Thats one of my competitors "ideas" and the one below it too.They don't work.
I've been involved with drag sleds for over 20 years and the boys I make parts for like to try every stupid and crazy idea that comes along.They are like myth busters.

A few years ago it was turbo cranks, they didn't work either.
We base lined this head at the stock CR and it didn't show any improvement over stock.I don't this stuff for free and until they cough up a boat load of money its going to collect dust.

Bob I have test my Zen cylinder with the loose toroidal head on it . There is only a few liter of fuel through it because my boat supplier was busy with a new type of hull and I will only receive it this week . My Previous modded engine Zen 30.5 . was going very well . The loose toroidal button on the modded Zen cylinder was fitted with a 29mm crank . I do not want to commend on the performance now . The reason ... the nationals is due in 3 months time and I do not want to awake the competition . There is always the tendency for some to wait and see how "new" parts operate and perform before they buy it and there is nothing wrong with it but for now they can guess or buy their own .... I will give feedback again maybe good maybe bad who know

All the best testing Nic, just remember, you will be testing 2 changes at once. Increased compression, and toroidal head.

Thats the wrong way to test and expect accurate results, You make one change at a time so you know what made a power difference.Thats why this project was based lined with stock CR.

Guys you are correct to make it more interesting is the fact that I will run it on the water to test it . it is a crude method of testing and the only means to test it is to compare it against the boats I use to run with by means of performance against them . I have got my dyno ready but working from my house in a neighbor hood make it difficult to do dyno runs . I have another option i am looking into regarding that. People are different and different things tickle them . You get some that want to knew the smallest details and need to knew exactly what make some thing work the way it works. Usually that the type of person who produce a new invention or put a new product that's better on the market . I would say that's in my opinion the Allan,Les,Lohring,Carlo,Daniel,Todd , Bob etc type of person .
Then you get other and I am under that group . My work place is a mess tools all over . My wife say she doesn't understand how I can function there ! Well i some times wonder myself ... For me it doesn't count what make more power is it the toroidal head or the higher compression , is it the higher octane fuel or the lower octane fuel ? . Is it he sharp edge on the squish band or not . What count is is it better....
I could buy myself a top notch engine and race with it but it is not me . I want to try different things with porting ect to make it go better myself . With a lot of grace ,luck trail and error I have got my engines to compete with the best and that is satisfying for me. I have not got the theoretical knowledge to sit and discuss with professional engine builders how the squish band width and the degrees of the squish band influence the performance ect . I just enjoy my own failures and accomplishments and is glad that some people provide us from time to time with new things and if it is better i say thank you that i may benefit from your effort and Idea . When I move closer to the best with my scratching and see the effect he scratching provoke I just want to scratch some more Bob I doubt it if the average guy have got the know how to do accurate tests to determine what make the head work . Its up to you to do the test yourself if that fascinate you that much . I cant understand why you just don't want to except it is better . I have used cylinders with higher compression before and the performance gain was not as noticeable than with the toroidal head . Buy a head do the test as you want and come with a explanation of your finding of what make the darn thing tick the way it does ...

I can't sell anything unless I know it is better and can prove it is better.
You can't buy these type of heads for the engines I'm working on.

Bob I have bought lots op products that does not perform as it should or as one expect it should . There is not really protection against that . I can tell you one thing if it didn't perform as Les state it should I would have been like a swarm of bees over him . I imported 12 cylinder heads and not one customer complain it is not working or perform better than the old original head . I have witness it myself with others that it work . Even if Les did what ever test you want him to do and proof it is better you would still have some thing negative to say I am sure about that ...

Never happen, no one in rc will ever test it properly outside of QD..No one listened to Mitch when he posted his results.

Missed his results ?

For those that have used the Toroidal head for the QDHT, QDP, TK and the Zenoah 36mm kits and have seen little or no significant improvement across the entire rpm range it is because the design of the Toroidal head is not being utilized correctly...
1- one will see very little or no gain in performance by having a squish larger than .010" ....optimum is .0025"-.005" squish
2- one is using a fuel octane rating over 87
3- the engine is getting hotter and more cooling is required
4- the pipe needs adjustment (the QD Steel Hot Pipe works best)

To install the head and run the engine without doing #1 and #2 above as a minimum and say it didn't perform much over stock have no clue on why the performance wasn't there when they tested it.
The single most power increase one can acheive from a 2 stroke engine is by raising the compression ratio and in doing so the detonation demons can easily surface and as far as setting up the engine with a toroidal head for those that think the toroidal head should have the same compression as a stock head for comparison ..they are going in the wrong direction and for those that think of doing so for comparison is the way to do it they are as dead wrong as someone telling you that theTrick Flow or the Dart 1 cylinder heads for your Chevy or Ford should be installed and setup to have the same compression ratio and use the same higher octane fuel as the set of stock cast iron heads, which is different than what the manufacturer suggest so you can see if there is an improvement is definite proof that they do not comprehend the design nor follow directions for that matter.
I have mentioned before and I will mention it again....using the toroidal head with a tight squish and using 55-87 octane fuel will not have any detonation issues with the higher compression...the design makes that possible...just accept that ..unless one wants to make a bunch of heads ...be my guest!

I just do not understand why some want to do it differently than what the head was designed to do and say it doesn't work!

The toroidal head is nothing new except for in the hobby market and it has been around for sometime in 2 stroke engines and of course the shapes are different between some designs although not all of them will work to their full potential and that is why by making one or two toroidal heads and the results are no different than stock and then say they are useless is one who did not have the determination to make several heads that vary in shape, squish angle and volume and test those different heads with the same tight squish and then start lowering the octane to determine the best shape and chamber volume with the available lower octane fuel.
The design for these heads had at least 8-10 + different shapes, different metal alloy and angles until one design of the toroidal head performed beyond the others that were made and tested...that is the design that is available today and the individual results that vary is from the end user not the design.