Help fixing my mates TR2

[turbo pete]

My friend is into classic cars. he ahs a TR2 which is currently overheating all the time.

He has just put a new unleaded head on it as he thought the previous head might be blocked. It still overheats.

We have taken the thermostat out and it still overheats.

We have replaced the fan belt and checked the pump is spinning. Even checked the top of the radiator to see that there is tell tales swirls caused by water flowing through it. So the pump must be pushing the water through.

checked the timing. it is fine.

Back flushed the rad and it was clean as a whistle.

What the hell could be causig it to overheat?

i reckon either a blocked rad or faulty new head.

Can't believe it is the head it is a new rebuild. and the rad surely would have had crud in it if it was blocked internally?

i don't know what to suggest to him.

Any ideas guys and gals.

cheers
turbo pete

[andyf]

Moving..

[Billy]

If I remember rightly the TR's rad was a bit marginal, so if it is partially blocked then that could be the problem. Clean flushing water only tells you that the clear tubes have nothing coming off them, but they may be coated in well anchored fur or oil that will impede the heat transfer. When the engine is hot, feel all over the rad for cold spots. There shouldn't be any.

If it's not the rad, then there may be a problem with the cylinder liner bottom seals (it's a wet liner engine, isn't it?) that would cause the same symptoms as a blowing head gasket, ie oil and water mixing, but won't blow bubbles in the cooling system, and won't cause overheating directly but will cause water loss which will make it overheat.

[Jon]

Most water hoses are double skinned. It's possible for the inside to collapse from age while looking OK outside. Will still allow some water to pass but not enough.
but, if removing thermostat had no effect, only the hoses between thermostat and radiator are possible culprits ?

Daft suggestion. The TR2 may have an engine driven rather than electric fan. Is it still there?

[turbo pete]

Thanks fellas
Forwarded suggestions for next round.
Cheers