Fuel additive advice

[The_Handier_Man1]

From: Taddpowl1  (Original Message)
Sent: 2/3/2004 1:06 PM

I have a 1973 21 foot winne, 440 engine. When I purchased it the previous owner had been adding an additative to compensate for the lack of leaded gas. Is it necessary, for me to continue? it runs better I think with out it  Jim. Answer me direct taddpowl@comcast.net.



From: Liv42dayOK
Sent: 2/3/2004 1:46 PM

Since those engines were designed to run on leaded gasoline, although they will run ok on unleaded, without the additive, you will eventually burn up your valve seats. - Sob



From: mightybooboo
Sent: 2/4/2004 8:41 AM

"I have a 1973 21 foot winne, 440 engine. When I purchased it the previous owner had been adding an additative to compensate for the lack of leaded gas. Is it necessary"

Denison,can you comment on this if you know? I think I  heard older engines that arent run at high RPMS can do OK with unleaeded,is that true?
BooBoo



From: denison
Sent: 2/4/2004 2:40 PM

I sent taddpowl1 a long winded email on the topic. Basically I sort-of try to put something in, either one of the additives, or a little motor oil, but I don't consider it a big item. I expect my engine to wear out from lack of use, corrosion on the cylinder walls, piston rings, long before it has the problem of valve seat recession down into the head. My 413 engine is 32 years old this year, 91,000 miles on it. Its heads have never been off, but the plugs are getting cruddy sooner, like at 10,000 miles - due to oil getting by the piston rings. I think most of the deterioration is from the minor rust of disuse, not from use. Someday it will need rebuilt, at which time I will ensure it has hardened valve seats in the heads, if it doesn't already. If I drove my winny 25,000 or more miles annually, I might concern myself with the life of the valves, and would take more care in putting in an additive, or small amounts of motor oil. denison 



From: Im-still-Lefty
Sent: 2/4/2004 6:09 PM

Booboo, Leaded gas did two things, first it raised the octane, and second, it lubricated the valve seats. An older engine designed for leaded fuel has non-hardened valve seats. The rate of wear using unleaded fuel will increase without the additive but since these rigs usually don't see very many miles per year like the family car might, it is hard to say just how long it would take to wear them out before they would need replacement. My guess is that it would take many years before damage to the seats would occur, however, I do recommend using at least plus grade to keep the octane up high enough to prevent detonation (pinging). As to myself, I use it.  Lefty



From: denison
Sent: 2/4/2004 9:17 PM

Those of us with the 413 engine can use regular - due to the 8 to 1 compression ratio. I would think you could retard the spark to prevent pinging with the 440, on regular 87 octane fuel. denison 



From: UluzYarx
Sent: 2/6/2004 1:47 PM

Hi Tadpole,

Wow, this is the site for questions that have tricky answers.

Must be why I like it so.

The valve seat â€" valve â€" LPG humbuggery was a nice little earner for a whole shedfull of unscrupulous people

Your valves and seats hardened during their working life.

Just bang two lumps of steel (iron) together and you work harden it, ask any blacksmith.

They are well impregnated with lead too

They will wear quicker than special valves and seats, but not that quickly

I run mine on straight unleaded, but keep the revs off the amber line, which your automatic will ensure anyway (unless you play boy racers

As and when the time comes for a valve job, get hardened seats and valves at that time

Nothing serious goes wrong on unleaded, you’ll just need that valve job a bit earlier

Independent research by certificated laboratories over here in the UK suggests that very few additives work anyway, that different additives work for different engines, that you are in trouble if you change additives or if you change petrol brands, and that they are expensive.

I may be able to find some if you are really interested, but its the sort of thing that goes all 'rind the Wrekin to git theyre'.

The Wrekin is a bit of a 'tump' (hump or hill in Shropshire).  'Rind' is Black Country talk Black Country is where they made things from 'Black' iron, the same as in Blacksmiths.  It is near the Wrekin (sort of).

All the best - Dave