Amazon: conversion to unleaded petrol

[Burdekin]

Originally Posted by morwenna240

Can someone say, Army, 142, exactly how necessary is it to have the seats done? I recall soeone saying it doesn't, in fact, matter overly. My engine is going to be fairly tuned, so, good idea?

Get them done if you are building the engine. About £300 to get them fitted, well that is what it is up here.

[142 Guy]

Originally Posted by morwenna240

Can someone say, Army, 142, exactly how necessary is it to have the seats done? I recall soeone saying it doesn't, in fact, matter overly. My engine is going to be fairly tuned, so, good idea?

It will depend on how much you drive the car. With conventional valve seats, the TEL (lead) in the gasoline acted as a wear reduction agent. Wear wasn't much of an issue on the intakes; but, it is an issue on the exhausts. With conventional valve seats and no TEL in the gas, the seats will wear allowing the valves to recede into the head also causing the clearances between the tappet to reduce and loss of spring pressure.

If you don't drive the car a lot, the rate of recession of the exhaust valve will be small and you may never have to address the problem. In the ancient days of pre TEL gasoline and unhardened seats, people just lived with this problem. If you drive the car a lot, then you may find out how quickly it becomes a problem. Don't ask me how many miles it takes for recession to become a problem with unhardened seats because I have never tested this.

My cost experience is a bit dated; but the £300 quoted by Burdekin seems extreme for just installing and cutting 4 exhaust seats. That is about 5 times the additional cost I paid for hardened seats - although my work was carried out at the same time as I was having general head work done. If I had gone in to the shop and said ' just the seats please' the cost would most certainly be higher. Based upon my incremental cost it was not a hard decision to make for me. £300 would be a slightly harder pill to swallow.

[c1800]

Hi, I don’t know the cost of hardened seats, but if your going to all the work of having your head refurbished, why not get everything done? Yes, I’ve heard that years of running leaded petrol will have hardened the seats, however do you want to do this all again in 1-2-5 years?

[Army]

Originally Posted by morwenna240

Can someone say, Army, 142, exactly how necessary is it to have the seats done? I recall soeone saying it doesn't, in fact, matter overly. My engine is going to be fairly tuned, so, good idea?

I really can't claim to know enough to be considered to be an expert on Volvo engine longetivity - all I can say is that they seem to be well built and as they are still in use today on land and water they can't be all that bad!

I have however spent lots of money in the past at machine shops.

In my experience the cost of "just replacing the valve seats" becomes more involved. More often than not the valves will need to be replaced or re-cut. The valve guides will also probably need to be replaced and reamed to size. Most machine shops will want to skim the head (which frequently has a knock on effect for all of the valve "depths"). For certain engine types new valve springs with the above work is often advised (sorry don't know about the B18/20 - but this could be the case)

On well worn engines there might be work on the valve train.

####

Burdekin's estimate of the costs in Scotland would be a very good deal here in the Netherlands (assuming the additional work I'd expect to have to be done was done). Under five hundred euros for a quality machine shop to do that kind of work here in Holland would be a rare escape (!)

That's why I suggested earlier on in the thread to consider the ready done options - replacement heads - available from Swedish parts sellers...

####

Other aspect to consider:-

(!) FUEL (!)

Things ain't going well for old petrol engines at the moment.

For the best part of ten years here in Holland unleaded Euro95 has had 5% ethonol added. This has caused trouble with classic cars, camper wagons, motorbikes, garden machinery that generally get used periodically. The water content in the ethonol splits from the fuel and causes corrosion.

More recently the ethonol content in Euro95 has been upped to 10% ethonol. So in effect it should be labeled as E10.

This fuel not only eats some old fashioned gaskets and fuel lines but it produces more heat.

For the conversation in this thread - hardened valve seats become more important as the ethonol content gets increased.

The most recent Land Rover Series 2 Club magazine (sorry other vehicle manufacturers than Volvo do exist!) has an article on "what to do now". From this it seems like the UK advice could very well be "fit LPG"...

...if (and I think it is a big IF) LPG becomes the go to fuel in the UK for classic vehicles hardened valve seats would again be necessary.

The only other "dino" fuel option I have come across for petrol engines is Alkylate fuel. I've been using this in my 4 stroke garden machinery. It is very expensive compared with the price of pump fuel at the moment however...

https://www.kroon-oil.com/en/catalog...timum-4t/5447/

^^^^ This burns clean - claimed to be 97% cleaner than real petrol apparently and will sit for years in a fuel system - does not leave carbon poo behind in the engine either ^^^^

I don't think it is a viable option for classic car use just yet. But never say never.


####

All in all if you have a tuned engine / a heavy right foot like me then I'd certainly go for the hardened valve seat option.

[Burdekin]

Originally Posted by Army

I really can't claim to know enough to be considered to be an expert on Volvo engine longetivity - all I can say is that they seem to be well built and as they are still in use today on land and water they can't be all that bad!

I have however spent lots of money in the past at machine shops.

In my experience the cost of "just replacing the valve seats" becomes more involved. More often than not the valves will need to be replaced or re-cut. The valve guides will also probably need to be replaced and reamed to size. Most machine shops will want to skim the head (which frequently has a knock on effect for all of the valve "depths"). For certain engine types new valve springs with the above work is often advised (sorry don't know about the B18/20 - but this could be the case)

On well worn engines there might be work on the valve train.

####

Burdekin's estimate of the costs in Scotland would be a very good deal here in the Netherlands (assuming the additional work I'd expect to have to be done was done). Under five hundred euros for a quality machine shop to do that kind of work here in Holland would be a rare escape (!)

That's why I suggested earlier on in the thread to consider the ready done options - replacement heads - available from Swedish parts sellers...

####

Other aspect to consider:-

(!) FUEL (!)

Things ain't going well for old petrol engines at the moment.

For the best part of ten years here in Holland unleaded Euro95 has had 5% ethonol added. This has caused trouble with classic cars, camper wagons, motorbikes, garden machinery that generally get used periodically. The water content in the ethonol splits from the fuel and causes corrosion.

More recently the ethonol content in Euro95 has been upped to 10% ethonol. So in effect it should be labeled as E10.

This fuel not only eats some old fashioned gaskets and fuel lines but it produces more heat.

For the conversation in this thread - hardened valve seats become more important as the ethonol content gets increased.

The most recent Land Rover Series 2 Club magazine (sorry other vehicle manufacturers than Volvo do exist!) has an article on "what to do now". From this it seems like the UK advice could very well be "fit LPG"...

...if (and I think it is a big IF) LPG becomes the go to fuel in the UK for classic vehicles hardened valve seats would again be necessary.

The only other "dino" fuel option I have come across for petrol engines is Alkylate fuel. I've been using this in my 4 stroke garden machinery. It is very expensive compared with the price of pump fuel at the moment however...

https://www.kroon-oil.com/en/catalog...timum-4t/5447/

^^^^ This burns clean - claimed to be 97% cleaner than real petrol apparently and will sit for years in a fuel system - does not leave carbon poo behind in the engine either ^^^^

I don't think it is a viable option for classic car use just yet. But never say never.


####

All in all if you have a tuned engine / a heavy right foot like me then I'd certainly go for the hardened valve seat option.

Just had mine done; seats, exhaust valves, guides and head skimmed. I was getting a new cam, clutch lightened flywheel and timing gears so thought it made sense. No 1 was a tiny bit down on compression which may have indicated some passing at the valves. Considering 97 or 100 octane fuel with lead was the original specified; hardened seats, highest octane fuel at the station and some lead replacement octane booster probably not a bad idea as well. You should then also be able to set timing as per the manual.

Millers booster and ethanol protection; add 50ml to each tank. https://www.millersoils-shop.co.uk/v...plus-multishot

[Army]

Originally Posted by Burdekin

Just had mine done; seats, exhaust valves, guides and head skimmed. I was getting a new cam, clutch lightened flywheel and timing gears so thought it made sense. No 1 was a tiny bit down on compression which may have indicated some passing at the valves. Considering 97 or 100 octane fuel with lead was the original specified; hardened seats, highest octane fuel at the station and some lead replacement octane booster probably not a bad idea as well. You should then also be able to set timing as per the manual.

Millers booster and ethanol protection; add 50ml to each tank. https://www.millersoils-shop.co.uk/v...plus-multishot

Millers seem like a reputable company. If their product works then it is a cheaper option than the Alkylate fuel at the moment. Based on your advice that's an extra 3 quid a tank which isn't so bad.

Something else to remember though (I'm not always consistent enough to add in the additive!) and makes partial tank fills a bit of a fuss.

Still this is it isn't it? The only reason why petrol is used at the moment is because it is conventient. If it gets taken away it is going to be worse than owning a diesel engined car in the UK in the early 1980s (when you had to go to the local bus depot to try and buy fuel).

If anyone here still has their heads stuck in the sand about fossil fuels - go and see what is happening in the world on the Fully Charged channel on youtube. Some might think it is anarchy!

In this country at least - where they have started to consider the effects of nitrogen in the atmosphere as well as other polutants - it seems possible to me in the foreseeable future there will be an explosion in the use of electric vehicles not only to power transport but to support the national (power) grid. I expect petrol stations selling fossil fuels will start to become thinner on the ground...

[Burdekin]

These fuel/timing charts might be a good guide for folk as well.

[Burdekin]

Originally Posted by Army

Millers seem like a reputable company. If their product works then it is a cheaper option than the Alkylate fuel at the moment. Based on your advice that's an extra 3 quid a tank which isn't so bad.

Something else to remember though (I'm not always consistent enough to add in the additive!) and makes partial tank fills a bit of a fuss.

Still this is it isn't it? The only reason why petrol is used at the moment is because it is conventient. If it gets taken away it is going to be worse than owning a diesel engined car in the UK in the early 1980s (when you had to go to the local bus depot to try and buy fuel).

If anyone here still has their heads stuck in the sand about fossil fuels - go and see what is happening in the world on the Fully Charged channel on youtube. Some might think it is anarchy!

In this country at least - where they have started to consider the effects of nitrogen in the atmosphere as well as other polutants - it seems possible to me in the foreseeable future there will be an explosion in the use of electric vehicles not only to power transport but to support the national (power) grid. I expect petrol stations selling fossil fuels will start to become thinner on the ground...

Air pollution in cities is a real health problem. As a civilised society it makes sense to care about others wellbeing so clean vehicle zones are a good thing. Here in Aberdeen we will be getting a small area in the near future. We are only a small city so will be just around the high street where you have pollution and pedestrians etc, makes sense. You guys in the Netherlands and Denmark etc have it sussed with the cycling. Copenhagen is an amazing example of a cycling city which reduces car traffic and therefore makes it easier to get around in a car if needed.

[Army]

Originally Posted by Burdekin

Air pollution in cities is a real health problem. As a civilised society it makes sense to care about others wellbeing so clean vehicle zones are a good thing. Here in Aberdeen we will be getting a small area in the near future. We are only a small city so will be just around the high street where you have pollution and pedestrians etc, makes sense. You guys in the Netherlands and Denmark etc have it sussed with the cycling. Copenhagen is an amazing example of a cycling city which reduces car traffic and therefore makes it easier to get around in a car if needed.

Please don't group me with the "You guys" - I'm English!

Anyway - cycling in most large towns and cities in the Netherlands is quite simply cheaper, more often than not quicker and more versatile than using a car. I see no reason why this wouldn't be the case for any other large town or city in the so called developed parts of the world.

When I first moved here the feeling of freedom of cycling on purpose built cycle lanes was amazing - I resented all of those years I'd spent stuck in traffic in the UK - the car parking wars - the road rage - the car parking costs...

Unfortunately not all of the Netherlands is cycle friendly. Where I live now (in Dutch terms out in the sticks) there are very few purpose built cycle lanes. Most of the yokels like to drive around in LS3 powered pick-up triucks - they love tractor pulling (!) - lots of public money is being spent on roads but bicycles and the needs of cyclists out here are ignored (a bit more like the UK as I remember it back in the late 1990s)...

...I suggest that bicycle integration as a transport solution in the busier parts of the Netherlands was only introduced as a necessity rather than for green reasons. The Dutch are no way near as green as their reputation in the rest of the world might suggest.

[142 Guy]

Originally Posted by c1800

Hi, I don’t know the cost of hardened seats, but if your going to all the work of having your head refurbished, why not get everything done? Yes, I’ve heard that years of running leaded petrol will have hardened the seats, however do you want to do this all again in 1-2-5 years?

The recession of the exhaust seats is caused by micro welding of the exhaust seat to the valve contact area and subsequent tear out of microscopic pieces of the seat. Recession is not an issue on the intakes because the metal temperatures are much lower. The lead compounds in the gasoline do not harden the actual valve seat; but, form a protective coating on the valve seat (I believe it is an oxide of some sort) which reduces this micro welding. Once you switch to non leaded gas, this protective coating starts to disappear and recession sets in. I don't know how fast that occurs.

On the purely speculative front, valve recession rates will probably be engine specific. A higher compression engine will have higher combustion temperatures than a low compression engine as will an engine with a longer duration or higher lift camshaft. A B20A with a single carb OEM cam may go a long time before recession becomes an issue. A modified B20B or B20E with aggressive cam profiles and valve springs with higher seat pressures may see fairly quick onset of valve seat recession. This SAE paper indicates that for the same engine, engine speed is actually a bigger contributor to valve recession than engine load.

https://www.jstor.org/stable/44718153?seq=1

'Tuned' engines usually come with higher engine speeds so that should be a factor in assessing the risk of valve recession.

If you enjoy being paranoid, this reference to reports on testing of Continental Aircraft Engines cites a reduction in engine performance on un leaded fuels being detectable after 10 hours of operation.

https://generalaviationnews.com/2012...s%20to%20the%2

Continentals are air cooled engines which run with higher head surface temperatures and aircraft engines tend to run at fixed RPM for long periods of time so that probably represents an absolute lower limit for the onset of seat wear.