just want some reassurance on combo choices

Maniacmechanic1 said:
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Big Tube Race Headers.
1000 cfm carb. Be a 1085 CFM Listing Holley 4150 baseplate design.

Street Trim next.
Click to expand...
I'm just trying to jkee this car in the streer with good manners
 
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Ok.
Still Very Impressive Guys.
1-5/8" primary tube headers. I like to call them Dinky Tubes.
750 CFM Carb.
Enough to put a hurting on many yet Street racing.
Enough torque down low to work with the Muncie M21 Close ratio with a 2.20 : 1st gear.
Enough to pull 3.42 gears in a civil manner on the street at 2,000 rpms.

Unsure of the high Valve Overlap.

Have to trust Grumpy that it works on the street and not load up the spark plugs.

Been there with High Overlap cams idling too long.
Just takes 10 minutes in the past for me.
Need to stab the gas hard WOT to redline every few minutes to clean off the spark plugs.
All Ok then.
Cruising at 3000 + No issues. Plugs stay clean.
 
Ok.
I ran the Keith Black UMP Dynamic compression ratio calculator with Grumpy's Crane HR 306 Grind.
Same Parameters as before otherwise.
Have a Problem.
The Limit with Grumpys charts shows 8.0:1 Dynamic is the Limit with Pump Gas 93.
We have seen the problem 1st hand with Rick's T bucket 400 SBC with Aluminum Heads.
He was a bit over 8.0:1. Slight Detonation issues.

8.839 :1 is over the limit by a wide margin for 93 octane.
Could retard ignition timing.....Kill all the Torque & Power.
Easily Lose 50-75 Ft/lbs torque throughout the Power band & Peak HP likley be down 75-100 numbers.
 
Using an Inverse Ratio formula with 8.0:1 Dynamic on 93 RM/2 octane gasoline ,
8.839 :1 Dynamic calculated with the Crane HR306,

I calculated we need 102.7 RM/2 Octane Fuel.

Say 105 Motor Octane .
 
DCR Octane #
7.1 87.5
7.2 88.0
7.3 88.5
7.4 89.0
7.5 89.5
7.6 90.0
7.7 90.5
7.8 91.0
7.9 91.5
8.0 92.0
8.1 92.4
8.2 92.8
8.3 93.2

Its our basic Dynamic Compression Ratio Chart We use here.

http://garage.grumpysperformance.co...octane-for-compression-ratio.2718/#post-68131

Direct Link Chris above. Take time to read tonight.


Its always a compromise somehow.

Work on the other Cams you want me to DD2000 simulate run later, likley early in the morning.
Tired from working today.
Drive 140 miles roundtrip to my job as a Mechanic.

Brian R.
 
Maniacmechanic1 said:
DCR Octane #
7.1 87.5
7.2 88.0
7.3 88.5
7.4 89.0
7.5 89.5
7.6 90.0
7.7 90.5
7.8 91.0
7.9 91.5
8.0 92.0
8.1 92.4
8.2 92.8
8.3 93.2

Its our basic Dynamic Compression Ratio Chart We use here.

http://garage.grumpysperformance.co...octane-for-compression-ratio.2718/#post-68131

Direct Link Chris above. Take time to read tonight.


Its always a compromise somehow.

Work on the other Cams you want me to DD2000 simulate run later, likley early in the morning.
Tired from working today.
Drive 140 miles roundtrip to my job as a Mechanic.

Brian R.
Click to expand...
SPEC CARD# 10833106
PART # 12-000-9 CS SPECIAL ROLLER
CORE C12-9G CS CHEV 265-400 8620 SEMI
GRIND # CS 3017S-3018S HR106
DURATION @ .050
INTAKE 236 ROCKER ARM RATIO
VALVE ADJ INTAKE HYD DURATION @ .050 EXHAUST 242
INTAKE 1.60
VALVE ADJ EXHAUST HYD LOBE LIFT INTAKE .3630
EXHAUST 1.60
VALVE LIFT INTAKE .580 LOBE LIFT EXHAUST .3660
VALVE LIFT EXHAUST .585 LOBE SEPARATION 106.0
DURATION .006 INTAKE
C/L 106.0
TAPPET LIFT INTAKE 286 ADVANCE 0

TAPPET LIFT EXHAUST 292 HYDRAULIC Y
VALVE TIMING .050
VALVE OPEN INTAKE 12 JOURNAL DIAMETER STD
1.868
VALVE OPEN EXHAUST 47 RECOMMEND VALVE SPRINGS
VALVE CLOSED INTAKE 44 DEPARTMENT P
VALVE CLOSED EXHAUST 15 SPC INSTR FOR CUSTOMER
 
Christopher Williams said:
SPEC CARD# 10833106
PART # 12-000-9 CS SPECIAL ROLLER
CORE C12-9G CS CHEV 265-400 8620 SEMI
GRIND # CS 3017S-3018S HR106
DURATION @ .050
INTAKE 236 ROCKER ARM RATIO
VALVE ADJ INTAKE HYD DURATION @ .050 EXHAUST 242
INTAKE 1.60
VALVE ADJ EXHAUST HYD LOBE LIFT INTAKE .3630
EXHAUST 1.60
VALVE LIFT INTAKE .580 LOBE LIFT EXHAUST .3660
VALVE LIFT EXHAUST .585 LOBE SEPARATION 106.0
DURATION .006 INTAKE
C/L 106.0
TAPPET LIFT INTAKE 286 ADVANCE 0

TAPPET LIFT EXHAUST 292 HYDRAULIC Y
VALVE TIMING .050
VALVE OPEN INTAKE 12 JOURNAL DIAMETER STD
1.868
VALVE OPEN EXHAUST 47 RECOMMEND VALVE SPRINGS
VALVE CLOSED INTAKE 44 DEPARTMENT P
VALVE CLOSED EXHAUST 15 SPC INSTR FOR CUSTOMER
Click to expand...
Ran the compression ratio calculator.
Dynamic is to high at 8.9 to 1.

Dropping static compression down with a 15 CC Dish cup D piston results in 9.5 :1 static.
Dynamic comes in at 7.9994 to 1.
Good to go on 93 octane.

Desktop Dyno 10.5 :1 power is 499 Hp at 6,000 rpm. Peak Torque 512 ft/lbs at 4500 rpm.
2000 rpm torque is 434 ft/lbs.
 
Isky 272/282 HR is no fuss best so far.
Giving up some torque but not much.
Excellent Hp at 542 all on 87 octane gasoline.

10.5 to 1 static compression ratio.
Flat Top piston with 4 CC valve relief.
Zero deck engine.
 
Maniacmechanic1 said:
Isky 272/282 HR is no fuss best so far.
Giving up some torque but not much.
Excellent Hp at 542 all on 87 octane gasoline.

10.5 to 1 static compression ratio.
Flat Top piston with 4 CC valve relief.
Zero deck engine.
Click to expand...
I agree. What about it vs grumps Crower 00471? I saw a few mean Dyno runs of it. Curious to see how they compare trend wise
 
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