I have come across a pair of 57 vette power pack heads and the dual quad intake to go with them! Can any one tell me what the cam specs might have been for the original 283? I have to peace together the bottom end and I want it to be as close to original as possible.
The cam was a Duntov 097 .012 .018 valve lash, the last three numbers of the part number was 097, thats all i can remember...Ed
the complete part number was 3736097, cost $29.15 in the 1959 parts book specs on this and other cams here http://www.geocities.com/MotorCity/Downs/3000/cmspec.html
This is the way I remember it, also this was the first year for one HP per cubic inch. Chevy was real proud of this, and used it for new Corvette sales pitch...Ed
there were a few different hp versions of the fuelie in 57...the only one that made the famous 1hp for 1 c.i. was the fuel injection with the fresh air option. the 2 dual 4 versions were 245 and 270. the 270hp version is known as the high lift cam option in the gm service manuals I have http://www.rogerscorvette.com/specs/57r.htm
The 245hp engine was basically the 220hp power pack engine with dual quads instead of a single 4bbl. The 270hp engine had the Duntov cam, popup pistons, all centrifugal dual point distributor, and "single tower" heads instead of the "single pyramid" heads.
The 245 had a hydraulic lifter cam, the 270 and the feuly had solids. If you can find a good 283 block, this stuff will make it run good. Like a time machine.
anybody make a hydraulic equivelent to the 097 cam? I don't really feel like adjusting valves every few thousand miles......
Valve adjustment should last longer than a few thousand miles. and if you don't run the solid cam, it won't sound right.
ran solid cams in my vw midget motors and had to adjust those after every race. they were 300hp alcohol injected motors though. those clearances that are listed for those cams seem pretty big, are those supposed to be adjusted hot
You were lucky, some guys racing vws get to change motors after every race. Chevys don't work like that....mostly
just depends on how they are built. the motor I built from the ground up never had a DNF, 8k rpm every race for 22 races a year. that motor raced for 4 years straight with many wins on dirt. now my pavement motor that I bought used is a different story. I spent more nights putting that motor back together than I care to admit
That's why they invented Poly locks...but I don't think they fit under the "script" valve covers. My street driven solid lifter Corvette got lots of miles between adjustments using only the original crushed nuts. Of course those were the lazy days when you were looking for things to do to your baby whether it needed it or not.
Hey Squirrel (or anybody that knows the answer), Just got my '56 power pack engine running. Have about 40 miles on new parts and fresh machining. Reground the cam to "097" and put in solid lifters. It runs great and now it is time to take out the break in oil and adjust the valves. It does have roller rockers because my engine machinist/builder, Motor Masters, Hartford, Wisconsin said the stock rockers don't have a long enough slot for the high lift cam and would eventually snap the rocker studs off. My question is: Do I adjust the valves cold? .012" and .018" seems like there would be a lot of clatter. If you have 2 cents on this subject, please toss 'em in. Thanks.
I just adjusted my 097 valve lash cold to .010 and .016, based on what I read somewhere on the net. Chevrolet recommended the intake to be .008 for weekend racing, but I didn't go that far.
It may be different today but back in the 60s we adjusted the valve while warm and running. I know there are ways to do it cold and not running but to us back then they were wuses. A real hotrodder had special clips to go on the rocker arm and keep the oil from squirting all over the engine compartment. I think I still have mine. Mine came in a steel holder for storage between adjustments. There were 2 different types... both just plugged the hole in the rocker arm stopping the oil from flying. A Corvette house will probably have the clips for the old Corvettes. Back then Snap on sold them. I drove a 63 2 topper 327 340 Hp solid lifter Corvette. If you've ever seen a Chevy calve cover with a slot cut in the top in a flea market, it was cut there to adjust the valves while the engine was running and stop the oil spray.
yes there were 2, 2x4 283s in '57 and they were rated @ 245 HP and 270 HP. I don't know the difference in cam spec, they were both 9.5:1 compression engines and had the same heads so the cam shaft must have made the difference. OK went back and checked my information the 270 horse had a solid lifter cam.
I ran an 097 back in the 60's and adjusted valves weekly until I pinned the rocker arm studs. The pressed in studs will move if you run solids and get into any high RPM's. Pin them or go with screw-in studs.
I ran an 097 in my 57 for years and almost always set the valves with the engine HOT & running. I used the Snap-On brand clips shown in the bottom pic, and still have them hanging on the pegboard. When I get the latest SBC buttoned up, I'll be doing it again with the '70 vintage LT-1 cam. I love the clatter of solid lifters.
Yes you do with those clips in place so it doesnt oil the whole engine bay. I had a 283/270 57 Corvette. Complete engine bleprint specs are avaaiable on NHRA's stock eliminator engine blueprint specs. Just do a Google search for them
We used to adjust em running with the clips in place and a junk steel valve cover with the top sawed off installed. Don't remember where we got em but we had long (10-12") feeler gauges bent 45* to feed in whilst running. Kept em and used em on my 70 1/2 Z when it was new.
The Jalopy Journal
