Don Terrill’s Speed-Talk

digger wrote: ↑Sat Apr 27, 2024 11:48 pm quality over quantity

......and correlation isn't causation. Two aspects likely not addressed when drawing conclusions by the worlds most prolific dyno tester.

Eroy wrote: ↑Sat Apr 27, 2024 8:20 amIMG_4092.png

Where did DV post this comment? Can't see it on the 'Why less Power' video.

His comment does beg the question if 98% of the cam industry is doing it wrong the why hasn't he gone into business making and selling his own cams?

Sharp38 wrote: ↑Fri Apr 26, 2024 7:49 pm
What's wrong with 1.75 turns.

Don

It could be letting more fuel in with transition slot fuel when vacuum goes up as rpm goes up.

Right now, I have PJ of 76. The IFR is .029. With IAB of .075, I was too rich in cruise. I put in the IAB of .08, hoping to get on the other side. Idle adjustment screws out 1.75 turns (4). That set up is .95 ish (lambda) at idle. Then, slowly going from .95 ish (1200 rpm) to .80 ish (2000 rpm) as ...

PRNDL wrote: ↑Thu Apr 25, 2024 8:30 pm Or I could just get a AVS-2 800

If you're a gambling man.....

So maybe do something radical that will have an impact like blocking some emulsion. This isn't to cure or solve the rich @ 3000rpm problem but create a cause and effect and gather new information and data that may well point you in the direction of the solution. This is why I like the fully adjustab...

IFR is the how much the fuel supply tap is open - quantity. IAB regulates how much the engines vacuum can, for want of a better term grab the idle well fuel and pull it through. Big iab and the engine vacuum can’t grab as strong so therefore as long (loses its grip) as when the iab is smaller. Stayi...

Eroy wrote: ↑Wed Apr 24, 2024 12:00 pm

hoffman900 wrote: ↑Wed Apr 24, 2024 11:33 am I don’t know how anyone can look at that graph and think “this is a good test, let me put it on Youtube”.

Its the ongoing quest for relevancy that drives it!

With a big dose of hubris and ego to go with it!

Richard Holdener doesn't have an opinion, he has a dyno. The 2.165/1.590-inch valve combo in this lsa test also responded favourably power wise to a 108* lsa https://www.motortrend.com/how-to/1506-lobe-separation-angle-explained-and-how-it-affects-horsepower/ It’s a wide open throttle dyno test fro...

Richard Holdener doesn't have an opinion, he has a dyno. The 2.165/1.590-inch valve combo in this lsa test also responded favourably power wise to a 108* lsa

https://www.motortrend.com/how-to/1506- ... orsepower/

Unity video ties it together. 416ci Cam is NLA BTR 239/254 .631/.610 114+3 They cut the AFR heads to 62cc, don't know if they were flowed before or after. 72cc from AFR ? Wrong heads for that motor anyways. https://youtu.be/TJS8PNPWnDA Would have been good if pre dyno he said “DV thinks with the sm...

You cannot do test like this using a chassis dyno. It’s very hard to control engine temp, oil temp, trans temp, rear end test, and tire temp. All of these can make up the difference. The engine dyno is easier to control things. I've seen 20hp disappear from strapping the car down harder to get more...

No but the AFR has a smaller intake. But by his measures the head with the smaller intake valve has the potential to move more air. And it did at lower engine speeds. I wonder whether it's the old flow bench doesn't pull as hard as a high revving engine causing the discrepency. I hear what your say...

digger wrote: ↑Mon Apr 22, 2024 9:30 pm

HQM383 wrote: ↑Mon Apr 22, 2024 7:24 pm Video 1 neither head is backing up in flow.

The flow drops sharply at 0.720” ?

Sorry, yes it does. Missed that on the chart. Wasn't looking at this.
But does the thick blue line jump out as a lower hp producing head?

Standard cam for DV's? Then it's all about curtain area. Both the ports are probably too big for a small cam. Big ports don't need big cams. DV showed us nothing again. No but the AFR has a smaller intake. But by his measures the head with the smaller intake valve has the potential to move more air.