Source: Lotus West
Author: Dallas Webster
Title: THE TWIN-CAM TILT
There seems to be a lot of confusion about Lotus motor mounts, some of which has been perpetuated by L/W itself, the result being that numerous Loti are scooting about with engines tilted and carbs and fuel pumps banging on the foot-wells, their owners thinking it just a sadistic quirk of C. Chapman (E.g., four of five early Elan owners in this area had mismounted motors.). Herein lies an expose of some persistent fantasy and misinformation, followed by the ultimate truth.
Let us begin innocently enough with the Elan Service Parts List, which indicates three different mounts: a right-hand (#026E0374) and left-hand (#054E6000) mount for early Elans; an ambidextrous mount (#026E6011) for later ones. The List omits the changeover data. I have been told variously that the first two mounts are for early Weber engines (again, whatever "early" means) and for all Weber engines. It seems a bit strange that early Elans use a Europa (054) mount while later Elans use a Series 1-2 (026) mount. This is an error in the Parts List, but a harmless one since the 054E6000 and 026E6011 are apparently the same mount! In fact, Lotus East's Parts Manager, Phil Mahoney, has never seen an 054E6000 and supplies the 026E6011 in its place. Don Tingle of Tingle's Lotus Center has seen both and says there is no difference. We might also note that the mount that is drawn in the Parts List diagram is neither of the two (three?) Elan mounts! Finally, Lotus' Price List, which unfortunately gets updated far more often than their Parts List, currently shows an 026B6011Z mount in place of E6011.
Now the two 026 mounts are significantly different. Installed correctly, the early mounts make your engine slant ever so slightly to its left side. Reverse them and the air-box (and possibly the fuel pump) will rest solidly on the RH footwell structure. Moreover, you won't be able to get your oil pump off without raising your engine. (The mounts can be installed upside down, but anyone who would do this after looking at the mounts might be well-advised to let someone (anyone?) else service his car.) Unfortunately, it is fairly easy to reverse them, since they are seldom marked with Lotus part numbers. However, the RH (0374) mounts are often stamped on top with the sequence F208 while the LH's (6011) have F082 and a Ford sticker with the number 109E6038A. In any case, they can be easily distinguished, since the right-hand mount is the one that will hold the engine higher. It's as simple as that, but for those who like details, the RH mount has straight sides and is "offset" in the sense that there are two small "ears" that stick up above the top of the mount (See the diagram of the two mounts, viewed from the engine.). A final distinction is the price -- the LH is $5.54 but the RH is $14.28! This is because the LH mount is a Ford (Anglia, at least) part while the RH is a special Lotus part.
Let me conclude with a few of the reasons that so many mounts have been mismounted. One reason is dealer ignorance or incompetence. Another is the habit of naively continuing the incorrect practices of the previous owner. A third, possibly quite significant, source of motor mount errors is the diagram on page El6 of the original Series 1-2 Workshop Manual (#26T327) which clearly shows the right side of the Elan block but the left-hand mount!! Later shop manuals (#36T327) delete this diagram (as well as many good ones) but offer no information regarding the asymmetry of the mounting system. A final, disappointing source of problems is L/W Tech Article #26MC080. "Right" and "left" are used in exactly the wrong ways, each appearing where the other should have been. It is the early right mount that is offset and different from the others. (Conceivably, the word "offset" could be interpreted to make part of the statement correct, but no one I know who has read it has interpreted it that way. Besides the offset one is surely the one that differs from the others.) In addition, Anglia mounts replace all left mounts and late right ones. And Don Tingle tells me emphatically that Twin-Cam Cortina mounts do not fit the Elan.