"real Olds engine"
Connoisseur d'Junque
Joined: Sep 2010
Posts: 21,183
From: The Hudson Valley
Googling the words "oversquare design" brought me a first result of this Wikipedia entry, in which it is stated, "An engine is described as oversquare or short-stroke if its cylinders have a greater bore diameter than its stroke length, giving a bore/stroke ratio greater than 1:1."
The link is worth reading if you're not familiar with the concept.
- Eric
The link is worth reading if you're not familiar with the concept.
- Eric
Still on the planet...
Joined: Feb 2014
Posts: 214
From: Texas Hill Country
^^^ This is correct, I misspoke/typed? 
Terminology and brain fade does get in the way when Ol' Folks (like me) are involved. 
The basic premise is small bore & long stroke = torque, and conversely big bore & short stroke = rpm regardless of the terminology used. The 455 Olds bore is 4.126 in (104.8 mm) and stroke to 4.25 in (108 mm).
Terminology and brain fade does get in the way when Ol' Folks (like me) are involved. The basic premise is small bore & long stroke = torque, and conversely big bore & short stroke = rpm regardless of the terminology used. The 455 Olds bore is 4.126 in (104.8 mm) and stroke to 4.25 in (108 mm).
Last edited by Lonestar; Mar 28, 2014 at 08:29 PM.
'87 Delta 88 Royale
Joined: Dec 2010
Posts: 2,514
From: Margate, England
Ford and Chrysler managed fine with one range of engines, Ford, Mercury, or Lincoln, not forgetting Edsel, all had Ford corporate engines under the hood, Chrysler, Dodge, Plymouth, Imperial (and De Soto) all had Chrysler corporate engines.
Mopar and Ford umbrella buyers didn't have issues with their Lincoln or Imperial having a low price car engine powering it, mostly the upmarket models had the bigger more powerful versions which did a fine job.
Sure, they had strengths and weaknesses, so did all the GM offerings, as indeed did every car engine ever produced in significant quantities.
Maybe it was because of GMs massive market share that each division could afford the luxury of making their own engines, I wonder how difficult it would have been to make 350 cu in V8 with oversquare bore/stroke as simultaneously provided by all divisions except Cadillac at one time and fine tune it to suit the perceived desires of each divisions loyal customers?.
Roger.
Mopar and Ford umbrella buyers didn't have issues with their Lincoln or Imperial having a low price car engine powering it, mostly the upmarket models had the bigger more powerful versions which did a fine job.
Sure, they had strengths and weaknesses, so did all the GM offerings, as indeed did every car engine ever produced in significant quantities.
Maybe it was because of GMs massive market share that each division could afford the luxury of making their own engines, I wonder how difficult it would have been to make 350 cu in V8 with oversquare bore/stroke as simultaneously provided by all divisions except Cadillac at one time and fine tune it to suit the perceived desires of each divisions loyal customers?.
Roger.
Last edited by rustyroger; Mar 30, 2014 at 09:51 AM.
Registered User
Joined: Jun 2003
Posts: 1,226
From: Southeast Michigan
I'm working off of memory here, but I believe the reason the Chevy engines were put into Oldsmobiles was because Olds was selling the hell out of the Cutlass (Olds was 3rd in overall sales behind Chevy and Ford) and the Oldsmobile engine plant capacity could not keep up with the demand. I think the PR disaster of that (and Roger Smith's descent into insanity) led to the "Corporate Engine" idea, and the cookie cutter body styles. Apparently in the smaller Oldsmobiles nobody cared as there was never an Olds engine available in the '75 - '80 Starfire. The 4 was a Pontiac, the 6 was a Buick, and the 8 was a Chevy.
Totally random thought out of nowhere, I wonder if anyone has ever put a Grand National v-6 into a '75 - '80 Skyhawk? I'll have to ask my buddies over at the H-body forums that question.
Everyone please feel free to point out each of the wrong statements in the above
Totally random thought out of nowhere, I wonder if anyone has ever put a Grand National v-6 into a '75 - '80 Skyhawk? I'll have to ask my buddies over at the H-body forums that question.
Everyone please feel free to point out each of the wrong statements in the above
Registered User
Joined: Aug 2013
Posts: 12,804
From: Evansville, IN
Not sure what type of information you're interested in specifically but if you let me know I'll do my best to point you in the right direction. My comment is based on the bore/stroke, rod length & rod ratio, c/d, deck height, rpm limitations imposed by the valve train geometry, intake runner length, head cc's, valve train design, rotational weight, flame travel, and more. This info is available through any source that lists engine specs.
BBO's are limited by their "oversquare" design and relatively low rpm range in applications where exceeding stock parameters is desired. However, this design provides a very smooth, linear torque curve and is quite impressive for your daily driver. History has proven the design of the BBC and it's response to performance modifications borders on legendary. In short, it would appear that Chevy considered the BBC's performance potential heavily during it's evolution. Oldsmobile as we all know, was more concerned with producing a "gentleman's" performance vehicle that combined comfort, performance and handling. in my opinion, the two divisions took an entirely different approach to engine design and ultimately how they marketed their products.
My personal experience includes (drag) racing stock and super stock Olds in the mid to late '60's. While my Dad owned an Olds dealership during that time and we definitely wanted to sell on Monday, my personal choice for a heavily modified racing engine has been a BBC since 1970. The BBC's basic design has allowed the aftermarket companies to produce products and provide horsepower levels considered impossible just a few years ago. That info and a few bucks will buy you a cup of coffee
Hopefully I've answered your question or given some food for thought. If however you were only interested in the "as produced" engines please accept my apologies!
BBO's are limited by their "oversquare" design and relatively low rpm range in applications where exceeding stock parameters is desired. However, this design provides a very smooth, linear torque curve and is quite impressive for your daily driver. History has proven the design of the BBC and it's response to performance modifications borders on legendary. In short, it would appear that Chevy considered the BBC's performance potential heavily during it's evolution. Oldsmobile as we all know, was more concerned with producing a "gentleman's" performance vehicle that combined comfort, performance and handling. in my opinion, the two divisions took an entirely different approach to engine design and ultimately how they marketed their products.
My personal experience includes (drag) racing stock and super stock Olds in the mid to late '60's. While my Dad owned an Olds dealership during that time and we definitely wanted to sell on Monday, my personal choice for a heavily modified racing engine has been a BBC since 1970. The BBC's basic design has allowed the aftermarket companies to produce products and provide horsepower levels considered impossible just a few years ago. That info and a few bucks will buy you a cup of coffee
Hopefully I've answered your question or given some food for thought. If however you were only interested in the "as produced" engines please accept my apologies!
The thing that I was trying, and probably failing, to point out, is that, while I agree with the above, I don't agree with the religiously held, and often contradictory, beliefs on any of the car forums on the internet that THEIR brand of GM engine is revolutionarily above the other divisions' engines. I don't agree with it because: no one can back it up with any data, people are biased towards their cars, and it doesn't make sense.
If any GM division had figured out variable valve timing, multi valve setups, port and direct fuel injection, modern aluminum blocks, overhead cams, etc, etc, etc, that sort of next level design tech would have been shared. Yes, they would have tuned their designs to their goals, but that sort of awesome concept or material would have been shared to level the whole company up.
I hope that explains my point better this time around.
Registered User
Joined: Feb 2010
Posts: 1,587
From: West Michigan
Koda, I think you give GM too much credit for being "one company." Today, yes. In the 60s and 70s, heck no. These really were independent companies under a motherly umbrella. Good ideas were eventually shared, but it took many years, and the other divisions were typically not required to use the ideas. They were each allowed to go down their own development paths.
As for PROVING that one division's engines were better than another:
First, you have to define "better." HP per cubic inch? low-rpm torque? longevity? Ease of maintenance? Once you've defined "better," then of course someone could prove that one is better than the other. Do we all have access to the data? No. But that doesn't mean it can't be done. And as for generalizations, there's usually at least a grain of truth behind them.
As for PROVING that one division's engines were better than another:
First, you have to define "better." HP per cubic inch? low-rpm torque? longevity? Ease of maintenance? Once you've defined "better," then of course someone could prove that one is better than the other. Do we all have access to the data? No. But that doesn't mean it can't be done. And as for generalizations, there's usually at least a grain of truth behind them.
Registered User
Joined: Jun 2003
Posts: 1,226
From: Southeast Michigan
Koda, I think you give GM too much credit for being "one company." Today, yes. In the 60s and 70s, heck no. These really were independent companies under a motherly umbrella. Good ideas were eventually shared, but it took many years, and the other divisions were typically not required to use the ideas. They were each allowed to go down their own development paths.
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