Desktop Dyno help needed 383
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St. Jude Donor '09, '24
Desktop Dyno help needed 383
Will be firing up the 383 at the dyno soon and would like to see what the desktop version says the engine combination power curve will be. If any motor person can run these numbers I would greatly appreciate the help. 
Block bored .030 over, H beam 5.7 rods, 11:1 compression with 65cc Bordix IK200 heads with 200cc intake runners. The cam is a Comp roller 286H-R10 with .560 lift at a realatively short duration of 230. Should get plenty of low end touque out of this 383. It will be a Holley 950 Commander FI setup used with 85# injectors so the total CFM of fuel will be close to 950 if needed. When running the dyno program you can use whatever the best cfm is for the application and I should get very close to that value with the FI setup. After reading the long post on 383 heads (Kurt81s thread) the AFR 215s looked like everone's favorite. Has any Forum member used the Brodix IK200s on a 383? I would like to see if the motor preforms as well on the dyno as the desktop dyno says it will, houstonvett
Block bored .030 over, H beam 5.7 rods, 11:1 compression with 65cc Bordix IK200 heads with 200cc intake runners. The cam is a Comp roller 286H-R10 with .560 lift at a realatively short duration of 230. Should get plenty of low end touque out of this 383. It will be a Holley 950 Commander FI setup used with 85# injectors so the total CFM of fuel will be close to 950 if needed. When running the dyno program you can use whatever the best cfm is for the application and I should get very close to that value with the FI setup. After reading the long post on 383 heads (Kurt81s thread) the AFR 215s looked like everone's favorite. Has any Forum member used the Brodix IK200s on a 383? I would like to see if the motor preforms as well on the dyno as the desktop dyno says it will, houstonvett
Safety Car
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From: Youngstown Ohio
Your combo is very similar to my former combo,... 383ci, Comp 286H-R10, 5.7 rods. Mine had 10.9 compression and used 1.6 rockers to up the lift to .595. Using AFR 195 heads, and a Mighty Demon 825 carb, my Desktop Dyno showed peaks of 472 hp @ 6000 rpm, and 479 tq @ 4500 rpm. I believe the real engine had around 20 hp less than the virtual one, but that's fairly close and was quick enough for mid 11's performance. Hope this comparison helps you out somewhat.
BTW, the more CFM you input in the DD calculations, the more HP the virtual engine makes (you could input 2000 cfm and your calculation will really look promising), so you should use the usual reasonal carb selection processes.
BTW, the more CFM you input in the DD calculations, the more HP the virtual engine makes (you could input 2000 cfm and your calculation will really look promising), so you should use the usual reasonal carb selection processes.
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2024 C3 of the Year Finalist- Modified
You might be screwing yourself with 230 duration. Detonation is a problem up around 11. My original 383 used a 232/240 solid roller and was always on the verge. I finally pulled the cam and cured my problem
You smallish heads might work in you favor though because you have less air to compress
82 pound per hour injectors are for big inch high reving motors. You can look up some online injector calculators. The problem with too big is you can't set a short enough pulse time for low rpm. so you end up overly rich. It is smarter to run a lower pound per hour and if it gets lean at high rpm you can use additional fuel pressure to compensate
Dart 215 or AFR 210's are about ideal for sub 400 ci motors
You smallish heads might work in you favor though because you have less air to compress
82 pound per hour injectors are for big inch high reving motors. You can look up some online injector calculators. The problem with too big is you can't set a short enough pulse time for low rpm. so you end up overly rich. It is smarter to run a lower pound per hour and if it gets lean at high rpm you can use additional fuel pressure to compensate
Dart 215 or AFR 210's are about ideal for sub 400 ci motors
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St. Jude Donor '09, '24
Thanks C3 Stroker for the comparession to your motor. I like the high lift small duration cam for getting torque out of a motor and this Comp guy looks to fit the bill. Those are good numbers for a good street motor, with some 3:73s in the rear end. Gkull I run the throttle body setup and not the TPI fuel injection system. The tuned ports are a better system but a TBI system is easier to troubleshoot. You really don't lose that much preformance using a TBI unit instead of the tuned port system. So the 85# injectors running full tilt with the TBI system should give you close to a 1000 cfm. The beauty of the fuel injection system is you can tune the CFMs until you hit the air/fuel mix ratio right on the number it has to be for the best preformance. I have some World Motown heads with 220 intake runners and 2.08 valves. I think these would be 2 big for the 383 and I would lose to much torque. They will have to wait for a 427 buildup, houstonvett
Team Owner
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From: Reno Nevada
2024 C3 of the Year Finalist- Modified
I guess that i should have ask how many injectors you were using. All my heads used on my 383 were 2.08 or 2.10 valves. I also consider high lift way over .600 inches
Are going to run some kind of detonation sensor for timing retard?
Are going to run some kind of detonation sensor for timing retard?
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From: Who says "Nothing is impossible" ? I've been doing nothing for years.
Wow I'm all over this one, nothing like a real comparison of software to what happens in the real world. I am usually pretty close within 20HP but we will see, is this going on an engine dyno ?
My only concern is the fuel injection that might skew my numbers. Give me a few minutes and I'll whip you up a DD printout
My only concern is the fuel injection that might skew my numbers. Give me a few minutes and I'll whip you up a DD printout
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From: Who says "Nothing is impossible" ? I've been doing nothing for years.
THis is on an engine dyno with open headers, no accessories, not even the water pump is driven by the motor. DD tends to get a little optimistic with roller cams for some reason.
This is the Magnum 286HR cam
I would not expect to see numbers quite this high, knock 20-30HP and Tq off and we will wait for the real world dyno results. You should make over 500HP/500TQ
This is the Magnum 286HR cam
I would not expect to see numbers quite this high, knock 20-30HP and Tq off and we will wait for the real world dyno results. You should make over 500HP/500TQ
Le Mans Master
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From: Seattle WA
St. Jude Donor '14
The torque curve is a bit of an artifact from DynoSim at high flow where the modeling isn't as good.
The build isn't really set for low-end torque, but if you've got the gears that's a solid build. There's about another 20HP in there for AFR 210 Comps with this cam; I didn't model any other cams.
The build isn't really set for low-end torque, but if you've got the gears that's a solid build. There's about another 20HP in there for AFR 210 Comps with this cam; I didn't model any other cams.
Last edited by billla; Aug 27, 2009 at 10:26 PM.
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St. Jude Donor '09, '24
Thanks to all of the help from the forum members. It is a good build for a street motor. With close to 500 HP and 500 #s torque this should motivate a C3 down the road and still be a good driver. Gkull I think I will be OK and not have to worry about detonation in this guy. You have probably a lot bigger lift cam and I don't think I will be packing the cylinder with as much CFM as you are. I have looked at what the rice burners are doing with their water injection units. Some of the rice burners are running ultra high compression, on the order of 21:1 and higher. The burners are using a high end water injection unit along with sensors to curb the detonation problems they encounter at those compression levels. It works very well and is 1 reason some of those 4 cylinder motors are making over 700 HP from their tiny block. If I do run into detonation problems I might just look into using 1 of their injection units, houstonvett
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From: League City TX
I have looked at what the rice burners are doing with their water injection units. Some of the rice burners are running ultra high compression, on the order of 21:1 and higher. The burners are using a high end water injection unit along with sensors to curb the detonation problems they encounter at those compression levels. It works very well and is 1 reason some of those 4 cylinder motors are making over 700 HP from their tiny block. houstonvett
Le Mans Master
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From: Seattle WA
St. Jude Donor '14
I think you've kind of set your course, but I agree that you're pushing limits here that from my experience don't need to be pushed. There's a BIG difference between what can be accomplished on a small displacement DOHC engine with modern head, cam, induction vs. a GEN I SBC. A little "give" on some of these power targets will deliver a much more streetable engine.
Last edited by billla; Aug 28, 2009 at 12:26 PM.
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From: Who says "Nothing is impossible" ? I've been doing nothing for years.
If I had ( and I have had ) an 11:1 cr I would be looking in the 240-250 duration range at a minimum and this would be a solid roller, no telling what would be needed for flat tappet or hydraulic rollers. Good luck and I hope you don't run into any problems.
Just a side note I am able to run 91 octane with my 650HP 427ci small block with 10.5:1 cr and 248/254 duration solid roller with a .640" lift on AFR 227 Eliminator heads. My grandmother could drive this Vette around town.
And as I have stated before, when I build a motor, I build it for the street so I tool around at 1600RPM all day long with 3.08 rear gears, but when you put your foot into it you better hold on
Just a side note I am able to run 91 octane with my 650HP 427ci small block with 10.5:1 cr and 248/254 duration solid roller with a .640" lift on AFR 227 Eliminator heads. My grandmother could drive this Vette around town.
And as I have stated before, when I build a motor, I build it for the street so I tool around at 1600RPM all day long with 3.08 rear gears, but when you put your foot into it you better hold on
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St. Jude Donor '09, '24
Driveshaft I will look into this again. I believe the RaceDeck SRT-4 used at least 20:1 if I remember right. I will look to see if I still have the file. There is a person in SW Houston who produces some very fast rice burners. He is in the Murphy rd and 59 part of town and makes some serious high HP 4 cylinder motors. I will ask him also next time I pass on by his shop. I know 1 thing, there is not much left of the block when 1 of those 700 HP 4 cylinders bottom end decides to grenade into pieces.
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From: Who says "Nothing is impossible" ? I've been doing nothing for years.
Yes they are making 700HP if not more with huge turbos so the compression ratio has to way up there. I have a turbo PT Cruiser I was going to take to the track tonight to get a baseline but it it raining.
I will eventually put a bigger turbo on that. No sense in running my Vette, they will give me the boot after one pass. At least I can play around with PT Cruiser and watch go faster and faster and if it blowed up too bad
I will eventually put a bigger turbo on that. No sense in running my Vette, they will give me the boot after one pass. At least I can play around with PT Cruiser and watch go faster and faster and if it blowed up too bad
