Hey folks,
I've been distracted the past year rebuilding my 1980 Chevy k20 4x4. Still another six months before that's done, about two years (or is it three???) in the making. I put a new build SBC into it, just can't wait to get her on the road. You all will be happy that I resisted abandoning the truck project and putting the sbc into the Camaro instead. It looked really nice sitting next to it on the crate. Tempting.
Anyways, the Camaro is a cruiser and not a track star and I still am not satisfied with it. 0-60 is tepid at best due mostly to the low-end performance. Higher rpms sing. Gas mileage is horrendus. It’s spring, time to do some work to get this car running right.
There's a number of things that I did right with the build but more things that I did wrong. I'll put a list here.
Good
1) converted 230 to 250, flat head pistons
2) 200-4r upgrade from the power glide
3) headers and Clifford intake
4) stainless exhaust
5) electronic ignition
Bad
6) too big a CAM for my use compcams 260H p/n 61-233-4 (yeah, you told me so…)
7) widened exhaust valves (yeah, you warned me…)
8) too wide tires on rear for this engine (235/60r15). Well, too wide in general for the car.
Neither good nor bad
9) Holley 4 bbl carb
10) 2200rpm torque converter
Manifestations:
- Slow off the line at lower RPMs, but will chirp the tires shifting 1st to 2nd.
- Requires richer jets, gas mileage is awful (13 or 14, even with OD).
- Timing needs to be very far advanced at low RPMs (i.e. 18 without vacuum at idle) to get any sort of performance out of this.
Dealing with #6 and #7, the timing is very far advanced, but the distributor is not set up properly.
Now, there are things I can do and things I can try and things I can fix…
One Experiment I could run: Put the original points & condenser distributor back in, measure the timing curve and compare to my aftermarket EFI. See how it runs. I think it would be rather interesting to put the original distributor back in and try it out. I think the resistor wire is still there for me to use.
Things I can do:
- Install Rhoads lifters to accommodate the larger CAM and larger exhaust
- Get the distributor adjusted properly for this engine
- Convert to 2 BBL Holley EFI carb
- Smaller tires (225 or 215) on rear
- Put a smaller CAM into it (ugh)
I’d like your thoughts. The biggest issue is the CAM, bigger exhaust valves and loss of low-end torque. That needs to be addressed first.
Thanks,
Mark
