Vk, valve saver

[Ben.]

hey ive got a vk carby black moter do i need to add the valve saver?
thanks ben

[DANNY8]

More then likely yes, if the head hasn't been modified to run ULP. To run ULP ya just need new valves and seats I think.

[Ben.]

Alright too easy i have been adding it, sham i cant tell if they have been changed over its life,
thanks

[vkberlina]

I have posted this several times before this place is becoming like groundhog day

Now reasons for running correct octane fuel...

When you run a low or insufficient octane fuel, your engine pinks (detonates, pinking, pings, knock what ever you get the point.) Under load.

Now this causes huge increases of heat in the combustion chamber. Now what this does is causes your exhaust valves to get to point where they begin to melt on the surface. Now generally under high load and/or high-RPM this can/will cause engines to fail.

Now you don’t _have_ to run lead or an upper cylinder lubricant. Under normal every day driving conditions your exhaust valves wont get hot enough (using fuel of sufficient octane) to cause valve seat recession. Even under higher load scenarios this will mostly be the case as well.

I Oz we have had fuels with 98 octane like Shell V-Power and the mobil, BP & Catel Vortex 98 these generally exceed the octane rating for most cars. As you have sufficient octane the car wont pink, because it isn’t pinking you have lower combustion temps so your valves don’t get as hot. As they are not getting, as the valves don’t micro/localise weld themselves to the seats so you don’t get valve seat recession.
note Regular unleaded is around 94 from memory & premium is 96 along with caltex vortex which basically is premium with injector cleaner. V Power, Vortex 98 and the other flavours by mobil & BP are all 98 octane fuels.
Now with the advent of E10 91 octane fuels the problem will become worse, the lower octane ethanol fuel mix burns at much high temps which will cause even quicker valve seat recession. On high performance alcohol cars and rockets water has been used up to 25% mixture to lower combustion temps which could be adapted to a road car. Also fuel mixtures are all wrong so with carbie jetting needs to be changed or EFI computers remapped noral fuel/air ratios are about 14.1 to 15.1, but for ethanol fuels its lower so you need more fuel to the same amount of air to get the same bang, hence the higher fuel consumption on ethanol fuels.

If you drive an older car like a VB-VK and it is driven in a low-stress application, basically used as a daily driver, then you need have no real need to run upper cylinder lubes or lead. As long as you use a fuel that meets or exceeds the octane rating for your engine. Really the only time you hay require an upper cyl lube is high sustained loads and RPM all the time.

If you rebuild your engine the best way to overcome this from ever happening is to install hardened exhaust valve seat inserts and exhaust valves of harder materials, such as 4N stainless.
Also if you lower your compression this will enable you to run a lower octane fuel. Simply retarding your timing isn’t really the proper way to tune an engine to run a lower octane fuel. Although you can advance your timing when you run a higher octane fuel this is because the cars timing was retarded from factory to pass emissions laws etc.

If your car pinks for a longer period of time you may experience pre-ignition or overrun when you turn your engine off. Basically what’s happening is your cylinder is so hot it’s igniting the fuel without the need for spark. This generally wont last long as your engine will destroy itself pretty quick.

The early commodore engine were designed for 97 octane super. If you run 98 octane fuel you wont need to run an upper cylinder lube. Super used to contain approx .14grams per litre of lead, Potassium, Manganese, Sodium & Phosphorus based upper cylinder lubes wont do the same job as leaded fuels, they burn at a lower temperature than lead does. Although they may aid in protecting they wont do the job as well. Sodium based substitues have been linked to damage to turbo charges.
Most additives will also contain a octane booster component. The higher the octane fuel the cooler the compustion temperature will be.

cya
Scott

[ari666]

^^^ thats all correct (even though i didnt read it all)

[Drewie]

I have been running our VC 202 on 95 octane and Flashlube for the past 5 years without any problems, 98 octane is closer to the correct octane rating originally specked for the engine
but it seems to run fine on the 95 octane, for the small cost involved why not use the additive, a litre bottle treats 1000 litres of fuel and from memory was under $20.
The lead that was in Super grade fuel as well as lifting the octane rating also left a thin film on the valve seats thus cushioning the exhaust valves and helping prevent valve seat recession, the additives probably don't do as good of job as the lead did but would have to help, for the small cost I always pop it in when filling up. I bought a litre bottle and a small 50ml bottle that treats 50 litres, I just refill the smaller bottle and keep it in the glovebox.

[vkberlina]

or just spend the slight extra money for 98 octace each fill up and not need to worry about the upper cyl lube at all. without doing the calcs it would prob be around the same price as 95 with lube.

cheers
Scott

[PirateJoe]

^^^ thats all correct (even though i didnt read it all)

lol, ok then mate. whatever you say.

Change your mind now?? Maybe you should read it all..

[ari666]

??? i dont understand. your keeping this up in another thread? why? do you really feel that you have to get a point across?

sad.

[PirateJoe]

If its sad mate why bother with the banter in the first place? Was only pointing it out, precious.