los aditivos....esos grandes amigos desconocidos
lo peor de las gasolinas actuales no son la falta de aditivo de plomo, sino el exceso de etanol
la falta de plomo produce un efecto llamado seat valve recession, por el cual se arrancaban micro trocitos de material del asiento de valvulas de culatas antiguas cuyo material de asiento de valvulas era demasiado blando
cuando se retiro el plomo de las gasolinas entro en tromba una serie de productos como aditivos que incluian varios componentes, desde fosforo, sodio, potasio hasta manganeso
La tonica comun de estos productos comerciales es la falta de declaracion del componente y de su porcentaje, resultando muchos de ellos en un balsamo de fierabras o snakeoil sin ningun efecto positivo, e incluso con el riesgo de efectos negativos en el motor
hubo un estudio extenso de la federacion de vehiculos historicos de UK que sobre 10 motores ford probaron exhaustivamente varios aditivos, los resultados eran bastante significativos y no recuerdo todos en detalle, me quedaron claras dos cosas, que era muy malo mezclar aditivos de fosforo y de sodio (o sea si usabas uno mejor seguir con el y no cambiar) y que lo que mejor funcionaba era el manganeso, pero el bote cuesta de 6 a 10 euros por deposito de 40 litros.
problema, no suele haber esos aditivos en la gasolineras españolas, y ademas son caros (porque el 3CV que no sirve para NADA cuesta 2 euros, y tranquiliza nuestra conciencia suficientemente)
https://www.fbhvc.co.uk/fuels
The following additives have been tested as being effective against valve seat recession, and are approved for use by the Federation of British Historic Vehicle Clubs
Tetrosyl Automotive
Carlube Lead Substitute (supersedes potassium-based Nitrox 4 Star Lead Treatment and manganese-based 4 Lead Substitute and Octane improver). This additive is said to prevent engine knocking and pinking, in addition to preventing power loss (due to valve seat recession) in older vehicles. Tetrosyl Automotive, Bevis Green,Walmersley, Bury, Lancashire, BL9 6RE. Tel. 0161 764 5981.Website:
http://www.tetrosyl.com
Castrol
Castrol Valvemaster and Valvemaster Plus Incorporating phosphorus. Castrol’s Valvemaster is claimed to protect engines under all driving conditions, to help keep the fuel system clean and to provide excellent corrosion protection. In addition, Valvemaster Plus incorporates an octane booster for engines running with relatively high compression ratios. Castrol,Wakefield House, Cambridge, CB4 5QZ. Tel. 01954 231668.Website:
http://www.castrolclassicoils.co.uk
G. T. Autochemilube
GTA Power Plus Formula 2000. A potassium-based additive. GTA is now supplier of Castrol products. G. T. Autochemilube Ltd., Unit 4, Riverside Business Park, Tramway Road, Banbury, Oxfordshire, OX16 5TE. Tel. 01295 272799.Website:
http://www.gta-oil.co.uk
Millers Oils
Millers produces a wide variety of petrol additives for road and track use. Millers VSPPlus is a manganese-based additive, which benefits from the inclusion of an octane booster, raising the octane number of the fuel by two (so, for example, 95 octane fuel is effectively rendered 97 octane by the use of VSP Plus). New launches include CVL and CVL Turbo; lead replacement and octane booster additives aimed at the enthusiast for fast road, track day and motorsport use which, when combined with Shell Optimax, are claimed to have the same values as racing fuel. Millers Oils Ltd., Brighouse,West Yorkshire, HD6 3DP. Tel. 01484 713201. Website:
http://www.millersoils.net
Delta Oil
Red Line Lead Substitute Employing sodium to deliver the goods, Red Line Lead Substitute is said to clean intake systems, carburettors and injectors in addition to preventing valve seat recession. It was developed in the U.S.A. Delta Oil Ltd., Unit F1, Market Overton Industrial Estate, Market Overton, Rutland, LE15 7PP. Tel. 01572 768311.Website:
http://www.redlineoil.co.uk
Superblend
Superblend Zero Lead 2000 relies on potassium to prevent valve seat recession. The dilution rate of the latest version (in terms of the ratio of Superblend to petrol) is lower than its predecessor, meaning that less of the product is required for a given volume of fuel; in other words, it is now cheaper to use! Superblend Lubricants Ltd., Unit 2, Feldspare Close, The Warrens Industrial Park, Enderby, Leicester, LE9 5SD. Tel. 0116 286 1001.Website:
http://www.superblend.co.uk In addition to the products tested and approved by the FBVHC, there are many other products available which claim to reduce/eliminate valve seat recession. Just one is the manganese-based Redex Lead Replacement Octane Booster. Check out STP products too
adicionalmente existe un documento de BMW de 1987 que establecia que un coche con 50000 km recorridos con gasolina con plomo habia depositado suficiente plomo para lubricar sus asientos de valvulas forever (un poco flipante, pero bueno era oficial)
las culatas de coches BMW desde el año 80 tenian asientos endurecidos, no se las de las motos
y hasta aqui puedo leer
yo no uso aditivos