SAVAGEJIM

I've noticed that many engine makers do not like to advertise horsepowers (NovaRossi, Picco, Traxxas, etc.) because of they claim there are too many factors and unstandardized means of measuring hp for nitro engines.
I say that all nitro engine makers should pick up the standard already in place for standard i.c.e.'s (internal cumbustion engines). That standard is the SAE standards and corrections for calculating net hp. Also, a standard dynometer type should be adopted to further rule out dynometer discrepencies.
Also, to keep the advertised hp constant concerning fuel, they should use the common 20% nito fuel (preferably a common blend of nitro, oil, fuel, synth lube, etc. that most fuel makers make). I'm not too certain if there is a common blend fomula that most fuel makers use since they too try to keep their formulas secret; but if one fuel maker is using the same formula blend that another fuel maker uses, they should all be honest and tell us that. Maybe most nitro fuels are so similar as to be the same; I'm not sure. I've only used three different brands of fuel. Aside from retuning my engines, I have not noticed much difference when I run the different fuels through a given engine. Maybe the fuel fomulas are all the same, just like in regular unleaded gasoline we pump into our cars. Everyday, people think that Chevron with Techron is better than Texaco with TexRon (or whatever they call it). Little do the public know that Techron and TexRon are the same; its methanol mixed into gasoline in accordance to federal law. One gas company calls the methanol one thing and another calls it another and claim it increases power and cleans the jets or injectors. Thats true, methanol does that but since it is more volatiile, it has less BTU's per weight and in the end, modern unleaded gasoline burns more quickly. Sorry for the rant, back to what I was saying.
For tuned pipes and headers, each engine maker should use their own headers and pipes best suited for each of their engines they advertise. This is to hopefully convince the buyer that the engine by itself is not the only factor to pull out max powere out of a given engine.
I believe nitro engine makers can quote a hp rating and more usefully, give us torque and hp curves. A turque curve is useful so you know what RPM band the egine best performs at. If the engine has a "spike" or "peaky" torque curve, the graph of the curve will give the driver an idea at where to maintain his engine RPM (of course, by listening to what pitch the engine sounds like at the peak).
What I'm saying is rc nitro engines should pick up standardized means for measuring hp and torque. I hope they will soon. If there are other factors I have not mentioned or what I mentioned about nitro fuels is missing some information, please reply and let me know. I'm just peeved at engine makers hiding behind the excuse "we don't quote hp because of too many variables!".

dustin7837

My Feedback: (1)

Things like altitude, humidity, air filter, ambiant temperature, and engine break in will affect the numbers too.

Also, to try and get better numbers, manufacturers are likely to over lean the engine. It's not like they are worried about longevity on their test engine.

SAVAGEJIM

Thats true, I should have also added the engine manufacturers should post the best break-in methods for each of their specific engines.

Also, when advertiseing their engine's output, engine makers should also post at what temp the engine was at when it was making the advertised hp. That way, we will know if the hp is actual or unrealistic.

As far as altitude, humidity, ambient temp, the SAE standards assume sea level and have a correction factor concerning air density and ambient temp. If nitro engine makers can adopt these standards and fuel makers make consistent fuels in comparison from one brand to another, I believe standardized nitro horsepower can be achieved.

I am also curious as to what other factors are out their that cause one hp measure to vary widely from another hp measure when testing a given engine. Anyone out their, please tell me (I'm not a nitro expert).

dustin7837

My Feedback: (1)

I think we pretty much have most of the variables covered, but I think that if you really want EXACT measurements for comparison sake, you would have to have all the engines dynoed on the same machine in the same place wtih the same conditions. Because who knows, maybe altitude or humidity will affect one engine more than another, so it would be hard to create a correction factor.