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la2alle

la2alle

Bad Fish 65
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Ok, need some advice on what you guys think I can do to make my car run better. I just started a rebuilt 273 from a 1965 barracuda (automatic). What I have in it are the following;


bored .30 over / 10.1 pistons / dont remember what type.


302 swirl port heads / rebuilt with the bigger valves


Comp Cam specs ADV DUR. INT 268 - EXH 268
DUR @: .50 218 218 Lobe SEP: 110.0
Valve lift: 454 .454

With comp cam lifters and adjustable rockers


Holley #80457 600 cfm


Weiland Intake / Action plus # 8007


Mallory Unilite distributor and coil


Rebuilt 904 tranny with a quick shift kit.



Problem is the car is not accelerating as I think it should, kinda sluggish. Could the Carb be to big? advice would be appreciated.
 
Converter information would be helpful as well as rear tire diameter.
 
Still has the 7 1/4 rear end, according to the cam specs you can use your standard converter. Rear end will be changed soon to an 8 3/4 3.23 gears
 
How about the timing?
Huge gains or losses can be had there.......
Is the cam centerlined?
3:55 or 3:91 gears in an 8 3/4 rear end would help a lot too.
 
What size rear tires?

Likely WAY too tall gears, 323 might not help much

Where is cam degreed? Makes a HUGE difference

Is distributor recurved? stock? late model smogger?

14 BTC might not be enough. Search some of crackedback's posts on adjusting timing.

and..................converter..............

My "budget" backyard build was "run what ya had."

I had a used 360 out of a van with a GREAT big converter about 1800?? stall with a smaller cam than you. It was no stormer out of the chute, with 370 rear gear,
 
Spend some time and effort tuning what you have and see what the motor wants and correct as needed. If you want to spend some money, get a wide band exhaust meter and install for about a half year or less.
 
Are they the dome hi compression pistons? (see pic below) let me guess it starts comen alive apx 3000 rpm then screems to about 6000 rpm right? if timing,carb tuning & such are good got 10 bucks sayen yer stock converter is waaaaaay to low of a stall. my set up has a 2500-2700 stall & its almost enoph. 3.55's or 391's would help alot! or get a later 904 that will accept the wide raito planetry (2.76:1) 1st gear raito. Whats yer cranking compression?
 
thanx, I went on the stock convertor because thats comp cam said I could run. Might need a higher stall.
 
Are you running a vacuum advance and is it hooked to the right vacuum port on the carburator? What total advance are you running?

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The 273-4 had slightly higher stall torque converter and governor (shift points) from factory.
 
First, where is your timing set?

Have you recurved the distributor?

Did you set the accelerator pump linkages to .015" clearance. Lack of this adjustment can make it sluggish.

The 80457 is a nice carb. I've run them on 318's with 340 cam and 2.76 and 3.23 gears with stock converters. Your carb is just fine, you just may need to tune it in.

Set your timing to 34 - 36° BTDC @ 2000/2500 rpm.

Next make sure you set the accelerator pump clearance.

Get the Holley secondary spring kit and put the short yellow spring in your vacuum secondary pod.


For your application, I would prefer the Wiand Stealth intake. The action plus is made for a spread bore, the stealth is for a square bore. Your carb is a square bore.


CHRYSLER SMALL BLOCK ACTION +PLUS INTAKE MANIFOLD
PART #: 8007

Installation Notes
Square bore Carburetors may require
plate P/N 9006 to seal properly. Rotary
A/C compressor will not clear on 1978 and later applications.


Features
High Rise Dual Plane Design
Universal Mounting Flange
No EGR Provisions
Power band: Idle-6000 RPM
Height: Front 4.88", Rear 5.94"
Port Size: 1.96” height 1.00" width

View attachment Wiand 8007 Action plus lg.jpg

http://www.holley.com/8007.asp


CHRYSLER SMALL BLOCK STEALTH™ INTAKE MANIFOLD
PART #: 8022



Installation Notes
Rotary A/C compressor will not clear
on 1978 and later applications.


Features
High Rise Dual Plane Design
Square Bore Carburetor Mounting Flange
No EGR Provisions
Power band: Idle-6800 RPM
Height: Front 4.88", Rear 5.94"
Port Size: 1.96” height 1.00" width


View attachment Wiand 8022 Stealth lg.jpg

http://www.holley.com/8022.asp


Then use this gasket:

BASE GASKET
PART #: 108-18

Features
Fits Holley Model 4150™, Model 4160 and Model 4180™
1 9/16" Throttle Bore
.204" Thick

View attachment Carb Gask Holley 108-18 lg.jpg


http://www.holley.com/108-18.asp


I don't care for the carburetor adapters to convert from spreadbore to squarebore or vice-versa.

I feel that it's best to use a manifold that is made with the proper flange.

The stealth also is rated for up to 6800 rpm, where the action plus only goes to 6000 rpm where both 'start' at idle.

Then use a gasket just like the one above with the dual plane (split) down the center to keep the plenum all divided up to the carb base. This will keep your low end torque. With the 5/16" thickness, it also helps insulate the carb from heat of the engine/intake. This will keep the low end torque that the intake was designed for.

If you don't keep the plenum divided and use an "open" gasket with no divider, you loose some of the low end torque that the dual plane provides. The squarebore to spreadbore adapter may loose some of that low end torque that you are looking for.
 
Hipo65 said:
... let me guess it starts comen alive apx 3000 rpm then screems to about 6000 rpm right? ...
Click to expand...

This is how a High Performance 273 runs. I think you have a good combination. It is always worth finding true TDC on your Vibration Damper. They are always off and I've seen them over 10 degrees off. If you did not do this when you built the engine you can get or make a piston stop and check it now. Do a search, it has been covered before.
 
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