ring and pinion gears

[Robert G.]

Re: ring and pinion gears

Meant to say appreciably, wouldn't lower the RPM's appreciably. He looked up on the chart and would only lower about 300 RPM's at 60 mph. My mistake for leaving that out.

[Duke W.]

Re: ring and pinion gears

It's simply the ratios of the ratios. 3.08, 3.36, 3.70, and 4.11 are about 10 percent different, and 3.55 splits the difference between 3.36 and 3.70.

Duke

[Jim L.]

Re: ring and pinion gears

My 63 340HP has the close ratio 4 speed. It is a bit of a chore to get it moving with the 3:55 gears..

I've seen similar comments like this and I don't understand the problem at all.

My '60 has a 283 probably with the same cam as in your '63, a close ratio 4 speed, and 3.55 gears. It's not a problem at all to get it moving. In fact, it's a delightful combination.

To put a finer point on it, after I back my '60 out, I have to immediately go up a 25% grade to reach the road. The car motors right on up.

I can't imagine an issue, given the greater torque of the 327.

[Duke W.]

Re: ring and pinion gears

My 340 HP/CR/3.08 axle SWC is a bit tough to get off the line, especially in hilly Seattle where I lived for the first five years of ownership, but it's only turning 3100 revs at 80, gets 20-22 MPG on the highway, and tops out at 150+. It's like a five speed with no first gear (75+ at the redline in first), so it's no drag racer.

Duke

[Richard G.]

Re: ring and pinion gears

I frankly don't know how the C2's, with stock tire size, even broke into the 14's in the quarter. The tread on the 15 X 670 is 4-3/16 wide!
The as built condition of my car would have been 340HP and 4:11. I just can't imagine getting anything but tire smoke out of this combination.
Or did one have to use only part throttle till the car got up to speed to even come close to the 14"s? I would have to put three of the 670's tires on each side of my 2006 Corvette to even come close to having the same amount of thread on the ground as the stock tires. A lot of things have changed in 50+ years and tires is one of the big ones.
When others drive the 63, that aren't used to the car, they inevitability have issues taking off the first time. Even though they are all experienced clutch drivers. I doubt this would be as noticeable if the ratio was the stock 3;70's. I don't think of the 340HP as a torque monster.
Rick

[Ronald L.]

Re: ring and pinion gears

For about eh same money - the big change is to get a 5 speed that fits the C2 package, that will keep you with a great off the line and appreciably drop the rpm at 70 plus.

[Duke W.]

Re: ring and pinion gears

I frankly don't know how the C2's, with stock tire size, even broke into the 14's in the quarter. The tread on the 15 X 670 is 4-3/16 wide!
The as built condition of my car would have been 340HP and 4:11. I just can't imagine getting anything but tire smoke out of this combination.
Or did one have to use only part throttle till the car got up to speed to even come close to the 14"s? I would have to put three of the 670's tires on each side of my 2006 Corvette to even come close to having the same amount of thread on the ground as the stock tires. A lot of things have changed in 50+ years and tires is one of the big ones.
When others drive the 63, that aren't used to the car, they inevitability have issues taking off the first time. Even though they are all experienced clutch drivers. I doubt this would be as noticeable if the ratio was the stock 3;70's. I don't think of the 340HP as a torque monster.
Rick

There's a lot more to tire adhesion than just width. Tread compound is more important.

A few times back in the mid-sixties I took my 340 HP/3.08 axle SWC to the Puyallup (WA) drag strip on "run what you brung" night. Classes were set up based on ET.

My car was all stock other than the spark advance map, and I had exhaust cutouts and 6.70-15 Michelin X radials that had a pretty hard tread compound. Any attempt to "launch" the car with revs just lit up the tires, so I just had to "drive" it out of hole like an aggressive street start, and then floor it. I shifted to second about halfway down and crossed the finish line at about 6500 in second gear, about 100 MPH. My best ET was 14.42 (I still have the time card.), but with a 4.11 it would have easily been in the thirteens.

A popular tire back then on the West Coast was the Atlas Bucron (Standard Oil of California) that had a very soft compound, which gave excellent off the line traction compared to other normal road tires, but wore out quickly. Then there were the "cheater slicks" that some guys ran - a soft compound recap on a bias ply casing with just enough tread grooving to meet "stock class" rules.

One night there was a red XK-E coupe, and I desperately wanted to face off against him, but couldn't work it out. Then I saw him on the highway 99 viaduct as we passed by downtown Seattle along the waterfront. He wanted to race, too. So we faced of at about 40 MPH. I was in first gear and immediately blew him off. For the XK-E driver it was like taking a knife to a gun fight!

Duke

[Michael J.]

Re: ring and pinion gears

One night there was a red XK-E coupe, and I desperately wanted to face off against him, but couldn't work it out. Then I saw him on the highway 99 viaduct as we passed by downtown Seattle along the waterfront. He wanted to race, too. So we faced of at about 40 MPH. I was in first gear and immediately blew him off. For the XK-E driver it was like taking a knife to a gun fight!

Duke

You should have raced all the way to Dead Man's Curve.......

https://www.youtube.com/watch?v=S1Cuekbklkg

[Steven B.]

Re: ring and pinion gears

Duke, love those Bucrons! I had a set on my 2X4 3.70 '57 in 1964-5. They really gripped and as you said didnt last long. They are now stacked in the garage next to the '57. I wish they were still available. Steve