Don Terrill’s Speed-Talk

Flashback to the cam calculator I tried to make

http://www.filtrexsg.com/turbo-s10/CCC. ... 0&lifter=4

Kinda close

Getting a little off topic but I recently bought a crank from a forum for $200 (ls1 scat 4.000 stroke crank) and at that price I assumed it would be a cast crank The only markings on the factory box are in purple marker LS1-4000. When I googled it said it was a $1000 forged crank. It does appear to ...

If you look at my cam selector you'll notice everything is listed at 050 and special attention was given to the overlap triangle. I think the overlap is the #1 factor Exhaust open gives the pop Intake close has the least effect I'm hoping this is a misstatement. If not, am I wrong in finding it iro...

Had to retard the cam 3* and picked up 12 hp

Isn't that what they have been doing with the ls2 spec motor?

If u have have 8* extra exhaust and 4* advance the evcp is in the same spot. By tight lashing the exhaust you may have moved the evcp after tdc at 050 (or 037 or whatever number your particular engine was sensitive to based on everything from valve seat angle, width to breather to mufflers to idle r...

EVO doesn't have any effect at idle, because the charge is so small that it's burned very quickly. IVC doesn't affect it much, because it's very throttled, and only takes what it needs to turn the engine and accessories. Pushing charge back out balances out in the end. Overlap is the killer - it bo...

I took a crack at it, pretty easy to get the opening on but needs the negative acceleration.

Also can somebody explain 'jerk' to me?
Lift, duration, acceleration, velocity all very easy to understand but I'm lost on the terminology for jerk

Just my opinion. It may not be correct and it seems counterintuitive BC it contributes greatly to reversion at idle.
Still what I think.

I think the overlap is the #1 factor
Exhaust open gives the pop
Intake close has the least effect

If you look at my cam selector you'll notice everything is listed at 050 and special attention was given to the overlap triangle.

He's possibly/probably referring to btdc vs after Tec

In other words you may only show 28* btdc ivo but bc of the ramp speed in a few degrees it acts like a much larger cam

Also CamKing mentioned opening too fast earlier regarding UD and flexing of the valve train

The carb is a restrictor and always will be. That's how it works. The restriction is what sucks the fuel into the air stream.

Another thing to keep in mind is the smaller carb is a restriction.

And by doing so having the turbo at a slightly higher p/r you may end up in a more efficient island.

Click on the 'dist' folder then double click on 'CurveFitting.jar'

I left a couple example files to get people rolling.
I felt the NASCAR vs Prostock cam test was very very interesting