22 replies to this topic

[MiniMadRacer]

 

 

 

In my experience Mini (A series) head gaskets rarely fail unless a few things have come in to play...

 

1) Poorly fitting in the first place, this includes cheap gaskets, incorrectly torqued head nuts, warped head inferior bolts etc etc

2) Abused in use, ie run with inadequate cooling ending in a massive over heated engine.

 

Assuming none of the above, how long has the engine been running without any issues.

 

Though those readings are low, I would suspect other issues, like total lack of maintenance, including the ignition system, but of course I am guessing

 

You say the readings are low.  What would you expect?

There's further info in my reply below.

Thanks for sharing your knowledge and experience.

 

 Peter
 

 

I like to see around 160 PSI, but this come with a good few caveats, not necessarily a complete list

 

1) Mileage

2) Throttle held wide open

3) Fully charged battery

4) All plugs removed

5) Engine hot and oil up to temperature

6) CAM dependent (Sportier CAMS will give lower PSI reading at cranking speeds)

7) Healthy starter motor

 

 

He's done very few mils since the (re)build, we only turned it over until we got a reading on each cylinder, the battery is good/new, each cylinder was tested, one at a time, the engine was cool, he has a high lift cam and a Janspeed stage 3 head, hence the likely lower than expected readings?

 

Peter 

 

If its very low mileage, back in the day "BMC" / "British Leyland" recommended a running in period of between 500 and 1000 miles. If this has not been done maybe the pistons rings have not fully bedded in yet

[Peter_NottinghamS]

A quick update on this post.

I carried some of the work over the weekend and I'm 90+% sure it's not the head gasket: no pressure build up in the radiator, no bubbles, no milkiness in the coolant or in the oil.

 

Compression seems okay-ish and I've convinced myself it's the carb and failed choke O ring as suggested above.

I didn't get as much done as I wanted as I have arthritis in my hands and the cold and wet weather at the weekend was not good 'arthritis weather', so there's a little more to do.

 

My plan is to send the carb to AC Dodd but whether I can get it running will determine when.  I've been suspicious of the carb since we got Marvin as the dash pot securing screws are burred indicating to me that the wrong size screwdriver has been used to over-tighten them. 

 

I really appreciate the help, comments and post of support.

 

This is fun.

 

Peter 

[andyapanel]

Is the manifold gasket healthy?

[Peter_NottinghamS]

Is the manifold gasket healthy?

 

Looks okay but I'll add it to the list to check anyway.

 

Thanks, Peter

[andyapanel]

Good luck

[kevin12]

It could be head gasket. I've faced that kind of trouble. So I made up my mind to change my hed gasket fixing by following the instruictions. 

[mini-mad-mark]

 

1. Get the horn to work. The one it came with stopped working and I cannot find the second wire to fit to the new one.
2. Brakes: they are awful and pull violently to the left under emergency braking.  No servo; do I need one

Bit of input

 

1 Later minis there IS only one wire to the horn  - a 12v feed and then it earths through the body of the horn (if a standard Rover horn) - many after market horns have two terminals, one live, one earth, so just run a short wire from the earth to the mounting bracket (or source a horn that earths through the body of the horn)  Early minis (Mk 1 only I believe) had two wires; live to the horn and earth from the horn to the push button in the centre of the column

 

2 Servo assists pedal pressure, doesn't improve the brakes themselves - you don't say what brake set up you have.  

My personal experience (but others may have different)

- 7.5 discs a servo does make the brakes feel nicer - they work fine without but it just makes them feel nicer (IMHO)

- 8.4 discs no servo required and doesn't appear to make them feel any better (to me)

- Drums - I had a servo on my first drum braked mini - would stand on its nose but they were very sharp - I used to adjust them once a month or less and have new shoes at least twice a year  (maybe I drove harder then!) 

- My latest mini has 4 piston alloy callipers and from what I read I have no servo as I believe they will give good brakes with the correct pads for my intended use (project nearing completion so not tried them yet so not personal experience

[Lplus]

Personally, I think the 7.5" discs should have a servo.  Yes they do work with sufficient pedal force, but BMC didn't fit the cooper S with a servo out of the goodness of their hearts.  Even with alloy 4 pots a servo does help.  Yes, I have both setups.