1971 MGB GT - Engine is now cranking over correctly - see page 17

9,945 · December 1

30 minutes ago, High Jetter said:

Hang on, you've got separate sidelights - why the pilot window in your headlamp?

No idea.

What purpose does the little round window serve?

9,945 · December 1

19 minutes ago, Zelandeth said:

The needle in the oil pressure gauge isn't just stuck on the broken bit of illumination diffuser is it?

As for the dash lighting, I'd be checking the rheostat first, they're usually scratchy as hell at the best of times, never mind if having not been used in years.

Can it be that simple? I haven’t noticed the rogue bit of the diffuser. I shall investigate tomorrow!

13,235 · December 1

19 minutes ago, Peter C said:

No idea.

What purpose does the little round window serve?

The window allows a sidelight bulb to be seen through the SBU, on cars without separate sidelights IIRC.

9,945 · December 1

1 minute ago, High Jetter said:

The window allows a sidelight bulb to be seen through the SBU, on cars without separate sidelights IIRC.

So I have the wrong headlamp?

I don’t think it matters, does it?

13,235 · December 1

2 minutes ago, Peter C said:

So I have the wrong headlamp?

I don’t think it matters, does it?

No, not really, but you don't need a window on your replacement SBU.

11,138 · December 1

Chuck the sbu s and buy a pair of halogen conversion units , upgrades to H4 bulb .. and see at night ... for just 30 quid. Domed glass or flat glass available on ebay..

25,894 · December 1

If you fancy getting shot of the sealed beam units these should fit straight in. These are the ones I recently fitted to the Trabant, though I know a version without the sidelight hole does exist.

They came complete with bulbs for less than a pair of branded H4 bulbs from Halfords!

11,138 · December 1

1 hour ago, Zelandeth said:

The needle in the oil pressure gauge isn't just stuck on the broken bit of illumination diffuser is it?

As for the dash lighting, I'd be checking the rheostat first, they're usually scratchy as hell at the best of times, never mind if having not been used in years.

Zel has the eyes of a hawk ! Great spot !

9,945 · December 1

@LightBulbFun wouldn’t approve of the headlight conversion.

18,971 · December 1

15 minutes ago, Peter C said:

@LightBulbFun wouldn’t approve of the headlight conversion.

its a shame that you cant really get Halogen sealed beam head lamps for car use over here as they combined the best of both worlds of Halogen technology and a fully sealed and precisely aligned reflector system, but sadly I am not sure how available they are here, (they are still a thing in the US where sealed beams remained for much longer, however even then some of the cheaper ones cheat, as halogen capsules, dont "need" to be gas tightly sealed, so they often glue on the lens rather then flame seal it, and then at that point its no longer really a sealed beam lamp!) proper quality halogen sealed beams given you the best of both worlds, of halogen performance and a fully sealed and aligned reflector system

however I will concede in cases like this, in this day and age if your using a car after dark a lot, then a H4 halogen upgrade is probably the way to go, just because sadly you cant really get high quality sealed beam lamps anymore

but I do feel like seal beam lamps get a an underserved bad rep, especially when people do modern day comparisons of an old worn out sealed beam incandescent lamp on old crusty 50 year wiring/connectors, vs a Modern Halogen unit often with different wattages (an old sealed beam is 45W/60W where as a Halogen H4 is 55W/60W)

lamp manufactures used to sell adapter kits so you could fit a sealed beam lamp in place of an Lucas 7 inch British Prefocused light unit, here is an excerpt from a 1975 Osram-GEC lamp catalog

but given the option if I had to service a car with 7 inch head lamps and could choose between a H4 unit or a proper name brand (Osram, Philips, Sylvania, GE, etc) Halogen Sealed beam lamp, i'd go for the latter for sure

25,894 · December 1

13 minutes ago, LightBulbFun said:

its a shame that you cant really get Halogen sealed beam head lamps for car use over here as they combined the best of both worlds of Halogen technology and a fully sealed and precisely aligned reflector system, but sadly I am not sure how available they are here, (they are still a thing in the US where sealed beams remained for much longer, however even then some of the cheaper ones cheat, as halogen capsules, dont "need" to be gas tightly sealed, so they often glue on the lens rather then flame seal it, and then at that point its no longer really a sealed beam lamp!) proper quality halogen sealed beams given you the best of both worlds, of halogen performance and a fully sealed and aligned reflector system

however I will concede in cases like this, in this day and age if your using a car after dark a lot, then a H4 halogen upgrade is probably the way to go, just because sadly you cant really get high quality sealed beam lamps anymore

but I do feel like seal beam lamps get a an underserved bad rep, especially when people do modern day comparisons of an old worn out sealed beam incandescent lamp on old crusty 50 year wiring/connectors, vs a Modern Halogen unit often with different wattages (an old sealed beam is 45W/60W where as a Halogen H4 is 55W/60W)

lamp manufactures used to sell adapter kits so you could fit a sealed beam lamp in place of an Lucas 7 inch British Prefocused light unit, here is an excerpt from a 1975 Osram-GEC lamp catalog

but given the option if I had to service a car with 7 inch head lamps and could choose between a H4 unit or a proper name brand (Osram, Philips, Sylvania, GE, etc) Halogen Sealed beam lamp, i'd go for the latter for sure

Does anyone even make a halogen sealed beam units with a beam pattern suitable for left hand traffic?

It's one of those areas like fuses where I tend to lean towards what is practical in the sense of being able to stop at any parts store if something dies while you're out and about rather than having to keep half a car's worth of spares on you.

No reason the original parts can't be kept with the car and reinstated by a future custodian if they so wish.

9,945 · December 1

For now I will opt for the cheapest solution, although I still haven’t ruled out replicating the look of I’s Jag.

4,393 · December 1

If you can get them I thoroughly recommend Cibie Z180s.

In my experience they are far superior to sealed beam units.

19,459 · December 1

The handiest thing about not using sealed beams is being able to keep spare bulbs in a reasonable amount of space.

25,894 · December 1

30 minutes ago, captain_70s said:

The handiest thing about not using sealed beams is being able to keep spare bulbs in a reasonable amount of space.

Being able to find bulbs readily at less than £30 apiece is a nice bonus as well!

December 2

14 hours ago, Peter C said:

No idea.

What purpose does the little round window serve?

sidelight for early (proper) mini ...

9,945 · December 2

@High Jetter Thank you for the heads up on the light units, I have ordered two from the MG Owners Club.

@Zelandeth You, sir, are the big winner today. Thank you for spotting something that was right in front of me!

I removed the bezel and glass from the front of the gauge, taped the offending plastic surround together and put it back where it belongs.

I had to use adhesive to secure the bezel back, hopefully it will stay on.

And the news is.....

We have a working oil pressure gauge!!!!

Whether the gauge is accurate is not for me to say but almost 70 lb / sq inch is a decent reading for a 93k mile B-series, admittedly that's cold with the choke out but hey, who's counting.

I will confirm what readings I am getting next time I drive the MGB.

December 2

Sounds like you have a very healthy engine there. I suspect regular oil changes and sympathetic driving style might have a lot to do with it.

9,945 · December 2

9 minutes ago, 2flags said:

Sounds like you have a very healthy engine there. I suspect regular oil changes and sympathetic driving style might have a lot to do with it.

No way of knowing how many of the previous ten owners have treated it well but I do know that the engine runs and pulls well, doesn’t leak any fluids, doesn’t overheat and now we know it has good oil pressure.

I just need to adjust the tappets and job done.

According to my research, the tappets should be set to 0.015 inch. However, as I only have a metric feeler gauge, I will set the gap to 0.35mm, which based on my calculations, is about right.

25,894 · December 2

So long as the gauge is showing "some" at idle when warm and it's not horribly rattly you should be fine.

Glad the gauge was a simple fix! Nice when a fault is relatively obvious like that rather than some in depth defect.

9,945 · December 2

11 minutes ago, Zelandeth said:

when a fault is relatively obvious

It wasn’t for me!

4,393 · December 2

1 hour ago, Peter C said:

@High Jetter Thank you for the heads up on the light units, I have ordered two from the MG Owners Club.

@Zelandeth You, sir, are the big winner today. Thank you for spotting something that was right in front of me!

I removed the bezel and glass from the front of the gauge, taped the offending plastic surround together and put it back where it belongs.

I had to use adhesive to secure the bezel back, hopefully it will stay on.

And the news is.....

We have a working oil pressure gauge!!!!

Whether the gauge is accurate is not for me to say but almost 70 lb / sq inch is a decent reading for a 93k mile B-series, admittedly that's cold with the choke out but hey, who's counting.

I will confirm what readings I am getting next time I drive the MGB.

That's very close to where my 64,000 mile engine sits.

11,138 · December 2

Those capillary pressure gauges are pretty accurate

9,945 · December 2

On 01/12/2024 at 17:04, Zelandeth said:

As for the dash lighting, I'd be checking the rheostat first

Can I by pass it? Just have the lighting on full blast?

25,894 · December 2

1 minute ago, Peter C said:

Can I by pass it? Just have the lighting on full blast?

Should be able to. If nothing else that's one way to prove the point of failure. At worst the lamps won't last quite as long.

12,781 · December 2

On 01/12/2024 at 15:29, Peter C said:

remeber we replaced these couple of the times on the series 3 landy, then binned for bulb'd units

9,945 · December 3

12 hours ago, stuboy said:

remeber we replaced these couple of the times on the series 3 landy, then binned for bulb'd units

Why?

Did they keep failing?

1,870 · December 3

14 hours ago, stuboy said:

remeber we replaced these couple of the times on the series 3 landy, then binned for bulb'd units

2nd hand?
They're supposed to be much more resilient than bulbs in bulbed units.

December 3

3 hours ago, Peter C said:

Why?

Did they keep failing?

... series 3 landy ... rough roads/tracks lots of 'jiggling' about ....

1,880 · December 3

I could swear a dog to a cat that these are the inertia seat belt mounts for the front seats?

Pete are you just being different or is it supposed to be like that?

1971 MGB GT - Engine is now cranking over correctly - see page 17

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