Performance upgrades

[friend]

All,
I have been listening to the electric fan workup, and looking at the design there is a very good reason for the fan and housing put in the way they are.  Put the bolts in (and the washers and center pipe along with good cushions) using the correct amount of torque and locktight for the threads, and the engine will be cool.  The part that is missed is the oil.  While the fins on the cylinders cool down the engine, the transmission will and does bake the oil.   So, better filter, better oil cooling, and add about a quart in the deal and you will have an engine that will run smooth for a very long time.
Even if you add an electric fan, you have to jury-rig the thing in place.  Using the old fan housing is the best bet, but here again,  the blades of the fan have to line up with the housing and bent in the right direction to administer good flow.  If you leave the shrouds off then you are loosing CFM around the cylinder fins and cooling.
 Just because a radiator fan looks like it will do the trick it is made for a different purpose.  If you look at the makeup of a radiator and the layout of a Honda 600 motor, there are huge differences.  Where the Honda fan pulls air across the fins more than 8 inches to the front of the engine, the radiator fan is mounted on the radiator.
If you really want to find out if it works, have a machine shop make a oil drain plug bolt with a center drilled to fit a sender and mount a temp gauge under the dash and watch your engine oil temp clime.  Even with a electric fan sucking air over the cylinder fins, all the oil travels through the engine once every minute at idle.  It does not cool enough and your temp gauge.  Attach a cylinder head temp sender under one of the spark plugs and find out what the temp is on the head.  The cylinder head will sit at around 350 Degrees.  The oil temp will run into the 235 to 250 area.  Every engine you open up will be dark brown to black from oil turning into tar.  Hook an oil cooler and remote filter up to it, leave the original fan in place and the gauges and watch the change.
Bill

[lyletrudell]

Hi Bill, good points, you have been working on these issues awhile.
With the electric fan, I was only thinking of HP loss driving the idler pulleys, bearing loss, belt tension....
I was going to keep the fan shroud as is, as you say that is the key to getting air flow past the fins. I wanted to use a 8" electric fan in place of the belt driven one.
I agree the oil cooler is the best idea for engine cooling and longer life! Living in Florida that is something I will add for sure.
I also like the temp gage under the spark plug, I could use the one off my racing Go-Kart.
Thanks for the ideas.
Lyle

--- In
anzhonda600owners@yahoogroups.com
, wrote:
> All,
> I have been listening to the electric fan workup, and looking at the design
> there is a very good reason for the fan and housing put in the way they are.
> Put the bolts in (and the washers and center pipe along with good cushions)
> using the correct amount of torque and locktight for the threads, and the
> engine will be cool. The part that is missed is the oil. While the fins on
> the cylinders cool down the engine, the transmission will and does bake the
> oil. So, better filter, better oil cooling, and add about a quart in the
> deal and you will have an engine that will run smooth for a very long time.
> Even if you add an electric fan, you have to jury-rig the thing in place.
> Using the old fan housing is the best bet, but here again, the blades of
> the fan have to line up with the housing and bent in the right direction to
> administer good flow. If you leave the shrouds off then you are loosing CFM
> around the cylinder fins and cooling. Just because a radiator fan looks
> like it will do the trick it is made for a different purpose. If you look
> at the makeup of a radiator and the layout of a Honda 600 motor, there are
> huge differences. Where the Honda fan pulls air across the fins more than 8
> inches to the front of the engine, the radiator fan is mounted on the
> radiator.
> If you really want to find out if it works, have a machine shop make a oil
> drain plug bolt with a center drilled to fit a sender and mount a temp gauge
> under the dash and watch your engine oil temp clime. Even with a electric
> fan sucking air over the cylinder fins, all the oil travels through the
> engine once every minute at idle. It does not cool enough and your temp
> gauge. Attach a cylinder head temp sender under one of the spark plugs and
> find out what the temp is on the head. The cylinder head will sit at around
> 350 Degrees. The oil temp will run into the 235 to 250 area. Every engine
> you open up will be dark brown to black from oil turning into tar. Hook an
> oil cooler and remote filter up to it, leave the original fan in place and
> the gauges and watch the change.
> Bill