I’m a Skeptic, but I’ll never grow wise enough to be skeptical of every design I see. If I were to write to capture your interest, I’d have written this in reverse order, but I write it like the mystery I saw it to be.
It really is hard to believe, but it is so typical to hear someone say “I wanted a Lotus Elise, but I waited till I could find an unmolested one.” I guess there is a case where that attitude pays dividends, but I think it should be reserved for the none too curious, perhaps even the mechanically challenged? I mean what would you expect a DIYer to do with a Lotus?
Like so many other things, a stock Lotus is just an ‘Annie In’ like some do when they play poker. From there you can spend more than the original cost of the car on sorting it out, and upgrades. But after all that work is done, the collector might say.. “too bad you molested that car”. If I said all I wanted in this post, it would be 300 pages long, so I’ll do my best to stay focused, But this is an example of many things in life.
It’s all about continuous learning, it never stops for the DIYer. I tie a lot of things back to the Lister 6/1. One is the funny wear in the top bushing on the crank pin. Nothing runs cooler than a lister 6/1, that massive piece of cast iron takes a long time to heat, and the water jacket might as well sit across the galaxy from the oil sump, it doesn’t really heat the oil like it should. With modern oils, 275 degrees is not too much, and hotter oil is a better lubricator. In the case of the 6/1, we’re talking a 1930s design, and it is my thought it is a legendary one.
Heating the oil up runs the water out, and that water in the oil doesn’t improve it’s lubricating properties. We also know that water holds acids, and acids can and do etch cranks and more. Running it hot enough and often enough keeps trouble away.
But the mention of the Lotus Elise you ask? The first year we Americans could own one street approved was 2005, the car was equipped with two oil coolers up front that year. It came stock with a Mocal sandwich plate that bolts to the block and then the oil filter screws into the sandwich plate. From the plate, a hose delivers oil to the oil coolers, and the hose returns to the same plate, a thermostat in the plate is supposed to help with maintaining temperature. This is a very common part sold to racers around the world, so it has to be a good one……right?
The engine in the Elise is a high winder, the 2ZZ designed by Yamaha, and some of the enthusiasts I attempt to follow claim there are a lot things similar in this engine to those developed or adopted by Cosworth, and of course many of us know that Cosworth was spawned by Lotus Engineers. My engine’s redline is 8600 rpms, at that speed, you need good and proper amounts of oil in all the right places, but I think there’s a lot of people that don’t have that!
The engine is said to suffer from cam failures, at least those who experienced a cam failure think so, and many think the cool oil temps could have something to do with it. Reading about it is like reading a good mystery novel, it’s just hard to believe this Mocal sandwich plate works the way it does, and so few seem to understand how it works or doesn’t work? Well it does work at cooling, but it doesn’t work to help the oil come up to temp or to maintain the oil temperature in a way that I could support. How many of us wait for temps to come up before we stand on the engine? In this case, you see the coolant temp is up, but your parts are still be bathed in cool oil!
One Lotus owner writes, “I took out the 160F thermostat, and put in a 200F thermostat, and it did nothing to improve (increase) the temperature.
Lotus makes wonderful cars, at least according to crazy canyon drivers, and people who enjoy track days, but that doesn’t mean Lotus doesn’t screw up. In fact there are people who think Chapman has done near everything wrong. I however took my first lesson from him when I watched the Lotus Cortinas with there 1.6 litre engines put on such a show in the 1960s. Low mass is magic around the corners, and the less you have, the less engine you need, and the smaller engine is less mass 🙂
Lotus deployed too much oil cooling in the 2005 Elise, it’s a fact because in later years they deployed half the cooling, and the car still had more than it needed. But I’m sure there are some people who are proud to have such great cooling capacity, even if they couldn’t make use of it at WOT in Death valley. In this case it’s not just too much capacity, it’s not enough control over oil temperature.
I think even the Lotus Engineers assumed the Mocal Sandwich Plate worked entirely different than it does, If they knew, we’d have reason to scold them I think. Watch this video.
GT86 Dude is a guy who likes a good mystery, like a dog with a bone, you’re not going to distract him, and he stays on task till he understands how it really works.
There is a forum called Lotus talk, if you’re interested, there’s some great threads on there about ‘Wiped Cams’, and they’re a good read. I think this too cool oil contributes to premature engine wear, same as too cool coolant does. On the Lotus Talk forum, you can study comment made by very informed people, and others who don’t yet seem to understand how the Mocal Sandwich Plate works.
If I lived in Death Valley, I’d have a different plan, but here in washington I could run this car flat out for an hour and not over heat the oil. Step one to to assure the oil runs warmer because I just replaced a cam, and I need do what I can to assure the replacement lives. I’ll do my modification KISS style, but we know we better add an oil temperature gauge so we can have confidence we’re up to temp before we stand on the throttle.
Of interest to me are the threads, many people STILL think the plug that caps off the Thermostat is British Standard, it’s not! I found it to be 1/2″ SAE with 10 threads per inch. I had a local vendor who does almost nothing but fittings verify same.
I’ve decided I don’t need the thermostat, it does way more harm than good, but I’ll keep the parts so some collector can return it to stock some day 🙂
Here’s my first mod.
The thermostat removed, and this hole is prime place to read oil temp! My sender will go here. But let me say that some fit an oil temp gauge by adding a ‘TEE’ fitting where the oil pressure once sat, and then screwing in both. Call me anal, but I think this is like checking the water temperature in a shallow eddy on the inside of a river bend.
It may be that the modified Mocal Sandwich plate is a great place to put an oil temp sensor, as all the oil goes right by the head of the sensor. If our turbocharger were to quickly elevate our oil temp, we are more likely to see it in real time, placing two identical sensors and observing how temperatures rise under WOT would give us veritable proof.
That piece closest to the threads was borrowed from the thermostat, the O ring from the junk draw, the sanded penny the seal. Of course you could machine an aluminum rod with an O ring slot in the center, and I’d do that if I were offering a kit to make this mod. If you had the right wrenches and or sockets this would be a mod you could make in the car in 10 minutes once you were on your back, looking up at the oil filter.
Now reassemble everything, hook up the hoses, and it all works just like there were no coolers, but you don’t have hoses tied up, and things getting dirty. the collector will be happier, the enthusiast can go on to prove he never needed the coolers. With modern synthetic oils you likely don’t and the new Corvettes make a lot of heat on the track, and racers say 270F for the oil is not too much. I’ll watch the gauge, and be surprised if it ever gets to 200F.
I want to close by sharing a snippet off Mocal’s website. If you read this would you ever question how their product worked?
“Prolonged use of a car engine in conditions where the oil cannot reach its correct working temperature will cause sludge formation and crankcase oil dilution, leading to excessive wear especially in the cylinder bores. Optimum engine power will only be delivered at correct temperatures. The elimination of drag in engines caused by cold oil is a most important consideration, especially with a racing engine, revving the engine without a load will not put much heat into the oil and devices for preheating the oil may not be available. It is therefore desirable to control of the oil flow through the cooler by a thermostatic device, we call an oil stat, set to divert oil to the cooler at 80ºC (although a wide range of settings is available for special applications). This is the minimum temperature required to evaporate and dispel contaminating substances.”
Hat’s off to GT86 Dude, he’s a DIYer for sure, and perhaps an engineer to boot? when you watch his video, consider hitting the like button.
I’ll leave you with an idea as to how far a true DIYer might go to modify his Elise?
All the best,