-------------- Original message from James Maher <deltaflyer@prodigy.net>: --------------

The setup:

·        Engine/Model/Year: 13B 6 port NA mixed

·        Source Condition: David Atkins Rebuilt for Aviation Application 

·        Modifications: Ported intakes and cooling for 180HP

·        Intake: Atkins short manifold w/TWM 48mm Throttle body

·        Exhaust: 321 SS tangential muffler

·        Engine Control: RWS EC2

·        Fuel Control: 4 Mazda 460cc Injectors, pri. in block & sec in manifold

·        Fuel Pumps: RWS

·        Cooling System: 2 – 9”x13”GM evaporator cores with 0.75” auto hose, stock water pump with 180F deg.-thermostat, 50/50 glycol\water mix.

·        Oil System: stock 1986 oil cooler

·        Installation: conventional – self built mount

·        PSRU/Re-Drive: Ross 2.85:1

·        Prop: IVO Magnum 74" 45-105”pitch in-flight adjustable

·        Power: 180HP? 

 

The issue:

On the ground, cooling stabilizes at 180-190F deg and oil is usually 10 degrees below the cooling with an OAT of 65-70F deg.

When running with higher OAT (75-85F deg) after about 0.5 hours of moderate taxi runs (up to 4300RPM) the cooling temps reach 212Fdeg with the oil about 200F deg.

 

The question:

Can something be done to get lower operating temperatures without redesigning the system?

Would switching to pure water help and if so by how much?

Would removing the thermostat help and if so by how much?

How much change should I expect if I were to do both?

You guys down south should have a good idea of how best to enhance cooling.

What are your suggestions?

Thanks,

Jim Maher(Dyke Delta)