Jump to content

Lead replacement /additive


Robin
 Share

Recommended Posts

Robin,

I used to use a fuel additive but it turned my plugs pink and I couldn't tell if I was running lean or rich. :lol:  Our cars ran for years on leaded fuel and the head valves got a coating of lead, people call this the memory of lead. The engines will do 10s of thousands of miles more before there's a problem, unless you've had a de-coke!  Valve recession is what eventually happens and slowly. When it starts is the time to think about un-leading with stronger exhaust valve seats. Of course a de-coke will remove the lead. 

So I would say spend the money on petrol not additives..

Doug

Link to comment
Share on other sites

Hello Robin,

As you have intimated, this is a topic that has been covered heavily but always worth going over again - you can search archive information via the search option.

In brief, cylinder heads have long term lead memory and as such are resilient to unleaded fuel although over the decades this will become less. If on the other hand you drive at fast speed all the time and /or use full revs available then the lead memory will diminish far quicker.

Some say yes you should add, others will say it's not worth it - it really is a personal choice at the end of the day and what you feel comfortable with for your engine. I presume from your photo you have a Vitesse Mk2 or perhaps 2Ltr ?? Both cars like to be used sportingly and if I were in your position I would use it for that vehicle whereas a far more sedate Triumph may not benefit from the additive; it really comes down to use of the car.

I have an unleaded head on my Vitesse, but my Daimler does not and cannot - as such I use lead replacement. In my case Castrol Valvemaster. I do like Redex products and in addition it is worth looking at Millers products. The latter you can use in conjunction with a combined anti-ethanol agent. I have not tried Wynn's so cannot comment.

As you can see the topic does have a ripple effect, but in essence your question is covered in my first few paragraphs.

All the best.

Richard.

Link to comment
Share on other sites

1 hour ago, Robin said:

Apologies if this has been covered elsewhere but there seems to be quite a price difference between Wynnes and Redex lead additives products - is it worth spending the extra on Wynnes?

Thanks

Robin

 

Dont think either of those received FBHVC endorsement as their list only shows Millers, Red lIne, Castrol and Tetra Boost. On longer high speed runs I use Millers lead/octane booster with 95 fuel in my Vitesse 2L as it runs better. Also I hope it protects my valves as they have been reground and I believe, for a period, suffered quite severe valve seat recession although this was probably due to running a weak mixture due to air leaks which have now been cured....

Link to comment
Share on other sites

I'd say pick Wynnes - but don't buy it.  Instead work out how many fill-ups you could do per-bottle and every X fill-ups put the cost of a bottle of Wynnes in a jam jar.  By the time you have any noticable valve seat regression you'll have enough in that jam jar to pay to have unleaded valve seats fitted in your head.

Link to comment
Share on other sites

im sure if you run on **95 ron you need to retard the timming , up the combustion heat and stand more chance of valve burning 

so why not use what triumph intended and 97ron or higher if available and save the additive in Mjit's     jam jar  

sounds a better plan 

Pete

Link to comment
Share on other sites

17 hours ago, johny said:

orrrrr use Millers VSPe at 5p a litre of fuel to up 95 to 97ron so that normal running can be maintained while protecting your valve seats and so (hopefully) the jam jar will not be needed.....

At some point an engine rebuild, probably with head skim will be required so the content of that jam jar will be required regardless of leaded/unleaded, additive/no additive.  Yes, maybe sooner running without additive than with but at some point regardless.

Link to comment
Share on other sites

but its a no brainer if as most people find 95 gives pinking but they want to maintain standard timing then instead of going to 97 use an octane booster + lead additive which works out cheaper per litre fuel and additionally gives the possibility of avoiding VSR. The new concentrated 500L treatment container is convenient to use and although its valve protection is an unknown (it was certified in the tests however) I can confirm the immediate reduction in pinking it gives....

Link to comment
Share on other sites

7 hours ago, johny said:

but its a no brainer if as most people find 95 gives pinking but they want to maintain standard timing then instead of going to 97 use an octane booster + lead additive which works out cheaper per litre fuel and additionally gives the possibility of avoiding VSR. The new concentrated 500L treatment container is convenient to use and although its valve protection is an unknown (it was certified in the tests however) I can confirm the immediate reduction in pinking it gives....

I do one better than that, I use Tesco 99ron (whenever possible) plus Castrol  valvemaster plus (lead additive & octane booster) hopefully to get my GT6 to run on something like it was designed to (101 Ron)

2 years and about 5,000 miles later.....timing set to factory, no pinking at all, plenty of power and no pink plugs!????  

Works for me anyway!

Link to comment
Share on other sites

I think you might be going overboard a bit. First of all higher octane in itself gives no more power but just allows the engine to run at the correct ignition timing without excessive pinking (pinging, knocking etc). This is optimum if a correctly running engine stops pinking on reaching 2000rpm when under full acceleration in 4th gear on the flat (air temperature will have an effect so best to do the test on the hottest day) and all you need is a fuel/additive that achieves this, any more is unnecessary.

Note that valve seat recession is another matter that can occur with or without pinking taking place so other measures may be needed to prevent it. 

Link to comment
Share on other sites

Looking on line it turns out that ethanol is actually an octane booster and the petrol companies now produce a lower octane petrol specifically so that on mixing it with ethanol it gives the correct reading. Of course unfortunately for some engines it can bring other problems.....

Link to comment
Share on other sites

Just now, johny said:

I think you might be going overboard a bit. First of all higher octane in itself gives no more power but just allows the engine to run at the correct ignition timing without excessive pinking (pinging, knocking etc). This is optimum if a correctly running engine stops pinking on reaching 2000rpm when under full acceleration in 4th gear on the flat (air temperature will have an effect so best to do the test on the hottest day) and all you need is a fuel/additive that achieves this, any more is unnecessary.

Note that valve seat recession is another matter that can occur with or without pinking taking place so other measures may be needed to prevent it. 

You have to retard the ignition to reduce the pinking when running on a lower octane. By retarding the ignition you reduce the power and torque of the engine.

Also there come a point when you can't retard any more as you get into the run on region.

Dave

Link to comment
Share on other sites

30 minutes ago, johny said:

I imagine if you take the octane too high you might actually be making the mixture more difficult to ignite or certainly changing its combustion characteristics....

More difficult to control.

RR redeveloped their Merlin engine to take advantage of the increase in octane of Avgas and as a result obtain nearly double the original output. That's when they started to introduce lead in fuel to increase the octane.

From the late 1950's through the 1960's the octane of vehicle fuel increased up to 101 octane. The car makers took advantage of this to increase the power output of their engines. Most offered a low compression version with a tame camshaft to countries that only had lower octane fuel. Needless to say the power on these versions of the engine was down on the normal.   

Dave

Link to comment
Share on other sites

yes I think you have to match the petrol octane to the engine compression or even the other way round if, as in some countries, the necessary octane additives arent available. Of course if you have got a higher octane petrol you can run more compression and so make more horses even though the energy content is pretty much the same whatever its octane.....

Link to comment
Share on other sites

I was in Moss -- Europe this morning and noticed that they sell the Dynolite range of oils and stuff.

They do a VSR £8 for 250 litres of fuel  and an octaone booster + VSR for £10 for same quantity

 

Don't use it myself but it is there.

Roger

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share

×
×
  • Create New...