Hi Andy I have a question to kick it off,.....

Whats the basic difference between normal (if you can call it that ) and SLV ?

I know its all very tecno / rocket science but in terms mortals can understand why pay more for SLV ????

Thanks X Rachel

Hi, is the 20%slv due out any time soon i the uk?

Hi Andy.
When will the SLV 20% be here in Switzerland??

SLV Fuels

Hi Guys,

I will answer the questions in two parts. Firstly cost. SLV oils are a new development with KLOTZ which came about after meeting with there production manager last August whilst out at the World F3C Competition. Klotz being close to Muncie Dave and I stayed on for a couple of days after the Worlds and visited them.

Whilst there we discussed at lenght our feelings about oil and it was decided to make some test batchs of a new oil. The proviso here is that it must have the same film strenght as the oil we were using so it would be at least as good at protecting the engines under load as the other KLOTZ oils. We were told this could be done and that the viscosity could be lower, test batches arrived and Dave and I set about testing the new product. Interestingly after the first tank I got a call from DF and he actual words were 'Andy this is the biggest step forward in modelling in recent history'! We knew we were onto a good thing. Further testing was undertaken to set the oil % and we swapped to testing in fixed wing with the UK Nat Champion F3A and did some testing with the UK Freestyle champion all loved it, more power, better than 50% faster recovery rate and lower operational temperature and more economy, 26% longer runs.

So our thoughts about viscosity were bourne out, we had already broken the mould as being the first manufacture to exclusivly go to low viscosity fuels across the board.

So to pricing, this is really a function of volume. We buy three types of oil from KLOTZ and the SLV oil is not the largest volume so we do not get quite such good prices as the volume grows prices will no doubt either come down or stabalise, KLOTZ oil has risen in price three times in the past year none of which have been passed on to the consumer. If the fuel volumes go up then the likelihood is prices might reduce! Just as a point of interest we have a container of oil on route all the time as we do nitro to ensure stocks are always available, a big commitment to making sure you do not see OPTIFUEL out of stock!

On the issue of SLV20, we are quite away down the testing road with data coming back all the time, in fact every flyable day this I have to say looks stunning so we will see. One or two pilots have had the fuel to try and they like it we are doing oil% testing and temperature profiling at this time and headspeed/load monitoring. All I can say is it is way better than standard 20 as for when and if we bring to market I suggest you keep an eye on the website.

Fading Colour

Hi Andy,

I've seen posts before about Optifuel fading in colour but I've never seen this before. This is a new build LE - Flew two tanks of fuel last week. This week (6 days later) the fuel in the header has faded but the main tank remains normal.

The heli has not been in the sunlight. Does this give any clues ?



The fuel flew fine.

Faded fuel

Dear Mr Slater,

Firstly can I recommend you do not leave fuel in either the main tank or header tank after flying as this will degrade the clunk tubing more quickly than you might think! Depending on the type of engine exhaust pressure or crank pressure the effect is much worse with exhaust pressure systems.

The burnt gas mixes with the fuel and this will damage the clunk tube prematurely not as bad with crank pressure systems.

The fuel will fade over time if it’s had gas in it as this reacts with the UV stabiliser in the fuel dye. The dye is not added by us its part of the oil pack, the colour of the fuel is determined by KLOTZ not OPTIFUEL. The other issue of perceived colour if the optical path length (OPL) you observe it over. In the case of a small volume in a short OPL the colour will look different to a larger volume over a longer OPL. The other part of our company (Process Measurement & Analysis Ltd) as it happens actually are the UK leaders in colour measurement using online spectrophotometers so colour is something we actually can and do measure and know a lot about, it is also part of the QA procedure under our ISO9001 testing criteria. In addition we do long term colour testing with some fuels over three years old now and still on colour testing and still stable!

We did have a batch of OH3020SLV which did fade and this was a manufacturing issue on the first batch which went to the contracted pilots, it does not look very good but the fuel performance is not impacted in any way and there is no danger with using it.

The other reason why fuel might discolour is moisture contamination. As I said earlier leaving it in the tank is not a great idea in my view and people do have different views on this particularly if using a fuel magnet but fuel is at least 50% methanol which is hydroscopic, give it any chance to absorb water and it will!

I hope this helps.

Andy,

What are the real differences between different brands of fuel? Methanol is methanol right? What makes Optifuel any different to say CoptaMix or RotorRage? Being new to helis, but having lots of nitro buggies, I can't really say I notice any difference between brands aside from colour and price!

Cheers,

Ian

Rusty bearings seems to be a big problem for some, esp with the higher nitro contents... Any comments on this?

Andy,

On the subject of bearings, I've just sourced and replaced my back bearing with a stainless steal version. Is it still likely to suffer ?

Run the engine dry at the end of the flying day - i.e. clamp off the fuel lines, fit the glow driver to the plug and turn the engine over using the starter. Do this until it stops running/firing.
This helps to get out the vast majority of fuel from the engine.
Turn the engine by hand until it sits at top dead centre to seal off the exhaust port, and bung the muffler as well.

On a Hyper 50, do the crank shaft webbing mod. The standard crank allows fuel to remain between the crank webbing and the bearing hiding below it in a sort of vacuum. If you don't leave the engine at top dead centre so the piston blocks the exhaust ports, air can get in through the muffler and the Methanol in the fuel will make use of that to attack the bearings.

The Hyper 55 doesn't need this as OS removed it for us, finally!
YS engines don't need this mod either.

I don't recall the last time I changed a bearing in my engines (any of them) although I do know that I changed one once in my old OS 91 HZ - I remember this as I used a YS 91 back bearing! I just can't remember how long ago that was.

Cheers,
Rob

What are the chances of doing this and keeping the engine balanced ?

How do you shave off the webbing ?

OS are not daft - there will be a good reason the webbing is there otherwise it would have been removed on recent engines.

Personally I will not be attempting the mod, Primarily because several of my friends run 55's and still need to replace back bearings (most follow the end of flight procedure described above)

On this evidence I would contest that it actually makes no difference.

Since I put the stainless bearings in I've had no problems and have the opinion that the solution is a stainless bearing.

Yet to be totally proven though the stainless has only been in for 2 gallons but no sign of rust yet,

My main reason for asking, I dont have problems at the moment, But Im running 12% opti in a TT39. But soon will be moving to a 50 size with a 55 in it and threads keep coming up about rusty bearings. But the consensus on the cause seems to be wide. When I move to the 55, I will be looking to move to 20% and this is where the problems seem to start. I burn off last bit of the fuel, use afterrun oil and close ports plug exh etc, and always have, and will continue to do so. But some seem to think that the problem is with the fuel.

Unfortunately, there doesn't seem to be an easy way to know how well each person is truly looking after their engine.

If you're not having problems at the moment, that is likely down to you following good practice. I really do not think you will have any problems when you move up to 20% if you keep doing what you are doing.

Cheers,
Rob

MSlater... I take it you didn't read the linked article, or indeed my entire post?
LOL

Cheers,
Rob