So how do you get a flat torque curve?
Thread Starter
Le Mans Master
Joined: Dec 2002
Posts: 5,270
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From: Seattle Area WA
Here is what I came up with EA, my current cam (LPE213) vs a custom cam I played around and made up.
I'll try to post up a copy of my dyno graph when I get it.
Thoughts?
The custom cam is a "aggresive hydraulic roller"
I'll try to post up a copy of my dyno graph when I get it.
Thoughts?
The custom cam is a "aggresive hydraulic roller"
Race Director
Joined: Apr 2000
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From: Who says "Nothing is impossible" ? I've been doing nothing for years.
The torque curve is a result of all the parts working together and displacememt has a lot to do with it
That said I do not know the exact theory as to why the solid roller helps flatten out the torque curve like it does but I do know that I would not get the same result of the torque only changing about 40ft/lbs from 2000RPM to 5000RPM and probably 6000RPM froma any other type of cam.
I have an idea it is partially a result of being able to obtain a much higher lift while keeping the duration relatively low due to the aggressive ramps.
Here are the specs on the cam :
And here's a pic of really cool Chevelle just for fun
That said I do not know the exact theory as to why the solid roller helps flatten out the torque curve like it does but I do know that I would not get the same result of the torque only changing about 40ft/lbs from 2000RPM to 5000RPM and probably 6000RPM froma any other type of cam.
I have an idea it is partially a result of being able to obtain a much higher lift while keeping the duration relatively low due to the aggressive ramps.
Here are the specs on the cam :
And here's a pic of really cool Chevelle just for fun
Team Owner
Joined: Mar 2001
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From: Boston, Dallas, Detroit, SoCal, back to Boston MA
Variable cam timing, intake length, and exhaust is another way to due it. You see this a lot on small displacement engines.
But a variable exhaust is now on the C6Z06, a valve in the muffler.
That's something that could be tried on any street car.
But a variable exhaust is now on the C6Z06, a valve in the muffler.
That's something that could be tried on any street car.
Thread Starter
Le Mans Master
Joined: Dec 2002
Posts: 5,270
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From: Seattle Area WA
Hmmm, don't really feel like swapping around intakes so much. Can you do variable valve timing on a SBC, sound much $$$ if so. (Not that I know)
Anyway Brian, glad to see you are back from the gulf!
Anyway Brian, glad to see you are back from the gulf!
Team Owner
Joined: Apr 1999
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From: Reno Nevada
2024 C3 of the Year Finalist- Modified
All my cams were .050 timing. Your cam of 101 lsa ???????????? real radical race motors might get down to 106 and have 2000 rpm idle because of so much overlap.
Your motor is really wimpy to not exceed 500 hp
Your motor is really wimpy to not exceed 500 hp
Thread Starter
Le Mans Master
Joined: Dec 2002
Posts: 5,270
Likes: 3
From: Seattle Area WA
Originally Posted by gkull
Your motor is really wimpy to not exceed 500 hp
I am not sure if I follow, I don't know what to expect from a EFI 383, I didn't think that was that bad...
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Team Owner
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From: Reno Nevada
2024 C3 of the Year Finalist- Modified
I went back and looked at that dyno sheet you posted. 454 hp and 411 TQ
Let me get this straight - your doing that with a LPE 213 cam which is 213 intake duration .050 You need to input the cam event numbers to get closer to true results on these desk top dyno programs. Seat to seat numbers really don't mean much. .050 lift numbers are much better.
Let me get this straight - your doing that with a LPE 213 cam which is 213 intake duration .050 You need to input the cam event numbers to get closer to true results on these desk top dyno programs. Seat to seat numbers really don't mean much. .050 lift numbers are much better.
Thread Starter
Le Mans Master
Joined: Dec 2002
Posts: 5,270
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From: Seattle Area WA
The stats for the 213 cam are here:
http://cranecams.com/?show=browsePar...73&lvl=2&prt=5
The actual motor itself, on the dyno in my vette, made peak 326rwhp/400rwtq.
http://cranecams.com/?show=browsePar...73&lvl=2&prt=5
The actual motor itself, on the dyno in my vette, made peak 326rwhp/400rwtq.
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From: Lackey, my own dragstrip VA.
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Little stroker motor in my 97' is flat...............
417 cid NA DRM/Cartek stroker (4.010B X 4.125S)
VR-1B ram air system
ported LS6 intake
STAINLESS WORKS 3" Exhaust,
LS1-EDIT
Cartek 1-7/8 headers
3.73 gears
Rossler built stage 2 A4
TCS Converter 3500 stall
mild .581 cam
417 cid NA DRM/Cartek stroker (4.010B X 4.125S)
VR-1B ram air system
ported LS6 intake
STAINLESS WORKS 3" Exhaust,
LS1-EDIT
Cartek 1-7/8 headers
3.73 gears
Rossler built stage 2 A4
TCS Converter 3500 stall
mild .581 cam
Team Owner
Joined: Mar 2001
Posts: 30,847
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From: Boston, Dallas, Detroit, SoCal, back to Boston MA
Since the intake and exhaust lobes on a SBC are on the same camshaft, there's only so much you can do...save the lifters.
'bleed down' lifters have been around for a while. At low rpm they bleed off both lift and timing, and higher rpm they let the full range of the camshaft is seen by the valves.
On the new Impala, the pushrod V6 has variable timing, so it's coming.
'bleed down' lifters have been around for a while. At low rpm they bleed off both lift and timing, and higher rpm they let the full range of the camshaft is seen by the valves.
On the new Impala, the pushrod V6 has variable timing, so it's coming.
