Bleedin' radiator! HELP/discuss pls......

[ROD]

its behind the rad and it pulls
 Just bought a digital thermometer gun.The trike temp gauge appears to be reading accurately
 
  Heres some figures.....revving trike at a standstill.
  Gauge 80  / rad top  72   /rad bottom  42
  Gauge85  /  rad top  88   /rad bottom   78 <<< assume this one is when stat is opening,throwing hot coolant from engine into rad??(starts opening at 88)
 
  Its hard to be dead accurate with readings!
 

[fifer]

Rod , standard practice on Reliant is to connect a hose to the small radiator overflow pipe /stub and run it to the bottom of the header/overflow/expansion bottle {  whatever you want to name it  } .

There is only one feed into the bottle at the bottom .

The top of the bottle has an overflow pipe/stub situated in the neck of the bottle in a similar place to where it is on the Radiator .

The rad is filled to the bottom of the neck and a blank pressure cap is fitted on the rad .
 
The bottle is filled up to the marked fill line or , if no marks , to about halfway .

The 13lb or 7lb rad cap is fitted to the bottle .

In theory , as long as the bottom of the bottle is higher than the oveflow on the rad it should increase your available coolant and function ok .
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[hunter]

That sounds about right fifer.

[ROD]

I see what youre saying fifer. I did similar to that previously on your suggestion,and found that the highest point on the system(the pipe running from rear of head )wasnt getting any fluid replaced,probably by an air lock caused as it drained down.The bottle was filling to the top and overflowing ,therefore losing fluid from the system.Your other suggestion of fitting a filling point 't' into the rear hose didnt work,as I would have been constantly topping that up. A standard Reliant set up doesnt have the rad 3" lower than the thermostat.This is the problem Im trying to overcome by fitting a sealed expansion system which introduces a 'head' of fluid into the system,with bottle the highest point to allow expansion into it..
  Remember I described it is keeping cool at lowish speeds,but at constant 50 plus speeds the temp climbs.Before I go spending mega money on a new elec fan,Im going to get one today from the breakers,temporarily fit it on the front of the rad as a 'pusher' (adding to the 'puller' I already have fitted)and see if that will keep it cool at the higher speeds.If it doesnt,I have decided to sell it ,cos enuf is enuf!

[terry t]

Rod you mentioned in an earlier post about head gasket and c/o in the water have you tested for this as it can cause water expansion and over heating.
your local garage should have a cylinder head combustion gasket leak test kit

[Olds]

Adding a fan on the front is worth a try Rod.
You may well have thought/checked all these things but please consider-
 To be expelling that much coolant I believe that either you are not getting the 7lb pressure required or the water temp must be exceeding 122deg. C. somewhere in the engine and it is boiling.
 Is it possible that the mechanical advance/retard is not functioning?
 Is the carb functioning correctly (not gummed up)and is the float bowl clean and float height set correctly?
 Is the fuel filter clean and designed for this size engine?
 Finally is the fuel pump giving enough flow?
 What you have described really does sound to me like lean running under load. It takes a lot more fuel to run at speed than to just bumble around.
Hope you manage to get this sorted.

[kapri]

You don't need another fan at speed , ram air effect  provides all the cooling you need. Got to admit this one has me flummoxed at the mo.

[Olds]

You don't need another fan at speed , ram air effect  provides all the cooling you need. Got to admit this one has me flummoxed at the mo.

Perhaps not. Rods rad is set at quite an angle to the air flow, that coupled with no plenum effect, may cause the air to flow down the face rather than through the rad.
Though generally I agree.

[terry t]

You don't need another fan at speed , ram air effect  provides all the cooling you need. Got to admit this one has me flummoxed at the mo.

Perhaps not. Rods rad is set at quite an angle to the air flow, that coupled with no plenum effect, may cause the air to flow down the face rather than through the rad.
Though generally I agree.

Try fitting an air scoop on the bottom of the rad. one other point is the water pump ok may be the fins or worn and not pumping the water around the engine and just enough to go around rad via the byepass hose from the pump to the stat housing them to the top hose

[ROD]

All points absorbed! Fitted a fan on front of rad this morning,admitedly not tight to rad and air must be escaping out the side gaps etc,but not too bad. You would expect this to have some effect to overcome any air passing across instead of through the fins,but it didnt. I rode at constant 50/55 mph for around 10 miles-temp up to 100c,turned on 'new' fan ,no temp drop after a couple of miles.badoosh!,out came the coolant at around 105 degrees.Checked fan is pushing,which it is.Next tried altering timing a bit at each layby. Apart from making it run like a bag of s**te,with sometimes no real acceleration,it had no temp affect at all.Tried altering mixture whilst still on the move,but didnt want to know at any other setting.Theres no mayo in the filler cap.I have read that sometimes the water pump impeller can slip on the shaft,but it is brand new,so Im guessing its ok. Havent tested for gases in the water.I tried a 10lb cap yesterday,which seemed to have a longer spring and mechanism,but it didnt make any difference.The fuel filter is a bit hazy inside,but I have never had a fuel delivery restriction problem with running at 50 mph in any other car that caused it to 'lean out' and overheat,only to 'hold back' due to lack of fuel delivery.
 
 Im still not convinced that the expansion bottle is plumbed correctly.but TBH I cant be bothered anymore!
 
 The last thing Im gonna go out and try as soon as Ive had some grub,is a higher poundage cap on the exp. bottle. I'll 'borrow' the one from my kit car ,its around 13lb I think.
 
 UPDATE ...Just been to a mates garage,he did the water test,ALL OK! He also mentioned that he thinks the pipes are connected wrongly to the exp bottle. Told me what he reckoned to do,so Im off out to the garage to re plumb it!

[andyrennison]

Good Luck Rod. keep going, you will get there

[ROD]

Ive now re fitted the pipework,but temp doesnt seem much different at tickover than before at tickover.. P'raps it will settle once driven hard and it burps the air out? Its sitting at 90 degrees,which I presume is what it should be with the stat opening at 88.As long as it stays constant when driven hard it should be ok.I did notice that it reached thermostat temp much quicker with the new pipe arrangement,whether thats good or bad I dont know! At present I have the fan coming on at stat opening point.Got to get the rad overflow tube repaired tomorrow,before I can test run it at 50mph

[kapri]

What poundage pressure cap do you have on at the mo ? Actually throwing water out at 105 says that it isn't working correctly anyway unless it's only a 5b cap . Every 1lb of pressure above atmospheric should add 2C to boiling point

EDIT, just reread above and with a 10lb cap  water shouldn't even start to boil until 120C, sounds more like trapped air re my post below

[kapri]

Also forgot to say , did you bleed the system before fitting the cap ? If it's not 'teaching Grandma' you should start the engine from cold with top off expansion tank, run until stat open and rad burps, top up the 'normal' mark and then fit cap.

[ROD]

I see your point Kev.I tried the 10 lb cap but got confused what happened with it fitted! Ive now reverted to the 7 lb cap (now renewed)After I get the rad overflow tube repaired tomorrow ,I will refill it as per your instructions.
  Ive now re plumbed the tank,with the larger bottom outlet t'd into the rad bottom hose. The smaller diam top stub will be connected into the rad overflow. Im still not sure this will remove the air,as I thought the smaller hose should be fitted into the highest point of the system where the air congregates,eg the thermostat housing,or maybe the upstand I built in to the front to back pipe (where I orig had the smaller pipe) .I have noticed that now this small pipe is connected to the rad overflow,it has hardly any water flowing from it to the bottle. Surely if coolant comes off at this point,it will create a void of air in the rad top tank?,but when it was connected to the upstand it was flowing in strongly.I may end up refitting it to the upstand .
  When running up this system for the first time(as I say it got hot quick) I watched the temp gauge and saw it drop a bit when the thermostat opened,then rise slowly to 90 degrees where it stayed. I ran it up the road for a couple of miles at about 25/30 mph (to get more jubilee clips  )and the temp stayed steady (but there again ,it did on the other system)