355 CI
13:1compression
stock body 3200 lb 67 Camaro

It is running a large dome piston with pro topline heads that have a compact combustion chamber.
The spark plug was isolated from the squish area, the engine required 45 degrees of ignition timing for maximum performance. This set up was causing poor flame travel and detonation resulting in scoring of the piston skirts.
The solution proved to be one groove in each combustion chamber linking the plug side of the chamber to the squish side. We have been working on the tune up and the results prove to be very interesting.
Over all the engine is performing flawlessly. With a .700" lift camshaft it idles at 600 RPM. The plugs are burning clean and the car is much more consistent.







BEFORE Mod
timing = 45 deg
idle = 1100 rpm

AFTER Mod
timing = 5 deg less
idle = 600 rpm
temp = 20 deg F. less
jets = 4 sizes smaller
1/4 mile = 0.3 sec faster
           4 mph faster
Best time 10:35 ET @ 128mph

The cool dry air of fall delevered lower ET and higher MPH

10.19 @ 130 MPH!