just want some reassurance on combo choices

8KyZWeM.png


Using a 15 CC D-dish Cup Piston I result in a Dynamic Compression Ratio of 7.994 .
About 8:1 for 93 octane. Good to go then.

I am going to engine simulate with 9.5 :1 static compression with the Crower 00471 Cam Next.
Likely see Power down from other DD200 Runs.
Grumpy's Crane Cam HR306 with 9.5 static compression will see severe power losses.
His HR 306 must have been used by him in the Good Old days when Leaded race Gas was just $2.99 per gallon 1990's, I recall too I was in my 20's then.
I burned Race Gas street racing every single day it was affordable.
 
The Crower 00471 Gives Respectible Power with 9.5:1 static compression that results in 8.0:1 Dynamic compression.
Where you might have a problem is Racing a New LS3 Powered Camaro or LS3 Corvette.
That Extra Punch to Win to get ahead & Stay Ahead is not there.

The ISKY 272/282 HR is still the Winner.
Unbelievable 542 HP on 87 octane gasoline with 7.0:1 Dynamic compression.
 
It will have the street manners also with that Isky cam you will know there is a cam there have good power with out the expense of the goodies of a full race. Unless you want that road those comp xfi lobes you posted in special grind.Are designed for beehive springs and higher ratio rockers. 1.7 giving you a lift in the .615 .620 respectively. Spring maintenance becomes an issue along with roller maintenance. I like double springs less a chance of a valve being swallowed. I also like bushing rollers. The isky grind is nice put it in have respectable power you know it has a cam but will surprise you how much when racing it. My solid roller has 61 overlap. My solid Isky in my 355 always got compliments how good it sounded it had 58 degrees of overlap. Good heads do not need as much overlap to make power. That is at least what I have gotten discussing my setup with some pros. Profilers are well known you go anywhere almost any site you are gonna hear for sbc profiler or afr.
 
Ok I have the CC XR294 Engine simulation done with 10.5 : 1 static compression.
I had to change the timing entry to .006". That is how Comp Cams Listed above on the Cam Card.

I can not complete my Keith Black Dynamic compression ratio calculator.
IVC must be at .050".

Power is good.
Not as Good as the ISKY 272/282 HR. Still the Winner.

Post results next.
 
Ok Guys.
I am reading on Speed Talk.
The timing figures need to be in .050".
This Last Engine dyno Simulation is BOGUS.
We can call it Bullshit.

The Comp Cams Race Hi Tech Grinds are done in .020" solids .
Comp always did .050" too in the past Just Like Crane, Crower, Isky Cams.

Its a sales pitch Bullshit .
Figure none will catch on putting timing events at .006".


THE ISKY 272/282 HYDRAULIC ROLLER WINS.
 
Brian your comparing apples to oranges and using the incorrect data to produce a stacked deck result, favoring isky
yoda.jpg

look at the crane roller
, you used 9.5:1 compression vs 10.5:1 on the isky below
look at the cam timing timing figures
you used ivo-12/ivc-44 for crane yet crane says its a 240/248 duration
you used ivo -44/ivc-73 for isky yet isky says its a 242/248 duration
does it seem logical to you that if both cams with very similar duration and lobe separation angles,
and lift are used in the same engine that you would get vastly different characteristics and results?
now does that seem even marginally logical to you or anyone else,
if its the same heads and short block< using your figures the intake valve closes 19 degrees later for the isky,
that change alone provides a huge reduction in dynamic compression,
between the two stated cams yet you state the shorter duration,
would have far lower dynamic compression on the same engine???

4n6tMC5.png


ICPk5Z1.png


http://garage.grumpysperformance.co...mbers-or-a-good-street-combo-your-after.5078/
 
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Grumpy said:
Brian your comparing apples to oranges and using the incorrect data to produce a stacked deck result, favoring isky

look at the crane roller
, you used 9.5:1 compression vs 10.5:1 on the isky below
look at the cam timing timing figures
you used ivo-12/ivc-44 for crane yet crane says its a 240/248 duration
you used ivo -44/ivc-73 for isky yet isky says its a 242/248 duration
does it seem logical to you that if both cams with very similar duration and lobe separation angles,
and lift are used in the same engine that you would get vastly different characteristics and results?
now does that seem even marginally logical to you or anyone else,
if its the same heads and short block< using your figures the intake valve closes 19 degrees later for the isky,
that change alone provides a huge reduction in dynamic compression,
between the two stated cams yet you state the shorter duration,
would have far lower dynamic compression on the same engine???

4n6tMC5.png


ICPk5Z1.png

http://garage.grumpysperformance.co...mbers-or-a-good-street-combo-your-after.5078/
Click to expand...
No Grumpy.
The Crane Run HR306 I left static compression at 10.5:1.

YOUR LOOKING AT THE CROWER 00471 DD2000 RUN WITH STATIC COMPRESSION KNOCKED DOWN TO 9.5:1 FOR A DYNAMIC 8.0:1.
 
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DD2000 is still excellent for Apples to Apples comparison.
I actually thought Grumpy WON LAST NIGHT.
Till I Ran the Keith Black Dynamic compression ratio calculator.
Isky Won by Default.
You can not argue with 542 HP on 87 octane pump gas.

SURE MUCH MORE CAN BE HAD.
ITS A WONDERFULL TRUE STREET CAM PROFILE.
272/282 HR ISKY.
 
I spent alot of time on the Trans Am Forum while I was gone Grumpy for almost 2 years.
Every single Pontiac Guy in the world all eyes on me.

DD2000 every day.
I dispelled many.
Furious Many.

Truth hurts at times.
 
Maniacmechanic1 said:
DD2000 is still excellent for Apples to Apples comparison.
I actually thought Grumpy WON LAST NIGHT.
Till I Ran the Keith Black Dynamic compression ratio calculator.
Isky Won by Default.
You can not argue with 542 HP on 87 octane pump gas.

SURE MUCH MORE CAN BE HAD.
ITS A WONDERFULL TRUE STREET CAM PROFILE.
272/282 HR ISKY.
Click to expand...
How does that cam act with a dual plane air gap? With 1.6 ratio rockers?
 
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