Re: Harmonic balancer info

Posted by Ross On 2014/4/9 6:15:06

The problem in that case seemed to be a slight droop occurring at the bell housing on the Ultramatic cars only. It is a long way from the front mounts to the rear mounts and I surmise some sort of harmonic vibration was set up by the flex plate. The fix, described as for early production cars only where the complaint was noted, was two little braces between the oil pan rail and the bottom of the bellhousing. Apparently they took care of the root problem with a casting or machining change as those braces were not used again till the 359 of 1954 with Ultramatic which all got them.

I have run my roadster which has 288 and Ultra to slightly over 100 with no problems noted.

A darned handy thing to have is an old Motors repair manual as it lists detailed specs for each car with out having to look very far. Worth every penny at a flea market or fleabay.

Most of the eights had their torque peak at 2000 until 1954 when they advanced the cam 5 degrees so that torque peaked at 2200. The 288 already had their torque peak at 2200 as they had less air to move through the same size ports as the bigger engines.

Peak horsepower was at 3600 rpm for all the two barrel cars because of breathing limitations, and rated at 4000 rpm for the 4 bbl cars as they did not start gasping for breath so soon.

Very nice performance gains are available with relatively modest porting efforts. That is why every L8 I do gets a quick and dirty port job; not only are they quicker, but with the stock carb they seem to get better gas mileage.