In case some people don’t know what it is. Flash lube kit injects a small amount of lubricant (oil) at certain intervals into your inlet manifold. The idea is to preserve valve seats from wearing out (recessing) due to LPG use, since LPG is gas & does act as lubricant like petrol.

My engine came with LPG stamp (I believe most 3rd gens did). Has anyone had experience with exhaust valve seats recessing in a 3rd gen due to LPG use or is this whole thing a myth? I can understand the need for it on engines that were designed to run on leaded petrol…

Reason im asking is because im getting VSI system installed tomorrow so might as well do it all at once.

Dude, people have dippferent opinions. Some swear by them, some dont. At the end of the day, Its cheap insurance. Usually an installer will throw it in for nothing.
You can now get electronic ones, not the old school screw valve ones. At the end of the day, why not. Cant to any harm or damage.

WHat SVI system you having put in?

Andrei, how much Is your kit costing?

Im not sure about what brand it is, VSI kit will cost me $2600 fitted since i have lpg tank already from my old venturi system. New flashlude kit is around $100 i will get the guy to put it in for free....

2600 before or after rebate?

Im not getting one because my car already has LPG fitted, you can not claim rebate if your car has any kind of lpg system already........ So its basically $2,600 to take the old system out, like mixer, ecu, converter & put in new VSI system. What really buged me about venturi system is that mixer took up to much room in the intake & significantly reduced performance while on petrol.

Flashlube kits were popular when car manufacturers were faced with a reduction of lead in petrol. The theory was that the lubricant would prevent the valve seats from wearing down. There are three reasons why in a modern car flashlube is a waste of dollars.

(1) The oil is not likely to end up on the valve seats, its in the air/fuel mix and flies past the valve seats at a considerable speed.
(2) Valve seats these days are hardened and don't wear. LPG certified engines have "special" hardened seats.
(3) Even when popular, there was no technical info on the efficiency of the system. How hard is it to run 2 identical cars, say 50,000 miles, strip the heads and show how good your product is? It has always been sold as "a good thing, take our word that it works" type of based-on-faith proposition.

Having seen the valve seats in my TS V6 with 240,000 km on it, and a number of Sigmas with similar mileage, I don't think the problem of valve seat recession due to lack of lubricant is a problem, but then I don't think it ever was, unless you were running a 1940's car with an iron head with the valve seats cut straight into the metal of the head.

The front TS V6 head had a burnt exhaust valve, 5 mm crescent shape burnt out of the valve, which caused a low throttle misfire. The valve seat was undamaged. They are pretty tough.

It would be good to have a look at my cars valve seats, its done nearly 270,000 with over 150,000 on LPG.

I wouldn't strip your engine down just to look at the valve seats though. lol

hahaha couldnt agree more.....

As said dude, cheap insurance.
Know mates with ECOTEC commodores and one burnt his valves after 75,000k's on gas without flash lube and the other with the flash lube is still running fine with over 200,000 on it.

Flashlube kits were popular when car manufacturers were faced with a reduction of lead in petrol. The theory was that the lubricant would prevent the valve seats from wearing down. There are three reasons why in a modern car flashlube is a waste of dollars.

(1) The oil is not likely to end up on the valve seats, its in the air/fuel mix and flies past the valve seats at a considerable speed.
(2) Valve seats these days are hardened and don't wear. LPG certified engines have "special" hardened seats.
(3) Even when popular, there was no technical info on the efficiency of the system. How hard is it to run 2 identical cars, say 50,000 miles, strip the heads and show how good your product is? It has always been sold as "a good thing, take our word that it works" type of based-on-faith proposition.

Having seen the valve seats in my TS V6 with 240,000 km on it, and a number of Sigmas with similar mileage, I don't think the problem of valve seat recession due to lack of lubricant is a problem, but then I don't think it ever was, unless you were running a 1940's car with an iron head with the valve seats cut straight into the metal of the head.

The front TS V6 head had a burnt exhaust valve, 5 mm crescent shape burnt out of the valve, which caused a low throttle misfire. The valve seat was undamaged. They are pretty tough.

I Disagree with this mate as we pulled the intake manifold off my KJ with a flash lube system today and saw that all the intake ports were lined with a lube/oil substance all the way down to the valves which is the flashlube. To say it doesnt end up on the valves and passes straight through is false. There was quite a layer of lube all round the port holes right down to the valves.

As a person who has pulled apart many engines and heads, while I would not pay for the kit, most places when you get gas will include for free thus I would not say no

MadMax, you are really missing the important thing in your arguement, the Sigma was not designed for ULP, it was designed for Leaded Petrol which used lead to lubricate seats etc etc. When ULP was removed from the market, these cars now had to run with no upper cyl lube thus they start wearing. Also a TR/S in comparison to a new off the line car or even for that matter a 10yr Old TJ is a very bad comparison. Your statement also contradicts itself, so do most new cars have hardened seats or only those certified to run LPG?

At the end of the day, there is absolutely nothing wrong with flash lube, many people years ago used to run Castrol R40 or similar when running high octane fuel as upper cyl lube and this did work, flash lube is really not that much different aside from the fact it does not rely on a person putting the correct amount each time they add fuel

Flashlube - some people swear by it, other people swear at it. lol In the end, you make your own choices, and spend/not spend your own moneys.

Now if someone could explain how oil on a valve seat can stop it from recessing by being hammered by a valve thumping into it, I'm all ears. Better still, show me a link to a scientific paper of two identical cars, one with flashlube, one without, and the effect on valve seats after 80,000 to 160,000 Km. Blind faith has its place in the world . . . . . this isn't it.

I know that i was getting better milage from my old 2.6l isuzu trooper when using moreys upper cylinder lube and injector cleaner, added to the tank. anyone used the moreys system that drip feeds it into intake manifold?

In order to know how an upper cyl lub works it really helps if you know how an engine works, no not that it starts when you give it a kick with the key, but what happnes internally

The valve does not just "slam" up and down, it rotates, that is right it spins

The action of the rotating valve on a seat that is not hard enough causes....wear

Now Lead used to be the lubricant to slow this process down thus why cast heads got away with no seats as such and only used the casting for a seat, bring on ULP, the greenies decided that lead was soooo bad and to shut them all up the governments around the world gave in and gave us Benzine, that cancer causing chemical which does not lubricate at all but does reduce the instance of pre ignition, which was another property of Lead.

Now with Gas, there is no lead or Benzine or anything for that matter, the gas being either injected or pushed into each cyl is not the best thing to lubricate thus the addition of the oil in the mix will help reduce seat wear

Think a little outside of the square and think on how a 2 stroke works, no valves but then again what happens if you remove the oil from the fuel, the engine seizes. Those here old enough to remember super fuel would remember that a 2 stroke would still run for a time withno oil when there was super, the damage would still be there in so far as bearing damage but the bores etc would often be saveable. Now not so.

As they say in the classics, on that bombshell, it is now time to go, good night.....