Stupid questions about motorised conveyances

[Eddie Honda]

Let the garage buy the calliper if needs one. It's all tax-deductible.

[paulplom]

I went to the factors and got the discs to match the borg and beck pads I bought the other week. They keep the callipers in stock anyway and it's just around the corner from the garage which itself is about 3/4 of a mile from the house.
They were recommended by two other garages so I'm hoping they're decent.

[SubPar]

Folk with experience of carbs, points, etc. I have need of your help.

I've been helping with a series Land Rover. It has an erratic misfire on tickover (erratic as in not on every revolution of the engine), plus it backfires through the carb under load on more than about half throttle.
It's running on E5 with no other additives (head is unleaded compatible).

What needs adjustment? We've already retarded the timing a bit to get it to this point, and it was running nicely for a while before doing this.

It also won't stay in high range, but that may be due to it having no floor at the moment, so it's lacking various springs etc on those levers...

[Jerzy Woking]

Why do head gaskets fail?

What can be done to prevent this happening?

[DodgeRover]

Folk with experience of carbs, points, etc. I have need of your help.

I've been helping with a series Land Rover. It has an erratic misfire on tickover (erratic as in not on every revolution of the engine), plus it backfires through the carb under load on more than about half throttle.
It's running on E5 with no other additives (head is unleaded compatible).

What needs adjustment? We've already retarded the timing a bit to get it to this point, and it was running nicely for a while before doing this.

It also won't stay in high range, but that may be due to it having no floor at the moment, so it's lacking various springs etc on those levers...

Have you checked valve clearances?

[Hooli]

Why do head gaskets fail?

What can be done to prevent this happening?

Depends on the engine as much as anything.

The K series that's famous for it is because steel bolts go through an alloy block. So because the block expands more than the bolts it's not clamped as right went cold and that's when they tend to pop.

[Jerzy Woking]

Thanks. Always wondered about the K series. So swapping steel for alloy bolts would stop that?

[Scruffy Bodger]

Thanks. Always wondered about the K series. So swapping steel for alloy bolts would stop that?

In your neck of the woods and Portugal from what I know it's much less of a problem if at all because the temps differential Hooli mentions simply don't happen? Weren't plastic dowels or something fucking stupid a problem too? K series stuff is very well documented now if you look. IIRC they finally fixed the issues with the Freeloader?

I've seen loads of old Rovers tootling round happily on the Algarve the last couple of years.

On old Pugs head gasket failure seemed to be a combination of earlier technology/cost at time of manufacture as well as poor maintenance. If the radiator rots, springs a leak and it cooks, you'll warp the head and the gasket fails, iron block, ally head, it's going to happen. If you don't put the right coolant in with anti corrosion inhibitors for years things rot, equals head gasket failure.

The other one is winding boost up, the inevitable happens with the original gaskets. https://en.wikipedia.org/wiki/Head_gask ... 0elastomer. MLS gaskets make that issue go away as superior technology. Tom's car was running circa 3 times standard power in the end and head gaskets weren't an issue.

[Hooli]

Thanks. Always wondered about the K series. So swapping steel for alloy bolts would stop that?

I don't think they'd be strong enough without a redesigned block to allow for much thicker bolts.

The plastic dowels mentioned were an issue too. They were to locate the head laterally, probably for when the bolts didn't clamp it right as you don't see that on other engines I've touched.

IIRC the LR kit to fix it was a relocated thermostat housing to remove hotspots, a bigger 'ladder plate' the steel plate that went under the block, around bigend height & the head bolts screwed into it. I think there was different bolts & steel dowels to replace the plastic ones as well.

[Scruffy Bodger]

All of that rings a bell ^