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Nautilus · 12-31-2017, 01:39 PM

Background: did too many short city trips, engine took some time to warm itself up.

Problem: too much driving when cold wears engine out, burns too much fuel, and runs the engine pretty noisy and rattly - hydraulic tappets and hydraulic timing chain tensioners need oil at the correct temperature to run properly.

Car: Seat Leon Mk 1 with 1.8 20VT engine. Same mechanical parts as VW Golf Mk 4 GTI / Golf 337 / VW Beetle Turbo / Audi TT Mk 1.

Cooling system construction:

- pump draws directly from spherical Coolant Recovery/Overflow Tank before it pumps into the block;
- no flow to or from the radiator before themostat opens;
- oil cooled and heated by coolant/oil heat exchanger;
- turbo cooled by coolant and oil.

Found out how the Prius thermally-insulated coolant tank worked. 1.8Ts can't be fitted with something similar, unless very complex and costly mods are performed (auxiliary coolant pump, separate "thermos" tank, valves, piping, wiring, dashboard controls etc).

The design is made as such because the 1.8T timing belt also runs the coolant pump. So, when changing the timing belt and coolant pump, the coolant in the pump housing and recovery tank has to be drained away and when the tank is filled again, the coolant flows directly to fill the pump housing. (Otherwise the pump would run dry and destroy itself when starting the engine).

Were the tanks thermally insulated, the warm coolant would be drawn into the cooling system while the thermostat was still closed, and the warmup would be quicker, with less engine wear, quicker heating of the cabin heater, and a slight improvement in fuel economy. It takes energy to heat the engine, energy which otherwise goes wasted when cooling down.

Insulated the Coolant Recovery/Overflow Tank thoroughly with Eurobatex pipe insulator (similar to neoprene mattressese), every inch, all pieces glued together lip to lip. Doubled the insulator thickness on the lower half of the tank, where there is more space, and also where most coolant stays. Glued also thin foamy insulator on the inner side of the fender, just below and behind the tank, insulated full innner fender and suspension turret. Return pipe from the A/C radiator in front of the car, which ran below the tank, had also been insulated previously with a foamy pipe insulator. Carefully left out the plastic catches for the wires and a small "overflow tube" on the side of the tank. Removed the metal plate that holds dipstick and N249 valve and insulated also the hose from the bottom of the tank to coolant ingress in the lower block.

Warmup time reduced itself to half as before. If the car is parked outside in the cold, the block and tank could keep the coolant warm for many hours. In summer temperatures, the engine heats as fast as a Prius, even below 2 minutes from a stop to 90°C

Also:

- took the pains to keep the engine bay as insulated from the outside as possible (lower plastic shield, all plastic covers and sheetmetal in the engine bay insulated with spongy material, the factory "blanket" on the underside of the hood, the factory rubber seal at the hood front lip);

- improved radiator aerodynamics by sealing all gaps which led to other places than radiator and leaving it in a "funnel" to channel outside air through it;

- insulated the intercooler from the engine bay and channelled the air to exhaust into the wheel arch.

From this moment, all air flowing into the bumper must flow either through radiator or through intercooler, because it has no other place to go.

12-31-2017, 01:39 PM	#24 (permalink)
Nautilus EcoModding Lurker Join Date: Dec 2016 Location: Romania Posts: 45 Simba - '05 Seat Leon FR Thanks: 22 Thanked 29 Times in 17 Posts	Background: did too many short city trips, engine took some time to warm itself up. Problem: too much driving when cold wears engine out, burns too much fuel, and runs the engine pretty noisy and rattly - hydraulic tappets and hydraulic timing chain tensioners need oil at the correct temperature to run properly. Car: Seat Leon Mk 1 with 1.8 20VT engine. Same mechanical parts as VW Golf Mk 4 GTI / Golf 337 / VW Beetle Turbo / Audi TT Mk 1. Cooling system construction: - pump draws directly from spherical Coolant Recovery/Overflow Tank before it pumps into the block; - no flow to or from the radiator before themostat opens; - oil cooled and heated by coolant/oil heat exchanger; - turbo cooled by coolant and oil. Found out how the Prius thermally-insulated coolant tank worked. 1.8Ts can't be fitted with something similar, unless very complex and costly mods are performed (auxiliary coolant pump, separate "thermos" tank, valves, piping, wiring, dashboard controls etc). The design is made as such because the 1.8T timing belt also runs the coolant pump. So, when changing the timing belt and coolant pump, the coolant in the pump housing and recovery tank has to be drained away and when the tank is filled again, the coolant flows directly to fill the pump housing. (Otherwise the pump would run dry and destroy itself when starting the engine). Were the tanks thermally insulated, the warm coolant would be drawn into the cooling system while the thermostat was still closed, and the warmup would be quicker, with less engine wear, quicker heating of the cabin heater, and a slight improvement in fuel economy. It takes energy to heat the engine, energy which otherwise goes wasted when cooling down. Insulated the Coolant Recovery/Overflow Tank thoroughly with Eurobatex pipe insulator (similar to neoprene mattressese), every inch, all pieces glued together lip to lip. Doubled the insulator thickness on the lower half of the tank, where there is more space, and also where most coolant stays. Glued also thin foamy insulator on the inner side of the fender, just below and behind the tank, insulated full innner fender and suspension turret. Return pipe from the A/C radiator in front of the car, which ran below the tank, had also been insulated previously with a foamy pipe insulator. Carefully left out the plastic catches for the wires and a small "overflow tube" on the side of the tank. Removed the metal plate that holds dipstick and N249 valve and insulated also the hose from the bottom of the tank to coolant ingress in the lower block. Warmup time reduced itself to half as before. If the car is parked outside in the cold, the block and tank could keep the coolant warm for many hours. In summer temperatures, the engine heats as fast as a Prius, even below 2 minutes from a stop to 90°C Also: - took the pains to keep the engine bay as insulated from the outside as possible (lower plastic shield, all plastic covers and sheetmetal in the engine bay insulated with spongy material, the factory "blanket" on the underside of the hood, the factory rubber seal at the hood front lip); - improved radiator aerodynamics by sealing all gaps which led to other places than radiator and leaving it in a "funnel" to channel outside air through it; - insulated the intercooler from the engine bay and channelled the air to exhaust into the wheel arch. From this moment, all air flowing into the bumper must flow either through radiator or through intercooler, because it has no other place to go.