I am thinking about purchasing a 1979 Mini with a brand new rebuilt 1380 engine. The engine has only 1500 miles on it since the rebuild. It looks like a good deal. Someone told me, however, that the 1380 engines have a periennial problem with overheating. I live in the hot west with hills and mountains all around. Do any of you have experience with the 1380 engine? Does this engine have a tendency to overheat? Thanks for your help.

 

As we build at least one of the 1380 version almost every week, we do have a little history with them. The 13800c engine has no less of a tendency to run hot than any 1275cc Classic Mini motor. The 1380 is simply an over-bored 1275cc. The base unit runs on the warm side if normal maintenance and common sense are not used. Mixture must be set correctly, ignition timing is important with no more than 30 degrees advance at 3,500 RPM, should use a 160 degree thermostat and strongly suggest the use a modern capacity radiator. The latest aluminum radiators do an excellent job.

 

I have a 1380 and have been battling that issue for years.....before anyone asks, I had the distributor re-curved for the lump, timing is spot on, put a fan on it pulling hot air out of compartment, wrapped headers in header wrap, have an aluminum radiator, improved water pump and re-plumbed heater by-pass to top of radiator and yes, the fan is on correctly....still ran hot on hot days here in New England. What fixed it? Putting a smaller water pump pulley on it!
Now, on a hot humid New England summer day it runs about 185-190...on a normal day it runs about 180. Running a BCE needle with the HIF44 carb.
Let me know if you'd like pics....

 

Thanks Don. This is great information. I don't know if I'll have this problem or not but I would like to see the pictures, Ronnoco, just in case I do. Thanks.

 

check and see if you have the correct thermostat fitted..............I have never had an overheating problem with My 1380 and I have driven it for 3hrs at 70-90 mph solid on the M5 in the UK

 

I had a similar issue with my 1330 but it turned out that deleting the heater core (I assume that's what you did) made a HUGE difference in the cooling efficiency since it reduced the coolant volume about about 25-30%. After an Arizona summer of really worrying about my engine I retrofitted an aluminum heater core in the engine bay with a small electronically controlled pusher fan ... the core mounts between the heater bypass and the hot side of the radiator. That was the solution for me.

Interesting ... I haven't heard of anyone running a smaller pulley to solve that problem but that makes sense. Did you come up with idea or did you get that suggestion from someone?

Jeff

 

My issue was that the coolant temp would rise when I was at stop lights in stop/go traffic and didn't rise when running at speed where air was being forced through the radiator.

How hot was the ambient temp when you were running on the M5?

Jeff

 

The idea for a smaller pulley came from a friend who had a boat that was overheating and he fixed it by a smaller pulley on his boat's water pump. Since I had thrown everything else at my problem what is a $12.00 pulley?
Truth be known...it now probably runs too cool in the New England fall! I have no heater and don't drive it in the winter so the h--- with it. Works during my driving season....you throw enough time and money at a problem and sooner or later something has to stick. By the way, I have more time than money.
Ronnoco