Dyno O-ring head

Tested the O-ring conversion today.
Must say I'm pleased to see some gain, had hoped it would be more.
Also found some interesting results, regarding the heading off the pipe now it is wrapped. It starts to loose power.
Still investigating this problem

On the way to the surprise party

She remembered it quickly

Here you have the best two runs a 25,9HP and a 26,0HP
But these runs where done when the exhaust was at it coldest
After these it went slowly down hill

Here you have the average runs at the beginning, around the 25,8HP Mark

Here you have the best two runs with stock head setting vs the O-ring conversion
The tighter squish and less combustion volume really helped that's clearly now.
On average I would say this mod gives around 1,0 a 1,5 HP

Here the problem shown,

yellow is 26HP one off the max measured when exhaust is relative cold
Red is 25,8HP the average from a couple off begin runs
Green is the 24,2HP after about a run off 15
Orange is 24,8 from the stock head (to show that the engine is revving higher with the wrap)

Now you can understand that I like to hold the high power outcome and not the low power outcome
This problem concerns me

Here just a quick run