D/Dart of 1966 Super Stock option

Don Whitmore · 08-05-2010, 07:05 PM

Paul,

I'm curious.

What was in Chrysler's mind when they created the 273 ci? It is an interesting motor. If the corporation needed a small displacement motor, why one with its particular specs (fairly long stroke for that ci, long rod, small bore, overall small ci)?

A friend of mine had a 273 ci Commando back in the day, and I've always been curious about them, but the upcoming 340 ci soon made a bigger splash...

Dwight Southerland · 08-06-2010, 06:38 AM

Quote:

Originally Posted by Don Whitmore

What was in Chrysler's mind when they created the 273 ci? It is an interesting motor. If the corporation needed a small displacement motor, why one with its particular specs (fairly long stroke for that ci, long rod, small bore, overall small ci)?

Economics. Same crank & rods they had been using for years (318 stuff). Bore was small enough to get the displacement in the range they were targeting while still being able to use the 318 heads. Very few new pieces they had to engineer.

Paul Ceasrine · 08-06-2010, 08:48 AM

The 'LA' engine 283/180HP was to be the plain-jane V-8 for the
A-body's.
Chrysler had to make a lighter engine for the #2700 lb. cars, and the early 318's were much too heavy.
3.61 x 3.31 bore/stroke = 273c.i. is much in line with the
general small blocks of the day, but it did limit Mopar on optional
performance applications.
The 273 4-barrel 235HP Commando which came in 1965, was in direct response from 1964 A-body car purchasers who were
dissappointed in the 273/180HP performance.
In the 235HP range, it was competitive with the 283/230HP Chevy and 289/225HP Ford, in stock format.
Biggest draw-back, 4-bolt pattern cylinder head mounting, and the
small bore 3.61 limited up-grades to the cylinder head valve train.
It was simply what it was, a good low-to-mid range torque car.
paul

08-05-2010, 07:05 PM	#1
Don Whitmore Member Join Date: Aug 2004 Location: Central Illinois Posts: 140 Likes: 0 Liked 0 Times in 0 Posts	Re: D/Dart of 1966 Super Stock option Paul, I'm curious. What was in Chrysler's mind when they created the 273 ci? It is an interesting motor. If the corporation needed a small displacement motor, why one with its particular specs (fairly long stroke for that ci, long rod, small bore, overall small ci)? A friend of mine had a 273 ci Commando back in the day, and I've always been curious about them, but the upcoming 340 ci soon made a bigger splash...

08-06-2010, 08:48 AM	#3
Paul Ceasrine VIP Member Join Date: Apr 2009 Posts: 2,546 Likes: 0 Liked 10 Times in 10 Posts	Re: D/Dart of 1966 Super Stock option The 'LA' engine 283/180HP was to be the plain-jane V-8 for the A-body's. Chrysler had to make a lighter engine for the #2700 lb. cars, and the early 318's were much too heavy. 3.61 x 3.31 bore/stroke = 273c.i. is much in line with the general small blocks of the day, but it did limit Mopar on optional performance applications. The 273 4-barrel 235HP Commando which came in 1965, was in direct response from 1964 A-body car purchasers who were dissappointed in the 273/180HP performance. In the 235HP range, it was competitive with the 283/230HP Chevy and 289/225HP Ford, in stock format. Biggest draw-back, 4-bolt pattern cylinder head mounting, and the small bore 3.61 limited up-grades to the cylinder head valve train. It was simply what it was, a good low-to-mid range torque car. paul