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HI,
After having some experience with oil coolers on small block kohlers i will pass this knowledge onto others . As u will read the requirement for a large effiicient cooler on a 6x6 etc is almost compulsory
This info would apply to small engines of similar type briggs etc
Back ground
kohler in 90f plus conditions
heavy load
oil temp 230--250 f constant
ALL OILS DEGRADE OVER 212F ------- SOME QUICKER THAN OTHERS [ this includes synthetics ]
212 f is the max allowed for constant running
TAKE CARE OF YOUR OIL AND IT WILL TAKE CARE OF YOUR ENGINE
TO HOT IS BAD FOR YOUR ENGINE OIL
TO COLD IS BAD ALSO
Prior to fitting a cooler the oil at change was typically black smelly etc equivilant to a car that had gone way past its service requirement .
After fitting the cooler this improved greatly
[a oil does suspend particles within itself and therefor discolours oil any way ] By fitting a cooler the oil is in a better condition at the same change interval there for the oil can do a better job at protection
== longer lasting engine
Firstly i will mention the basic 2 types of cooler available
1/ serpentine [old fashion style trans coolers etc ]
continious pipe
poor cooling performance for its size comopared to same size stacked plate cooler
typically cause pressure drop from inlet to out let connection
in the standard form inside the tube most of the oil does not contact the tube walls there fore does not cool well
There is another version of this with baffles inside the tube but really u may as well buy a stacked plate type
2/ stacked plate with or with out fins
functions similar to a crossflow radiator
no or very very little pressure drop across inlet and out let connection
for the same temperature drop a stacked plate will always be smaller by 20-30%than serpentine
cooler theory for a given sized cooler
double the air flow cooling is way better
double the oil flow cooling decreases
the closer the oil temp to ambient the harder it is to cool a bigger sized cooler is needed for the same result
oil flow is hard to cool below 2 gallons per min
poor fittings can cost up to 5psi per 90 degree bend
Actual fitt up
kohlercommand 25hp v twin
40-50psi oil pressure standard at 3600rpm
1-2 gallons per minute oil flow
race car type fittings size -8 earls ,speed flow etc [smooth radius bends etc]
remote filter
leads to remote oil thermostat [thermostat can be purchased in oil filter housing also ] 180 f
leads to 11x9 x 1 1/2 stacked plate cooler 1/2 npt fittings
10 inch high air flow electric fan
simple fan electrics sender switch inline[make fitting] temp around the 195 f
install sender switch in the line with oil coming out of the engine to filter
Results
55f to 65 f reduction in temp
oil pressure drop tested 20w/50 140f oil temp ambient 70 f 5psi
engine receiving 35psi at oil line going back to engine at 3600rpm
10psi per 1000 rpm is the min
uses 10w/40 oil
caution/ notes
due to long hoses ,small oil pump etc engine may take up to 1 second to acheive oil pressure
very important to run a oil that allows quick pressurization of system
review
i personally ran a more complicated fan control go with what i have suggested above
Remember to install the cooler with the fittings at the top so it does not drain out . Keeping the cooler full allows quicker pressurization when starting . U can have a fitting made at the top so u can acces and therefore suck the oil out at service time .
In a install with space i would install the 11x 11 x1 1/2 cooler
tomo
After having some experience with oil coolers on small block kohlers i will pass this knowledge onto others . As u will read the requirement for a large effiicient cooler on a 6x6 etc is almost compulsory
This info would apply to small engines of similar type briggs etc
Back ground
kohler in 90f plus conditions
heavy load
oil temp 230--250 f constant
ALL OILS DEGRADE OVER 212F ------- SOME QUICKER THAN OTHERS [ this includes synthetics ]
212 f is the max allowed for constant running
TAKE CARE OF YOUR OIL AND IT WILL TAKE CARE OF YOUR ENGINE
TO HOT IS BAD FOR YOUR ENGINE OIL
TO COLD IS BAD ALSO
Prior to fitting a cooler the oil at change was typically black smelly etc equivilant to a car that had gone way past its service requirement .
After fitting the cooler this improved greatly
[a oil does suspend particles within itself and therefor discolours oil any way ] By fitting a cooler the oil is in a better condition at the same change interval there for the oil can do a better job at protection
== longer lasting engine
Firstly i will mention the basic 2 types of cooler available
1/ serpentine [old fashion style trans coolers etc ]
continious pipe
poor cooling performance for its size comopared to same size stacked plate cooler
typically cause pressure drop from inlet to out let connection
in the standard form inside the tube most of the oil does not contact the tube walls there fore does not cool well
There is another version of this with baffles inside the tube but really u may as well buy a stacked plate type
2/ stacked plate with or with out fins
functions similar to a crossflow radiator
no or very very little pressure drop across inlet and out let connection
for the same temperature drop a stacked plate will always be smaller by 20-30%than serpentine
cooler theory for a given sized cooler
double the air flow cooling is way better
double the oil flow cooling decreases
the closer the oil temp to ambient the harder it is to cool a bigger sized cooler is needed for the same result
oil flow is hard to cool below 2 gallons per min
poor fittings can cost up to 5psi per 90 degree bend
Actual fitt up
kohlercommand 25hp v twin
40-50psi oil pressure standard at 3600rpm
1-2 gallons per minute oil flow
race car type fittings size -8 earls ,speed flow etc [smooth radius bends etc]
remote filter
leads to remote oil thermostat [thermostat can be purchased in oil filter housing also ] 180 f
leads to 11x9 x 1 1/2 stacked plate cooler 1/2 npt fittings
10 inch high air flow electric fan
simple fan electrics sender switch inline[make fitting] temp around the 195 f
install sender switch in the line with oil coming out of the engine to filter
Results
55f to 65 f reduction in temp
oil pressure drop tested 20w/50 140f oil temp ambient 70 f 5psi
engine receiving 35psi at oil line going back to engine at 3600rpm
10psi per 1000 rpm is the min
uses 10w/40 oil
caution/ notes
due to long hoses ,small oil pump etc engine may take up to 1 second to acheive oil pressure
very important to run a oil that allows quick pressurization of system
review
i personally ran a more complicated fan control go with what i have suggested above
Remember to install the cooler with the fittings at the top so it does not drain out . Keeping the cooler full allows quicker pressurization when starting . U can have a fitting made at the top so u can acces and therefore suck the oil out at service time .
In a install with space i would install the 11x 11 x1 1/2 cooler
tomo
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