desktop dyno please
Thread Starter
Drifting
Joined: Oct 2000
Posts: 1,526
Likes: 1
From: Harrison Township, Mi
desktop dyno please
OK guys, here's what I've got going together....If anyone can give me the results, I would much appreciate it.
SBC 383 stroker
Ported 1970 LT1 heads 2.02/1.60
9.8:1 Compression
Roller rockers (1.5)
Hyd. Roller cam (.509/.528 222/230 @ .050 112 LC)
LT1 aluminum intake
Holley 750 or correct LT1 780 (undecided as of yet)
Port matched and extrude honed 2.5" exhaust manifold-needed for factory appearing drag racing...can't use headers.. I know it's probably going to cost me 30 horsepower
2.5" exhaust
Thanks in advance. Also if anybody is bored and wants to run a desktop drag simulator on it, It's going into my 72 Vette. 4 spd, 3.70 gears, 3350 lbs. w/driver.
SBC 383 stroker
Ported 1970 LT1 heads 2.02/1.60
9.8:1 Compression
Roller rockers (1.5)
Hyd. Roller cam (.509/.528 222/230 @ .050 112 LC)
LT1 aluminum intake
Holley 750 or correct LT1 780 (undecided as of yet)
Port matched and extrude honed 2.5" exhaust manifold-needed for factory appearing drag racing...can't use headers.. I know it's probably going to cost me 30 horsepower
2.5" exhaust
Thanks in advance. Also if anybody is bored and wants to run a desktop drag simulator on it, It's going into my 72 Vette. 4 spd, 3.70 gears, 3350 lbs. w/driver.
Drifting
Joined: Dec 1999
Posts: 1,462
Likes: 1
From: Reno nevada
Re: desktop dyno please (randy72)
Your cam is on the mild side. I run a solid 238/248. Your compression is also low. I'm running @10.5 with 186 casting double hump heads. I took the time to polish out the chambers and the ports are about as big as they can get. I'm using the LT1 intake port matched 750 cfm Holley
Melting Slicks
Joined: Dec 2000
Posts: 2,635
Likes: 0
From: Union Ontario
Re: desktop dyno please (Lt1er)
Randy, here are the numbers.
Just remember I am a beginner at Desktop dyno
Peak HP 370 HP @5000rpm
Peak Torque 450ft-lbs @3000rpm
I'll send you a screen shot of the graph, The heads I used were low performance, ported, big valve( nothing else matched as well- everything was race oriented). I think thats whats bringing your HP down. If you have flow numbers for your heads, that will help greatly.
Also if you give me your cam mfg, and model number, the cam would be exactly right.
I hope your happy with the engine, I would be.
Just remember I am a beginner at Desktop dyno
Peak HP 370 HP @5000rpm
Peak Torque 450ft-lbs @3000rpm
I'll send you a screen shot of the graph, The heads I used were low performance, ported, big valve( nothing else matched as well- everything was race oriented). I think thats whats bringing your HP down. If you have flow numbers for your heads, that will help greatly.
Also if you give me your cam mfg, and model number, the cam would be exactly right.
I hope your happy with the engine, I would be.
Thread Starter
Drifting
Joined: Oct 2000
Posts: 1,526
Likes: 1
From: Harrison Township, Mi
Re: desktop dyno please (Lt1er)
The car is driven on the street a lot and I didn't want it to become a bear to drive. $3.00 a gallon gas sucks. I'll send the cam info later today.
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Drifting
Joined: Dec 1999
Posts: 1,462
Likes: 1
From: Reno nevada
Re: desktop dyno please (randy72)
I looked up your Crane cam and it should be a nice one for a 383.
Fair idle, moderate performance usage, good mid-range HP, mild bracket racing, auto trans w/2500+ converter, 3000-3800 cruise RPM, 9.5 to 10.75 compression ratio advised. Basic RPM 2500-6000
You see the upper 10.75 c/r number it's the max. Crane determined the C/R that could be run with this cam with pump gas with a knowledgable person tunning.
This is my solid flat tappet.
[b]1. PowerMax Mechanical Lifter Camshafts for Non-Emissions Controlled Vehicles
Application Series & Grind Number
Fair idle, moderate performance usage, good mid-range HP, bracket racing, 3400-3800 cruise RPM, 10.0 to 11.5 compression ratio advised. Basic RPM 3000-6500 PowerMax F-278-2
replacing:
CC-278-2
Cam Specifications
Degrees Duration @ .050 Int./Exh. Degrees Advertised Duration Int./Exh. Degree Lobe Separation Open/Close @.050" Cam Lift Int./Exh. Lash Hot Int./Exh. Gross Lift Int./Exh.
238
248
114 10 48
63 5 .022
.022 .480
.500
Do to the .050 cam timing spects it bleed off more pressure so the max C/R is raised to 11.5. That's why my 10.5 works so well with 92 octane. Your roller has other advantages also
Fair idle, moderate performance usage, good mid-range HP, mild bracket racing, auto trans w/2500+ converter, 3000-3800 cruise RPM, 9.5 to 10.75 compression ratio advised. Basic RPM 2500-6000
You see the upper 10.75 c/r number it's the max. Crane determined the C/R that could be run with this cam with pump gas with a knowledgable person tunning.
This is my solid flat tappet.
[b]1. PowerMax Mechanical Lifter Camshafts for Non-Emissions Controlled Vehicles
Application Series & Grind Number
Fair idle, moderate performance usage, good mid-range HP, bracket racing, 3400-3800 cruise RPM, 10.0 to 11.5 compression ratio advised. Basic RPM 3000-6500 PowerMax F-278-2
replacing:
CC-278-2
Cam Specifications
Degrees Duration @ .050 Int./Exh. Degrees Advertised Duration Int./Exh. Degree Lobe Separation Open/Close @.050" Cam Lift Int./Exh. Lash Hot Int./Exh. Gross Lift Int./Exh.
238
248
114 10 48
63 5 .022
.022 .480
.500
Do to the .050 cam timing spects it bleed off more pressure so the max C/R is raised to 11.5. That's why my 10.5 works so well with 92 octane. Your roller has other advantages also
Melting Slicks
Joined: Dec 2000
Posts: 2,635
Likes: 0
From: Union Ontario
Re: desktop dyno please (Lt1er)
Putting that exact cam in the engine it goes to
Peak HP 355 HP @5000rpm
Peak Torque 464ft-lbs @3000rpm
I think I have found some flow numbers on a set of 186 heads(original Lt1 heads). I'll post when I put them into the program.
Peak HP 355 HP @5000rpm
Peak Torque 464ft-lbs @3000rpm
I think I have found some flow numbers on a set of 186 heads(original Lt1 heads). I'll post when I put them into the program.