lubricating system against vsr

[LPGmalta]

Hello,

I just had a chat with my supplier who said that as a company they do not believe in valve saver kits. They think that vsr can be eliminated by using petrol injections whilst on lpg.

From experience, are they correct?

[classicswede]

In some cases yes but not in all. I prefer to use a oiler system and then petrol addition as an extra in some of the worst engines

[LPGmalta]

Thanks to your input. Which engines do you consider the worst?

[LPGmalta]

Thanks to your input. Which engines do you consider the worst?

[robbie1003]

A oiler system?
This topic is of interest, I run the 4.7 jeep grand Cherokee that's supposed to have issues with vsr and not wanting to suffer the pain of head removals. Im disgusted at the cost of flash lube products and believe there is a cheaper and more accessible product that would work in similar way. With our vehicle it gets more stop start running so it does get petrol use which is saving the valves but not good for the fuel use but never the less it allso goes through allot of flash lube.

[bbstrikesagain]

Experiences may evolve.

Many engines had hardened valve seats since unleaded was introduced, so VSR might have been minimal, for a while.

However, more recently (perhaps since 2006-7) manufacturers have been aggressively taking out costs. Some have gone back to just-tough-enough soft valve seats, okay on modern gasoline with enough additives - maybe. Soft-seats may also be helped out a little by the fact that many engines are now designed to consume a bit more oil - it's burned and is specified to be safely catalysed. In the same way makers have shifted back from forged pistons to cast pistons, all to save costs.

Funnily enough I hear that failed pistons crowns, break downs due to low oil between services, and even VSR are all back on the menu for more recent cars, even running on petrol as designed. Progress eh?

If "some" LPG installers keep insisting that extra valve protection isn't required, or that a lump of metal in the LPG tank can do the job, then I fear customers may start to get their fingers burned over the next few years.

[bbstrikesagain]

Im disgusted at the cost of flash lube products

Flash-Lube, JLM and V-Lube have each been independently tested and shown to halt VSR that had been progressing after switching to LPG without lube.

Dosing with any of those, at normal 1 ml/l dose rate, costs about 1 to 1.5 pence per litre of LPG used. Not sure I feel too ripped off?

[Gilbertd]

Some have gone back to just-tough-enough soft valve seats, okay on modern gasoline with enough additives - maybe.

That and a lot of engines these days are considered service items with a design life of no more than 100k miles. Try buying a set of big end or main bearing shells for some modern engines, they just can't be got. The theory being that if an engine is so badly worn as to need them, you just fit a new one rather than rebuild the one you have. That's why the engines that are known for being good for starship mileages, are the ones that take well to LPG conversions. I'm thinking of things like Saab (proper Saab not later GM), older BMW, Merc, Land Rover (my own being a good example with 280,000 miles on it), Volvo (although only proper Volvo and not the modern Ford units) all of which are know for going on forever.

[LPGmalta]

What kind of systems do you usually use, as the ones depending on vacuum from the inlet manifold, do not flow the lubricant at full throttle due to the fact of low vacuum, and that is the time a valve saver is required the most.

[Gilbertd]

It is but the protection is already there. Back in the days of the switch from leaded to unleaded it was normal to run one tank of leaded to 3 tanks of unleaded. The one tank was enough to keep sufficient lubricant on the seats.

[bbstrikesagain]

What kind of systems do you usually use, as the ones depending on vacuum from the inlet manifold, do not flow the lubricant at full throttle due to the fact of low vacuum, and that is the time a valve saver is required the most.

JLM and Flash-Lube tests were with their own respective vacuum systems. V-lube test was with single point electronic system. All three were with naturally aspirated engines.

Electronic might be better for forced induction, but not sure that has been proven. Even blown engines suck a fair amount of the time...