Radiators in series........
Posted: February 17th, 2010, 7:24 pm
I was to the point of making up my cooling hoses when I had a decision to make.
I had a choice of jacking around w/making T/Y fittings to splice the hoses together...... or just connect the return hose to the top of the left radiator and have the pump feed come from the bottom right.
That same question has been asked, regarding proper radiator efficiency, with people responding against the idea.
Just for the fact to simplify things, I decided to experiment and go for it. After all, my whole build has been an experiment for me.
The old-style engine.........
We know the issues of using an old cylinder w/the rear coolant feed......the fat expansion chamber interferes w/routing the hose to the back of the jug.
I studied the water jackets and took another gamble in reversing the coolant flow. The inlet feed is to the top of the head, and exit flow is now from the back of the cylinder (turning the L fitting 180*).
I figured the reverse flow will allow the cylinder to have a more consistent front-to-rear temperature. Instead of having a cold area where the coolant normaly feeds in.
Anyway, I've put almost 100 street miles on the bike in the last month. The Vapor unit shows coolant temps to be in the 120* range w/a 70* ambient temp.
The hottest day I've ridden so far the air temp was in the mid 80s, and coolant never climbed over 140.
The strange deal w/the Vapor is it won't show a coolant temp below 100*.
I'll start the bike, and spend time putting on my gear....it takes a blast (an easy trip) up the street to finally get a meter reading.
I made one stop to fumble w/the back pack, dump some fuel in the tank and take time to do a check-over (about 10 minutes) while the bike idled. I noticed the engine temp had climbed to around 180*, but rapidly fell as soon as minimal air flow returned.
I guess my gamble paid off.
I was expcting higher temps, so I'm relieved to see it run so cool (maybe too cool). A far cry from the 480 running an average 300+* head temp.
I had a choice of jacking around w/making T/Y fittings to splice the hoses together...... or just connect the return hose to the top of the left radiator and have the pump feed come from the bottom right.
That same question has been asked, regarding proper radiator efficiency, with people responding against the idea.
Just for the fact to simplify things, I decided to experiment and go for it. After all, my whole build has been an experiment for me.
The old-style engine.........
We know the issues of using an old cylinder w/the rear coolant feed......the fat expansion chamber interferes w/routing the hose to the back of the jug.
I studied the water jackets and took another gamble in reversing the coolant flow. The inlet feed is to the top of the head, and exit flow is now from the back of the cylinder (turning the L fitting 180*).
I figured the reverse flow will allow the cylinder to have a more consistent front-to-rear temperature. Instead of having a cold area where the coolant normaly feeds in.
Anyway, I've put almost 100 street miles on the bike in the last month. The Vapor unit shows coolant temps to be in the 120* range w/a 70* ambient temp.
The hottest day I've ridden so far the air temp was in the mid 80s, and coolant never climbed over 140.
The strange deal w/the Vapor is it won't show a coolant temp below 100*.
I'll start the bike, and spend time putting on my gear....it takes a blast (an easy trip) up the street to finally get a meter reading.
I made one stop to fumble w/the back pack, dump some fuel in the tank and take time to do a check-over (about 10 minutes) while the bike idled. I noticed the engine temp had climbed to around 180*, but rapidly fell as soon as minimal air flow returned.
I guess my gamble paid off.
I was expcting higher temps, so I'm relieved to see it run so cool (maybe too cool). A far cry from the 480 running an average 300+* head temp.