Outer Limits 4x4 Board

swapped out my twin carbie setup for a 350 holley on the weekend and now the rover overheats bigtime! a few heater hoses didnt line up due to the manifold being slightly different but i managed to make some up. but now the gauge goes all the way up to H for hot and will never sit below half. its weird because whilst driving, it will stay under H but when i stop it goes over then as i start to move again it drops slightly. also when its cold and i fill the radiator up with coolant to the top and run the engine it spits out nearly 6 litres of coolant out the overflow hose.

Has anyone had any overheating issues related to carbie swaps? or is there a problem with swaping a later model intake manifold with one of an earlier year i.e 1978 to 1981?

ill take some photos tomorrow and post up.

It wont be the carb swap as such but more like something you did during the swap, i swapped twins for a modified stock manifold with 350 holley and never had any cooling issues.

Done lots of those types of swaps , except I use a 38MM DGMS weber , 10 times better than the Holley , but never seen a overheating problem . Check your thermostat , ensure the bleed hole hole is in the right position , fit a Holden 165F stat , is it still running the preheat /choke heat circuit ? Also check your spark timing isnt retarded .LAst thing is whether your cavitated the back out of the timing case , which is the front of the water pump ,

Its got no thermostat in it. ive disconnected the old choke coolant line as my new modified manifold (for the holley) does not have an inlet for it.

could it be an issue of having the heater lines the wrong way round? also i noticed that the right hand smaller hose coming out the back of the water pump now goes straight into the bottom of the thermostat housingas thats the only inlet there is. on the old manifold it goes into a separate inlet that more off to the right of the manifold and not part of the removable thermo housing.

The only thing i touched during the swap was the intake manifold itself so it cant be anything to do with the electrics or fan or anything thing because it was running fine before the swap.

G`day , could be that

if it`s spitting the 6ltrs from cold as in it happens shortly after starting , it`s telling you you have an air lock .

An air pocket is getting hot the coolant is turning to steam/vapour and because of this very hot pocket is spitting the coolant , you can probably hear odd noises as well .

If it was ok before the swap , it sounds as if there is something wrong in the way it is plumbed ( coolant conections ) or maybe it has pipe work etc above the height of the top tank (radiator )

Any V8 Rover manifold will work if fitted right your pics may tell more .

Cheers
Peter

ive just changed my dizzy to hei and had same problem apart from chucking out 6 ltrs off water .i put new radaitor in and solved my problem. could be one reason.or you have put wrong wire on to thermastate housing, but sounds more like just bad air lock .remove top radaitor hose and fill motor up with water with radaitor top plug out .untill over flowing and reconnect hose and plug. then top header tank up start motor up

What sort of manifold is it?

If it is a cut down standard manifold it may be that it is the highest point in the engine and it has an airlock up under the carb.

The standard manifold has a bleed line to the radiator in the centre and if it blocks then you get an airlock and overheating.

I do not think the heater lines will have anything to do with it.

If the manifold is a home done modded one maybe drill a hole in it and screw in a nipple and hose to the RH rad tank where there should be a nipple.
Also when filling it point as steeply up hill as you can when you fill it.

Regard sPhilip A