FE Power Cylinder Heads on the Dyno, Round 2

[427mach1]

I saw a demo , from LaVision, a few years ago. Basically you seed the air with tracer particles, and use a pulsed laser, along with a sophisticated computer program. Something the oems use.
This gives you a plot, with tumble and swirl.  Not inexpensive, but if one needs that type of data, and has the resources, it's the cat's meow.

Laser doppler velocimetry (LDV) or particle image velocimetry (PIV), technologies that have been used in wind tunnels and water tunnels for many years.  They are also used for many engine applications such as fuel injector measurements and quantifying the flow inside an engine (using transparent panels to see inside).

[FERoadster]

Understand some of this. Back in 1968-9 I was getting ready to graduate from Oakland University in Rochester Mi and was specializing in Fluid Dynamics ,
Worked as an intern for a Dr. Edgerton who was working on pulse technology in jet stream analysis. He used a piston to slam a pulse into a jet stream of water and experimented with various nozzle patterns and flow rates to get a uniform "donut shape" in the stream I rigged up the high speed camera with electrodes to initiate the pulse when the donut triggered the flash.  Graduated in 1969 before he published his work.
This thread made me remember those times. lots of solitude in the lab late nights.
Richard

[bluef100fe]

Jay, Glad you are getting some positive results. I’ve done some 514/532 inch BBF builds and they usually have 12-20 degrees of split depending on the combo. That cam does seem huge for the hp peek rpm, irregardless how good the exhaust is the engine still needs the exhaust valve open long enough to let the spent gasses out. Other thing I’ve experienced with the big ford is trying to extend the rpm range higher in truck pulling applications, found out shortening the intake runners will move the hp peak around if the cam, intake, heads, etc are good enough, which it sounds like they are on your parts. That may be what you are experiencing. If you change to a shorter duration intake lobe on the cam and the Tq peak moves down and the hp peak stays the same I would point at the intake runner length. Cool stuff for sure, neat to read your progress on here. Keep up the good work!

[manofmerc]

Cody on your 514s camshafts was that with stock heads (I am guessing ported ) or aftermarket aluminum.Doug

[blykins]

I don't know of many FE (or Ford heads in general for that matter) that don't benefit from a considerable amount of split, with the exception of maybe some Pond heads, BBM, or some Pro Port stuff where you can control the bias.   A lot of FE heads have 60-65% intake/exhaust flow ratio and that really needs to be helped with the camshaft.   I rarely do custom camshafts without an 8-10° split at least, unless the exhaust port is really good or I'm trying to band-aid an overlap problem.

On some of my high rpm pulling truck engines, I have almost a 30° split. 

Even on street engines, dyno testing here has proven that going from a 4° split to an 8° split on Trick Flow heads will net a 12-15 hp bump. 

[bluef100fe]

Cody on your 514s camshafts was that with stock heads (I am guessing ported ) or aftermarket aluminum.Doug

Both... the air pump doesn’t care...

[4twennyAint]

I probably missed this in these lengthy texts somewhere, and Jay, you are the master of methodology...but I was wondering if you monitored the vacuum pump to be effectively functioning ...

[jayb]

Yes, I have a line to crankcase vacuum plugged into one of the dyno sensor channels.  During this testing it was giving about 9" of vacuum during the pulls.  Interesting to note that it was only giving 5" of vacuum at first, then we tightened up the valve cover bolts, and went immediately to 9".  It's easy to miss some of these minor leaks, that can make a big difference...

[e philpott]

Camshaft make it in yet ?

[MRadke]

Do you log exhaust temperatures and would they provide a clue as to whether you have too much or too little cam on the exhaust?