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Old motors and unleaded
Sawz
Member Posts: 6,049
Have an old boat motor that needs leaded I have used lead additive in the past. My mechanic says that if you use the right oil and or oil additive it will take care of the guides anybody heard of this before?
Comments
Just get a new boat motor. My father in law swears by Honda 4 strokes.
This is a sterndrive inline 6 cylinder (Inboard outboard) its the little chevy 6 cyl. 250 or 4.1.
Seats and valve guides is what I have read maybe more seats but still guides
http://www.chevron.com/products/prodserv/fuels/technical_safety_bulletins/use_unleaded_gas.aspx
here is a link from chevron
http://www.chevron.com/products/prodserv/fuels/technical_safety_bulletins/use_unleaded_gas.aspx
Thanks for that link sounds like If I run Premium or octane booster will be better for the engine
from that website
quote:Mercury, who is a major supplier of Stern Drive Engines for marine use, advises that their engines are automotive based and have hardened exhaust valve seats. Most of Mercury's outboard engines were developed with unleaded gasolines, and Mercury's only concern is with octane number.
quote:Originally posted by grumpygy
Lead was not for the Guides. It was for the valves and valve faces. Lots of old engines have been converted with new valves and seats.
Yes seats were hardened so the need for lead was not more. Most times I just changed the valves too.
Replace valves, valve seats and guides only as needed after inspection.
Boat motors don't see the loading (BMEP) motor vehicles put on them.
An old Case tractor from the early fifties original valves
Ford 8M original valves
International KB5 original valves
Plus a couple if other old pre lead engines in other units
These are not sit in the stall units, all are run on unleaded fuel. Usually run diesel lube oil in them for the zinc additive for the lifters, not convinced that is even necessary. Over winter simply turn them off in the fall with no additive to the fuel and they run fine in the Spring.
I have no problem with unleaded, have no reason to believe lead additive is needed
quote:Originally posted by savage170
here is a link from chevron
http://www.chevron.com/products/prodserv/fuels/technical_safety_bulletins/use_unleaded_gas.aspx
Thanks for that link sounds like If I run Premium or octane booster will be better for the engine
from that website
quote:Mercury, who is a major supplier of Stern Drive Engines for marine use, advises that their engines are automotive based and have hardened exhaust valve seats. Most of Mercury's outboard engines were developed with unleaded gasolines, and Mercury's only concern is with octane number.
Better fuel and octane boost isn't really gonna fix it. have to use lead substitute.....
Still runs great.<1FMJ>
I rebuilt the V-6 in my 1965 Evenrude boat in 1989 I call OMC and asked about leaded gas.Engeneer said to switch to premium higher octane fuel.And not to get valves hardened.As it will not be worth the added cost.
Still runs great.<1FMJ>
That was 1989. unleaded fuel require's hardened valve seats. wanna see what happens in one of our racing engines with 'old heads'? they swallow valves......