Why is a c3 engine not centered?
Instructor
Joined: Jan 2011
Posts: 102
Likes: 1
From: St. Jacob IL
Regarding the engine offset effect, let's do the math. Let's assume a BB engine and transmission weighs 700 pounds. If we move it one inch we have a weight/moment arm of 700 pounds times one-twelfth of a foot, equaling 58.3 foot pounds. A typical driver (lets say 190 pounds) sits about ten inches to the left of the vehicle centerline. That weight placement is 190 pounds times (10/12 of a foot), equaling 158.3 foot pounds. The offset driver has about two and a half times the effect of the offset engine.
(Disclaimer: Freshman statics class was decades ago. I welcome anyone doublechecking my work.)
Drifting
Joined: Aug 2005
Posts: 1,443
Likes: 65
From: Wauconda IL
As is usually the case, it's all about the packaging...
Most cars I've worked on over the years seem to have a slight offset to the right and many cars had different part numbers for the left and right springs (front), depending on how it was optioned.
Most cars I've worked on over the years seem to have a slight offset to the right and many cars had different part numbers for the left and right springs (front), depending on how it was optioned.
Race Director
Joined: Jul 2001
Posts: 15,892
Likes: 42
OK, I was just kidding before with the hole in the hood thing.
The real, real, reason is that GM wanted to build a car that would compete right out of the box in the new super-secret RACSAN roundy-round car racing. It was just like NASCAR except that the cars would go the opposite way on the tracks and only turn right.
The engine was offset to the right to get the best balance in the banked corners.
None of the other manufacturers were able to come up with a car that would be competitive so GM was awarded the championship in perpetuity and th series cancelled. This means that we're all driving factory racin' cars.
True story.
The real, real, reason is that GM wanted to build a car that would compete right out of the box in the new super-secret RACSAN roundy-round car racing. It was just like NASCAR except that the cars would go the opposite way on the tracks and only turn right.
The engine was offset to the right to get the best balance in the banked corners.
None of the other manufacturers were able to come up with a car that would be competitive so GM was awarded the championship in perpetuity and th series cancelled. This means that we're all driving factory racin' cars.
True story.
Le Mans Master
Joined: Apr 1999
Posts: 6,134
Likes: 46
From: Raleigh North Carolina
Just for grins I just measured the offset at the bellhousing and at the pinion. The offset is 1.5 inches at the bellhousing (+/-). This means in order to center it... the bellhousing would have to move 1/2 of that or .75". The center of the pinion is about .5 to .75 offset from the center of the carrier. I had to eyeball that one with a ruler. Assuming it's .75, the engine is offset to keep the driveshaft & u-joints in alignment with the offset pinion shaft/gear. The pinion shaft/gear is offset by design to mesh with the ring gear.
This is the explanation I received from an old engine builder when I was 14 years old and laying underneath my first car wondering why it was crooked.
This is the explanation I received from an old engine builder when I was 14 years old and laying underneath my first car wondering why it was crooked.
Last edited by Tom454; May 5, 2013 at 02:56 PM. Reason: Brain Fart
Le Mans Master
Joined: Feb 2001
Posts: 6,317
Likes: 289
From: Ocala FL
I can't believe all these Corvette people and no one has the right answer.
The right answer is that Mr. Duntov wanted it that way.
It accomplished several things.
1. More of a straight line with the rear end pinion.
2. Narrower drive shaft tunnel.
3. Additional room for driver, in a cramped passenger compartment.
4. Some weight balance. For the one figuring out the driver is still heavier, you forgot about that big plastic covered chunk of lead next to the engine.
5. Clearance on the steering box. Otherwise, the off the shelf Impala box wouldn't work.
The right answer is that Mr. Duntov wanted it that way.
It accomplished several things.
1. More of a straight line with the rear end pinion.
2. Narrower drive shaft tunnel.
3. Additional room for driver, in a cramped passenger compartment.
4. Some weight balance. For the one figuring out the driver is still heavier, you forgot about that big plastic covered chunk of lead next to the engine.
5. Clearance on the steering box. Otherwise, the off the shelf Impala box wouldn't work.
Le Mans Master
Joined: Apr 1999
Posts: 6,134
Likes: 46
From: Raleigh North Carolina
So what you're saying is that if Mr Duntov didn't care about all of that, the Corvette (and all others in the world including my 1959 Ford) would have been sold to the public with an engine & diff that don't line up? Just wondering.
Le Mans Master
Joined: Apr 1999
Posts: 6,134
Likes: 46
From: Raleigh North Carolina
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Tech Contributor
Joined: Jun 2004
Posts: 20,864
Likes: 960
From: I tend to be leery of any guy who doesn't own a chainsaw or a handgun.
I can't believe all these Corvette people and no one has the right answer.
The right answer is that Mr. Duntov wanted it that way.
It accomplished several things.
1. More of a straight line with the rear end pinion.
2. Narrower drive shaft tunnel.
3. Additional room for driver, in a cramped passenger compartment.
4. Some weight balance. For the one figuring out the driver is still heavier, you forgot about that big plastic covered chunk of lead next to the engine.
5. Clearance on the steering box. Otherwise, the off the shelf Impala box wouldn't work.
The right answer is that Mr. Duntov wanted it that way.
It accomplished several things.
1. More of a straight line with the rear end pinion.
2. Narrower drive shaft tunnel.
3. Additional room for driver, in a cramped passenger compartment.
4. Some weight balance. For the one figuring out the driver is still heavier, you forgot about that big plastic covered chunk of lead next to the engine.
5. Clearance on the steering box. Otherwise, the off the shelf Impala box wouldn't work.
Melting Slicks
Joined: Jul 2010
Posts: 2,503
Likes: 33
From: McGrady NC
St. Jude Donor '15-'16
I like Mike Ward's most excellent answer.
Why is the grass green and the sky blue? Because that is how it is supposed to be. If the drivetrain was centered the whole universe would be off-balance and the earth would spin off its axis! We would be hurtled into outer space!
Simple psychophysics! Which actually means we're all crazy....
Why is the grass green and the sky blue? Because that is how it is supposed to be. If the drivetrain was centered the whole universe would be off-balance and the earth would spin off its axis! We would be hurtled into outer space!
Simple psychophysics! Which actually means we're all crazy....
Drifting
Joined: Aug 2010
Posts: 1,839
Likes: 45
From: nassau co. new york
"mr jones you bring up some good points,universe off balance,earth spinning off it's axis,hurtled into outer space"."these are mysteries that we must ponder.""we are all crazy?"."yes we are". 
