New to all this - Fuel confusion

[AlanM]

Hi All

I just bought a 1966 Vitesse Mk1 convertable that started off it's life as a 1598 but in the late 70's was upgraded to 2Ltr.

The car is running very smoothly, needs some body work but is in a reasonable condition.

My question is about fuel/Petrol

1.  What the best for this age vehicle ?

2. How can I fathom out what is already in the tank ??

Any help or advise would be really appreciated.

Thanks,,  Alan.

 

[sparky_spit]

Hi Alan - welcome to the CT forum.

If you are pretty sure that the 2ltr engine has been in there for 30-odd years and has been used during that period with good old leaded fuel, then there will be a good "lead memory" effect contained in the cylinder head's valve seats.  This will mean that you can use modern E5 petrol with relative safety and not have to worry overly about valve seat recession. It may be that the previous owner had hardened valve seat inserts fitted, in which case you don't need to worry at all. You can really only tell if inserts have been fitted by taking the head off and having a look, but it's not worth doing that just for that reason.  If you want to be 100% sure of avoiding possible valve seat recession then you could use a fuel lead substitute.  Most owners i know don't bother.  My Spitfire engine has done tens of thousands of miles without an additive and the valve seats are fine.

One thing you might consider is to use the highest octane rating petrol you can find, such as Tesco 99, or Shell V-Power, and the like. This will give your engine the best chance of running well at near to manufacturer's ignition advance settings. Again, choose the fuel with least ethanol content.

Don't worry too much about it; use the fuels as mentioned above and enjoy driving your new (old) Triumph.

If you know the history of the car and it has been used frequently and recently, then just fill up with 99 octane petrol and use it.  If you are uncertain of how long the petrol has been in there, or it has been standing idle for a long period, then it would be best to drain it off and fill with fresh stuff. Modern petrol absorbs the water content from ethanol (or something like that) over time and you can end up with water in the tank, which is obviously not what you want. If the car has been used regularly before you bought it then it should be fine.  

[thescrapman]

Alan, do keep an eye on the valve clearances.

the most susceptible Triumph engine for recession seems to be the Mk1 2lt.

The only engines I Remember suffering have all been of that type. Though it is only a handful.

And those have all been driven hard.

[RobPearce]

Quoted from thescrapman-

the most susceptible Triumph engine for recession seems to be the Mk1 2lt.

The only engines I Remember suffering have all been of that type.

Oh? The only engine I've ever seen VSR on was my Toledo - after doing RBRR with a faulty carb float valve and hence running lean. The Mk1 Vitesse seems perfectly fine.

[glang]

Yes think a lean mixture has a great deal to do with it as it seems my Mk1 Vit has suffered pretty badly after only a few hundred miles but at higher speeds with worn carb spindles😞

The valves have been reground in the past so losing any residual lead protection and I didnt notice it when driving (perhaps leaking spindles change the mixture disproportionally at higher revs so a weak mixture doesnt show when adjusting the carbs at tick over)....

[thescrapman]

I had forgotten you had had it on the Toledo

My VSR was due to having reduced lead memory as I rebuilt the head just before lead was removed from petrol, and no hardened seats.

James Carruthers and Craig Gingell both suffered it ISTR, and those engines will have been worked very hard.

There was a couple of others as well, deep in old forum.

Very uncommon in Triumphs would seem to be the order of the day, but you don't know what a previous owner may have done ( ground valves in etc)

[Rutty]

Having not experienced  VSR myself I assume you can tell if you have it with out removing the head by the fact that the tappets are at the limit of adjustment.

Mark

[glang]

As the tappet clearances tend to close up the engine doesnt get any more rattley. If youre doing routine maintenance youd find this strange as normally the gaps get bigger. Otherwise the first youd know is low compression on a cylinder due to a valve being held open and if not rectified the situation will worsen as the valves get burnt. 

[ferny]

I had to adjust my valves on a 10CR with a mk4 Spitfire engine. They'd been done just before the event and apparently it was an unleaded head. Also had plenty of VSR on standard 1.3 Herald ones whilst using Castrol additive. Maybe I just used to work them harder than most...

 

You'll notice it's happening on your regular service checks. Or, if it's bad as in my cases, you'll notice the power drop off. 

[RobPearce]

Quoted from ferny-

You'll notice it's happening on your regular service checks. Or, if it's bad as in my cases, you'll notice the power drop off. 

The clue with my Toledo was that it refused to start the morning after RBRR. A compression test showed no compression on any cylinder (well, that's a slight exaggeration, they all showed about 40psi). That was a rather extreme case, though.

[AlanM]

Hi everyone.

Many thanks for all the responses. As I'm not exactly sure of the engine history I think the best course for me to follow is to...

1. Drain the tank.

2. Refill with high (97/98) octane fuel

3. Use Castrol lead replacement, certainly for the next 500 miles or so, maybe longer.

 

Anyone violently disagree  ?

 

Thanks again folks..

 

[glang]

If youre looking for higher octane and lead replacement it might be worth looking at a combined additive. I use Millers VSPe which is purported to do both and also protect against any ethanol effects which means you can then use the cheapest fuel you can find. Unfortunately I didnt have it added when my car suffered VSR mainly because I didnt realise there was a problem but at other times I have found it pretty good to avoid retarding the timing and stopping run on. However its worth noting that Ive also found ensuring my engine runs cool helps a lot.... 

[RobPearce]

Like glang says, it seems redundant to use both additive and "super" fuel when there are additives that do both jobs.

It also seems pointless to use additive "for the next 500 miles" - if your engine needs additive then it will need additive until you have the valves done, if it doesn't then there's no benefit using it now.

If you want to "find out" then I'd say don't use additive - just fill with ULG (98 octane if you drive hard) and put some miles on. Then in about 500 miles or so, check the valve clearances. If they've closed up you need to start using additive.

[PeteStupps]

Hi Alan,

Certainly wouldn't violently disagree :)

But if the car runs happily enough I don't think you gain much from draining the tank. Add some Valvemaster or similar to the existing fuel if you like but otherwise I'd just fill up with 97 or 98 at your next refill. A few more miles on lower octane fuel won't do anything catastrophic (famous last words..!).

If you don't know any recent history at all, I'd be more keen to change the engine oil (and filter) than the petrol. 

Pete