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As Bill pointed out, using a stock-ish airbox is better than an open air filter like a K&N. K&N claims their fileters are freer flowing, so more air will get into the engine, and it will make more power. That would be true if all else were equal, but it's not. The airbox breathes cool, dense outside air, while the bare air filter breathes HOT, less dense engine bay air. The result is that less air on a 'mass' basis enters the engine via an open filter, so the engine makes less power.

There's an ideal trumpet length, depending upon your goal... longer for more low end torque, shorter for high rpm horsepower. On the stock 907 with Dellortos, Lotus used 45mm long trumpets in their airbox.

But in the real world, the trumpet length is limited by the air filter that is applied over it. Using K&N as an example again, their basic oval, open filter is available in different widths... narrow, medium, wide. Within the available filter space, the open end of the trumpet must not get too close to the filter's far wall, or airflow will be restricted/ pinched-off by a narrow gap between the trumpet and filter housing. Rule of Thumb: the gap between trumpet & housing should equal the Inside Diameter of the trumpet.

In early Weber DCOEs, the trumpet didn't just bolt to the carb's inlet flange. It also had a 'neck' that slipped into the carb's throat, and buttet up against the choke/ auxiliary venturi. When the trumpet's mounting bolts were tightened, it also pinched the choke/venturi tightly into place. Runing without the trumpets on those early carbs means the carb assembly is incomplete, and there is some elevated risk of fuel leaking out of the carb inlets.

Later, modern Weber DCOEs are more like Dellortos in that regard. They use a trumpet that just bolts on, without the neck that slides into the throat.

In either case, the real fuel leak risk will be a function of adjusting the fuel level too high, having an old leaky float that is taking on fuel and becoming too heavy, or an inlet valve that is not shutting off cleanly, and allowing excess fuel to enter the carb. "IF" the fuel level in the float bowl is correct, no fuel should spill over into the throats. Fuel leaks out of the carb inlets are not due to trumpet lengths... something else is at work. Trumpets are a secondary influence. Get the carbs 'right'.

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The little hose spigot high-up on the filler neck is for collecting fuel vapors. A hose from each filler neck goes to a vapor cannistor first. There, any liquid fuel that gets into the vapor hoses is trapped, and remains until it evaporates. Only 'vapor' exits the cannister and continues to a charcoal cannister. All this is in response to government emissions mandates, and the need varied by market/ country.

If your car has none of that, then it shouldn't even have the hose spigots on the filler necks. The fact that the spigots are there indicates that the rest of the vapor control system should be there, but isn't.

Either way, if you're going to run without it, then use a length of fuel hose to connect the two small hose spigots. It won't 'collect' vapors any more, but it will equalize pressures within the two tanks. The original cross-over hose was routed above the window in the firewall. It was immediately above the window, under the edge of the carpet trim.

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do they make a cover for the distributor...

Lotus didn't, and I'm not aware of an aftermarket cover. As Bill mentioned, it would be possible to fabricate a cover by cutting-up a plastic bottle (HDPE or PP plastic, but not PET or PETG). But a shield that effectively hides the distributor from any fuel leaks will also keep you from reaching it. Even with a shield, any fuel leaks will still collect in the many pockets between ribs on the side of the block. And liquid fuel will evaporate, creating a flammble cloud around the distributor or starter. Sparks and a flammable vapor are still a problem, and the real solution is to prevent/ not tolerate leaks... not to make an umbrella for the 'inevitable' leaks. :-/

Steven DuChene is a Lotus/ Jensen-Healey owner how had put together a distributorless ignition system for the 907, based on Ford EDIS parts. He sells a few special parts (not a complete kit) plus a set of instructions on how to make your own. But it's not a plug-n-play kit, you have to be the crafty type who can make and assemble the rest per instructions.

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I'm firmly of the opinion that in all the photos you see of Esprits and other 9XX powered cars burning to the ground, it's the negligent owner's poor maintenance that is to blame. Not the crappy Lotus design, or the dangerous carbs as the storyline accompanying the flaming picture usually states.

Rubber gets old... that's a known fact. Whether it's hoses, or internal O-rings and diaphragms. It gets old, dries out, cracks and leaks. NORMAL maintenance is to regularly replace all of those on a TIME schedule BEFORE they get that old.

Similarly, carburettors are supposed to be pro-actively rebuilt on a TIME schedule. No, you do not way until you see/ feel tangible evidence that fuel is leaking from somewhere. A responsible owner doesn't wait for evidence of a leak. A responsible owner stays ahead of the maintenance schedule, and rebuilds the fuel system & carbs BEFORE anything goes wrong.

In those pictures of flaming cars, it's the cars that are victims of their irresponsible owners, not the owners that are victims of those crappy, dangerous cars. Unfortunately, in this modern phone app culture, far too many owners think washing & waxing the car, and filling the tank is maintenance... it's not.

Build your Weber DCOEs and supporting fuel system correctly, then maintain it on or ahead of schedule. Focusing on building a shield/ umbrella for the distributor (how about the starter?) is planning for the leak you feel is inevitable. The better solution is to build and maintain the system such that it doesn't leak in the first place (it does not leak by design), then commit to maintaining it properly over time.

Regards,
Tim Engel


05/22/2022 9:08PM ZenHorizon zenhorizon@... wrote:

I have a 79 series 2 esprit. I am close to done with the car, but have 2 bigh items coming up. I have weber 45 dcoe's that the previous owner installed years ago. I rebuilt them with a kit, but there are no velocity stacks. I know the engine was known as the torque less wonder, But i dont know what Stacks i Shoudl run. My car has no airbox, and i have a dreaded fear of the car catching fire due to leaky carbs. So my question is what stacks should I run for the best sound and least chance of leaks, or what air filters on the carbs for the 907.

My 2nd question is I just installed 2 new fuel tanks for sps sportscars. I have run the main line from both tanks from the fill port to the tank and the bigger vent to the tanks as well as a new style cross over pipe. I noticed on the drawings and on the filler neck there is a very small port and it shows a hose going to an evap tank. My car doesnt have this and I cannot find one on any vendor. DO I need this or is there any other way to set something up with those holes. As it is I am afraid gas will pour out that little port when I do fill ups or put fumes into the engine bay.

My 3rd question is do they make a cover for the distributor so if gas does leak it doesn't start a fire? I have seen rubber distributor covers on other cars but cant find an option for our model of distributor. If i went electronic distributor would it eliminate this threat? I researched distributorless ignition and lotus pbc sells a kit but its rather pricey but looks nice.

Regards, Blake in norfolk, VA