444 CamShaft/Compression please advise

[funsummer]

Hi, First post so be kind..
Ive read a lot of forums and bought all my bits.
Read 2 books Back to back..
Bottom end is built, cam is timed.
And im concerned that my comp ratio is too low..
Ive calculated it at 9.4 to 1..
Im in aussie and regular unleaded is 91 octane.
The galaxie has a 300hp thunderbird special in it, its original, tired and pings like crazy on regular unleaded.
New motor is...
390 block, fully machined,main cap stud girdle.
4.250 rpm steel crank, scat h beam rods, diamond 4.080 pistons.
All balanced.
Edelbrock Keith Craft stage 2 heads 76cc
T&D rocker assy
Pistons are 17cc dished, and sit 0.007 in the hole.
1020 felpro head gaskets
Cam is Lunati Voodoo hydraulic flat tappet 62004
Intake port matched edelbrock perform rpm
ICE dizzy and spark controller
pro systems holley  850 cfm.

My biggest concern has being to match all the bits to get a combo that works.
Cam specs are.

Hydraulic, Hot street or bracket cam for 390 c.i. engines or heavier 427-428 c.i. vehicles. Will need 9.5 or better compression, 2800-3000 stall speed converter and 3.55-3.73 gears. Likes up to 200 HP nitrous. Cam has a very rough idle quality!
Advertised Duration (Int/Exh): 276/284
Duration @ .050 (Int/Exh): 233/241
Gross Valve Lift (Int/Exh): .564/.583
LSA/ICL: 110/106
Valve Lash (Int/Exh): Hyd/Hyd
RPM Range: 2000-6000
Includes: Cam Only
Part Number: 62004

This motor is going into a original 1965 LTD galaxie fast back.
It has A/C and power steer.
Automatic.
Also a diff ratio thats really tall.. Maybe 3.00
And standard wheels and white wall tyres with original hubcaps..lol

Might need a wheel/tyre upgrade..

Is my compression enough??
Is my cam correct??
To get the galaxie to go and match this motor, what size high-stall and diff ratio..
Will i get 500HP and 500ft?? or 

[jayb]

When I run your numbers I get a slightly higher static compression ratio, 9.8:1 rather than 9.4:1.  This is with a 4.25" stroke, 4.08" bore, pistons .007" in the hole, 17cc dish in the pistons(including valve reliefs, I assume), 76cc chamber in the heads, and a 0.041" thick head gasket.  Are these the numbers you are using?  How are you getting 9.4:1?

With your cam, the dynamic compression ratio I calculate (assuming 9.8:1 static is correct) is 7.9:1.  That's actually not bad for a street engine; with your heads you could go up to 8.5:1 and still run on pump gas if everything else is right, but 7.9:1 is OK.  You might think about running a slightly thinner head gasket; you could get away with a .030" thick head gasket since your pistons are a little in the hole.  If you did that, I calculate that static CR would be 10:1 and dynamic CR would be 8.08:1, which is moving you in the direction of more power.

If you really are at 9.4:1 static CR, I would definitely look at the thinner head gasket, and maybe shaving the heads to reduce the chamber volume.  For every .040" you take off the heads you will lose about 7cc from the chamber, and you can cut the heads quite a bit without causing problems.  I wouldn't be afraid to take .060" off the heads if necessary to raise the compression.  So, assuming you really are at 9.4:1, going with a .030" thick head gasket (probably a Cometic), and cutting .040" off the heads, you will raise static CR to 10.2:1, and dynamic CR to 8.2:1, which is right where you probably want to be.

Your cam sounds like a good hydraulic grind, and there is no reason it won't work in your car.  I'd figure on putting some better gears in the car though, probably 3.70s or 3.89s.  And I'd run a 3000 RPM stall converter.

You won't be making 500 HP with that setup, but you should be around 450.

Hope that helps, and welcome to the board - Jay

[hotrodfeguy]

I agree with Jay, I ran the Lunati 30507 very close to yours in a 410 combo. I would say in a good stall set up you could even go with 3.50 gear set and be happy. I would even say if the block was decked and head trued up go for a shim gasket. cause if your regular gas is starting at 91 octane you can step up on CR. Cheers mate!

[afret]

Did you or KC measure the actual combustion chamber volume?  KC seems to like the Edelbrocks with the bigger 76 cc chambers so is that where you got the number?  I have a set of KC stage 2 heads but the heads are the Edelbrocks with the smaller chambers.  The actual volume was way over 80 cc somewhere around 86 or 88 cc so I had KC cut the deck .05" to get the volume down to 78 cc.  It's been awhile but if I recall correctly I might have had him machine the chambers to stage 3 specs so the volume may be more than on a regular stage 2 head.

[jayb]

That is a very good point.  In order to really know what you've got for compression ratio, you should measure the chambers.  Have a local shop do it, or get a cheap plastic 25cc syringe and do it yourself...

[plovett]

My "72cc" Edelbrock heads are actually 79cc.   The shop measured them.  Then later when I had my heads off I measured and got the same volume.

Just FYI,

paulie

[Barry_R]

Older Edelbrock heads had some chamber variation - but the last few we've measured have been pretty close - 72-74cc.  When we CNC profile the chamber it comes in at 81-82cc.  I know Keith seems to like the 76cc Edelbrock chamber, I do not use those very often and cannot say how close they are running to size.  You would think they'd be pretty close considering they are completely machined, but....

I ran the compression calces and came up at 9.6 assuming a .290 crevice volume above the top rings - common dimiension with the catalog Diamond pistons.

If you can keep the valvetrain smooth past 5500 you just might get between 475 and 500 - probably closer to the smaller number.  But the 3.0 gear & stock converter would make it a real pooch in the car - upgrades are gonna be mandatory...

[funsummer]

Firstly and foremost thanks for your help.
Ok,
I have re checked all measurements..
And i made a few errors before.

Piston height is zero. its flush with block.
Heads are 77cc, checked by local machine shop.
I have being using diamond racing online calculator.

With these new numbers im coming up with 9.6 CR
If i want to get to 10.1

1- cometic 30" gasket and face heads to 74cc
2- 1020 41" gasket and face heads to 71cc

Questions is 30" a safe quench gap?
Is cometic a long term gasket? I wont to leave these heads on a long time..
What is HP gain from 9.6 to 10.1 comp ratio
If i want to use 100-150hp nitros for limited use at drags only with 98 octane fuel what ratio prefered and why?

Also 6000rpm has always being the goal.

Springs fitted to heads are
double springs plus damper
112lbs @ 1.970 on seat
330lbs @ 0.550 valve lift
0.750 coil bind
comp 747-16 retainers

Springs recommended on cam card are
singles plus damper
120lbs @ 1.820
315 @ 0.570

Have lunati hyd lifters with no oil feed to pushrod
T&D street rocker system
Pushrods- Not yet ordered Please advise.
Can easily shim springs if required.

Do you think that these spring pressures will be enough for these components to do 6000 rpm?

Also T&D rockers have cup adjusters with a center oil feed to pushrod,
Do i just order ball/ball pushrods with solid balls to restrict oil flow or??

Once again thanks to the experienced folk sharing there wealth of information with other builders.
Much appreciated.
Joel

[JamesonRacing]

Seems like a good combination to me, I don't see a problem with the CR, especially if you're current engine is having issues with pinging.  I doubt you'd be able to feel a difference between 9.6 and 10.0, so it's a lot of expense for little gain.  I wouldn't worry about the absolute HP number, that combination is going to be plenty strong.  Make sure you have good exhaust/ignition/fuel delivery systems, and a suspension that can use all the extra power and torque the engine will deliver.

Good luck, send pics!

[plovett]

1/2 point of compression might gain around 1-1/2% more power.  Maybe slightly more.   So on a 450 hp engine you might gain 6-8 hp.   Not worth messing with.  I also think a 0.030" quench distance is too tight.  Certainly not worth the small gains.   I would say .040" to 0.050" is the sweet spot for quench in most applications.

JMO,

paulie

[funsummer]

Thanks for info.
I will keep compression as is and install heads.

What are recommendations for quality push rods in custom length and do i want oil to flow down center of pushrod to lifter area or use solid balls to stop flow from rockers.
Im using T&D street system and they have adjustable cup style with oil feed in center.

Joel

 

[Chad D]

I have had good luck with Smith Brothers pushrods, they can accommodate pretty much any requirement.  http://www.pushrods.net/  T&D does also offer pushrods.  The FE rocker arm assembly is generally not oiled through the pushrod (they are oiled through a passage in the cylinder head), though it is possible with the correct parts combination.  I'm not familiar with the T&D street system, so it might be best to ask for their recommendation.

[jayb]

+1 on Smith Brothers.  As far as oiling through the pushrods, go with what T&D recommends with that rocker setup.

[funsummer]

Ok, how time changes things...
So ive just had a mate remove a wiped out solid lifter cam in a ford cleavland 351.
Then he fitted a new cam and wiped 2 lobes of it in less than 5 mins! Then in went a solid roller.
He is a well known speedway racer who builds his and others race car and street engines..Had a long chat with him and he convinced me after half a bottle of bourbon that i should go a hydraulic roller cam..
So ive committed to by one from BarryR on ebay.
287 293 234 240 .594 .598 112°
So a very small step up to my original cam with just a touch more lift and 2 deg more LSA, and slightly more advertized.
Heads are now in shop getting springs shimmed to try achieve 145 seat / 375 open. Will machine faces to raise comp closer to 10.1.
Cant believe im onto my second cam and the engine has not even run..
Im hopping the magic 500hp/500tq is now a reality..
This is a sunday driver galaxie ..
Have i selected a cam big enough? Would the one below better match my combination?
286 294 236 242 .636 .634 112°
 I dont want to buying a 3rd Cam !!!