Fuel Additives

[ianh1968]

I've just fitted an standard-type iron head to one of my engines and
was wondering what thoughts people have about the best additives to
use.

A while back I used "SuperBlend 2000", but more recently, "Millers CVL".
I can't remember what the price of the SuperBlend was, but the Millers
is about £8 per fill-up at the recommended dose.

I have seen "RedLine" but the stated dose seems tiny compared to the
products that I have used before. Says on the bottle "Treats 120 gallons..."

... but then again, text accompanying adverts say ...
"Recommended dosage: 1 Ounce (355ml) treats 10 Gallons (37.85 Litres)"

Something not quite right here with the arithmetic? In US speak, there
are 16 fl-oz in a pint. (20 fl-oz, UK). A pint is 568 ml, therefore 1 oz (US)
must be 35.5ml - Surely there's a decimal point missing and 355ml should
be 35.5ml?

If we go with what it says on the label, ie 120 gallons, this works out at
less than £1 per tank for the RedLine, compared to £8 per tank for the
Millers. This sounds too good to be true...

Any advice would be welcome as I've just had to cough up £800 for a
new head and am now currently very poor as a result.



Ian

[Spider]

Ha, yeah, does sound like a decimal point is missing for sure!!

Just to be clear and reading between the lines here, you are referring to a lead substitute type additive? Sorry, I don't have much to off, but will be looking on with interest.

[Lord Croker]

I've been using Red-Line lead substitute since the day this dreadful unleaded fuel was imposed upon us. At the recommended dose of 8ml per 10 litres of fuel, a 355ml bottle will treat about 440 litres (96 gallons), but it is recommended that you double the dose in racing situations or prolonged motorway use. When I first used it, the price was about £4 a bottle, but the government of the day decided that since we were burning it in an internal combustion engine, it was subject to road fuel duty, pushing the price to around £13. I have used it regardless of whether I was using iron exhaust valve seats or unleaded inserts & on inspection, there was no difference in the condition of the seats & it also combats the drying effects of unleaded fuel, but it is an additive, it will not change the burn characteristics of the fuel in the way that tetra ethyl lead will, but in my experience it will protect your valves & provide upper cylinder lubrication.

[pad4]

I was jyst about to try the millers Vsp+ super or whatever its called - has a bit of octane boost, lead substitute and ethanol stuff

£5 a bottle from demon tweeks

[ianh1968]

Just to be clear and reading between the lines here,
you are referring to a lead substitute type additive?

Yes, it's a lead substitute that I am looking at.

The CVL does provide an "Octane Boost" , but it's the seat protection
I need. I do have a few bottles of CVL left that I will use first.

I am hoping that this will be short term only... Sometimes these
projects take a while to come about, so I am just trying to gauge
opinion for a longer term solution.

Sorry, I don't have much to off, but will be looking on with interest.

Spider, I was rather hoping that you would be able to come up with
some valve seat recession graphs from your extensive archive....


Ian

[cheleker]

Use Redline.

[LMM76C]

From what I recall, the FBHVC tests had Millers (manganese) as best, Castrol (phosphorus) second and Red Line (sodium) third in effectiveness, with the potassium based LRP a distant fourth.

[Andrew1967]

This is not a suggestion to anyone not to use an additive but.....

I had hardened inserts put in on my 998 Cooper engine and have had no problems with valve seat recession after some 15000 miles.

I have not done anything to the heads on my 850 or my S engine and have had no problems at all with VSR. If anything I have had the usual loosening of valve clearances. Both have done around 4000 miles since their engines were rebuilt prior to being returned to the road after restoration.

All engines are run on the high octane Super Unleaded fuel as 1) I find they run better on it (even the 850) and, 2) as a diesel user for our everyday cars, it does not seem to be an expensive option to use this fuel rather than regular unleaded.

My theory is to leave well alone and have the heads done in the future if there proves to be a problem. I have heard of numerous issues with valve seats falling out so that puts me off a bit as well.

So far so good.....

[foxy52]

This is not a suggestion to anyone not to use an additive but.....

I had hardened inserts put in on my 998 Cooper engine and have had no problems with valve seat recession after some 15000 miles.

I have not done anything to the heads on my 850 or my S engine and have had no problems at all with VSR. If anything I have had the usual loosening of valve clearances. Both have done around 4000 miles since their engines were rebuilt prior to being returned to the road after restoration.

All engines are run on the high octane Super Unleaded fuel as 1) I find they run better on it (even the 850) and, 2) as a diesel user for our everyday cars, it does not seem to be an expensive option to use this fuel rather than regular unleaded.

My theory is to leave well alone and have the heads done in the future if there proves to be a problem. I have heard of numerous issues with valve seats falling out so that puts me off a bit as well.

So far so good.....

...additives ??! I have never used them since an engine rebuild in 2006/7.. I had prev but !!!..I then I had issues with valve seats ,the head and overheating 2000-2006.. higher octane unleaded is all well and good bearing in mind the various quality of unleaded fuel in general...I have tried R spec fuels also and can honestly say my car gives me no probs with a decent choice of strait forward unleaded or at least touch wood has done for the last 7+ years..so to a layman it all seems bullshit to me additive use ??.. if 5 star near 100 octane fuel was still avail we would never have had unleaded conv debates and all our coopers and s types would have run better for it.!!!...progress eh ?? foxy52

[Spider]

Sorry, I don't have much to off, but will be looking on with interest.

Spider, I was rather hoping that you would be able to come up with
some valve seat recession graphs from your extensive archive....


Ian

Bhahaha, nah, I don't have any for that I'm afraid!

I have head the hard seat vs standard seat and the don't use additive vs use additive debate on and off over many years now, I will say that there there doesn't seem to be an easy or straightforward answer to this, as I've seen some very serious seat erosion on low mileage heads and conversely next to none on high mileage heads.

I'm no chemist, however from what I understand, at exhaust temps, the temperature and I think materials commonly used for exhaust valves causes a 'transfer' of molecules from the cast iron on to the valve, however it doesn't adhere to the valve, but gets blown out the exhaust. I'll happily be corrected on that, and as I say, I'm no chemist.

I'll also add that I feel that exhaust valve material does play a big part in all this and that in later years the factory did fit inserts, perhaps as an arse cover exersise, though I really doubt it. I think there's some good info over on Race Valve's website on this subject.

If inserts are of the correct material, shape, size and fitted correctly, they won't fall out. For the record, I fit them in all our cars as I'm too lazy to use an additive, however, if I didn't have them in there, then I would use an additive, probably more as an insurance rather than an absolute.

If you don't take precautions, fair enough, however, I would suggest keeping a regular check on rocker clearances, it could save you from a burn valve or even a cracked head.

[Smiffy]

IIRC Super Blend got bought out by Morris Oils, who now sell it.
http://www.lb-restoration.co.uk/cgi-bin ... ION&pid=15