'67 911S acceleration flat spot
 

Off the line under full throttle in my '67 S, she'll accelerate great up to about 5000 RPM. At that point she begins to cough, miss, and go flat. If I accelerate with half that amount, she'll accelerate smoothly up to 6500 or so RPM (I don't like getting her to redline).

Low-mile stock engine with a top-end rebuild 2K ago, 40IDS carbs (not re-built), valves dialed in, timing set (statically) with new points, rotor, cap etc.

Any thoughts?

Welcome to Pelican and the world of 2.0 911S. Our wonderful carbureted 2.0S’s don’t like full throttle below about 4500. Between 4500 and 5500 you can progressively get to full throttle. The reason is the large venture to handle the air flow in the 5500 to 7200 range. Yes, a 911S regularly likes to be run to 7200 with full throttle. This is why we own these cars. Just don’t give full throttle below 4500.

I think the only caveat is to get the oil temperature close to 180F first.

Now, a 2.8S with MFI is a completely different story. The MFI (any displacement) will handle full throttle at any RPM and will snap your neck.

Best,
Grady

Sounds good, thanks!