Oil tank

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Overview
Engineered for scaled-down Mustangs, Spitfires and similar aircraft, this all-attitude system is a dry-sump lubrication solution with an external cast aluminium main oil tank and a multi-stage pump. The design separates the main reservoir from the engine and uses one pressure stage plus multiple scavenge stages to deliver pressure lubrication and return aerated oil to the tank. An integrated oil/air separator mounted on the pump reduces aeration; effective separation begins at ~2500 pump RPM.

Flying in all attitudes
The oil tank geometry, scavenge distribution and ventilation are arranged to ensure reliable oil pickup and safe ventilation in any attitude. The tank features four chambers (one main oil chamber and three ventilation/'breathe out' chambers) and three swivels positioned to secure oil pickup and air outlet regardless of aircraft attitude. Scavenge stages are distributed to collect oil from all areas including the oil pan, valve covers, PSRU and supercharger return.

Key design notes
Smaller AN6 hoses route ventilated, oil-contaminated air from a lower 'breathe out' chamber to the supercharger drainback area and bleed air into the scavenge suction to assist vacuum lift. The pump is geared to run at approximately 84% of engine RPM (engine max referenced at 5000 RPM) so the separator maintains continuous de-aeration of the oil.

The Swivel strategy
The tank uses a three-swivel arrangement: a central horizontal swivel (360°) linked to two vertical swivels. The lower swivel (typically AN16) includes a weight so the suction remains at the lowest point in any attitude. The upper swivel (AN10) acts as the 'air out' port and remains in the highest air layer to avoid drawing oil into the ventilation outlet.

Valve covers and mechanical aspects
Valve covers for the ASE-650 Saga powerplant are machined from billet 7075 aluminium and anodized black. They are configured to act as bottom pans during sustained inverted flight, each with its own scavenge stage and a central oil suction point to ensure reliable drainage when inverted.

Construction and inspection
The tank is cast aluminium with a built-in 12° mounting bracket on the rear half for firewall installation. Two sight glasses are provided: an upper glass for visual level checks and a lower corner glass for diagnosing leaks, excessive oil level or ventilation issues. All tanks are anodized black. The system uses a top-line dry-sump pump (supplier referenced: Auto Verdi AB) with integrated separator.

Pictures and test rigs
Documentation includes images of valve covers, external tank views, the Auto Verdi dry sump pump and separator, internal tank parts, a test tank half with a lexan window to observe swivel movement, the supercharger drain area and AN oil return lines, and the rear half showing the main reservoir with three 'breathe out' chambers.

Technical specifications

• System type: dry-sump lubrication system with external main oil tank and separate pressure + multiple scavenge stages
• Pump: single pressure stage + multiple scavenge stages; pump speed in system ~84% of engine RPM
• Separator: oil/air separator mounted on pump; separation starts at ~2500 pump RPM
• Engine maximum operating speed referenced: 5000 RPM
• Number of scavenge stages: seven total (3 large on oil pan, 2 for valve covers, 1 for PSRU, 1 for supercharger drainback)
• Oil tank chambers: 4 chambers (1 main oil chamber + 3 ventilation/'breathe out' chambers)
• Swivels: three swivels (main horizontal swivel + two vertical swivels); bottom swivel typically AN16 with weight, top 'air out' swivel AN10
• Hose/fitting sizes referenced: AN6, AN8, AN10, AN16
• Valve covers: machined from billet 7075 aluminium alloy, anodized black, designed to act as bottom pans when inverted
• Tank material: cast aluminium; surface finish: anodized black
• Mounting: built-in 12° mounting bracket on rear half for firewall installation
• Sight glasses: two sight glasses (upper for level checks, lower for leak/ventilation diagnostics)
• Maximum safe oil capacity: 10 to 11 liters
• Weight (without oil, hoses and most fittings): 22 kg
• Pump supplier referenced: Auto Verdi AB (dry sump pump with integrated separator)