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TR4/4A TR4A overheating issue

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gubba

gubba

Senior Member
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Hi gang.. just got back from ATDI Penticton and I have a question. On the way there I had a terrible pinging going up hill. So I retarded the timing. The pinging was almost gone. On the way home the engine was overheating a little bit ( temp gage always in the middle.. but had risen to 3/4 up ) and the weather was cool. My question is would too lean of a fuel mixture cause this problem with the timing being retarded? TIA
 
Mixture too lean can sure make it run hot. And running hot will increase the tendency to ping (although my opinion, the timing should not allow pinging even if the engine is slightly overheated and working up a hill).

Late timing can also increase the tendency to overheat (lower efficiency means more heat generated for the same power output).
 
I am blessed with two TR4As. One never gets hot; the other overheats at any summer stop light. I've never been able to tell what the difference is between timing settings, mixture, etc. I do both the same way. Frankly, I'm ready for a new radiator on the one.
 
KVH said:
Frankly, I'm ready for a new radiator on the one.
Click to expand...
Very possibly the right answer. I've been through that twice now, once with my previous TR3A and then again with the current TR3. Nothing obviously wrong with the radiator either time; in fact this last time I took it to the radiator shop and they pronounced it "fine". (I made the mistake of asking them to do "whatever it needed".) But the third (or was it 4th) time I took it back, I told the manager specifically that I wanted it rodded and boiled. When they went to rod it out, they couldn't get the rods through the tubes! Apparently, none of the tubes were totally blocked, but they all had enough "mud" coating the inside to block the transfer of heat. Anyway, a new core made all my overheating problems disappear.

The first radiator was still the original type core design, where the fins run more or less straight across and the tubes go through holes in the fins. With it, apparently the tubes were no longer in good thermal contact with the fins, so even rodding it out did not show the problem. But again, a new core made all the problems disappear. The difference with it was really dramatic, I went from having the gauge climb slowly at freeway speeds even at 70F to staying cool even at 115F.

Of course there were a lot of other little improvements made along the way, trying to solve the problem, which I didn't bother to undo later. But the new core was clearly the right fix.
 
Its not really hot anywhere in the UK but we get quite a lot of guys with overheating on 4/4As.
We mess around with timing and mixture and water-pumps of course.

But often it turns out that sediment has built up around the wet-liners
A symptom is that you can remove the block-drain-tap and nothing comes out.

Much of our water supply here has high hardness because of extraction from wells in chalk. Maybe this is why.

Anyway, if all else fails investigate water circulation in the block.
Although its a bit of work, removing the liners and then the sediment is quite straightfoward.
 
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