Interesting you comments Andy. I set off to find out what 1,2,4-trimethylbenzene is and why it would be used as cetane boost. What I found was interesting. Seems 1,2,4-trimethylbenzene is most common in diesel fuel treatments such as anti gel addtitives and is also listed as a very small percentage of #1 and #2 diesel fuel itself. In fact Amsoil Diesel Concentrate Performance Fuel Additive otherwise known as ADF is about 29% 1,2,4-trimethylbenzene (also known as p-ethyltoulene) and about 8% 1,3,5-trimethylbenzene the remainder being mostly forms of naptha.

http://www.amsoil.com/storefront/adf.aspx

msds here: http://www.amsoil.com/msds/adf.pdf

Used as one ounce to 5 gallons.

So it is interesting as you believe it works as well as the Amsoil Cetane boost - octyl nitrate also known as 2 ethyl hexyl nitrate. Two very different products.

I am not questioning that it appeared to work but I am starting to question just what the ignition improvers do for our fuels. Some descriptions of how our fuel burns is that the ether ignites first which then causes the other fuel(s) to ignite and the DII (amyl nitrate, iso propyl nitrate etc) modify the burning rate to eliminate knock, in other words when the ether goes off it just doesn't cause everything to off all at once causing detonation (I think that is right term, I will have to revue ealier in the thread on that discussion). If this is the case then perhaps some of the octane boost compounds sold for use with gasoline might have the same effect ? Remember my earlier comments about the F2d team racers adding tetra ethyl lead and ferrocene to their fuels for much the same purpose and I recall that they tended to use amyl nitrate or IPN in the 1% ranges as well. And of course kerosene burns at lower rate than gasoline, maybe the DII work their magic better with lower grade kerosenes?

Andy has some of that Klotz Nitro power stuff which contains nitro propane, have you tried that in place of the Cetane boost? (he may have I just can't remember)

Maybe all this cetane boost stuff has been a bit of red herring. Useful in our fuels perhaps but not the be all that was thought. After all, high cetane numbers or index is preferable but if you can't create a high enough temperature to cause ignition and get the fuel atomized then it just isn't going to go pop.

Andy, also you discussion of making your connecting is also interesting. There seems to be quite a number of diesel and 1/2a nuts that also have an interest in metal working. I wonder if there is enough interest that RcUniverse would consider creating an engine builders forum?

cheers, Graham in Embrun near Ottawa Canada along the sunny banks of the Castor river.