Funny numbers

[flyinbrick68]

My destop dyno puts out a figure of my 451 at 480 hp 4750rpm and 601 ft lb. of torque at 3000 rpm. I think its way optimistic but that's using 9.7:1 compression with 2.08 intake 1.81 exhaust valves 224 intake 234 exhaust duration .518 lift intake .543 lift exhaust on a 110lsa advanced 4 degrees. 850cfm carb 1" spacer and timing at 36 degrees with a dual plane exhaust. I loaded a flow file for the heads which I hope I can achieve with porting my 346's that tops out a 255cfm at .600 lift. So to put it the best I can I think the software which is the virtual engine 2000 is way optimistic. I don't think they hold much water.

 

[commando1]

I've used the software only to see what changing different components will do to get the best bang for the buck.
The baselines the software packages come up with seem to have been plucked out of the Twilight Zone.

 

[flyinbrick68]

That's kind of what i thought also I just have a basic version so it limits you on a lot of things you can change. I just thought it was intetesting.

 

[heyoldguy]

We have a 440 +.030" (446 ci) with ported 346 heads and 2.08/1.74 valves on the dyno right now.

850 Mighty Demon carb
Edelbrock Performer RPM intake
Comp Cams XE285HL cam 241/247 @ .050" .545/.545 lift, 110 LS, 106 ICL
1.6:1 rockers
8.9:1 compression

The heads (by an accomplished head porter) are flowing:

.100..........88/59
.200........164/114
.300........210/158
.400........236/194
.500........259/211
.600........270/224
.700........280/234

And the engine dyno'd:

RPM.............TQ/HP

2800..........385/205
3300..........468/294
3800..........496/359
4300..........478/391
4800..........473/432
5300..........476/480
5400..........481/495

We haven't done much tuning but the fuel mixtures and the timing are close. You can run that through the desktop dyno and see what you get compared to these real numbeers.

 

[flyinbrick68]

thank you I'll plug em in and see how far off i am. It'll be a tremendous help! I'm learning and enjoying the process of head porting.even though it's time consuming. I'm hoping for an improvement though i don't know of a flow bench anywhere to test the results later. Thank you.

 

[flyinbrick68]

Hp is pretty close torque on the other other hand 100 ft lb. plus.

 

[70bigblockdodge]

Flyin brick you should ask heyoldguy to look at your port work and see what he says, he does some impressive work i have followed his threads over on fbbo.

 

[flyinbrick68]

He's a busy guy no doubt i'm sure. I'd be a lucky guy if he'd agree to look at some pics and give me some pointers. Lol im just hoping I don't screw it up too bad that it hurts things! Been cold here with snow and the garage doesn't have any heat so the heads have kinda been at a stand still for the moment.