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Seems like some people love them and others hate them.
What's your take on them?
Has anyone ever built one for power?
I had one in an old 98 Regency. I never did anything with it other than maintain & drive it. Frankly, if it weren't for the decal on the air cleaner, there's no way you'd know the difference between it, the 350, or the 455. And its performance and economy were pretty much "right in there among 'em."
They put a lot of them in Oldmobiles, Buicks and Pontiacs. Seen many late 70's Trans Ams with 403 engines. If I remember right, the bottom end was pretty weak.
They put a lot of them in Oldmobiles, Buicks and Pontiacs. Seen many late 70's Trans Ams with 403 engines. If I remember right, the bottom end was pretty weak.
Are you sure those were all the same engines? I'm not sure when they changed over, but it used to be that each GM brand had their own engines - even though they were often the exact same cubic inch displacement.
Honestly though, I don't know why Oldsmobile ever bothered even making a 403. They had the 350. They had the 455. They had had the 425, and even a 400.
Are you sure those were all the same engines? I'm not sure when they changed over, but it used to be that each GM brand had their own engines - even though they were often the exact same cubic inch displacement.
Honestly though, I don't know why Oldsmobile ever bothered even making a 403. They had the 350. They had the 455. They had had the 425, and even a 400.
What was the point?
Found this on Wikipedia: 403
The 455 "big block" Olds V8 was replaced in 1977 with the 403-cubic-inch (6.6 L) "small block" V8. It used a wide 4.351 in (110.5 mm) bore, the largest ever used in a small-block V8, with the Olds small-block standard deck and 3.385 in (86.0 mm) stroke. The bore was so wide that it was "siamesed" (similar to another GM 400 CID small block motor) — there was no space for coolant flow between the cylinders. This sometimes led to overheating problems. Some very early 403s were painted metallic blue like the 455, but most were painted GM Corporate Blue.
The Olds 403 was used by Buick and Pontiac in addition to Oldsmobile. The engine was only produced through 1979. Output was 185 hp (138 kW) and 320 lb·ft (430 N·m).
Speaking of GM engines, back in the 70's and 80's GM had a habit of putting the small block Chevy engine in all makes. If I remember right, there was a lawsuit over that because people didn't get the same make engine as the body make. Truth be told, they actually were better off with the Chevy engine.
^ Yeah, GM did a lot of stupid things, with engines, back in the mid-late 70s.
One of the all-time stupid maneuvers was to throw different heads, and an injector pump, onto an Olds 350 and make believe it'd be a good diesel engine.
The only 403 I had was in a 1977 98 Regency. I don't remember what color the engine was painted. The car ran great, got decent mileage (for the size of the beast) and basically was a good old Oldsmobile. On the other hand, I wasn't racing the car, nor did I try to build the engine for lots of power or torque.
In the mid-80's, I was in charge of a fleet of 455" Olds engines used in industrial applications. They ran huge water pumps out in the field, and ran 24/7/365, under a very heavy load. They were hooked to a natural gas pipe, so they never needed fueling.
Oldsmobile gave me a couple of these engines to try and see how they would work for that application. I could duplicate, in a few months, the use an engine would get in automotive use in a few years., so they used me for a test bed.
They couldn't begin to replace the 455 for Industrial use. As soon as they wore out, we dumped them.
They might fair better for hi-performance use, but I would have my doubts...
Speaking of GM engines, back in the 70's and 80's GM had a habit of putting the small block Chevy engine in all makes. If I remember right, there was a lawsuit over that because people didn't get the same make engine as the body make. Truth be told, they actually were better off with the Chevy engine.
It wasn't just Chevy engines....they also put Buick engines in Oldsmobiles, Buick engines in Pontiacs, Olds engines in Buicks....
Which was almost nothing new: since 1971 some Pontiac cars like the Firebird and the Ventura came with 6 cylinder Chevy engines. 2 years later Olds and Buick also received the same inline 6 in some of their cars. This continued on well into the mid 1980's.
The 455 "big block" Olds V8 was replaced in 1977 with the 403-cubic-inch (6.6 L) "small block" V8. It used a wide 4.351 in (110.5 mm) bore, the largest ever used in a small-block V8, with the Olds small-block standard deck and 3.385 in (86.0 mm) stroke. The bore was so wide that it was "siamesed" (similar to another GM 400 CID small block motor) — there was no space for coolant flow between the cylinders. This sometimes led to overheating problems. Some very early 403s were painted metallic blue like the 455, but most were painted GM Corporate Blue.
The Olds 403 was used by Buick and Pontiac in addition to Oldsmobile. The engine was only produced through 1979. Output was 185 hp (138 kW) and 320 lb·ft (430 N·m).
Speaking of GM engines, back in the 70's and 80's GM had a habit of putting the small block Chevy engine in all makes. If I remember right, there was a lawsuit over that because people didn't get the same make engine as the body make. Truth be told, they actually were better off with the Chevy engine.
Actuly truth be told any other division's engines were better than the pos chevy. Only morons lining their pockets in the board room think the piece of s#!+ no power no gas milage chevy engine was ok. Now back to topic at hand;
The 403 in completely stock form wasn't much on power (but still spanked the chevy engines of the day). But replace the stock no duration no lift cam with even a stock cam from the late 60's, 3 angle valve job, early pre-egr intake, and it made great power. I've made ver 550 hp with a 403 and yes, it lived. I've never heard of the 403 having any overheating issues in normal applications. You do not want to ever add nitrous to one though. That will takeout the open webbed mains. The 4.350" bore was a great way to go up from the 350's size but still use the same 350 crank casting. FCR (I believe they are in Omaha, NE possibly) has built even more power from the 403, but I am noyt sure short of welding in supports for the main webbing what they did to the block.
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