JimmytheTurbo]

On 22/10/2023 at 18:06, drdoom said:

Impressively ambitious program here, will be most interesting to see how it all holds up in service.

Cheers

I had my turbo and exhaust manifold ceramic coated by Zircotech.

 

10 years later its still good.

[Thartje]

16 hours ago, 99ESPRIT said:

Amazing work Tom!!        Kent

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.

 

 

15 hours ago, JimmytheTurbo said:

I had my turbo and exhaust manifold ceramic coated by Zircotech.

 

10 years later its still good.

 

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 😂 

[mike_sekinger]

17 hours ago, JimmytheTurbo said:

I had my turbo and exhaust manifold ceramic coated by Zircotech.

10 years later its still good.

Yes, same here.  Their high performance ceramic coatings are excellent

[Jason Rushing]

On 18/10/2023 at 02:25, mike_sekinger said:

The taller Westwood sleeve design is the one to go for if you are planning more boost - good decision.

This will be included in my eventual engine rebuild but I have a question. Did you have the heads and engine block machined a little to ensure flatness? If so would taller cylinder liners still be called for? I understand that does depend on how much material is removed but in general what are the thoughts on this or is that a must get block back from machinist to know for certain what liners to order? Mike I know you have posted elsewhere the part number another Esprit owner had used from Westwood so I'm curious if that is what @Thartje used and if not could @Thartje post the part number for the liner he ordered from Westwood? Much appreciated!

[mike_sekinger]

Tom specified his own dimensions and Westwood created a custom part# for his liners.

[Thartje]

On 28/11/2023 at 14:24, Jason Rushing said:

This will be included in my eventual engine rebuild but I have a question. Did you have the heads and engine block machined a little to ensure flatness? If so would taller cylinder liners still be called for? I understand that does depend on how much material is removed but in general what are the thoughts on this or is that a must get block back from machinist to know for certain what liners to order? Mike I know you have posted elsewhere the part number another Esprit owner had used from Westwood so I'm curious if that is what @Thartje used and if not could @Thartje post the part number for the liner he ordered from Westwood? Much appreciated!

 

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.

[Thartje]

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.

 

 

 

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.

 

 

 

 

 

[Thartje]

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 😂

 

 

[Steve V8]

Hey brother from another mother across the pond. 😉😉😉.

[Thartje]

1 hour ago, Steve V8 said:

Hey brother from another mother across the pond. 😉😉😉.

 

 

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

 

[Thartje]

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  😂

 

 

 

 

[Thartje]

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. 

 

[Thartje]

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.

 

 

 

 

 

 

 

[Thartje]

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.