More 301 Ponch questions

Hi, I'm new to the site and not really sure how posting works, but I had some cam questions in particular for the 301. I posted a message in 301 Ponhco questions. I have a '79 Buick that had a 2bbl 301 (spun rod bearing) and now have a 4bbl 301 from a '79 Bonneville. Please see the other thread. Thanks!

Jordan  

Thanks to PontiacMan8 for answering my cam question. As far as I know, the 4bbl 301 hasn't had any machining done. Also I'd like to say again that I'm not camming out the 301 to try and make serious power, just for the self satisfaction of actually doing it. This car is my first motor-swap and engine tear-down project and it's mostly going to be a learning experience for me.  

My frist engine build was also a 301 pontiac engine.

Your welcome and good luck with your frist build.  
professional hi-performance engine builder

Horsepower sells engines and torque wins races

email me for a good article on the 301 engine
smoke_young82@yahoo.com  

I figured out that the Holley carb I got with the 301 is a 700cfm. Is that going to be a problem? If I decide to go with a mild cam it should be fine, right? What kind of power figures should a cammed 301 with a Holley 4bbl make? I've also heard that the bottom end of this motor is weak. Is that to say that it is prone to spinning bearings? I did spin a rod bearing in my 2bbl 301. It was probably a little worn out already but I also probably was over-revving it. What makes this a "weak" engine and what can I do to prevent premature failure? Who has this 301 wisdom?  

The 301 has a very light weight crank and block, especially in the main cap area. This means that as load and rpm increase, the block and crank are less able to resist twisting and flexing, causing bearing issues and so on.
Properly assembled with new parts and quality machine work, it should be reliable to 5000 rpm. Remember to pick your cam from the low end of available grinds, due to the small cubic inches and short stroke of the 301. What would be mild in a 400 will be over-cammed in a 301.
It will run with a 700cfm carb, but throttle response and low end torque will suffer quite a bit. I would go with a 500-600 cfm or a Q-jet (which will flow a lot less than 750-800cfm if that's all that is required and the small primaries help low end torque and response).
I have the same article that sy82nj has offered and it is a good read for your project. Send one of us a PM and we'll email it to you.
Steve  
A little help... 'cause we don't all have to learn the hard way!

hello, friends, I had a 78 firebird with a 305 chevy motor and my buddie had a 77 manybe a 78 with a 301. due to lack of bigger motors(prduction wise,  they werent fast or brutal, but you couldnt kill them. unless you tossed a 4bbl intake and carb on them.Like barneyformula said these motors were not to produce power like a 400ci.a 400 is a torgue monster...on the low end. trust me i have a 81 turbo 301.. suppost to do 200hp iguess with a 1 of kind intake..? A 77-78 301 is max 160-175 hp..  

Barneyformula, you said you would go with a 500-600cfm or a Q jet carb for the 301.  I thought Q jets were rated at 650-750cfm, which is way out of the ideal 500-600cfm range for the 301.

I have a Q jet form an early '70s Pontiac V8.  Would that work well on my 301?  Wont that flow like 750cfm or so?

Maybe the best thing is to invest in a 500-600cfm Holley or Edelbrock??  
1969 GTO, YS code 400, 350hp/445 ft lbs of torque (stock specs), LT headers, H-pipe, 750 Holley 4160, Ignitor II ignition.  Complete Painless wiring.

True, the Q-jet can and will flow 750-800cfm...if the engine requires it. Because it is an "air valve secondary" (AVS)design, only the mechanical throttle plates will open wide open when you mash the throttle. The secondary air valves (the 2 big plates behind the choke) will only open as the airflow requirement of the engine allow. This is what made the carb so successful for GM, using it on everything from 250cid Sprint sixes to 500cid Caddy engines.
Vacuum secondary Holleys and AVS Edelbrocks work on a similar design theory, however they don't have the small primary bores of the q-jet that give the great low end response and economy. If you want to spend a big chunk of change on an aftermarket carb, get a small one, but remember to mount it on your manifold will require an adapter plate which may hinder airflow and will definitely raise the carb and air cleaner at least an inch.
Although any q-jet can be made to work, I would look for an original 301 carb or one from a 305 Chevy or 307 Olds, because the jetting and air valve adjustments will be close to what you need.
Clear as mud? Hope this points you in the right direction.
Steve  
A little help... 'cause we don't all have to learn the hard way!

Thanks, Steve for the great input. I have also read the 301 article and have new insight on what and what not to do with the 301 and have since changed my mind on a few things. So... a weak bottom end = more likely to wreck bearings. Not what I wanted to hear, but that's the cold hard truth. My LeSabre probably weighs near 2 tons and I believe it came with a crazy tall 2.29 rear axle ratio. Would that alone be putting to much strain on the 4.9? The original 2bbl also had a very high amount of sludge in the engine and probably caused unneccessary wear to the bearings. I saw this weekend that the 4bbl I just got is unusually clean inside for a 30 year old motor. I guess it was very well maintained.  

In average day to day driving your car wouldn't put undue stress on the engine. When you start making more power and using it is when things start to stack up. For a cruiser that isn't going to get pounded constantly the 301 will live quite happily, especially if all you want is to merge onto the freeway a little easier and get better mileage.
Steve  
A little help... 'cause we don't all have to learn the hard way!

Awesome Barneyformula, thanks for the carb info.  It makes sense to me, not clear as mud hahaha.  Why is an adapter plate needed to run an aftermarket carb on the 301?  As long as the carb is a spreadbore.  

79_Lesabre, you're guess is as good as mine about the stress caused by your gearing.  It makes sense to me that a 2.29 ratio would make your 301 work hard to move that beast.  In any case, I'd change out the gears for a 3.73 ratio, or something in that area.  
1969 GTO, YS code 400, 350hp/445 ft lbs of torque (stock specs), LT headers, H-pipe, 750 Holley 4160, Ignitor II ignition.  Complete Painless wiring.

the gears are not high in the 301 cars. i myself would go with a 600cfm and 373 are to much gearing 3.42 would be better. i will be re-doing a 301 soon.  

my plans: comp cam, roller rocker arms,4bbl intake p/p,600cfm holley,oem exhaust mani p/p,heads mildly p/p,e-fan,2.25 duals,th350 b/m shift,3.42 gears, and maybe some chrome under the hood to make my small block v8 pretty. this is the best you can do for the 301  

Built off the Chevrolet
Chevette platform, it's not regarded as a killer performer by any means. That's because its motivation came from a series of inline-four engines, none of which made respectable power. There are, however, two upsides to this subcompact-it's a featherweight, and it has rear-wheel drive. In the wrong hands, the T1000 can become pretty crazy. Enter Bob Humbrecht.

As owner of Casual Restorations in Hatfield, Pennsylvania, 42-year-old Bob is no stranger to building spectacular Pontiacs, although the T1000 is a departure from his normal creations. A touch of humor was invested in this three-week project. "It was built for the fun of it-you have to laugh at yourself," he says. Along with the chassis of choice getting little respect, the same can be said for the powerplant, a Pontiac 301, which is not known for being the strongest engine (Bob has several snapped crankshafts as proof). Nevertheless, he was intrigued by the idea of cramming the small-journal V-8 into the tiny engine bay.

A common swap for Chevettes has been small-block Chevys. Knowing that these were capable of fitting, Bob began doing his homework and taking measurements. He found that the Pontiac engine wasn't larger than a small-block Chevy by more than an inch in any direction.

According to Bob, very little was actually required to fit the 301. The motor mounts for the inline-four were cut out and replaced with those from a First-Gen Firebird. Spacers were made to lower the steering rack and sway bar in order to clear the oil pan, and a custom alternator mount was employed. It's a tight squeeze, but it clears.

Finding a healthy engine wasn't hard. "I owned a 'little-old-man car' '79 Grand Prix, and I was about to swap the 301 for a 455 anyway," he says.

Because of the light weight of the T-Body-2,225 pounds to be exact-Bob didn't feel the need to enhance the power of the 301 much. Even in stock trim at 150 net horsepower, the 301 pumps out considerably more grunt than the inline-four. To that end, aside from the installation of a used 273/289-degree duration 067 cam with 0.410/0.413-inch lift on a 113.5-lobe separation, the internals are entirely stock. Topped off with a pair of as-cast No. 01 cylinder heads with tiny 1.72/1.50 valves, 1.50:1-ratio rockers, and stock chambers, the engine produces 8:1 compression.

A 600-cfm Edelbrock carburetor was mounted to the factory intake via a Q-jet to Holley adapter that was milled to match the stock manifold angle and installed upside down. Jets are 0.098/0.095 inch, and the metering rods are 0.075 inch. The air cleaner is from a '67 GTO; it may be the most valuable part on the car given today's collector market. A pair of log-style exhaust manifolds flow into a custom 21/2-inch Y-pipe exhaust that runs a single muffler on the street, which is removed at the track.

For the spark delivery, an MSD Pro Billet distributor, a Crane Hi-6 amplifier, and an MSD coil fire things up via Taylor wires and Autolite plugs. Timing is set to 32 degrees total. The radiator support was trimmed to fit a larger radiator, and an electric fan was installed to cool things down.

Sitting behind the Pontiac mill is a rebuilt Metric 200 three-speed automatic transmission with a used 2,000-stall Level 10 torque converter out of a Grand National. The spider gears were welded inside the stock 6.5-inch 3.36:1-geared rearend to create a "poor man's posi." This worked fine until it sheared off the yoke at the pinion. Bob repaired it, and the car still runs the same setup as he rolls the