Additives

Cowboy Don · Sep 1, 2011

One for the Aussie Blokes,

I'm thinking I'm gonna run a lead replacement additive in my fuel, only 'cause I can't find any downside to it, even if the upside is sometimes debated. What, if any, brands are you using? I've seen Nulon here on our shelves at most the major auto retalers, the small bottle that you can carry with you. And do you run the ratio they recommend of 10ml/Ltr?
I fill up with BP 98 almost always, only time I don't is if I'm out on the road and there's no BP servo around.
And with the 98, is there any advantage/disadvantage to running an octane booster?
Any chances of damage to the Mikuni rubber inlet manifold running these?

Looking at bloody great weather on Saturday here in Adelaide.

stockie2 · Sep 1, 2011

I have used the Lucas stuff and also the Castrol at the servo. The Castrol in the big bottle has a natty dispenser system. I normally does her up at home before a ride.
I would not bother with octane booster, even 95 runs really nice in my 850. If you get stuck and have to use e10, try and use it all up before laying the bike up, or it will silt up the carbs.

Cheers Richard

Cowboy Don · Sep 1, 2011

Thanks Stockie,

With a name like that, I assume you are in Australia.
I checked out the Lucas lines on the shelf but couldn't find a lead replacement. Can you give me the name of their product you are using?

ashman · Sep 1, 2011

Hi Cowboy Don

I run Flash Lub in all my old engines that need lead, its the best one for lead replacement, have been using it for years with no problems but must be mixed at the right mixture 50ml to 50 litres of fuel, I buy a big bottle from Repco and it will last a few years if used right, I use a medience cup to messure the right mix, 11 litres fuel 11ml of Flash Lub and if I go on any trips where I will need to top up I have a small 50ml bottle in my bag that has 10ml marks on the side of the bottle so I can get the right mixture at all times, use to much and your bike will run richer.

Ashley

steveyacht · Sep 1, 2011

Can't speak for the quality of gas available where you are, but in my neck of the woods I use the following: Marine Stabil (the blue stuff), Octane Boost and a lead additive. For my roadster 2 gallon tank, I put half an ounce of each in an Airline booze bottle, the Mini bottle holds 1 7/8's ounce, is small enough to fit in tank bag, pack or pocket. I make up a few, keeping two or three in my tank bag, if going on a road trip I carry a few more, figuring 100 miles per bottle. Only problem is that I have to sacrifice myself to empty a few so I have them for use for fuel additives........ sigh. So far I have quite the collection, enough for 1500 miles at 100 miles per bottle!!!

Hobot · Sep 1, 2011

I got here in '51 in time to watch the progress of compression and pump octane to know that you can't directly translate today's anti-detonation ratings with yesteryears. I run 87 no lead in Combats w/o an issue as long as not racing about in summer Mt climbing long enough engine heat soaks. So far I've not been able to induce knock/ping with new 91 oct in my two Combats, which should never be lugged anyway. Coke and wrong plug heat range can cause detonation no matter the octane. If you exceed by much the needed octane to operate at max power-heat then you are not going to make as much max power as on proper lower octane. Over kill octane is mostly just waste of fuel money and ET's not engine parts thank goodness.

Gasoline Myth #2: Octane Isn't As High As It Used To Be

Truth: Octane content is basically the same as it always was, but the numbers are lower. That's because there are two methods of measuring octane level: Motor and Research. Gasoline used to be rated solely by the Research method, which yielded higher numbers than the Motor method. Today's fuels use an average of the two and are therefore numerically lower. 100 Research (RON - Research Octane Number) is 94 octane in today's rating system. Octane levels used to be managed with the addition of Tetraethyl Lead. Lead was phased out in the 1970s and gasoline now is mixed with less harmful substances such as methyl and ethyl alcohols.

comnoz · Sep 1, 2011

Why do you run lead additive. The steel valve seats in a Norton don't have recession problems that I know of. Serviced a lot of old cars with plain cast seats that had big recession problems however. Jim

steveyacht · Sep 1, 2011

comnoz said:
Why do you run lead additive. The steel valve seats in a Norton don't have recession problems that I know of. Serviced a lot of old cars with plain cast seats that had big recession problems however. Jim

The gentleman that rebuild my engine suggested the three items I add to each tank, as well as the oil I should use. It runs to pennies a tank and i can see no harm in doing it, so I will do as he suggested.

comnoz · Sep 1, 2011

steveyacht said:
comnoz said:

Why do you run lead additive. The steel valve seats in a Norton don't have recession problems that I know of. Serviced a lot of old cars with plain cast seats that had big recession problems however. Jim

Click to expand...

The gentleman that rebuild my engine suggested the three items I add to each tank, as well as the oil I should use. It runs to pennies a tank and i can see no harm in doing it, so I will do as he suggested.

That makes sense. Jim [I have never run anything but just gas]

bill · Sep 1, 2011

I used to see small block ford's and chevy's that had the induction hardened valve seats that looked like they were machined for a replacement seat.

comnoz said:
Serviced a lot of old cars with plain cast seats that had big recession problems however. Jim

Flo · Sep 1, 2011

No addatives for me. Put ordinary petrol in mine & it is a high compression motor.
Prefer to ride rather than worry.

bill · Sep 1, 2011

IMHO the only thing worth adding is MAYBE the stabil. nortons do not have a valve recession problem from soft seats. with a lower compression motor (NON COMBAT)our US high test is plenty.

steveyacht said:
I use the following: Marine Stabil (the blue stuff), Octane Boost and a lead additive.

comnoz · Sep 1, 2011

bill said:
IMHO the only thing worth adding is MAYBE the stabil. nortons do not have a valve recession problem from soft seats. with a lower compression motor (NON COMBAT)our US high test is plenty.

steveyacht said:

I use the following: Marine Stabil (the blue stuff), Octane Boost and a lead additive.

Click to expand...

Lucky you- you get the 93 octain stuff down there. We just get the 91 in Colorado. Actually no problem in my Norton but my van sure likes the 93. Jim

gjr · Sep 1, 2011

You are wasting your money on additives. Save it for parts. The valve seats don't wear. The guides will be all floppy before the seats show any wear. The compression isn't high enough to need more than what passes for pump premium. My '70 750 runs just fine on anything that will burn. When I was deep into the reserve, 85 octane worked great. I'm not racing so your experience may be different. Stabil is not a bad idea if your gas has ethanal in it since it goes bad in about 30 days.

Greg

Tim_S · Sep 1, 2011

Without getting too technical here just how much of the posted pump octane is actual useable numbers? Just curious ?

I remember our local station selling racing fuel with a pump posted 114 octane on the sign. But ,,,when you paid the cashier she gave out a brochure that stated you actually got 107 useable octane.
What do the old car guys use for fuel additive's? Most guys around here just run straight pump gas. As I do in all my old bikes from years 1935 to present.

Tim_S

comnoz · Sep 2, 2011

Tim_S said:
Without getting too technical here just how much of the posted pump octane is actual useable numbers? Just curious ?

I remember our local station selling racing fuel with a pump posted 114 octane on the sign. But ,,,when you paid the cashier she gave out a brochure that stated you actually got 107 useable octane.
What do the old car guys use for fuel additive's? Most guys around here just run straight pump gas. As I do in all my old bikes from years 1935 to present.

Tim_S

There are two standards used for octain tasting, MON and RON. If you ask the supplier they can give you either number.

The old car guys I know who actually put miles on there cars just use pump gas. If the valve seats fail then they install hard or powdered metal seats. I really don't know much about the additives that are available but it has been my impression that they do little if any good in stopping valve seat recession if it's going to happen. Many old engines run fine for many miles on unleaded fuel. It depends on the particular alloys used in the valves and seats along with operating temperature and camshaft closing rates. Mid to late 70's performance cars with lean carbs and hard valves running on plain cast seats were probably the worst for microwelding which is what causes recession. Jim

Hobot · Sep 2, 2011

It may be in the service advisories but no changes were needed to Nortons to tolerate no lead just fine. Best additive to me is a small dollop of caster bean oil as sold for the 2 smokes in cycle shops, but just a dab will do ya.

GRM 450 · Sep 2, 2011

Hello Don, if you must use a lead replacement use it sparingly. My mk3 runs without any additives and I have run it on 98 but 95 is fine. I have old single Ducatis that have bronze seats, I spoke to the tech fellow at Nulon and he suggested using their octane booster as a lead replacement and upper cylinder lube. 1mil per litre. After trying other products that tended to foul the plugs I tried the Nulon fellows recommendations with good success. I don't think your Commando would need anything but this stuff is ok. Graeme

Cowboy Don · Sep 2, 2011

Hmmm, I searched for additives and dug 6 pages deep and didn't get this much info. I gotta say, I rode my previous Commando on nothing but 93 without any additives, but it did drop a valve through the piston.
I might give the Nulon octane just to say I did, but it sounds like it's all a resounding "Snake Oil" verdict.

GRM 450 · Sep 2, 2011

Don't think a dropped valve was caused by unleaded, more like damaged seats and poor gas sealing.

Additives

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