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compression ratio

Started by Roger 68 charger, March 18, 2011, 10:08:03 PM

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Roger 68 charger

  I'm trying to figure out my compression ratio

440 block  bored 30 over
4.250  stroke
pistons are flat top with valve reliefs
pistons are sitting -.002 in the hole
Head gasket is .039 compressed
Edelbrock RPM Heads CNCed ported with 2.19 Int valves came out to 88.8cc

Any help would be appreciated
68 charger RT 505"
70 cuda
99 Durango

Domino

 can't get it right on without the volume of the valve reliefs.
(and gasket bore)

Can you get those two numbers?

Dans 68

1973 SE 400 727  1 of 19,645                                        1968 383 4bbl 4spds  2 of 259

FLG

.002 in the hole or .020?

Roger 68 charger

    My head gasket is 4.410 bore
    and on my spec sheet it has piston deck as -.002   I hope that means in the hole not out of the hole

    I tried the compression ratio calculator and I put in 5cc for the valve reliefs (guessing) and .002 in the hole and it came out as 10.9cr
   
    Does 5cc sound right for the valve reliefs?
68 charger RT 505"
70 cuda
99 Durango

firefighter3931

Quote from: Roger 68 charger on March 19, 2011, 07:51:15 AM
    My head gasket is 4.410 bore
    and on my spec sheet it has piston deck as -.002   I hope that means in the hole not out of the hole

    I tried the compression ratio calculator and I put in 5cc for the valve reliefs (guessing) and .002 in the hole and it came out as 10.9cr
   
    Does 5cc sound right for the valve reliefs?


The static compression ratio works out to 10.97 using 5cc for the valve relief which is about right for a flattop with reliefs.


Ron
68 Charger R/T "Black Pig" Street/Strip bruiser, 70 Charger R/T 440-6bbl Cruiser. Firecore ignition  authorized dealer ; contact me with your needs

Roger 68 charger

 Thanks Ron
Do you think that should be ok running pump gas with the aluminum heads?
68 charger RT 505"
70 cuda
99 Durango

Roger 68 charger

  what kink of HP # you think this build will bring?

440   30 over
H forged rods  7.100/.990
flat top pistons
stroked  4.25
10.9 compression ratio
Hyd Roller cam    Lift 541/541    Duration 240/248    LSA 112
Edelbrook RPM heads  --stage 3 cnc porting (Hughs engines) 2.19 int valves
Edelbrook RPM Intake ---ported, gasket matched
2" TTI headers
Quick Fuel 950

4 speed
411 gears
68 charger RT 505"
70 cuda
99 Durango

firefighter3931

Quote from: Roger 68 charger on March 19, 2011, 11:01:47 AM
Thanks Ron
Do you think that should be ok running pump gas with the aluminum heads?

That should work fine as long as the cylinder pressure stays reasonable.  :yesnod:

Quote from: Roger 68 charger on March 19, 2011, 11:22:06 AM
  what kink of HP # you think this build will bring?

440   30 over
H forged rods  7.100/.990
flat top pistons
stroked  4.25
10.9 compression ratio
Hyd Roller cam    Lift 541/541    Duration 240/248    LSA 112
Edelbrook RPM heads  --stage 3 cnc porting (Hughs engines) 2.19 int valves
Edelbrook RPM Intake ---ported, gasket matched
2" TTI headers
Quick Fuel 950

4 speed
411 gears


I would look at a cam with 10* more duration at .050 and keep it on a 112* lsa to widen out the powerband and bleed off some cylinder pressure. The static comp (10.97) is a little high with a "smallish" 240@.050 intake cam profile. A 250/258 split would work good, inmo. Those strokers eat duration !  :icon_smile_big:


That combo should make in the 600/600 range give or take a few.  :2thumbs:


Ron
68 Charger R/T "Black Pig" Street/Strip bruiser, 70 Charger R/T 440-6bbl Cruiser. Firecore ignition  authorized dealer ; contact me with your needs

Roger 68 charger

Quote from: firefighter3931 on March 19, 2011, 12:06:56 PM
Quote from: Roger 68 charger on March 19, 2011, 11:01:47 AM
Thanks Ron
Do you think that should be ok running pump gas with the aluminum heads?

That should work fine as long as the cylinder pressure stays reasonable.  :yesnod:

Quote from: Roger 68 charger on March 19, 2011, 11:22:06 AM
  what kink of HP # you think this build will bring?

440   30 over
H forged rods  7.100/.990
flat top pistons
stroked  4.25
10.9 compression ratio
Hyd Roller cam    Lift 541/541    Duration 240/248    LSA 112
Edelbrook RPM heads  --stage 3 cnc porting (Hughs engines) 2.19 int valves
Edelbrook RPM Intake ---ported, gasket matched
2" TTI headers
Quick Fuel 950

4 speed
411 gears


I would look at a cam with 10* more duration at .050 and keep it on a 112* lsa to widen out the powerband and bleed off some cylinder pressure. The static comp (10.97) is a little high with a "smallish" 240@.050 intake cam profile. A 250/258 split would work good, inmo. Those strokers eat duration !  :icon_smile_big:


That combo should make in the 600/600 range give or take a few.  :2thumbs:


Ron


:cheers:  That is the number I am shooting for  (600HP)

I guess I should have posted on here Before I bought my cam --My bottom end is together already--Trying to finish up the top end

what kind of #s do you think the charger will turn at the track?  (I know it depends on alot of things)
I will be running cal tracks and sub frame connectors
68 charger RT 505"
70 cuda
99 Durango

firefighter3931

The motor will make enough power to run 11's easily.  :yesnod:

How deep into the 11's depends on the driver  ;)



Ron
68 Charger R/T "Black Pig" Street/Strip bruiser, 70 Charger R/T 440-6bbl Cruiser. Firecore ignition  authorized dealer ; contact me with your needs