Newbie cooling trouble

AriesSnake · Post by **AriesSnake** » Sat Sep 08, 2007 6:49 pm

First off...HELLO !!!!

I found this forum while trawling the net trying to find more about V8s.... I havent had a proper good look around yet and will be doing that after finishing this here post.. I have a custom Rover V8 Trike...

Ive been having trouble with it overheating... It has a very strange setup.. No expansion tank..2 mini rads and possibly no thermostat (cant find one) and a wierd inlet manifold that is for the 4 twin choke webbers... Before I can get my head around what the original builder has done with it , I need to first know exactely how the standard cooling system works...what connects to what and why... Can anyone point me to a simple but detailed and accurate diagram of a V8 cooling system..?

Cheers...Bazza

Post by **katanaman** » Sat Sep 08, 2007 9:08 pm

Dont have a diagram but its simple enough:

From the front of the inlet manifold there is a coolant take off housing (1 1/2" hose) inside the the housing should be a thermostat. From the take off there is a hose that goes to the top of the radiator. On the opposite side of the radiator at the bottom a hose (1 1/2"hose) goes to the water pump. Whether the system has a header tank or not depends on what the engine is in and the type of radiator fitted. If the radiator has a filler cap then the top of the radiator is the header tank. If it doesn't then there should be a heater size hose from the top of the radiator above the bottom hose to the tank. There is also a fan at the radiator which standard is generally driven by the engine but some installs also had electric fans. If electric fans are fitted then there is a thermo switch which controls the fan.
The operation is the pump pushes the water into the block up through the heads and when the stat is open out the top hose through the radiator and back to the pump. The stat's vary in operating temperature but generally 82 deg C or 88 deg C is used. There will be another two connections on your pump but these are for the heater so are probably blanked off on your setup.

From your picture it looks like the radiators (assuming both are mounted by the back wheels) are at a very flat angle and there isn't going to be a lot of air going through them. Some kind of ducting would help a lot with that. Not sure at all if two mini radiators would be enough to cool a V8? You should connect the two radiators together, top of engine to top of one radiator, bottom of the rad to top of other and bottom of that one back to the pump.

Hope that helps a bit. Post more details on how its plumbed and I am sure someone will soon tell you if it sounds ok or not.

AriesSnake · Post by **AriesSnake** » Sat Sep 08, 2007 10:48 pm

Hi Marki, thanks very much for taking the time to post that...much appreciated. The system has seemingly been working okay for the last year and a half but has been playing up for the last couple of trips. The 2 mini rads have the electric fans on permanently. The right hand rad gets much hotter than the left rad..? Ive noticed a very small drip/leak from one rad when parked and assume that the system is loosing pressure and therefor boiling up.. Instead of getting 2 standard rads to replace, I took the opportunity to get a pair of high performance 4 row... When I removed the old rads I discovered a strange set-up..

The top frame tube is the resevoir/ filler...

It doesnt have a standard inlet manifold. There are 2 'outlet' pipes at the front of the engine, left and right that run seperately to the top of each rad..???? Then the 2 returns from the bottom of each rad connect together and run up to the waterpump.

Also there are very small 'overflow' connectors on each rad that connect together then run up to the filler neck...

I am thinking of doing exactly what you decribed/suggested, in as far as running the water through both rads in turn... (in series and not parallel)

Are the small rad overflow pipes needed..? Why was one rad cooler..? I have blown into and ran a hose through all the pipes and found no blockages or restrictions anywhere...

I am also modifying the rad mounting brackets to bring them out, more square to the airflow..

Heres a pic of where the hoses to the rads come out...

Heres a pic of the filler neck, showing the return pipe attached from the overflow on both rads..

And heres a pic showing right in the middle the 'T' piece where the 2 rad overflows meet before going up to the filler neck...

Your thoughts would be most welcome..

Bazza

Post by **katanaman** » Sat Sep 08, 2007 11:06 pm

Ok I think I see how it is done.

The two overflow pipes will be to let air out to the highest point on the system.

I cant see any form of stat control in there. On top of that it looks like you have one side of the engine going to each rad as in left bank to left rad and so on. This doesn't strike me as a good idea because in normal use when the stat is closed coolant will flow from one side of the engine to the other then to the pump and circulate. There is no way for your setup to to do this. My guess is that the right hand is hot because this is the flow side where the left is the return. I think anyway. You would be better to join your two top hoses together at the heads, fit a stat housing and run that to the top of one of the rads as I described before. I am pretty sure you can actually buy something that will do what I am describing, I will have a search tomorrow night and see if I can find it unless someone beats me too it.

Slothie · Post by **Slothie** » Sun Sep 09, 2007 6:55 pm

Hi Aries, from one V8 trike owner to another

Haven't got anything to say about your problem that hasn't already been said! Just thought I'd say hi!!

Ian

AriesSnake · Post by **AriesSnake** » Sun Sep 09, 2007 7:21 pm

Slothie wrote:Hi Aries, from one V8 trike owner to another

Haven't got anything to say about your problem that hasn't already been said! Just thought I'd say hi!!

Ian

Hiya, you beat me to it

Ive been having a look aound and noticed you...Ive had a peep at your site and have been meaning to say hi....

Bazza

AriesSnake · Post by **AriesSnake** » Mon Sep 10, 2007 12:51 pm

katanaman wrote:Ok I think I see how it is done.

The two overflow pipes will be to let air out to the highest point on the system.

I cant see any form of stat control in there. On top of that it looks like you have one side of the engine going to each rad as in left bank to left rad and so on. This doesn't strike me as a good idea because in normal use when the stat is closed coolant will flow from one side of the engine to the other then to the pump and circulate. There is no way for your setup to to do this. My guess is that the right hand is hot because this is the flow side where the left is the return. I think anyway. You would be better to join your two top hoses together at the heads, fit a stat housing and run that to the top of one of the rads as I described before. I am pretty sure you can actually buy something that will do what I am describing, I will have a search tomorrow night and see if I can find it unless someone beats me too it.

Hi, Ive had a good look around on the web for a remote stat..all the after market custom items are way way expensive.... what I have come up with is a Honda CX500 motorcycle stat that in fact has 2 inlets... Someone from a bike forum has put a free one in the post to me this afternoon... I shall fit it later this week with the new 4row rads and let you know how I get on... Coming from the engine, the pipe should go to the top fitting of the first rad...then from the bottom to the top of the second rad...? And then back to the pump...

Bazza

Slothie · Post by **Slothie** » Mon Sep 10, 2007 1:16 pm

Just my 2p-worth, but if the CX thingie doesn't do the trick, I can't see that it would be too hard to fabricate a base for the standard thermostat housing if you can weld, or know someone that can. Then you could use a Rover thermostat.

Actually, reading that again, you've probably already thought of that!