wondering what kind of power I can expect from a .030 over, mild cam Pontiac 389. also if anyone has any cam recommendations it would be much appreciated. car is a 1966 Pontiac catalina 650 cfm edelbrock 4 barrel true dual. looking to upgrade. car went down the track for its first time last night and ran a 15.26 1/4. not bad for a 4200lb car that's still on original drivetrain with 107k miles. to the moderator I apologize for previous post.
Mmmm....389 Pontiac, my favorite. Pontiacs respond to easy bolt on parts just like any other engine. Start with the easy stuff, carb, manifold, exhaust, heads and cam. Sounds like you already have the carb covered, next is headers (Headman makes a very nice shorty headed which might fit your car.) and a full 2.5 inch dual exhaust with free flowing mufflers. Then, a cam with about 225-230 degrees of duration at .050. If that isn't enough, you need a set of Edlebrock heads. But, if you spend all the money on good heads, you need an even bigger cam, and more compression, forged pistons, light rods, full roller valvetrain, a sheetmetal intake and three stages of nitrous. Don't forget a Fab9 rearend, coilovers, 4 link and a full rollcage. Probably wouldn't hurt to have a tube chassis....See how this is starting to snowball already??? If you are trying to have fun on a budget, do the exhaust first, go to the track and work on your 60 foot time, then if you want to go faster think about a cam swap. The cam is a big step because at that point, you have to be very mindfull of your rear gearing, torque converter and it can snowball pretty quickly after that. Do the exhaust and learn how to get out of the hole without spinning, then we will talk more about camshafts. Good luck and welcome to the HAMB. -Abone. PS. Hit the search button for lots of good Pontiac tech, lots of neat stuff to learn.
One more thing, get some cool finned valve covers and a nice chrome air cleaner. Pontiacs can look pretty spiffy with minimal effort. Here is my chief engine builder and the 389 for my '34. -Abone.
You might actually pick up with a factory "068" ram air cam. Can get thru autozone melling sp7. or one of the pontiac dealers like butler or kauffman . Also since it is a factory grind can still just torque rocker arms to factory spec and dont have to worry about adjustment. Not bad times at all for what you have
Pontiacs are torque motors, do not try to build one like SBC. They prefer dual pattern cams. there are a couple of good Pontiac threads here on the forum
Do some research to find the right Pontiac head to raise your compression. Some of the earlier heads can raise later engine's compression by 2 points or more. I have a 73 400 with # 390 (1966) heads that raised the compression by 1.5 points.
Depending on which specific engine option he has, a 1966 Catalina with an automatic transmission would already be at 10.5:1 compression so he wouldn't want to go any higher than that. There was a low compression economy motor at 8.6:1 or thereabouts for cars with a standard three speed manual.
15.26 in the 1/4 is good. Post a pic of your timing slip. Do YOU have much time on the track? Practice makes perfect. There are a lot of cheap things you can do not involving the motor to pick up your times. Do you have a posi? What rear gears? What size tires? Do you have a tach? What rpm did you shift? Did it get into high gear before the end of the 1/4? Where was the car on the track when it shifted into high gear? I would expect a car like that to be shifting into high about the end of the 1/4. Generally you should be in high gear by about the 1/8 mile. You can play with tire size to make that happen to some extent.
That is an impressive time for that car. Considering that is faster than my brand new 1973 dodge Charger 440 automatic with a 3.55 gear did when it was brand new. At Miami Hollywood on a cool day. Shoot that is only a little over a second slower than my 69 396 375 Camaro 4 speed 4.10 gear did back in 69. It only ran 14.00 at 100 mph pure stock through the mufflers. That is one fast Pontiac. Headers and gears and tires you will be in the 12's.
I used to do a lot of pontiacs in my younger days (80`s) and you can do a lot of little tweaks to help. One of my favorites is I would take the new hydraulic lifters and change out the cheap retainer clips for good jesus clips then punch news paper over the rocker studs and just smooth the tops off. Then replace the stock nuts with Mr. Gasket poly locks, the good ones with the internal allen screws. If you have the intake off then just put the lifter to the bottom of the cam lobe and adjust the push rod down until you can stick the end of a small paper clip between the lifter plunger and retainer. Tighten down the center Allen screw and your done then the next one. It's almost like running solids. It revs faster, idles smoother and just smoother all around. The next was playing with the timing. Curve kits and springs. I'd run around 10 to 12° initial with a total of 34 to 36° by 2500rpm. Ran a 160° thermostat to keep the motor around 170 to 180° Then you can go deeper, gasket port matching the intake and heads, then a good cam, I prefer the dual pattern cams in pontiacs. My favorite 389/400 cam is crane H 278 2, put it in 2 389`s, 1 auto and 1 4_speed, 2 400`s 1 auto and 1 4speed. It's a torque monster. Need to run a 2200 stall behind auto. But it comes alive around 3000 and pulls to 6200. Idles at 800 but low vacuum at idle. Let us know how it's going!!
The Jalopy Journal
