Desktop Dyno request thread
Burning Brakes
Joined: Nov 2004
Posts: 1,193
Likes: 176
From: Hillsborough NC
Fred, this was actually pretty easy - the only unknown here is the head flow numbers. I had a file for the '041s that were professionally ported and used that one...but there's clearly no way to tell exactly what yours are flowing without a bench report.
The only comment I had was regarding quench - .064 (if my math is right) is terrible
If the block and heads are flat, I'd consider using a steel gasket to drop it to .042 - better. Not an immediate thing...but something to consider especially if you've had problems getting a full 36 degrees of total advance. Probably a nit, but it crossed my mind.
The only comment I had was regarding quench - .064 (if my math is right) is terrible
If the block and heads are flat, I'd consider using a steel gasket to drop it to .042 - better. Not an immediate thing...but something to consider especially if you've had problems getting a full 36 degrees of total advance. Probably a nit, but it crossed my mind.1.52:1 roller tip rockers
.015 thickness steel shim head gasket
Installing the cam 4 degrees retarded (to keep DCR in the right range)
Motor is not built yet, so you are being very helpful.
Oh, and one question, did DD allow you to specify the rams horns with the bigger dumps, or did you have to use the standard ones?
Thanks again
-Fred
Thread Starter
Le Mans Master
Joined: Jun 2004
Posts: 6,231
Likes: 65
From: Seattle WA
St. Jude Donor '14
I think you mean advancing the cam - retarding the cam moves the power up in the RPM range and is generally not done. Advancing the cam 4 degrees moves the power peaks down about 500 RPM.
DD models "stock manifolds" and "stock HP manifolds". I use the latter. If the manifolds have really been heated up, then we'd expect to see about a 30 HP increase.
Le Mans Master
Joined: Jul 2005
Posts: 5,752
Likes: 4
From: Austin Texas
For forced induction, there's additional information required. I don't have a lot of experience with DD here - so we may get complete 
DD wants either the specific blower model (Vortech, Paxton, etc.) or:
Island flow cfm
Impeller speed rpm
Peak efficiency %
Belt ratio
Boost limit psi
Pressure ratio
Internal ratio
Intercooler %
Here's a sample screen:
DD wants either the specific blower model (Vortech, Paxton, etc.) or:
Island flow cfm
Impeller speed rpm
Peak efficiency %
Belt ratio
Boost limit psi
Pressure ratio
Internal ratio
Intercooler %
Here's a sample screen:
Racer
Joined: Oct 2004
Posts: 318
Likes: 0
This is a great tool you have come up with. Here are my #'s. And thanks for the useful tool that you have given to us.
Dave
454 BBC
Comp. 8.75:1
Cam 24502611 Hyd. Roller
Lift .510 I .540E
Duration .050:211I 230E
Heads 118 com. chamb. Cast Iron
Intake 2.19
Exhaust 1.88
Rockers 1.7:1
Holly 770
Air Gap Int
Headman 2-1/2 in. headers
My goal is to squeeze another 100 HP or so out of this. What cam and Head combo would you recomend? If you have that info.
Thanks again, Dave
Dave
454 BBC
Comp. 8.75:1
Cam 24502611 Hyd. Roller
Lift .510 I .540E
Duration .050:211I 230E
Heads 118 com. chamb. Cast Iron
Intake 2.19
Exhaust 1.88
Rockers 1.7:1
Holly 770
Air Gap Int
Headman 2-1/2 in. headers
My goal is to squeeze another 100 HP or so out of this. What cam and Head combo would you recomend? If you have that info.
Thanks again, Dave
Race Director
Joined: Jan 2003
Posts: 15,173
Likes: 86
From: State of Confusion
..... just for *****-and-grins.....
I plan-on using the as-OEM-built L-83 short-block from my 27,000 mile '82 Corvette for an upcoming bracket-race project:
don't know the exact particulars of the engine, other-than what is found on-line, and common-knowledge ~
4.000"-bore x 3.480"-stroke
9:1 compression with 76cc heads, unsure of valve-relief cc's
pistons 'typically' .025" down-the-hole
Since reliability/durability is imperative, the motor will-NOT be run as-hard-as it could, nor do we expect killer ET/MPH figures:
with 5600 RPM shift-points & trap-speeds, we are hoping for high-12s at 105 MPH.
To the stock bottom-end, we will add:
Edelbrock RPM-Performer heads, #60999
http://www.jegs.com/webapp/wcs/store...10002_69948_-1
Edelbrock Victor Jr intake, #2975
http://www.jegs.com/webapp/wcs/store...10002_27930_-1
Holley 750 cfm, double pump carb, #4779
http://www.jegs.com/webapp/wcs/store...10002_28022_-1
Comp Cams 292H Magnum cam
http://www.jegs.com/webapp/wcs/store...10002_29602_-1
Dynomax ceramic-coated headers (unknown diameter or length )
http://www.jegs.com/webapp/wcs/store...10002_16256_-1
Using the same carb/intake/cam on a 10.3:1 355" SBC with DART Iron Eagle heads, a 3700-pound '79 Z28 runs steady 12.80s @ 105 with 5800 RPM shift-point/trap-speeds (8" converter, 4.11-gears and 28" x 10" Goodyears on 8" wheels ):
I have felt the Z28 is making close-to 400 crank HP, but that might-be optimistic.
:bb
REGARDLESS of what HP/TQ levels we reach with the L-83 short-block, these are the parts we will use, as they are readily-available, and relatively-inexpensive:
we feel the above combination will make decent power, and if RPMs are kept-below 6000, it 'should ' last a few seasons, until I can buy a ZZ383 crate-motor.
Bracket-racers aren't paid-enough to 'go-fast', only to 'leave on-time', and run-the-number.
Thanks-in-advance!
Sincerely, Glen!
I plan-on using the as-OEM-built L-83 short-block from my 27,000 mile '82 Corvette for an upcoming bracket-race project:
don't know the exact particulars of the engine, other-than what is found on-line, and common-knowledge ~
4.000"-bore x 3.480"-stroke
9:1 compression with 76cc heads, unsure of valve-relief cc's
pistons 'typically' .025" down-the-hole
Since reliability/durability is imperative, the motor will-NOT be run as-hard-as it could, nor do we expect killer ET/MPH figures:
with 5600 RPM shift-points & trap-speeds, we are hoping for high-12s at 105 MPH.
To the stock bottom-end, we will add:
Edelbrock RPM-Performer heads, #60999
http://www.jegs.com/webapp/wcs/store...10002_69948_-1
Edelbrock Victor Jr intake, #2975
http://www.jegs.com/webapp/wcs/store...10002_27930_-1
Holley 750 cfm, double pump carb, #4779
http://www.jegs.com/webapp/wcs/store...10002_28022_-1
Comp Cams 292H Magnum cam
http://www.jegs.com/webapp/wcs/store...10002_29602_-1
Dynomax ceramic-coated headers (unknown diameter or length )
http://www.jegs.com/webapp/wcs/store...10002_16256_-1
Using the same carb/intake/cam on a 10.3:1 355" SBC with DART Iron Eagle heads, a 3700-pound '79 Z28 runs steady 12.80s @ 105 with 5800 RPM shift-point/trap-speeds (8" converter, 4.11-gears and 28" x 10" Goodyears on 8" wheels ):
I have felt the Z28 is making close-to 400 crank HP, but that might-be optimistic.
:bb
REGARDLESS of what HP/TQ levels we reach with the L-83 short-block, these are the parts we will use, as they are readily-available, and relatively-inexpensive:
we feel the above combination will make decent power, and if RPMs are kept-below 6000, it 'should ' last a few seasons, until I can buy a ZZ383 crate-motor.
Bracket-racers aren't paid-enough to 'go-fast', only to 'leave on-time', and run-the-number.
Thanks-in-advance!
Sincerely, Glen!
Last edited by Glensgages; Aug 29, 2007 at 02:14 PM.
Thread Starter
Le Mans Master
Joined: Jun 2004
Posts: 6,231
Likes: 65
From: Seattle WA
St. Jude Donor '14
Racer
Joined: Mar 2005
Posts: 393
Likes: 3
From: Dallas, TX
how much error +/- are in the dyno sim calculations? as for my gears, its a wide ratio BW T10 with factory 3.42 in the rear, I want to get a 4.11 gear set but would like to swap a whole unit so as to cut down on parked in the garage time.
-alex
-alex
Thread Starter
Le Mans Master
Joined: Jun 2004
Posts: 6,231
Likes: 65
From: Seattle WA
St. Jude Donor '14
I wouldn't take anything to the bank here; it's just a sim. I've GENERALLY found that the HP numbers are in the ballpark to a bit conservative if the flow and cam numbers are right. Torque is generally optimistic to +10%I want to be really, REALLY clear here - these are estimates that come from a computer program with a human bean making best guesses. I take no responsibility for the "accuracy" of the information.
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Race Director
Joined: Jan 2003
Posts: 15,173
Likes: 86
From: State of Confusion
ZZ383 (425HP/449TQ )
http://paceperformance.com/index.asp...D&ProdID=73193
ZZ502 (502 HP/567 TQ )
http://paceperformance.com/index.asp...D&ProdID=26942
Thread Starter
Le Mans Master
Joined: Jun 2004
Posts: 6,231
Likes: 65
From: Seattle WA
St. Jude Donor '14
dgruenke's right though - getting any results from the forum on the forum would be great!
Race Director
Joined: Jan 2003
Posts: 15,173
Likes: 86
From: State of Confusion
Thread Starter
Le Mans Master
Joined: Jun 2004
Posts: 6,231
Likes: 65
From: Seattle WA
St. Jude Donor '14
Burning Brakes
Joined: Feb 2004
Posts: 758
Likes: 14
From: Ville de la Baie Quebec. A winner is just a loser who tried again.
Thanks for the chart!! I know its only a sim but it gives an Idea. When I built the engine 3years ago, my goal was 300hp, I think its safe to asume I have reached it and maybe a little +. Its a wonderful little engine, very drivable.
Thanks again !!!
Michel
Thanks again !!!
Michel
Racer
Joined: Jan 2003
Posts: 385
Likes: 80
From: Old Monroe, Mo
Hey Billa, I been debating over actually getting it dynoed. Pretty mild setup and this one will be easy for ya. Thanks in advance.
350 .060 over stock bottom end with dish pistons.
stock vortec heads (excpet a little bigger springs to accept bigger then stock cam). the modified ones from SDPC.
Edelbrock Performer with 600 Holley.
1 5/8" ceramic Flowtech headers to sidepipes.
Comp XE262 cam http://store.summitracing.com/partde...2&autoview=sku
that work for ya ?
350 .060 over stock bottom end with dish pistons.
stock vortec heads (excpet a little bigger springs to accept bigger then stock cam). the modified ones from SDPC.
Edelbrock Performer with 600 Holley.
1 5/8" ceramic Flowtech headers to sidepipes.
Comp XE262 cam http://store.summitracing.com/partde...2&autoview=sku
that work for ya ?
Thread Starter
Le Mans Master
Joined: Jun 2004
Posts: 6,231
Likes: 65
From: Seattle WA
St. Jude Donor '14
I just don't know enough about the forced induction on DD to know what I get when I don't have all the data and I don't want to post complete BS :/ Sorry, dude...
