Melty Melty Alternator Wiring Loom - Perkins Engine

Working under the hood yesterday, I made this rather worrying discovery!
I've disconnected the battery and probably won't use the Defender much until i fix this problem. but i'm more worried about how it happened! could it be heat from the exhaust? anybody got any ideas? there's a perkins engine under there but i have no idea on model!

https://lh3.googleusercontent.com/bCgKBAIFoUF2icKYCCH-BMnGk_bxpFxMpHHGrXeefW-rSihgKIF0qHTLMjFPkt0PZXZ8byxwJmluA3AkVKvrLJQOydG-w_gqxU02NbL4r5kITzSKPRz2c99NhIrUy4INWL3c4e45nBBFf****Wuc03FTOqMx_zz-myySt4zOFxjGNDIIRiAdaWBjvPI5_kniMGVng-3uDW03s9wBHbxzf5xvuMvI4z8IM8vwWsN-zffLkyQFuFUlhEHLOV_YVE0dK3cqiIHdT2KyEmO0FIJXd06NbfdOpLe735VZiQE1VLJ7U13zzIN9az4J4jDLhQzsjXxCJjEsW8k061IdesEyTUIkUKTiA4XWsmByPVyHJBaIl-WzSQ3EgGQJoXuzxpX4yM5tfoD1OKhoJaeZ-oreqO6fu5JJMpldua5dA6D2o8c9izFxRh1l66rgq7emdFmK9eluNYSgN8NAtDyBbZ_fICzo8fiYTd3BW_LvLeJHRB-MyHPnRrWBk3MlwfAn1R8ck577shQymfk0UVz8-69BKZ86AR07XxxQ3ijm7nUomANpY5hUvr6lT7zCbcfyQWkT-OcQEwbj-GRFXxBV-TlgrP9YmXKeeQsqEaGTQ5TLE7rOrQ9QK8wpmhxSVkv36_wCX4CrfTihbchGiw783T_c0WC7YRXypVA5KYRvuJk4nW4ksi8UjMf8J_uA89afqgJ2uuE0iwwcuIegBnn1OhI=w432-h767-no

luk3jay said:

Working under the hood yesterday, I made this rather worrying discovery!
I've disconnected the battery and probably won't use the Defender much until i fix this problem. but i'm more worried about how it happened! could it be heat from the exhaust? anybody got any ideas? there's a perkins engine under there but i have no idea on model!

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It looks like a Perkins Prima engine. When you have sorted the wiring, you need to make a heat shield to protect the wires from the heat of the exhaust system. Not too difficult, you just need a sheet of alloy, and to make some little brackets to support it.
Also, if it was me, I would get rid of that silly little air filter, and fit an intake hose and a proper air box, both should be available from a scrapyard.

Turboman said:

It looks like a Perkins Prima engine. When you have sorted the wiring, you need to make a heat shield to protect the wires from the heat of the exhaust system. Not too difficult, you just need a sheet of alloy, and to make some little brackets to support it.
Also, if it was me, I would get rid of that silly little air filter, and fit an intake hose and a proper air box, both should be available from a scrapyard.

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Thanks, so you reckon it's melted from the heat rather than a more serious problem? That's what i was hoping as well tbh as it's only melted there, nowhere else!
intake hose and proper air box is a good idea! will that improve performance?

luk3jay said:

Thanks, so you reckon it's melted from the heat rather than a more serious problem? That's what i was hoping as well tbh as it's only melted there, nowhere else!
intake hose and proper air box is a good idea! will that improve performance?

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Not much, but it will protect the engine from contamination entering via the intake. Just looking at your other thread. I don't think that is a 4 litre engine.
I could be wrong about it being a Prima. I don't think it is a 4/203, they had the injectors mounted vertically in the head. It could be a 4/236, that would be about 4 litre.
There will be an engine number on a flat on the cylinder block, you need to find and record this, so you can order parts if needed, Perkins are still in business.
The numbers refer to the number of cylinders, 4, and the cubic capacity in inches, 203 or 246. Perkins never used cc on those engines, you can do the conversions yourself if you are bothered.

I am going to try and call up @freelance to assist with confirming the engine, he knows about this stuff.

luk3jay said:

Thanks, so you reckon it's melted from the heat rather than a more serious problem? That's what i was hoping as well tbh as it's only melted there, nowhere else!
intake hose and proper air box is a good idea! will that improve performance?

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BTW, if you want to improve performance, you need to raise the gearings. These engines have lots of power, but are very low revving, so road speeds will be low on standard gearing.

Turboman said:

BTW, if you want to improve performance, you need to raise the gearings. These engines have lots of power, but are very low revving, so road speeds will be low on standard gearing.

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Thanks, this is what i've been thinking! Do you know the best way to do this? i thought about swapping the gearbox, or the high/low range box, but i've heard the best way is to swap the Diffs with discovery ones?? Thanks!

luk3jay said:

so you reckon it's melted from the heat rather than a more serious problem?

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It looks to me like very localised heat damage from the outside rather than from the inside. Damage from overheated cable conductors would be more extensive and you would see burnt rather than clean copper conductors. Can you see what hot item it was touching?

Wimblowdriver said:

It looks to me like very localised heat damage from the outside rather than from the inside. Damage from overheated cable conductors would be more extensive and you would see burnt rather than clean copper conductors. Can you see what hot item it was touching?

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That's what i was thinking! Which puts my mind at ease at least

luk3jay said:

Thanks, this is what i've been thinking! Do you know the best way to do this? i thought about swapping the gearbox, or the high/low range box, but i've heard the best way is to swap the Diffs with discovery ones?? Thanks!

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Higher ratio transfer box, or higher ratio diffs, are the way to go. Look around, and see what you can find at a reasonable price.

And be careful when you are pulling away, these engines produce huge torque, and can snap or twist halfshafts with ease.

Turboman said:

Higher ratio transfer box, or higher ratio diffs, are the way to go. Look around, and see what you can find at a reasonable price.

And be careful when you are pulling away, these engines produce huge torque, and can snap or twist halfshafts with ease.

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Thanks! are all landrover parts interchangable? or do i need to look for specific types? / look at refabricating mounts? I'm new to the mods side of things!

Thanks,

luk3jay said:

Thanks! are all landrover parts interchangable? or do i need to look for specific types? / look at refabricating mounts? I'm new to the mods side of things!

Thanks,

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Not all, but a lot of transmission parts can be interchanged between vehicles, sometimes with a few light mods. Disco Diffs should be a simple swap into your axles.

Turboman said:

Not all, but a lot of transmission parts can be interchanged between vehicles, sometimes with a few light mods. Disco Diffs should be a simple swap into your axles.

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I thought disco diffs are the same ratio wise to 90/110?
Transfer box off a disco is what is needed Shirley.

Flossie said:

I thought disco diffs are the same ratio wise to 90/110?
Transfer box off a disco is what is needed Shirley.

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I think the diffs are higher ratio too, not certain, as I suggested earlier, the transfer box would also be an option.

The diffs may also require different half shafts and drive members, early Ninety and One Tens had less splines, IIRC.

Milner conversion, so is it perhaps the 4.212?

it does look like a 4.236 so do be careful with the torque! I found this which should help identify the engine https://www.powerlinecomponents.com/literature/perkins/per_number_guide.htm

adrian hogg said:

it does look like a 4.236 so do be careful with the torque! I found this which should help identify the engine https://www.powerlinecomponents.com/literature/perkins/per_number_guide.htm

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Knew I had seen that before, but my internet skills weren't up to finding it. All he needs to do now is find the engine number.

Discovery and 110 diffs are the same ratio, 3.5:1.
Discovery diffs will NOT fit a 110's rear axle as the 110 has a Salisbury rear axle.
You need to establish what ratio you have in your transfer box at the moment, if yours started life as a 2.5n/a it may still have the 1.6:1 ratio, which will make it slow no matter what engine is fitted.
Discovery transfer boxes have higher ratios, the V8 and V8 Autos I think have the tallest, but you would be wise to check if your engine will pull the higher ratios.
I suspect that it will, but someone will know for certain.

As for your burnt wire, there appears to be a new-ish "P" clip holding it down in your picture. assuming that you haven't fitted it, this may have been fitted to keep the wire away from the exhaust or similar and the problem may already have been fixed.

Rougharse Racing said:

Discovery and 110 diffs are the same ratio, 3.5:1.
Discovery diffs will NOT fit a 110's rear axle as the 110 has a Salisbury rear axle.
You need to establish what ratio you have in your transfer box at the moment, if yours started life as a 2.5n/a it may still have the 1.6:1 ratio, which will make it slow no matter what engine is fitted.
Discovery transfer boxes have higher ratios, the V8 and V8 Autos I think have the tallest, but you would be wise to check if your engine will pull the higher ratios.
I suspect that it will, but someone will know for certain.

As for your burnt wire, there appears to be a new-ish "P" clip holding it down in your picture. assuming that you haven't fitted it, this may have been fitted to keep the wire away from the exhaust or similar and the problem may already have been fixed.

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Any of the Perkins engines will pull any ratios, and pull tree stumps out if the ground while doing it!
A 4/203 produces about the same torque as a V8 petrol landrover engine, and the bigger engines produce substantially more.
The problem tends to be the effect that the torque has on the half shafts, and other transmission components.

Once you have identified engine model have a chat with Ashcroft Transmissions they do lots of gear sets with different ratios About 300 quid a set though.

Turboman said:

The problem tends to be the effect that the torque has on the half shafts, and other transmission components.

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So they're a bit too powerful for the drivetrain then? is it fine if i'm aware and careful?

adrian hogg said:

Once you have identified engine model have a chat with Ashcroft Transmissions they do lots of gear sets with different ratios About 300 quid a set though.

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300 squid is worth it for a decent performance increase! I'll give them a shout when i ID the engine, Thanks!