C2 Motor Orientation

[Michael S.]

After removing the hood on my '67 convertible for a re-spray, I noticed that the motor appeared slightly off center in the engine compartment. What do I mean ? Looking at the front of the car head on, the air cleaner is not centered on the windshield cowl hump (the humped area between the two wiper grills). It appears shifted left an inch or two. The car drives fine, no evidence of frame damage. It does not look like there is any adjustment on the motor mounts to shift the motor around slightly. Is this an assembly anomaly or might there be a hidden frame issue or other issue ?

Thanks

[Michael H.]

Re: C2 Motor Orientation

Mike,

Worry not. Your car is normal. If the engine was centered in the chassis, you WOULD have something to worry about because all C2 and C3 engines were moved slightly to the pass side of the chassis. Now that the engine is out, look at the length of each motor mount leg that is welded to the frame side rail. You will see that the right side is shorter than the left, by design.

[Kent K.]

Re: C2 Motor Orientation

Yogi Bair explained the C-2 engine off-center to me during Kissimmee as being designed to permit steering components clearance. This arraingement may be typical on many other cars also.
Kent #6201

[Michael H.]

Re: C2 Motor Orientation

Kent,

There were actually several reasons why the engine/driveline was offset in 63 and later Corvettes, unlike the "on center" drive of most GM passenger cars of the era.

The new for 1963 independent rear suspension system required equal length left and right components, including L & R drive shafts, to keep the wheel travel geometry consistant side for side. The differential had to be centered in the chassis which moved the pinion C/L a few inches to the right. The rest of the driveline, including the engine, was also moved this same amount.

Moving the engine and drive to the right increased driver compartment area which was required for ease of pedal operation.

The shift in engine/driveline slightly increased the weight per wheel of the right side of the car but with a driver in place, the left/right weight numbers went back to nearly equal which is important for handling/racing.

[Michael S.]

Re: C2 Motor Orientation

Thanks all. My next post was going to be why, now I get it. Appreciate all this. Saved me a lot of frustration and a restless night of sleep conjuring up even more problems.

[Kent K.]

Re: C2 Motor Orientation

Michael --- You are absolutly correct. The engineering reasoning for an off-center engine positioning obviously was coordinated for many reasons, not simply to allow for steering. My first guess in discussing this with Yogi was simply to account for the driver's weight.

Sorry to have missed you at Kissimmee.

Kent #6201

[Wayne M.]

Check Frame dimensions posting

by Barry K. on Jan 13th, last. (Link below should work). Shows that the trans rear cushion mount is to the right of the centerline, and that even at the mount for the rear diff front snubber cushion, the hole is about a half inch to the right of the centerline. To me, this means the diff was not pointing directly forward, even though the half-shafts were of equal length.




'65 frame dimensions

[Michael H.]

Re: Check Frame dimensions posting

Wayne,

You are correct, the print will show the engine, transmission and differential front lower bracket off to the right of C/L by roughly one inch but the differential housing is centered on the rear cross member. The difference is in the non symetrical left and right sides of the diff housing that relocates the pinion off center, about an inch to the right. In other words, the C/L of the drive shaft and pinion does not intersect the center of the positraction unit, which would position the diff and drive shafts at exactly 90* to the C/L.

[Michael H.]

Re: Check Frame dimensions posting *NM*