Topic: To lead or not to lead

[HondaYo]

Struck me as I filled up my -72 K1 today that it might be a good idea to check if I need to put lead-additive in my fuel. The head was refurbished during the past 10 years or so. I´ll check with pre owner. Any input?

[BomberMann650]

NO!!!! 

These bikes aren't that old 

[HondaYo]

Actually, the owners manual I found online says it´s recommended to add a few percentage. What say You?

[drumstyx]

I mean, the answer is indeed no, but I don't think it'd hurt, there's no catalytic converter.

I wouldn't bother obviously, but I've always wondered if it might actually be good for the valve train in all my bikes (which don't have cats) to run leaded fuel. Obviously bad for the environment and all, but would it reduce wear?

[TwoTired]

The aluminum heads have hardened valve seats, so lead is NOT strictly required.  Doesn't hurt though, to lube up those seats with lead.

I don't see a requirement, or need to worry about it.

[Lostboy Steve]

I don't even run lead additive in my 61 corvair. Just a little mystery oil in the amco top end oiler. A while back on here someone said they used a small amount of 2-cycle oil in their tank at fill up and I've tried that but have reverted to marvel for everything. I used to do belray 2 stroke in my ported rx-7, a qt per fill up.


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[TwoTired]

The biggest problem with lead loss is valve seat recession.  My 72 truck has cast iron valve seats.  Under load, the lubrication loss will cause seat erosion.  I don't even need lead in that truck unless I'm towing a trailer up grades.  I add lead substitute when that occurs.

I don't believe mystery oil works in the gas supply to lube valve seats, as it doesn't contain a lead substitute.  I also don't think a 2 stoke oil has enough lead in it to save valve seats.   But, unless you are working the motor hard, you don't really need it.

The SOHC4 already has hardened seat in the aluminum head.  Just don't strictly need lead for seat lubrication.

Cheers,

[Lostboy Steve]

The biggest problem with lead loss is valve seat recession.  My 72 truck has cast iron valve seats.  Under load, the lubrication loss will cause seat erosion.  I don't even need lead in that truck unless I'm towing a trailer up grades.  I add lead substitute when that occurs.

I don't believe mystery oil works in the gas supply to lube valve seats, as it doesn't contain a lead substitute.  I also don't think a 2 stoke oil has enough lead in it to save valve seats.   But, unless you are working the motor hard, you don't really need it.

The SOHC4 already has hardened seat in the aluminum head.  Just don't strictly need lead for seat lubrication.

Cheers,

Yeah so does the corvair.


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[drumstyx]

On this topic, if I wanted to add a lead/substitute additive, is there any definitive study on real lead vs lead substitute? Being in Canada, of course all we have is lead substitute.

[Bailgang]

  I also don't think a 2 stoke oil has enough lead in it to save valve seats.   But, unless you are working the motor hard, you don't really need it.

I think in regards to Steve using 2 stroke oil in his RX7 it has to do with keeping the apex seals of the rotors lubed and I'm not sure leaded gas would help much in a rotary. I don't know too much about Wankels but I do know that many if not all rotary's have some sort of oil injection system at least I know a friend of mine's RX7 had it.

[Lostboy Steve]

  I also don't think a 2 stoke oil has enough lead in it to save valve seats.   But, unless you are working the motor hard, you don't really need it.

I think in regards to Steve using 2 stroke oil in his RX7 it has to do with keeping the apex seals of the rotors lubed and I'm not sure leaded gas would help much in a rotary. I don't know too much about Wankels but I do know that many if not all rotary's have some sort of oil injection system at least I know a friend of mine's RX7 had it.

I would never spend the type of money I did on a project like that ever again. Those engines, yet distinctive and fun, are a nightmare in the long run.

The 2-stroke or marvel is just to help with lubrication. Air cooled engines get hot and every bit of extra lube helps.


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[HondaYo]

Obviously I spend energy worrying about  unnecessary things, when I should spend more time riding my bikes.
 Northern paranoia perhaps.
Thanks guys. Didn´t really know what the actual purpose of lead in fuel was til now.

Enjoy Your weekend!!!