383 bolt-ons/Desktop Dyno Sim

[firefighter3931]

Interesting....looks like 30 ftlbs at peak volumetric efficiency which isn't all that surprising given the rate of lift on that lobe family. What is surprising is that it falls off faster than the Magnum cam which shouldn't be happening due to the increased duration at .050 valve lift. 

They look pretty close to me....not sure i'd be swapping the cam out on that one at this point. 


Ron

[cougs]

Ron, are my specs right on the Magnum?  I show the magnum has more duration than the VooDoo

Magnum:
268/284 adv.
228/241 @ .050
.450/.458 lift
Lobe Center: 115
ICA: 113

VooDoo:
262/268 adv.
220/226 @.050
.475/.494 lift
Lobe Center: 112
ICA: 108

[Cooter]

Change the EXHAUST valve size to proper 1.740...If going from 2.080 to 2.100 is a big leap, you might as well get the best results you can with stock Magnum valve sizes.

[firefighter3931]

Ron, are my specs right on the Magnum?  I show the magnum has more duration than the VooDoo

Magnum:
268/284 adv.
228/241 @ .050
.450/.458 lift
Lobe Center: 115
ICA: 113

VooDoo:
262/268 adv.
220/226 @.050
.475/.494 lift
Lobe Center: 112
ICA: 108

Ok....the little lightbulb in my noggin just turned on, lol !!! 

Never thought to ask what specs you were using for the Magnum cam....the numbers you posted are partially correct but the actual duration is off. The correct spec is 208/221 @.050 and i''m going to guess you used 228/241 ? If that's the case then I can see why the numbers appear close. Try re-inputting the correct values and see what comes up 



Ron

[cougs]

Ron,
I corrected the cam specs and changed the valve open/close events to be tied to duration at .050 for both graphs.  This makes more sense with the way the stock cam behaves in real life!  I was always suspicious that a cam with those specs had such little top end!

Here are the sims.  Let me know what you think!

[firefighter3931]

Brock,

Ok, that looks better....the Lunati should be making more power than the Magnum cam with the more agressive lobes and increased lift & duration. 

Here are a couple others i like for unported iron heads. These are old Crower performance grinds with big split pattern and lots of additional exhaust duration to compensate for the weak ex port on an unported factory head.

Crower HDP 271 ( pn: 32242)

Crower HDP 282 (pn 32243)

http://www.crower.com/searchresults/

The 282 is probably a bit big for your needs but it'll be interesting to see what your dyno software shows with both of these grinds. I've used both in the past with excellent results 



Ron

[cougs]

Brock,

Ok, that looks better....the Lunati should be making more power than the Magnum cam with the more agressive lobes and increased lift & duration. 

Here are a couple others i like for unported iron heads. These are old Crower performance grinds with big split pattern and lots of additional exhaust duration to compensate for the weak ex port on an unported factory head.

Crower HDP 271 ( pn: 32242)

Crower HDP 282 (pn 32243)

http://www.crower.com/searchresults/

The 282 is probably a bit big for your needs but it'll be interesting to see what your dyno software shows with both of these grinds. I've used both in the past with excellent results 

Ron, here is what I show.  I don't know the install center line on these so I'm picking something that looks good.  The 32242 looks better for this.

[firefighter3931]

I like the HDP271 (32242) grind on this build....looks like the extra exhaust duration is helping it hang on longer in the upper RPM range. I had the HDP 282 (32243) in a mild build 440 with factory heads and it made very good power and was quite streetable. Good top end pull (5800 rpm)

With the smaller displacement 383 the 271 is a better choice. The other one is too big for the displacement with 9:1 compression.

I'd say it boils down to the 271 Crower or 262 Lunati....maybe run those two on the same graph and see what it shows.

Installed centerline on both of those Crower's is 108....fyi 



Ron

[cougs]

I'd say it boils down to the 271 Crower or 262 Lunati....maybe run those two on the same graph and see what it shows.

Looks like the Lunati wins.  Builds more torque with the same peak hp at the same RPM

[firefighter3931]

Thanks for running the comparisons Brock 

I'd have to agree with you....the 262 VooDoo cam is the best choice for this combination. The faster rate of lift lobe creates more torque and it's evident in a side by side comparison. I think we have a winner ! 


Ron

[XH29N0G]

Thanks both of you for posting all of this.

[Cooter]

Brock, if you'd be so kind....I got one as I have to really old version of this and not even close.
I'm curious about my 440 build. If you could, punch some numbers, I'd be much obliged.

440 std bore six pack pistons, .020 in hole.
stock rod.
stock crank
camshaft is Voo Doo..513 in. .533 ex. 234 in. 242 ex. @.050 duration.
Compression is somewhere round 10.8:1
"915" iron heads with 2.140 in. 1.810 ex. Heavily ported, no flow bench numbers, but bowl work as well as port work.
closed chamber.
700 Holley DP carb on Eddy. "Torker" intake.

2" primary headers, with 3" collectors.

[cougs]

Should I install new valvesprings when I install the cam?  The heads have the stock springs.  What about rocker arms while I'm there?

Also, I plan on running the Proform carb.  Vacuum or mechanical secondaries?  650 CFM or 750 CFM? 

I plan on doing this swap in a couple weeks.  Then I'll install the headers after I break in the cam. 

Ron and everybody else, thanks for your input on this!

[XH29N0G]

See what Ron and others say.  I did not install new springs, but I had recently swapped in RPM heads.  In my case, Ron recommended changing the pushrods.  After installing the lunati cam, I did get a tick that started - related to some of the stamped steel rockers.  When I swapped the bank of those, the tick stopped.  I do not know how common that is and assume it was related to wear and just became more obvious with the slight change in lift.

[cougs]

Cooter and Ken, Check your emails.  thx!

[70sixpkrt]

Would you be able to dyno mine?

440 bored .030=446
KB 237 pistons .003 deck height
Forged crank .010 under
Eagle 4340 H-beam rods
Comp is 10.25:1
Eddy heads 84cc with stage 1 and bowl blend
Straightline Cam 234/242@.050 540/525 solid with 112 lsa (4* built in) installed straight up
6-pack aluminum manifold with stock carbs. (Using ProMax stuff)
Comp pro-magnum 1.5 rockers with 3/8 Smith Bros. pushrods
TTI 1 7/8 headers with 3" X cross-over exhaust to the tips
MSD 8546 dist.
MP MSD 6AL
Dana 60 with 3:54

[cdr]

Would you be able to dyno mine?

440 bored .030=446
KB 237 pistons .003 deck height
Forged crank .010 under
Eagle 4340 H-beam rods
Comp is 10.25:1
Eddy heads 84cc with stage 1 and bowl blend
Straightline Cam 234/242@.050 540/525 solid with 112 lsa (4* built in) installed straight up
6-pack aluminum manifold with stock carbs. (Using ProMax stuff)
Comp pro-magnum 1.5 rockers with 3/8 Smith Bros. pushrods
TTI 1 7/8 headers with 3" X cross-over exhaust to the tips
MSD 8546 dist.
MP MSD 6AL
Dana 60 with 3:54

your car makes about 400 hp

[70sixpkrt]

Is that at the rear wheels? On the actual dyno mine made 491hp and on a chassis dyno it made 398hp. It can make a little more power since I was running rich.

[cdr]

there are some things to consider,,the baro,temp.humidity the day of your run at the track. the tune of engine,  this is off of your mph

Your ET / MPH computed from your vehicle weight of 3900 pounds and HP of 400 is 12.44 seconds and MPH of 107.67 MPH. this is flywheel.
this is from wallace calculator. http://www.wallaceracing.com/et-hp-mph.php

[Cooter]

I just wanna say to give props here, thank you Brock for taking the time to dyno my junk.
I know this can be a pita, and I am looking into this version if DTD. Again, I was surprised at how much power my old junk iron headed 440 was making.

[BSB67]

Is that at the rear wheels? On the actual dyno mine made 491hp and on a chassis dyno it made 398hp. It can make a little more power since I was running rich.

There seems to be a disconnect between the dyno numbers that you have gotten and the actual performance of the car.  Atmospheric conditions might account for it if you were racing in extreme conditions.  If you give me the actual race weight of the car, and the date and time and location of the runs, I can figure your actual and correct hp pretty close.    Fuel delivery problems can result in your mph (i.e. horse power) numbers to be off from what they should be.  Your measured hp numbers and parts list suggest to me that your car should mph at 112-113 in decent air.

The Moroso Speed Calc has you at 390 ish actual, net flywheel hp.  (not gross, and not corrected).

[firefighter3931]

Should I install new valvesprings when I install the cam?  The heads have the stock springs.  What about rocker arms while I'm there?

Also, I plan on running the Proform carb.  Vacuum or mechanical secondaries?  650 CFM or 750 CFM? 

I plan on doing this swap in a couple weeks.  Then I'll install the headers after I break in the cam. 

Ron and everybody else, thanks for your input on this!

Hey Brock,

I would install new springs and upgrade the pushrods. If the rockers are in good shape just run them. 

Here's your shopping list ;

Valvesprings : http://www.summitracing.com/int/parts/cca-911-16/overview/

3 bolt timing set : http://www.summitracing.com/int/parts/cca-2109/overview/make/dodge

Heavy duty chrome moly pushrods : http://chucker54.stores.yahoo.net/hydbchromemoly.html

Hyd lifters : http://www.dodgecharger.com/forum/index.php/topic,95605.0.html


As for the carb, with a heavy car and a 383 i would recommend a vac secondary 750 street series proform carb. You also need a throttle adapter (Holley 20-7)


That's a neat program and it looks to be pretty close to what a dyno would show. I have an ancient version of desktop dyno and don't even bother using it anymore.


Ron

[cougs]

Would you be able to dyno mine?

440 bored .030=446
KB 237 pistons .003 deck height
Forged crank .010 under
Eagle 4340 H-beam rods
Comp is 10.25:1
Eddy heads 84cc with stage 1 and bowl blend
Straightline Cam 234/242@.050 540/525 solid with 112 lsa (4* built in) installed straight up
6-pack aluminum manifold with stock carbs. (Using ProMax stuff)
Comp pro-magnum 1.5 rockers with 3/8 Smith Bros. pushrods
TTI 1 7/8 headers with 3" X cross-over exhaust to the tips
MSD 8546 dist.
MP MSD 6AL
Dana 60 with 3:54

No problem.  Check your email.  Just under 500 hp......

[cougs]

I just wanna say to give props here, thank you Brock for a king the time to dyno my junk.
I know this can be a pita, and I am looking into this version if DTD. Again, I was surprised at how much power my old junk iron headed 440 was making.

No problem!  Just for everybody's information, I was using Desktop Dyno 5 from Comp Cams.  Unfortunately, it's not downloadable but Jegs sells it.  It's about $70 if I remember.  It's worth it just for the entertainment value alone!!  It also works on Win 7 unlike the older versions. 

[A383Wing]

I got version 3.1 on my computer...have not used it for a long time now