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New Overheating Clue
Just got some new information about the overheating that occasionally plagues our cars. Seems that the water pump for the 4 cylinder Subaru engines has a tendency to cavitate over 6700 rpm. It might be that our water pump has the same problem. Cavitation occurs because the water pump creates an area of lower than atmospheric pressure that allows the coolant to boil at a lower temperature, creating steam bubbles in the coolant stream. That might be why a higher pressure radiator cap would help this problem, causing the bubbles to collapse sooner, before they have an opportunity to create havoc.
I have had a lot of difficult finding an "import" size high-pressure radiator cap. I have ordered a Crucial 1.4 bar cap (approx 20 psi), from Crucial Racing Products. Will be at Pocono next Friday and will post how it works.
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95 LS-i Red, 31,xxx; bone stock for now; Daily Driver
94 LS-i Emerald Pearl, 106,xxx,; 246 whp; Tomyx snorkus and HKS Cold air intake; PWR aluminum radiator, silicone hoses; Inline thermostat; enhanced coolant routing; external power steering and oil coolers; Phenolic intake manifold spacers; 2004 WRX 5 speed transmission; ACT Clutch Kit, Heavy Duty Pressure Plate, Lightweight flywheel, performance disc; Group N motor mounts; ‘07 WRX 4-pot front calipers, cryo-treated slotted Tribeca rotors; Hawk HPS ferro-carbon pads; Frozenrotor rear slotted rotors; SS brake lines, Axxis Ultimate pads; Rota Torque 17x8 wheels; 245/40-17 Bridgestone RE01-R's; Koni inserts with Ground Control coilovers, Eibach springs; K-Mac camber/caster adjustable strut mounts; Urethane swaybar bushings; Bontrager rear sway bar; Urethane differential bushing; Custom Whiteline adjustable rear lateral links; Outlaw Engineering forged underdrive pulley; custom grind Web intake and exhaust cams (11 mm lift, 250° duration); solid lifters; CP custom aluminum forged 11 to 1 pistons, Brian Crower coated SS intake & exhaust valves; Brian Crower upgraded springs w/ titanium retainers; NGK sparkplugs; RallyBob (Bob Legere) ported and polished cylinder heads; Eagle H-beam rods; ACL Bearings; Cometic Head gaskets; ARP head studs & fasteners; Hydra Nemesis EMS; Wideband O2 sensor; 740cc Injectors; Walbro 255lph fuel pump; Upgraded WRX starter; Equal length SS headers (3 into 1); dual Magnaflow cat converters; 2 into 1 into 2 SS exhaust with Bullet muffler; OT Fiberglass hood; Oil pressure gauge; Programmable shift light,
2017 Subaru Forester XT, metallic dark gray, 29,xxx
2005 Porsche 911 Turbo S Cabrio, 24,xxx
2006 Subaru Outback LL Bean, 166,xxx sold
92 LSL Dark Teal, Smallcar Shift Kit - sold
Last edited by shotgunslade; 03-22-2008 at 10:57 AM.
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