as the title says can a over heated motor thats just been rebuilt cause a glazed bore? also i had a topic last week about my car being really hard to start i worked that problem out it was a blown head gasket. just someone told me that cause i overheated my motor its most probably glazed it? im not a mechanic so what does some more experienced peeps say

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1964 smooth roof panel van
1967 Mk 1 X-Police cooper s
1970 mini k
1975 leyland

I am not a mechanic either....however, unless you cooked the hell out of it I would be surprised. The rings could lose their tension if it got hot enough which may cause it to blow smoke, lose compression and glaze the bores etc... However, I have seen some mini's get really hot and recover ok.

ok thanks a lot manaco. seems to be blowing smoke..... i think blue brother thinks white bit hard to tell only does it when i pull up at intersection and put the accelerator down and take off or rev it if its idling it blows a puff of smoke but then it seems to be fine when im driving. i have a cooper s motor in it i have a facet fuel pump just went down to repco and bought one the one they gave me.....fuel is basically wound all the way up so very little fuel getting to it splutters a little round a corner i take it from the starvation of fuel.

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1964 smooth roof panel van
1967 Mk 1 X-Police cooper s
1970 mini k
1975 leyland

hi

fuel pump should be fine. - little facet electric cube? - only needs less thn 3 psi pressure in fuel line and volume should not be an issue. Sputtering could still be fuel related - check fuel filter(s) - the little prefilter in front of pump. Sometimes the float needle doesn't allow fuel to flow if going round a corner - you may have to adjust the float level ( presuming an SU carb

hopefully your new head gasket is all good... Again just be sure you have addressed what was causing the overheating - the blown headgasket could be it, or it could be a symptom, so check radiator temps etc Cheers

cars not overheating any more i bought a manual guage, one that takes the actual temp of guage it hangs aroun mid 80s thats it. just the smoke that concerns me now..... i thought the smoke may have been fuel so thats why i backed the fuel off and thats when the spluttering started..... so that i think is def fuel related. just the smoke is worrying me

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1964 smooth roof panel van
1967 Mk 1 X-Police cooper s
1970 mini k
1975 leyland

VERY bad over heating can de-temper the rings. They lose their springiness and hence ability to seal..

Compression test???

Cheers, Ian

what should the compression be?

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1964 smooth roof panel van
1967 Mk 1 X-Police cooper s
1970 mini k
1975 leyland

Did a compression test on my mini cold and it doesn't look good I don't think..... Are they Spose to be all the same ? The readings were 4- 115 3- 95 2- 108  1- 135

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1964 smooth roof panel van
1967 Mk 1 X-Police cooper s
1970 mini k
1975 leyland

Compression test is usual done with a warm engine.

Cheers Shane

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If it's not a Cooper S, the mini was designed to be modified!

Compression test done with a warmer engine and very similar results
1- 125. 2-110. 3- 83. 4-115. I reckon I'm up for bother set of rings........

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1964 smooth roof panel van
1967 Mk 1 X-Police cooper s
1970 mini k
1975 leyland

Compression of each cylinder looks a bit low

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1969 Cooper "S"
1967 Mini Deluxe
1973 Clubman Van (the fleet spare)
1978 ex 1275 LS ("Wizard" Eaton Supercharged)
2015 HSV GenF GTS(occasional drive & tow car)
2019 MINI F55 Cooper S

You mentioned earlier the engine has been rebuilt recently, can I ask who "ran" the motor in?

If the motor wasn't "ran" in properly, the bores may have glazed up from the engine not being loaded up, so to speak. I did this in my younger years, I was too gentle running the engine in and glazed the bores. Engine needed pulling down and a re ring!

Have you removed the rocker cover and checked that the valves are closing fully closing and not staying open?

Cheers Shane

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If it's not a Cooper S, the mini was designed to be modified!

yea im a young fella myself.....it was rebuilt recently i drove it for a 20 minute drive when i got to my destination it was cooking because my temperature guage was not reading correctly..... i have an electric smiths guage didnt realise i was over heating it, then it was boiling when i got there. water all spilling out. so i pulled the radiator out and cleaned it with watered down phosphoric acid and leaks everywhere a mate said it would have been all blocked up so i put my alloy radiator in and bought a mechanical guasge so temp is fine now just blows blue smoke and compression is low.....

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1964 smooth roof panel van
1967 Mk 1 X-Police cooper s
1970 mini k
1975 leyland

He overheated it in the "running in" phase

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Number 3 looks low, outside the reasonable limit. Number 3 is usually the one that dies first. Can't really say what the compression gauge should read as it varies between gauges (quality). As a general guide you would want it to be around 150psi.