Cylinder head blanking
Turbo Mini Forums

Is there any advantage to having the heater tap take off on the cylinder head blanked or not blanked and used to drain into the bottom hose? I have no heater so no need for it really, unless its advisable to let water pass through it?

Some people say to do it, but in my mind it allows water to bypass the radiator. Personally I have blanked it.

You need to drain it into the top hose unless you route it through a heater matrix First. I'd do it.

Top hose? Surely it would need to drain into the bottom hose? I.e connecting where the other heater pipe would go? Therefore creating that circuit minus the heater?

No.

Agree with Vegard, route it back to the top hose to stop hotspots around no4

I seriously doubt it!

Ok sounds good, thanks guys. I currently have fittes the later metro thermostat housing with the outlet on the side, can i use this to attached the pipe from the heater side?

there is nothing wrong with a A-series that a turbo can't fix.

www.turbomini.nl

I've used this.

http://www.minispares.com/product/Classic/...k%20to%20search

That's what you mean? If so, perfect :)

I have the thermostat housing without the sandwich plate. This has a 8/10mm outlet to go to the header tank (if fitted). Can this be used instead?

I do believe the pipe should be routed back into the bottom hose and here is why. The metro uses a sandwich plate which allows the water pump to pump water through the block up through the head to the underside of the thermostat out through the sandwich plate to the heater matrix and inlet manifold if memory serves creating a bypass and continual water flow around the block and head until the thermostat opening temp is reached and the radiator is brought into the circuit.

If you are running the "A" plus head and water pump with the "A" series thermostat housing you have no bypass and no flow of water around the head and block so the only way for the water under the thermostat to get hot is through heat soak (unless you have drilled a series of holes in the thermostat). With the A series setup there is a narrow water way cast into the head under or above the main water jacket where the water to the bypass hose exits right under the thermostat, thus achieving continuos water flow around the head and block.

Therefore in order to achieve bypass if you are not using a sandwich plate but are using an A+ head in my mind you have to tap the water from the heater take of point and run it back into the radiator bottom hose. Ideally you would want to tap the water from under the thermostat.

Own the day

Ok, really confused now. To confirm; i am not using the metro thermostat sandwich plate, i can use either the metro or standard mini thermo housing as i have both in my spares box! I have no heater matrix fitted. I am using the minispares late type 'no bypass' water pump. I have a 74 degree stat with a few small holes drilled in it.

Either option for me is easy to do. I would prefer just to blank the feckin thing but i dont want this being detrimental to my engine!

From memory you are correct, the normal a series head has a slot under the thermostat, my head now doesnt as it does not have the horrible 'bypass' hose under the head.

I hope this helps, it seem different people do different things?!

You have the holes drilled in the thermostat plate to let the water circulate so there should be no problem.

Own the day

Thanks but im still unclear if that means, blank it? Or run the heater outlet to the bottom hose? Sorry to keep repeating!

Some have already given you the right pointers, but I can understand why you're confused with others stating the exact opposite....

Opening the heater tap outlet will help coolant flow around the no.4 combustion chamber. As you know with a closed tap, and without drydecking, no.4 has less then optimal flow compared to the other cylinders. This can cause some nasty effects (overheating, knock) whilst the other cylinders are still fine.

Ok, so opening the tap helps flow. This additional flow is only useful if it is able to take away heat from the engine, not reintroduce it at a later stage. This means the flow from this point should pass some form of radiator before it is reintroduced into the engine. For this you have two options:

1. Run the flow through an auxiliary radiator before you reintroduce it into the BOTTOM radiator hose. The standard heater can be seen just like this, an auxiliary radiator....which just happens to heat your interior in the process.

2. Run the flow directly through the main radiator, meaning a connection to the TOP radiator hose or thermostat housing.

Thanks for clearing that up evoderby. I will make a connection to my thermostat housing and connect the heater tap oulet to this. Thanks.

EVODerby exactly right.....