64 327 300hp problems HELP!

[MMM]

I completely agree with John Z. The lack of vacuum advance in combination with the cam is the issue. Just for the fun of it, advance your initial timing to 12 BTDC and see if that helps. It may knock some, but the point of the trial is to see if advance helps. If so you have your answer.
Mike

 

[allcoupedup]

How do you know when the secondaries kick in? If your carb is set up correctly you will not be able to feel this.


Regards,
brian

 

[milkdud99]

How do you know when the secondaries kick in? If your carb is set up correctly you will not be able to feel this.


Regards,
brian

when i stomp on it, you can feel a great amount of power at around 2300 RPMS... not a gradual increase in power, but a great deal of power increase.. leading me to believe its the secondaries.

 

[milkdud99]

After a talk with Crane Cams

Ok i just got off the phone with Crane Cams, and FINALY somone admitted that it is too much cam for the car. The guy that i talked to now recomended a new cam. does anyone here know enough about cams to tell me if this is a good one to get for mor hp than before, and a good daily driver?

The car has a carter AFB carb, stock intake, and stock ram head exhaust.

New Cam

thnks
mike

 

[vintagecorvette]

Why do you not put the OEM spec cam back in?

 

[milkdud99]

Why do you not put the OEM spec cam back in?

the same reason why i dont do alot of things.... cause im an idiot lol..

the real reason on why not the OEM spec cam is case i would like to get a little more power out of the engine. I dont want to go drastic, but just a little more bang.

thats why

 

[JohnZ]

More cam isn't going to get you more power without matching components to take advantage of it (compression, heads, intake, etc.), and more cam will always sacrifice some low-end torque; there's no free lunch and no magic when it comes to cams. "Race" cams work fine in "race" motors, but not in normal street motors. Unless you're going to change the heads and intake too, I'd put the stock cam back in it - the GM "929" 300-hp cam, originally GM #3896929, is still available from GM under P/N 12364051 - it's a kit with cam and lifters, manufactured for GM by Crane - lists for around $140. I'd also put stock GM valve springs back in it too - every GM factory cam, from the "929" up to and including the 375hp fuelies and Z/28's with solid lifters, used exactly the same "grocery-getter" valve springs (85# closed, 200# open). That's the beauty of the GM valvetrain designs - they all run great with reasonable spring pressures, and are bulletproof. The "929" cam has stump-pulling low-end torque, and that's what a good street engine is all about; how much of your everyday driving is spent at 6500 rpm with your foot flat on the floor at wide-open throttle?

You've just learned a valuable lesson about why it's a bad idea to mix "hot-rod" parts with an unmodified stock engine; if the entire system isn't matched, the results are always disappointing.