i am in need of some feedback on this i just don't know everything ther is to know about my motor internally. i have a '64 ranchero with a 289. my 289 is equipped with 351w heads,flat top pistons,low range cam,600 cfm edelbrock carb, and edelbrock performer intake. now this is my dilemma;i set timing to 8 degrees and i have no miss and low power. motor is noticeably low of power off idle. now if i advance timing ahead a shade the power is the motor revs faster and performs noticeably better, but then the motor has a miss at low rpm. i try to slowly retarding timing to clean up the miss, but end up right were i started. this motor is practicaly new i have only put 3000 on it and already can hear how i am destroying my engine. i need to know if maybe i should have used 351w cam instead of 289 cam.

 

It is not your camshaft.

I would check the harmonic balancer timing mark for accurate location and check your distributor for worn lobe, excessive played..etc..etc

 

Kwikford sounds right on the money. When a harmonic balancer gets old it will creep towards retarded timing. Try advancing the timing more just to the point of pinging under load then check with the timing light and back it off a couple degrees. A worn distributor will give you similar problems. Good luck Rich.

 

You also have more carb in terms of CFM than a 289 can draw enough air through at lower RPM to begin to idle, or work correctly off idle, on through low to mid range.

351W heads kill compression on 289s using Flat pistons under 10.5 or 11.0 :1 C/R, or else runing a Blower or turbo. The Big ports, valves & chambers also negativelt affect flow characteristics, draw and performance of smaller CID engines.

ALthough I agree with cobraguy & Kwikford, I also know your 289 seems mismatched pretty badly for a small cube engine with low compression to boot.

550 CFM is absolute max for 289CID w/ Carb in street, 500CFM is about ideal, IMHO.

Just my 02 on this thread.

FBp

 

I had a simaler problem, First, is the vacume advance hooked to the rh passanger side port on the carb? With a low cr you can run more advance. I fixed mine by getting a distributor that has lots of advance and one that comes on quick. So that you can set the timming ware it idles good and when you hit the gas it will advance the timming for the power. If it pings back if off. I may be wrong on this but worked for me.

 

i have similar 289 and i was to understand 351w heads up cr and not to mention the cam or flat top pistons.my dad back in the late 60's used same combo for added compession ratio.windsor heads have smaller chambers bringing valves closer to pistons.am i wrong?

 

Smaller chambers = higher compression ratio. another consideration is that in the 1960 the gas had a lot higher octane. A higher Octane rating in the Gas will allow it to support higher compression ratios.