Some 350 head pics.

Yep, never would have cleared without the valve notches!:eek2: I like that....Pro Stock!!!!:Brow: There should be plenty of Music coming out of the N-25's!

 

Cam analysis:

Lobe lift: .365/.365 I/E
Valve lift: .584/.584 I/E @1.6


243*/255* I/E @.050 (12*, 4.7% exhaust emphasis)
306*/318* I/E @.006 (12*, 3.8% exhaust emphasis)

63*/63* I/E lobe intensities (very mild for this type of cam -easier on the valve train)

LSA 107*; 101.5*/112.5 I/E centerlines, 102*/112* I/E goal after break in

Valve timing events @5*A (ICL 102*)

306/318 I/E; 107 LSA/102 ICL @.006

IVO is 51.0 BTDC ( - indicates ATDC)
IVC is 75.0 ABDC
EVO is 91.0 BBDC
EVC is 47.0 ATDC ( - indicates BTDC)
Overlap is 98

243/255 I/E; 107 LSA/102 ICL @.050

IVO is 19.5 BTDC ( - indicates ATDC)
IVC is 43.5 ABDC
EVO is 59.5 BBDC
EVC is 15.5 ATDC ( - indicates BTDC)
Overlap is 35

Compressions/strokes calculated assuming 3.83 bore x 3.85 stroke; 6.387 rods @ 0' elevation (sea level) with 0 psi boost:

Static compression ratio of 10.98:1.
Effective stroke is 2.70 inches.
Your dynamic compression ratio is 8.00:1 .
Your dynamic cranking pressure is 158.97 PSI.

Static compression ratio of 10.63:1.
Effective stroke is 2.70 inches.
Your dynamic compression ratio is 7.75:1 .
Your dynamic cranking pressure is 152.55 PSI.

Static compression ratio of 10.27:1.
Effective stroke is 2.70 inches.
Your dynamic compression ratio is 7.50:1 .
Your dynamic cranking pressure is 146.16 PSI.

With such an overlap, excellent flow characteristics and volume of air being moved, recommended dynamic compression would lean towards a bit less than these due to higher RPM N/A 'boost' of increased atmospheres.

IVC events indicate a healthy gulp of air to compress, with exhaust opening events further up BBDC indicates a shortened combustion cycle along with an extended exhaust evacuation cycle to enhance scavenging draw from intake.

This tells me your cam would work best with lowered compression (as previously mentioned) for use with premium pump gas with octane boost, with increased (or a healthy amount of) advance on the ignition for optimal performance. This would help mid range and top end power tremendously.

I don't know where your timing sits, but I'm sure the engine is tits.

By looking at your head ports, combustion chamber, TA intake with spacer, lift and duration on the roller cam, the engine would move some serious air.

Power band I'm guessing would be around 3500-4000 to 6500-7000, depending. With a bit of advance in ICL as you have it and ignition to match, I'd stab at a guess of a 4000 Stall and 6400-6600 RPM shift points. Am I close?

I bet your bottom end is pretty sturdy to handle this type of power band and top end.

Edit: I bet a single plane intake would wake it up even further and move the shift points a bit higher.

A big block with 243/255 would have a power band concentrated between 3700-6200 or thereabouts, so a 350 would be probably 300-400 RPM higher, so I'm probably pretty close.


Gary


EDIT2: Just noticed in your sig you have a 3,000 stall. Do you notice it a bit sluggish down low below 3500? I also see your static comp is at 10:1 in a previous post. Sounds about right, with some advance on your timing. Shift points may be a bit higher, more like around 6700-6900. Most of my analyses deal with much smaller cams. :shock:

I'm still sick with this damn head and chest cold, and I'm all medicated up so forgive me if my analysis is a bit off with the power band guestimation. I'm sorta in and out of it right now.

Awesome job on the engine. It looks and sounds great!

 

Thanks for the diagnosis Gary!

The vid posted in this thread is from the Voodoo 67003 cam, little less compression, and only a D5 convertor. Lost a lobe on that after 4,200 miles.

This new roller setup (.030 original block, forged TRW's, balanced, etc), is waiting for installation. Should be interesting with the 3,200 10", lower 1st gear on the 2004r, and the 390's out back!

Yes I need the new T/A single plane, (I can shelf the dual with 2" spacer). The 850 will help too, but I will break-in eng. with the 750 Holley, cause it's tuned already.

Timing is set to 16* int. and 34* total for now. May have to play with that.

Yes I want to stay with 93 pump gas. Put radius on all sharp piston edges, valves, combustion chambers, etc, to help eliminate detonation.

I would still like some trick alum HEADS!!!

Fun fun fun!

 

With a true 10:1 static and that roller cam's IVC point at 75* @5* advance, You're well into the safety zone I'd say. You should be able to run 93 octane no problems, even if the engine gets a bit warm (like in summer).

You could actually stand to bump it a bit to about 10.25:1 or thereabouts, if you wanted. That would put you right at 7.5:1 dynamic. With all the rest of the aspects reducing detonation risk, you could even put it to 10.5:1...

Leaving it at 10:1 you might be able to run mid-grade in it, or advance the timing a bit more and still be safe. I think you're good ta go either way. :TU:



Gary

 

Watched your video hundreds of time, thanks.

 

Great Job, enjoyed the port work photos. I'm to lazy to do that, waiting on alum heads ou:.

 

Thanks! Yes, cast iron dust is not the most pleasant aroma.:af: I'll buy a set of aluminum heads myself, and put these ported irons on my spare eng.

I'll be sure to post another video when everything goes back together this spring!:TU: