smally351

Just been playing around with my dyno program before I freshen my 351. Basically its 10.5:1 CR, ported iron 2v's with 4v valves, Crane F238 etc etc.

It seemed to make pretty good power and torque according to the program, 435 hp @ 6000 and 399ftlb @5000.

When I retarded the cam 10degrees, it jumped to 465 hp @6250 and 415 ftlb @ 5000. Not that I would retard it that far tho.

I'm not sure how accurate these dyno programs are, so Iwas wondering if anyone has actually tried retarding or advancing the cam timing with a similar combination and what the results were.

silver fox

hi my 351 stock stroke made 466hp @ 6800 and 409ftbs @ 5000 using f-246 +2 degress advanced 2v heads 2v intake valves 4v exhaust 750dp 10.5 comp active manifold

TruBlu351

What program are you using?

I normally use Desktop Dyno 2000. Drop those exhaust pipes and see what you get!

I got very close numbers with an F246 and mufflers on.

Attached Images

	F246-Dyno-Graph.jpg (55.5 KB, 32 views)
	F246-Dyno-Table.jpg (46.0 KB, 27 views)

__________________
XE Falcon
393 Tremec TKO 9"

TruBlu351

Now, for about 800 bucks your could turn that graph into this!....and drop the mufflers!

No guesses how

Attached Images

F246-Dyno-100-Nitrous.jpg (55.0 KB, 39 views)

__________________
XE Falcon
393 Tremec TKO 9"

davis

$800 would suggest a nitrous system, probably a high flowing setup.

As for your "mufflers" on being close, for a good quality race engine, large tubes w/mufflers seems to be right while with a "normal" hotted up engine, small tubes w/mufflers seems to be right...even on a real engine dyno without mufflers (except for the large diesel stack type with 5" pipe going into it!).

I suppose that the more recent version is more accurate and/or has more features?


:davis:

crochunter

Those dyno 2000 programs are never right. They just give u fantasy bragging rights.

__________________
http://motorvator.7.forumer.com/

TruBlu351

No fantasy. Just a GUIDE on what combos may work better that others.....saving $ and time.

I didn't think most racing teams use them on their R&D.

__________________
XE Falcon
393 Tremec TKO 9"

davis

Actually, it is a very powerful tool that is useful in R&D. Don't pay any attention to croc. It doesn't have to be exact to be useful in demonstrating a trend. As a computer simulation tool, it is very close...considering its limitations.

On my BBF 520" engine, it predicted 670 HP and the dyno showed 667. That is too close to call, IMO.


:davis:

smally351

Im using Virtual Engine Dyno Pro.

What I really want to know is has anyone actually tried retarding the cam in the real world??

4Vman

Fantasy bragging rights huh? im sure that's a topic you hold very dear to your heart and plays a bit part in your life!..

__________________
F6: the fastest factory 4 door falcon in the world!