350 Head porting

[Skyllark]

I rebuilt my 69 350 a few months ago.

I posished the combustion chambers.
Cleaned up the exhaust real good nice and smooth.

Cleaned up the intake, but did not gasket match them,
i was told it wouldn't make a noticable difference.
and that being the hardest :BEERS:part of the job i pass on it.

now that i'm running it at a 1/8th mile and trying to find 1/100 of a second, i'm thinking i should have matched the intakes.

question being should i pull em and do a gasket match.
also what else can i do to that head to make it better.

yes that's the A/C compressor-
Cheers!

[Wildcat_65]

Turn off the a/c :TU:

[gsjohnny]

Turn off the a/c :TU:


that's a cool reply :LAUGH::LAUGH: at least you didnt give him the cold shoulder.....

[Skyllark]

well if i'm going to shut off the A/c, i might as well release the parking brake-

[Skyllark]

Mr. Wildcat_65
Did you pick up that little a/c joke at Joe's Garage?

[gsjohnny]

well if i'm going to shut off the A/c, i might as well release the parking brake-


you GOT a parking brake too....holy moly.......:LAUGH:

[Daves69]

Give us some info on your combination. Cam, convertor, rear gears, tires.
What timesa and mph are you presently running?
What times would you like to see?

Dave

[Skyllark]

350 .030 over
8.5 CR?
Heads ported and polished (soon to be gasket matched)
Comp Cam 252H
T/A dual plane
Holly 670 Avenger 4brl. (today* jetted 74/78)
Petronix unit
Blaster coil
Mallory cap and rotor
TH350 Shift Kit
B+M Holeshot 2000
B+M shifter
Richmond 3.90 gear
Auburn Posi
Micky T 275/60/15 28"tall
Hotchkis sway bars ft+rear
Edlebrock control arms rear upper and lower
Edlebrock no hop bars
KYB's ft+rear

9.4 1/8mile @72mph

[TheFly]

kinda small carb for a 350 ehy? I dunno holley that well so I dunno but by straight CFM numbers it sounds small to me from what Ive read around here n elsewhere.

Dunno if jetting can make up for CFMs?

Quick google search finds them on allot of Chevy's but we all know a Buick needs more air.

[Daves69]

Combo looks good. You might want to try a shorter rear tire, depending on how the car launches, try raising the front tire pressure( less rolling resistance ).
Do you have an air bag in the right rear spring?
To check you carb try to rig up a vacume guage so you can watch it a full throttle. If you show a negative pressure at full throttle then the carb is too small.
Distributer curve should be in all in at 2500 rpms at 32-34 degrees total timing.
I noticed you have a ? on your compression. Is this an estimate or did you calculate it using your bore, stroke, head cc's, piston dish cc's, and gasket thickness? This will make a difference in your total compession. You might want to try to raise compression if you plan on removing the heads to do the gasket match. Try to get around 9.5:1 to 10:1 compression. You can do this by usng a thinner head gasket, and or milling the heads.
I think with some tuning you will be able to pick up some E.T and MPH.
Good luck.

Dave

[Skyllark]

THANKS DAVE-:BEERS:
I DO WANT TO UP MY CR, CAN YOU TELL HOW MUCH I CAN CUT THE HEADS?
WILL I NEED DIFFERENT PUSH RODS OR HEAD BOLTS?

I SEE THE .020 GASKETS ARE STEEL OR COPPER ($80.00)
I'D PREFER TO TORQUE A SET OF .040 FELPRO.
I THINK THEY WOULD SEAL BETTER.
OTHER STUFF?
I DON'T KNOW HOW MANY CC'S THE PISTONS OR HEADS ARE. GUESSING IS THE HEADS ARE 51CC'S.
THIS TIME I WILL MEASURE!
IS THERE A FORMULA ?

THANKS FOR YOUR TIME!!!!
TIM-GOTTA GO FASTER-:TU:

[TheFly]

Id get adjustable push rods.

[Eric Schmelzer]

kinda small carb for a 350 ehy? I dunno holley that well so I dunno but by straight CFM numbers it sounds small to me from what Ive read around here n elsewhere.

Dunno if jetting can make up for CFMs?

Quick google search finds them on allot of Chevy's but we all know a Buick needs more air.

I was thinking the same thing on carb size. The stock 350 in my 73 used a 750 Q-Jet from the factory.

[Daves69]

Tim,

Here is a good article on how to calculate your true compression. http://www.carcraft.com/techarticles/calculate_compression_ratio/index.html

Hope this helps

Dave

[Skyllark]

Dave,
Thanks for the facts!

Tim

[69GS400s]

Sweeeet looking car Tim :BEERS:

Gotta LOVE them '69s :BROW:

[Buicks4speed]

Need a 750 DP w/ a 1" spacer, cut the heads .040-.050". The intake, if an old TA, needs opened up at the flange BAD. Doesn't need to be gasket matched, just port matched. If you pull the heads, go with the new roller rocker conversion that uses the sbchevy rockers. Your best gains with port work is in the short-turn and bowl.

[gsjohnny]

has anyone check the length and c/line ratio of the sbc to sbb rockers to see if they are (near)correct????

[Buicks4speed]

has anyone check the length and c/line ratio of the sbc to sbb rockers to see if they are (near)correct????

THere is already a set mounted on a set of 350 heads. Geometry is great as is the length.