They built two engines, identical except for rod length and compression distance. I am not sure however if they published the necessary timing requirements between the two, but I can guarantee you that Brule ran timing sweeps on both.
They built two engines, identical except for rod length and compression distance. I am not sure however if they published the necessary timing requirements between the two, but I can guarantee you that Brule ran timing sweeps on both.
Ok, I watched most of this. I remember why I didn’t like the test.
There is no way, no way you would build an engine with a .2 point difference in r/s ratio and use the same cam timing.
You just can’t do that.
I get what Freiburger was doing. He wanted to isolate r/s ratio and changing cam timing would have taken away that isolation.
But that’s the rub. None of this happens in isolation.
If I get a minute I’ll do the math up for both combinations and show the difference in cam timing for both rod lengths.
I just need to go back and look at where peak torque and power occurred and what the exact compression ratio was.
Then I’ll do some math and post the results.
Frieburger also said there was a two degree difference in ignition timing, but he said the long rod wanted 34-38 and there was no difference in between. And the short rod engine wanted no less than 40-42.
I’m don’t think they used a curve because they had a crank trigger. Obviously they could have used a programmable ignition but I didn’t see what they are using.
IMO with a curve the long rod engine would have made more torque at and around peak and more power at and around peak.
That goes for both engines. But they would want different curves.