cooling system help

[RCCob]

Has anyone got a diagram of how the cooling system should be on a RV8 fitted with edelbrock inlet manifold, Cos I don't think this is right on mine
I fitted the edelbrock carb and manifold and now I having cooling problems.
On the su manifold there is a cooling port at the back going to cylinders 7 & 8 on the edelbrock these are blocked off. at present we have the following please see drawing that if I manage to attach it The only fill point is through the expansion tank, can anyone help? pls

[Stu J]

I think Chedz had an issue with this...

Yipeeee - My Rover V8 is finally cool

[demus]

Hello,

From your drawing, where abouts do you fill the cooling system? If the only place is your expansion tank then I would suspect you have air caught somewhere.

When I redone the cooling system on my RV8 I fitted the Dax header tank (as the highest point), which filled into the bottom rad hose, then had an air bleed hose from the highest point of the engine (which happened to be the top rad hose), to the top of the header tank.

Maybe worth also making sure you have a small air bleed hole at the top of the stat. Mine seems to fill up and behave ok like that, although I don't have the manifold like yours.

Have a search around on the site as its come up several times, and I'm sure someone will be along shortly who can explain it a whole lot better than me, or know something different.

Cheers, hope it helps..

[TINKA]

Make sure you have left the heater control open so that the water can circulate properly, if you turn it off you need a bypass so the water can still circulate or it will always boil over. Had this problem on mine.

As someone else has said though where do you fill the system up.

[RCCob]

Originally Posted by TINKA

Make sure you have left the heater control open so that the water can circulate properly, if you turn it off you need a bypass so the water can still circulate or it will always boil over. Had this problem on mine.

As someone else has said though where do you fill the system up.

Hi guys thanks for the replies, having done a bit of research before I fitted the inlet and carb, I did the same as Chedz did by drilling holes in the manifold to allow flow from the cylinder back to the temp sender and even out the temp. But the problem I have is filling the system as you can see the only fill point is through the expansion tank. Hard work so I filled the engine at the stat and the rad through the hose, then quickly pushed them together. As you can imagine this leaves air trapped at the top of the system Question is how do you get rid of the trapped air??? I did think of fitting a in-line filler right at that point of the hose but I think it would look crap sat on the top of the engine. any advice appreciated.

Regards Russ

[slogger]

Originally Posted by RCCob

Hi guys thanks for the replies, having done a bit of research before I fitted the inlet and carb, I did the same as Chedz did by drilling holes in the manifold to allow flow from the cylinder back to the temp sender and even out the temp. But the problem I have is filling the system as you can see the only fill point is through the expansion tank. Hard work so I filled the engine at the stat and the rad through the hose, then quickly pushed them together. As you can imagine this leaves air trapped at the top of the system Question is how do you get rid of the trapped air??? I did think of fitting a in-line filler right at that point of the hose but I think it would look crap sat on the top of the engine. any advice appreciated.

Regards Russ

RCCob, have a look on my gallery. There are two pics from the early days of my Dax with a RV8. It had a plain cap just past the stat housing for filling with a bleed to the expansion tank. The setup changed as the bottom hose caused problems and that horrible bit of pipe from the stat housing was temporary.

Could always fit a large bore connection from the bottom of the expansion tank to the bottom hose as Dax now do.

[slogger]

Originally Posted by slogger

RCCob, have a look on my gallery. There are two pics from the early days of my Dax with a RV8. It had a plain cap just past the stat housing for filling with a bleed to the expansion tank. The setup changed as the bottom hose caused problems and that horrible bit of pipe from the stat housing was temporary.

Could always fit a large bore connection from the bottom of the expansion tank to the bottom hose as Dax now do.

......forgot to add! ....and mod your stat housing to give an air bleed back to your expansion tank also, so you do not need to have that filler point on the top hose.

[Sidecarbod]

Graham (AKA Chedz) had a lot of problems with his cooling system even though he was running the same basic set up as my 3.5 RV8, his car would suddenly overheat for no apparent reason. (Edelbrock performer, sierra 2.3 rad etc).

The drilling of the manifold will certainly help but my car never overheated even without this mod, one difference between the two cars was that I was running a 74 dergee stat.

I have now done the manifold mod and drilled three holes about 6mm diameter round the edge of the stat to aid bleeding and also to provide some extra flow. (If you look how much a stat opens you can see that it is always going to be quite restrictive. Some restriction is required as this allows the pump to build up pressure in the block an 'pack' the coolant round the heads but I was paranoid about cooking my 4.6 lump so wanted some more flow).

By the way I would not do the manifold mod whilst the manifold is still on the car, its quite tricky to drill the holes as you can only do them at an angle. I used a centre punch then a very small drill to start with, building up to around 8mm in total. There is a hell of a lot of swarf produced, use a hosepipe to blast it all out. Be careful not to damage the stat housing gasket face with the chuck of the drill! (EDIT.... I see that you have already done this mod, oh well the info might help someone else!)

A guy on the V8 forum has been having overheating problems and he has done as I suggested and it cured his problem. Basically do the manifold mod, fit a 74 degree stat and drill 3 holes in it.

I still find that I can not fill the system from dry in one go, I have to fill it as much as possible, then run the engine at tickover with the cap of and pour in the extra coolent as the level drops, you can get another 2 litres into the system. Even then after a run, once it has cooled down I can get another 1/2 litre in. After that it remains constant.

HTH,

Pete.

[RCCob]

Originally Posted by slogger

......forgot to add! ....and mod your stat housing to give an air bleed back to your expansion tank also, so you do not need to have that filler point on the top hose.

Hi and thanks for the replies, Have you any pics of the stat housing mod? would be very usefull if you have.

Regards Russ

[TINKA]

It is all right doing all these mods but it seams it is only pilgrims that seam to have any problem, . My RV8 in the AK never had any problems at all and I know of other Dax, GD etc which don’t have this issue. Surely there is a fundamental problem with the Sumo set-up