Thread: Tri-Chevy Question?

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According to my book the 55Chevy was the first Chevy to offer the Power-Pak
The 245hp and 270 hp engines were 2x4 engines.
The 250hp and 283hp engines were FI engines.
The higher output versions had the solid lifter camshaft, commonly referred to by all knowledgeable Chevy folks as the "097" cam (last three numbers of the part number).
The lower power versions had the stock hyd cam.
ONLY the FI engines got domed (or commonly called pop-up) pistons. all other engines had flat top pistons.
ALLLLLLL heads had 1.72/1.5 valves.
In the 57 pass cars, there were a total of seven V8 engines:
265 2bl
283 2bl
283 4bl (commonly known as the power pac engine)
283 2x4 (hyd cam)
283 2x4 (solid cam)
283 FI (hyd cam)
283 FI (solid cam).

The 57 Vettes DID NOT get the 265 or the 283 2bl.

The top rated 57 283 was 283hp with FI and the 097 cam. BUUUUUUUUUUUUUUT, during CEC (Chevrolet Engineering Center) tests, the 283/283 FI engine developed a true 293hp!!!! This rating was downplayed SPECIFICALLY for advertising/promotional purposes so that Chevy could tout One Horsepower per Cubic Inch! the 58-59 solid lifter FI engines (which were virtually identical to the 57 engine) were rated at 290hp.

This is a little off from the original question about the “super” power pack, but I’ll throw my 2 cents in too.

The way most people identify a power pack engine is by the heads. The PP engines used the smaller combustion chamber head. There were a couple of different part numbers and depending on the year and who’s chart you look at they are anywhere between 59 and 62 cc combustion chambers (advertised). These heads all had 1.72/1.50 valves and can be identified by the triangle or pyramid marking on the ends of the head.

As far as I know they these were the only heads used on the factory 283 4BBL engines and as mentioned the FI and Dual Quad 283s. As a side note these heads were also used on some lower performance 327 2BBL engines.




Regardless of what they originally came on, the heads with these marking are generally referred to as Power Pack heads (like the double hump heads are referred to as fuelie heads even if they came off a carbureted engine).

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Originally Posted by Big Tracks

Well, Richard, I give up. I sat down here to prove you to be wrong....... and I could not do it.

A few years back I tried the same thing. I've forgotten what the subject was then but I do remember that it didn't work that time either!

Jim

Please keep those cards and letters comin' in Jim.....I'll be wrong sooner or later

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Originally Posted by cffisher

The top rated 57 283 was 283hp with FI and the 097 cam. BUUUUUUUUUUUUUUT, during CEC (Chevrolet Engineering Center) tests, the 283/283 FI engine developed a true 293hp!!!! This rating was downplayed SPECIFICALLY for advertising/promotional purposes so that Chevy could tout One Horsepower per Cubic Inch!

Chrysler beat 'em to it though, producing a 354 hp 354 cubic inch hemi in 1956. (more compression, hot cam, two 4-barrels)

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Originally Posted by techinspector1

Please keep those cards and letters comin' in Jim.....I'll be wrong sooner or later

If you need any help with that, just let me know.

“....Chrysler beat 'em to it though, producing a 354 hp 354 cubic inch hemi in 1956…”

Although the big advantage Chevy had was that their little 283s went into considerably lighter (and cheaper) cars than the Hemi normally ended up in. The exception being the D501s that Dodge built in 1957 when they stuffed the 56 Chrysler 354 Hemi into fifty or so Dodge bodies. The D501s were Dodges answer Chevys Black Widows ……both being primarily built for NASCAR. It sure would have been something to see those 2 tangle.

Arguably the SBC and the Hemi were the two most iconic Hot Rod engines to come out of the 1950’s.





Looking at them you can sure tell how they got their respective nicknames....... Mouse and Elephant.



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Originally Posted by MelloYello

What year was the "Super Power Pack Option" offered for the Chevrolet?
thanks,
Em

this option was added late in 1955. It included higher compression and a 15 HP increase