The Stovebolt Site Forums The Shop Area The HiPo Shop Power Pack definition.

Was given a 1957 Belair with a a 283 c.i. motor. Not my cup of tea yet. In my reading about this generation of mouse motors, I keep coming across the “Power Pack” phrase. Could someone tell me what if anything was done to the motor and add on’s to make this baby mouse a “Power Pack” motor and is it worth the effort and expense.
I already know this motor is an ‘FC’. The ‘C’ meaning a 4bbl. It now has a 2bbl setup. I’m going to have to spend money anyway to bring it back to original so now is time to find/buy the upgrade parts if ts adds GO to the equation. Thanks.

Believe power pack engines were good for 35 horsepower more than the two barrel counterpart with four barrel carb and pistons to bring the compression ratio to 9.5, the heads have 1.72/1.5 valves and about 60cc chambers.

https://www.wired.com/2011/08/chevrolets-mouse-that-roared/

https://www.onallcylinders.com/2018...e-upgrades-283-chevy-small-block-engine/

http://www.spokesman.com/blogs/auto...v8-and-beginning-chevy-high-performance/

https://auto.howstuffworks.com/chevrolet5.htm

https://www.chevydiy.com/guide-to-chevy-small-block-production-heads/

I have a 283 Power Pak engine in my "66 K20 and it is the healthiest sounding and running 283 I have ever owned or worked on.

Unless you are going for a numbers matching car, there are many aftermarket upgrades that are easier and cheaper to obtain.
The original Rochester 4 jet or Carter WCFB were OK for their time but would probably be more costly and not necessarily as efficient as
many newer products. The same with intake manifolds, there is little comparison between an Edelbrock dual plane manifold and the
stock 4 bl cast iron intake. About 90% of the people that look under the hood wouldn't know the difference anyway.
Fred

I prefer to go all orginial if possible. But then, I’ll have to see how much this ‘freebie’ is going to cost me. I’ll leave the tire smoke and burning rubber to the hot rodders. Thanks for the infomation as this post war stuff is new to me.

I've owned two of the earliest 283 engines and both were the power pack setup. Both drank gas and leaked oil...especially in summer months and especially at that oddball oil filter. In town the one from 1957 struggled...it would frequently stumble at intersections and in slow traffic it made you want to stop and go drink a Coke or something. It did have good and steady vacuum and good compression. Once you got on the highway and got it over about 2200 rpm, it was ok. The one from 1957 ran hot no matter what you did and did so at nearly all speeds. The one from 1958 didn't have those problems. Good luck with it. I'd take one if it was given to me, but I don't believe I'd buy another one.

I guess I got lucky.

The power pak engine was in my truck when I bought it in barely running condition but having worked for chevy for years and so many small block rebuilds done by me for me in the past I really wasn't worried about it. A long story short, all I had to do to it was adjust the valves, put a new set of plugs in it and rebuild the carb and the thing runs literally like new. Have yet to take the distributor cap off much less replace it or the points. rotor. condenser, or wires. 34 oil PSI at idle, it will idle or go down the road for hours and never overheat, I don't have to use the choke above 35 degrees, and I accidentally discovered that it will break all four tires loose in FWD on asphalt from a standing start ( I am sure the 4:56 differentials had something to do with that and I wont dare do it again, but it sure impressed me at the time). The only oil leaks were that the valve covers were sealed with cork gaskets and apparently torqued down by King Kong.

Did I mention the part about that on the day I bought it , it started up for the first time with some gas poured into the carb and a fresh battery after sitting in a barn for 15 years? I am not sure if it's just dumb luck or divine intervention, but I am really happy with it.

I read through all the data Xena posted plus did a search on the web for information. I read till I got blurry eyed about about different heads with numbers, bumps, and triangles, dual exhaust, even gas tank size. At this point I’m not sure anyone knows what that phrase actually means. About the only thing I got from this is the correct carb might be hard to source and better aftermarket heads, intakes, and carbs are available.

Back when they were new (yes, a few of us remember that!) "Power Pack" was an advertising buzzword for a 4-barrel engine with high compression heads. There were all sorts of factory "go fast" options (camshafts, etc.) that could be special ordered or dealer installed. The heads with a triangular shape on the ends had 58CC combustion chambers. If you find a set of those heads now, they've probably been rebuilt half a dozen times, or they're worn out to the point they're going to need new valve guides, valves, and possibly valve seats. Fortunately, they're not prone to cracking, so they can be reconditioned pretty easily. If you're not particularly interested in a "numbers-matching" engine, 58CC 305 heads give the same compression ratio and they have better valve size and port shape than the original heads did.
Jerry

Had a bunch of 283's when I was a kid. Many years and beers ago. They where great running little engines.

Yes, I can remember the introduction of the sbc in 1955. An interesting note to a hot rodder was the 2bbl non power pack engines had mechanical lifters while the 4bbl PP engines had hydraulic lifters. Maybe this was to limit rpms with valve float since the piston skirts on all 265's and early 283's would break at anything over 5k rpm. We thought we had hit the jackpot with the super light 2bbl mechanical lifters but soon learned stronger valve springs would run the push rod right through a lifter like a tooth pick in a hamburger bun. Till roller cams were introduced we used to bush the lifter bores and use the Ford Y-block mushroom lifter to get away with more radical cams. Upper end oiling had to be fabbed. Later mushroom lifters were offered in factory lifter diameter but one had to spot face the bottom of the lifter bore to give cam lobe clearance. This was for sprint cars so don't know if the drag people ever did this.

Don't forget the pressed-in rocker arm studs that pulled out of the cylinder heads if anything much stronger than a stock single valve spring was used. I've installed dozens of 1/8" spring steel roll pins through the edge of the stud bosses to solve that problem, long before screw in studs and guide plates were invented.

I'm in the early stages of building a SBC engine that's going to have a roller cam, a gear drive, a rev kit, a 3 11/16" bore, and a 2 7/8" stroke. I'm using NASCAR-recycled Carrillo tool steel connecting rods with Honda-sized rod bearings and a destroked 283 crankshaft. It should run 8K+ RPM all day long. I'll be running it in an Excalibur kit car that weighs in at less than 2,000 lbs.
Jerry

I'm assuming your pilots license and medical clearance are up to date?

I'll just be the old gray-haired geezer in his second-childhood toy until some baggy-pants hotrodder in his rice rocket with a beaned-up 4 cylinder wants to play at a stoplight! Then he will get an education!
Jerry

If one were to be in the market place for a set of 305 heads with 58 cc chambers, what year(s) should one search for?

You might find this link of interest

https://www.onallcylinders.com/2018...e-upgrades-283-chevy-small-block-engine/

The ones I've used are in this list, but there are several others:

https://www.enginelabs.com/news/quick-ref-small-block-chevy-cylinder-head-casting-numbers/

I like the casting number 14014416 heads, for the 1980-86 305 engine. They're cast iron, fairly commonly available, and have 1.84" intake valves and 1.5" exhausts. That's plenty for a street-driven 283. If you want to do some serious high RPM work, open up the heads for 1.94" intakes and 1.6" exhausts and do a little pocket porting in the bowl area under the valve. With the right cam, roller rocker arms and valve spring setup with screw-in rocker studs and guide plates, that setup should be good for 8K RPM.
Jerry

Don't know about heads and intakes, not my field.

As to better carbs available? To do what?

If a trailered race car, then yes, a somewhat larger Holley or Carter would give more WOT horsepower than either the Rochester 4-GC or Carter WCFB.

For a reasonably stock STREET 283, the only better carb would be the Carter AFB (either number 9400s or 9410s) and they are more difficult to source than either of the originals, and so in demand that they are more pricy. Plus, they won't fit the original manifold without an adapter.

Remember the stock 4-GC was rated 486 CFM, and the original Carter WCFB about 475 CFM. Both were really too large. The 9400s Carter AFB is rated 400 CFM and runs better on the street. Yes, you can increase efficiency with better heads, exhaust, and cam, and then need the larger carburetor.

The 283 is an extremely versatile engine, but its carburetion needs should be tailored to the rest of the engine and the desired application.

Both the original Rochester 4-GC and the Carter WCFB's are excellent carbs. (Opinion) BOTH are superior to the currently available clones. And as far as being difficult to find? There are 5 of the WCFB's on ebay at this writing.

Jon.

Beltfed,

If you post your question on the VCCA forum you'll likely get the answer from Gene Schneider. I think he had an entire career as a Chevy parts counterman and this is right up his alley. Chevy heads had a variety of raised shapes cast into the bottoms of the vertical ends. For example the "Fuelie" heads had the rectangle with double humps cast in. The "Power Pack" heads had a rectangle with an upward pointing triangle above the top of the rectangle. More specifics about heads are unlocked using the casting numbers.

This site https://www.mortec.com/castnum.htm shows casting numbers and other data for many Chevy heads.

This site -https://www.enginelabs.com/news/quick-ref-small-block-chevy-cylinder-head-casting-numbers/ says "Casting number 3795896. Manufactured from 1963-1965 on 283 Cubic Inch engines. Called the “Power Pack” cylinder heads. 1.72˝ intake valves and 1.50˝ exhaust valves. 60cc Combustion Chambers." but the year is wrong for your '57.

Here Chevytalk addresses your exact issue https://www.chevytalk.org/fusionbb/showtopic.php?tid/276171/

There is a ton of information out there.

Good luck!

Guys, Thanks for the help and infomation. For the first time I have a reason to actually looks at the tons of parts that appear at the “Turkey Run” in Daytona. I attend every year but with the oddball cars I redo, Packard coupe and Lincoln Zephyr 1938 coupe right now, there hasn’t been much reason to dig through the parts. Those car parts are made from ’Unattainium’. Best I’ve done was two years ago I scored a Lincoln Zephyr Owners Club license plate holder.