size bolt

[Hans Efde]

Hi guys,
Can anyone advise me on the size of a specific bolt?
I need to fasten a heatshield to my engine, but the bolt has gone missing. So I tried my supply of bolts, but no one fits.
There are 2 bolt holes in the RH side of the engine just above the clutch housing. They are near 2 freeze plugs. They look like M8, but an M8 does not fit. I have a few English size bolts, but they did not fit either. Can it be a UNF thread? Monday I am going to a boat builder nearby who seems to have a stock of imperial size bolts, so if anyone can shed a bit of light on the size of the required bolt that would be great.
Cheers, Hans

[manifold]

if its the ones Im thinking of....they are probably 5/16ths UNF.

Usually its UNF for cast iron and UNC (or course whitworth) for cast alloy.

I think they are used as mounts for the stabilizer bar on the mini setups.

Cheers,

David

[Hans Efde]

Thanks David, it's in the cast iron block so must be 5/16 UNF. I have to say these imperial size bolts drive me nuts.

[Rich]

This is where the engine stabiliser bar bolts in when fitted to a Mini isn't it?

Rich

[Geoff Butcher]

Yes, I had to ask this myself recently - they're 5/16" UNF

[Hans Efde]

I'll buy a few tomorrow, the front hole in the engine block looks like a good victim for a new place for the coil bracket. Mine is hanging on the front left headbolt, which seems to be the standard place. I don't like the position because it blocks maintenance to the oil related accessories.
I had a go this afternoon in my car with the new 3.1 diff. I am a bit disappointed because the car is still making too many revs on the highway. Although I found out the car is quicker than the speedometer, by calibrating it with the hectometer poles at the side of the road. It turned out 100 km/h is really 112,5 km/h! Oops. Explain that to an officer of the law. I also had tested the car at 130km/h with my son writing down the data, convertible style of course. So that was 146 km/h. I already thought it was getting a bit windy inside
With the 175/50R13 tyres which have a circumference of 1,545 m for 120 km/h cruising speed the engine revs 4000 rpm (4000/3.1x1.545=1993,5 meters/min /60 = 33,23 m/sec x 3.6 = 119,6 km/h). I recall my first Gold coupe driving much more relaxed with 3000 - 3500 rpm at 120 km/h. But I suppose the speedometer was overdoing it a bit and the tyres were bigger (165/60R13 with a circumference of 1,61m).

The next time the engine goes out I'll put a 2.9 in. I should have done the maths before I ordered the diff!

[manifold]

..... get an ETB dash Hans . The setup asks you for the gears (optionally up to 6) and final drive ratios, to work out your speed, relative to revs. Then its dead accurate. I know this as I can compare it to the GPS speed sensor built in....and my TomTom.

Using a metro dash requires knowing the correct ratio plastic gears to use in the gearbox realtive to final drive, relative to dash.

[manifold]

correction about UNF/UNC and usage.

All correct except head studs/nuts, which use UNC thread into block and UNF on the nuts.

The 2 extra studs (for 11 stud head fixings) are 5/16 UNC too.

I know what you mean about the Metro imperial/metric mix. It was a bit of a metric cross over point on the Metro. The front hubs being one good example. Metric on Metro, Imperial on Mini.

Cheers,

David