Fuel Additives?
Discussion
TL;DR Is it worth using fuel additives on a car that hasn't been modified to run on unleaded?
I have a '76 MGB GT that I bought with no history from a guy who only had the car for a month or so (risky I know), because it has no history, I have no idea whether it has been modified to run on unleaded fuel or not. Since I have owned it I have always put an additive in every time I fill up, I follow the ratios on the bottle exactly and have never filled up the car without it. Am I wasting my time and money?
The cost of the additive is pretty minor in the grand scheme of things, and I am now a regular in the very small and independent shop that sells this sort of thing, which can only be a good thing.
What happens if it hasn't been converted and I run it on unleaded? (Pinking?) and what are the signs I would look out for? Is there a way to tell if the head has been converted?
I can't afford to run it until the head is f
ked and then buy an unleaded head, which is one piece of advice I have been given, and the nearest garage that sells 4star is about 15-20 miles away.
Any ideas?
I have a '76 MGB GT that I bought with no history from a guy who only had the car for a month or so (risky I know), because it has no history, I have no idea whether it has been modified to run on unleaded fuel or not. Since I have owned it I have always put an additive in every time I fill up, I follow the ratios on the bottle exactly and have never filled up the car without it. Am I wasting my time and money?
The cost of the additive is pretty minor in the grand scheme of things, and I am now a regular in the very small and independent shop that sells this sort of thing, which can only be a good thing.
What happens if it hasn't been converted and I run it on unleaded? (Pinking?) and what are the signs I would look out for? Is there a way to tell if the head has been converted?
I can't afford to run it until the head is f
ked and then buy an unleaded head, which is one piece of advice I have been given, and the nearest garage that sells 4star is about 15-20 miles away.Any ideas?
If the car has been run for years with leaded fuel then it's probable thaat there is enough of a build up to run without lead for a long time before any damage occurs. Valve recession is the main worry as the valve seats erode but as I said this may take tens of thousands of miles before it becomes noticeable. However, if using additives gives you peace of mind and isn't shredding your budget why not carry on... you have nowt to lose.
I've used this for years now
http://tetraboost.com/
Not a lead substitute, it's kosher tetraethyl lead, the only additive that is. It looks expensive but you add 10ml per litre of fuel so not bad and I doubt you'll be doing mega miles. It also now protects against the effects of ethanol according to their website.
http://tetraboost.com/
Not a lead substitute, it's kosher tetraethyl lead, the only additive that is. It looks expensive but you add 10ml per litre of fuel so not bad and I doubt you'll be doing mega miles. It also now protects against the effects of ethanol according to their website.
The best additive is no longer made, but the Castrol one is pretty good, not that expensive to use and is easy to get although Halfords have ceased to stock it. (Their stock policy annoys me at times, ceasing the best product for one with a higher margin).
With a MGB, you are probably best advised to continue using an additive, although it's not that difficult to get the head removed, adapted and refitted, especially if you can do the head swap yourself (not hard).
Do read this:
http://www.fbhvc.co.uk/legislation-and-fuels/fuel-...
And this:
http://www.mg-tabc.org/library/leadfree.htm
With a MGB, you are probably best advised to continue using an additive, although it's not that difficult to get the head removed, adapted and refitted, especially if you can do the head swap yourself (not hard).
Do read this:
http://www.fbhvc.co.uk/legislation-and-fuels/fuel-...
And this:
http://www.mg-tabc.org/library/leadfree.htm
In 2008 I bought a Riley 1.5 (smaller capacity B Series engine as a MGB). I ran it without using any additives until earlier this year when the head gasket failed and the head came off. While it was off it made sense to have hardened seats fitted though there was no sign of valve recession (total mileage 75,000 of which approaching 15,000 have been done since I bought it). If the head gasket failure hadn't happened, I'd have continued driving it without additives, in my view they're unnecessary.
The most important fact for an old engine, ie one that officially isn't supposed to use unleaded - is how many miles it's done since being built.
The valve seats work harden over time - so I never found a problem with any engine run on unleaded - as long as it was old. A rebuilt cast iron cylinder head will suffer from valve seat recession if exhaust valve seat inserts aren't fitted.
Easy way to see what's going on is to check the rocker gaps - if they keep closing up the valves are receding - in which case have exhaust valve seat inserts (and new exhaust valves) fitted.
Octane ratings are a different matter, sometimes retarding the timing sorts out excessive pinking.
The valve seats work harden over time - so I never found a problem with any engine run on unleaded - as long as it was old. A rebuilt cast iron cylinder head will suffer from valve seat recession if exhaust valve seat inserts aren't fitted.
Easy way to see what's going on is to check the rocker gaps - if they keep closing up the valves are receding - in which case have exhaust valve seat inserts (and new exhaust valves) fitted.
Octane ratings are a different matter, sometimes retarding the timing sorts out excessive pinking.
It also depends on where and how it's being driven , high revs for a long period (motorways and the such) I would get the head done .
Normal pottering about just use higher octane (99ron preferred) unleaded without additives , it's the octane that causes more problems in older un-rebuilt engines .
Normal pottering about just use higher octane (99ron preferred) unleaded without additives , it's the octane that causes more problems in older un-rebuilt engines .
Before unleaded was forced upon us Practical Classics did some tests with various unleaded potions.
They tested various fluids, pills, in-line things and magic balls you dangle in your tank.
The one that came out on top was Valvemaster, it wasn't owned by Castrol then but i guess they saw it was good stuff and bought whoever it was out.
I have run many Fords with the stuff and i think most folk i know use it.
I bought a couple of cases of the stuff off Ebay and sold it to my mates £7 a bottle.
They tested various fluids, pills, in-line things and magic balls you dangle in your tank.
The one that came out on top was Valvemaster, it wasn't owned by Castrol then but i guess they saw it was good stuff and bought whoever it was out.
I have run many Fords with the stuff and i think most folk i know use it.
I bought a couple of cases of the stuff off Ebay and sold it to my mates £7 a bottle.
How do people get away with this, I pay about £11 per bottle
http://www.ebay.co.uk/itm/Castrol-Valvemaster-Plus...
http://www.ebay.co.uk/itm/Castrol-Valvemaster-Plus...
markymarkthree said:
Before unleaded was forced upon us Practical Classics did some tests with various unleaded potions.
They tested various fluids, pills, in-line things and magic balls you dangle in your tank.
Worth pointing out, the lead balls, and the fuel catalysts sold do absolutely nothing. One of which has a substantial web presence, but hopefully not this site.They tested various fluids, pills, in-line things and magic balls you dangle in your tank.
I'd use the additive, it's not dear given low mileage. As others have said, occasional fills with leaded if available will help out. In addition some engines may have had enough lead to coat the seats for ever, or they may harden in use. Some however may not, as other say if your valves are closing up then you need to get some leaded petrol or additive in there, or your valve seats will be eroded to the point of needing replacement.
The tests done for the FBHVC showed that Valve Seat Recession (SR) occurs at high power and high speed. Not many cars of any sort use both continuously, so unless you have a car that can just achieve 70 m.p.h. (or any speed that's legal) and insist on driving at that maximum speed for hours at a time there should be no VSR problem.
The snake oil men (in this case let's say the metallic tin or lead balls in the fuel tank men) can show that VSR does not occur when their product is fitted - and many of the rest of us can show it doesn't occur anyway in normal driving when their product has never been near our cars.
The snake oil men (in this case let's say the metallic tin or lead balls in the fuel tank men) can show that VSR does not occur when their product is fitted - and many of the rest of us can show it doesn't occur anyway in normal driving when their product has never been near our cars.
The 1980s Skoda owned by my Mum would run on unleaded but the manufacturer recommendation was to adjust the valves every 3000 miles. Maybe 6k, I forget. It was however frequent, so VSR is not as far away as all that, at least on that engine. An MGB with a few miles on may be different. As I said earlir, you could always have a go and keep an eye on your clearances. For an MGB doing a few thousand a year it might not be a problem.
Seems to be some confusion about valve seat recession and valve seat erosion. Recession is caused by the valves hammering, without any cushioning, on the seat and pushing the seat down. The valve seat literally recedes into the head and the valve gets lower and lower, eventually the valve clearance becomes zero and then the leaking valves burn out quite quickly. The (none lead) additives prevent this by increasing the octane rating to reduce the incidence of detonation but do little more than that. They have little effect on valve seat erosion which is caused by micro welding of the valve to the seat which slowly tears the surfaces apart. There are two solutions, either seats and valves made of modern materials which don't exhibit micro welding or lead in the fuel which both increases the octane rating and puts a film on the valves and seats which reduce the micro welding. None of these additives have lead in them. You will note that they claim to reduce "valve seat recession" and make no claim of protection against erosion, there is a reason for this omission, it allows them to sell an ineffective productive or at best a marginally effective product and not get sued.
With an B series 1.8 engine it's pretty easy to check if you have a problem. Just keep and eye on the valve clearances. If they start to close up start worrying. In practice unless the engine is being run ragged you will probably not have a problem. So listen to the tappets and if they get less and less tappy that may be a sign of a problem. I have run some old and unconverted engines on unleaded for many tens of thousands of miles without any detectable recession or erosion but a couple that were mercilessly thrashed did die quite quickly. Notably an 70's OHC slant 4 Vauxhall engine and a Pinto which both suffered badly after a couple of years of trackdays even though the mileage was quite low. Getting a B series converted is likely to be one of the smaller bills an elderly MGB presents you with.
With an B series 1.8 engine it's pretty easy to check if you have a problem. Just keep and eye on the valve clearances. If they start to close up start worrying. In practice unless the engine is being run ragged you will probably not have a problem. So listen to the tappets and if they get less and less tappy that may be a sign of a problem. I have run some old and unconverted engines on unleaded for many tens of thousands of miles without any detectable recession or erosion but a couple that were mercilessly thrashed did die quite quickly. Notably an 70's OHC slant 4 Vauxhall engine and a Pinto which both suffered badly after a couple of years of trackdays even though the mileage was quite low. Getting a B series converted is likely to be one of the smaller bills an elderly MGB presents you with.
FBHVC's tests in the very early 2000s may disagree 
- they used a series of unadapted A-series engines; their exhaust valve seats collapsed when neat unleaded was used while other test A-series engines' exhaust valve seats survived to varying degrees depending on the particular additive used (leading to FBHVC's now-historical recommendations of unleaded additives)...
Oh, and pinking (and reduction thereof by using unleaded additives resulting in higher octane fuel as suggested upthread
) has nothing to do with exhaust seat recession (and the higher resulting octane assertion is unmitigated bocks also), btw.
- they used a series of unadapted A-series engines; their exhaust valve seats collapsed when neat unleaded was used while other test A-series engines' exhaust valve seats survived to varying degrees depending on the particular additive used (leading to FBHVC's now-historical recommendations of unleaded additives)... Oh, and pinking (and reduction thereof by using unleaded additives resulting in higher octane fuel as suggested upthread
) has nothing to do with exhaust seat recession (and the higher resulting octane assertion is unmitigated bocks also), btw.Thanks for all of the replies. A lot of it went straight over my head but there was plenty of useful advice. I'm pretty new to the driving game, let alone the classic car game
I think for the time being I will carry on using the additive, its not costing me a lot and it gives me peace of mind
As you were.
I think for the time being I will carry on using the additive, its not costing me a lot and it gives me peace of mind
As you were.
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