Tapping into engine coolant for heat

[chuck c]

It looks like there are several places to tap into the system. It's hard to follow the word descriptions. I need pics! Part of my problem is I don't know the flow in this engine. Does anyone have a graphic or good description of the direction of coolant flow? I assume it's out of the pump into radiator, back to thermostat housing, thru tubes on top of engine, into heads, then internally back to the pump. How close am I?

 

[ekvh]

There's a good diagram, flow chart? In the shop manual which is under gallery tech references.

 

[Steve83]

Actually, it's into the pump, through the front cover, around the cylinders, through the heads, out through the elbows and tubes into the thermostat housing, out through the thermostat, through the radiator, and back into the pump. There's an internal thermostat bypass circuit that comes out of the thermostat housing (before the thermostat), through the block, through the front cover, into the pump cover, and into the pump.

The '85 and '86 fuel injected 1200's have fittings on the thermostat housing and water pump covers with hoses attached to direct coolant through the fast idle air control valve. There is no coolant bypass through these engines. These would be the perfect places to tap into for a heat source.

1200 FI thermostat housing:

1200 Thermostat Housing

• Steve83
• Nov 2, 2013

1200 FI water pump cover:

1200 CFI Water Pump Cover

• Steve83
• Nov 2, 2013

BTW, I got these on Ebay really cheap, so they're out there...

 

[chuck c]

OOOOOOO nice tip! I'll see if i can turn those up. If not I can tap them. I had the flow reversed. There's only one thing I don't like about buying those parts. It means an injected bike is being cut up for parts instead of made to run!

Q: will the those 1200 parts fit an 1100? From scanning pics I see some years have the bosses on the housing but they are untapped. That makes perfect sense, they used one casting and only tapped them for the FI model. Those should be much more common since every bike those years had one. They would be very easy to drill and tap for fittings since they have the metal and even a dimple to help locate the drill on center.

 

[canuckxxxx]

For heat to the plenum of the single carb manifold on my '82 I tapped into the back of the centre coolant collector tube on the top of the engine, for the supply. For the return I made a 1/2" thick spacer plate that went between the water pump cover and the lower rad hose fitting. Works well and the lower rad hose still fits.

hole in back of centre coolant chamber

• canuckxxxx
• Jan 23, 2014

hose connecting to coolant chamber 1

• canuckxxxx
• Feb 7, 2014

return plate 1 welded

• canuckxxxx
• Feb 6, 2014

return plate 1 welded on bike

• canuckxxxx
• Feb 7, 2014

 

[chuck c]

I like that!

 

[Ansimp]

Nice job :good:

 

[canuckxxxx]

A couple of things I should point out:

I used aluminum for the spacer plate but could have been made out of steel which would have been easier/cheaper to weld. That tube on the spacer plate is 1/2" OD x 3/8" ID with a 3/8" hole drilled through the spacer. Big hole in spacer is 1 5/8".

If you look at the first pic, at the threaded hole it looks fairly thick. That is because I glued a 1/8" thick disc to the inside using JB Weld. Otherwise it is only about 1/8" thick there.

Definitely worth going to all the trouble of heating plenum IMO. All running issues went away when I did that.

Good luck
Brian

 

[joedrum]

that is some fine work brian great job

 

[weightlifter99]

Nice job and thanks for the pics..it gives me a better idea on my 1100.

 

[El-Anders]

canuckxxxx » Fri May 09, 2014 1:55 pm[/url]


Definitely worth going to all the trouble of heating plenum IMO. All running issues went away when I did that.

Good luck
Brian

That looks really nice.
Would be really intresting if you cold compare before and after heated plenum. What was the problem without, and how well it is running now. I was thinking of welding a "floor" on to the plenum, and that would probably look very close to what you done.
I was thinking of heating with oil. Only because it might be a simple bolt on solution. Someone else here had found a oil cooler kit that would fit a wing, can't remember who.
Would you say that heating the plenum bottom is enough, and forget the runners?

 

[sgq700]

i ran mine with and without plenum heat and it made zero difference, however: i live in southern arizona and it really isn't very cold often! Last week it was in the 40's when i went to work and it didn't run correct untill it warmed up so.. i have to agree that if you don't live here or some place as warm.. you need plenum heat in the winter!

 

[canuckxxxx]

El-Anders » Sun Jan 11, 2015 10:53 am[/url]":1ibd31wf]

canuckxxxx » Fri May 09, 2014 1:55 pm[/url]


Definitely worth going to all the trouble of heating plenum IMO. All running issues went away when I did that.

Good luck
Brian

That looks really nice.
Would be really intresting if you cold compare before and after heated plenum. What was the problem without, and how well it is running now. I was thinking of welding a "floor" on to the plenum, and that would probably look very close to what you done.
I was thinking of heating with oil. Only because it might be a simple bolt on solution. Someone else here had found a oil cooler kit that would fit a wing, can't remember who.
Would you say that heating the plenum bottom is enough, and forget the runners?

I did my single carb conversion over the winter of 2013/14 so did the first test rides in March, April. That is still pretty wintery here...temps around freezing or a bit above.

Without heat to the plenum the bike would just bog down when I openned the throttle. So when starting from a light or exiting a corner I would give it gas and it would just die. Unless I did it very gradually. Once past that it would really take off so I knew it had potential. Looking back now, it might have been better if the air temp was warmer.

When I added the floor to the plenum and plumbed in the coolant lines the plenum got very warm...hot almost, including the base of the carb. I attached a digital thermometer to the bottom of the plenum and read 65 to 85 degrees C. Bike ran really good with this heat.

Brian

 

[El-Anders]

Thanks for the info. Here is hot, and sometimes very humid, and 100F summers, so I don't know if I need heat. But a couple of test runs in March, (when it can be cold) would probably tell me if I need it or not. So heat didn't affect idle that much? That's the area where I seem to have a slight problem right now?

 

[slabghost]

Check the carb threads. Idle is most often too rich on the webers.

 

[sgq700]

mine has always been a little rich at idle,i set my idle after i calms down(about 200 rpm) or 1100 rpm then it will slow down to 900 rpm after a few seconds. the rich idle doesn't bother me at all as i don't spend that much time at idle, only at red lights and such, not much in town riding

 

[joedrum]

well yes as long as it seems everyone knows ....at idle all motors become the same ... smaller motors like a oldwing will tend to be on the rich side with this carb ...not horribly so but rich ... ive seen some rather close close also...cubic inch is small here as oppose to what the carbs were design for ...

ive made some huge mods to the idle circuit lately but not posting much on it till i can properly ...seat of the pants test it ...it might be a really great mod to do ...

 

[Swjones214]

So, I know I'm late to the party here, but thought that I'd share my solution for using hot water from the engine to add heat. I'm going to come off one side with a water hose welded into the elbow at the top of the head, into an aluminum heat exchanger welded to the Empi, and back into the water circuit with a straight-in pipe welded behind the two cross-over pipes. Pics will follow when I figure out how to do it... Fortunately I work with a bunch of guys who could TIG weld the Mona Lisa, so it's certainly not my welding skill that will get this done.

 

[joedrum]

looks great .....nice work

 

[canuckxxxx]

That looks good SW. It should flow enough coolant to warm the plenum and yet it is not altering the normal flow pattern. What size tubing are you using?

What are you doing with the bottom of the plenum? If you have free or inexpensive TIG welding at your disposal you could consider closing in the whole bottom with Al sheet.

Brian