Hot Rod Magazine article on diesel oil use in gasoline engines

Pretty sure that vintage Cutlass was a 307 Oldsmobile engine. Different block and heads. Similar power limitation. Good engine for durability.

It was a Chevy 305. 100% sure. It was a Cutlass Supreme Brougham, four door.

That car was actually in a movie once lol. It's in the trailer here at 1:53. They paid us $150 to use it for a day and filled it with fuel

 
It was a Chevy 305. 100% sure. It was a Cutlass Supreme Brougham, four door.

That car was actually in a movie once lol. It's in the trailer here at 1:53. They paid us $150 to use it for a day and filled it with fuel


Interesting, as our 86 Olds Custom Cruiser wagon had the 307.
 
I took a serious look at upgrading the 5.0 in my 1985 Trans-Am. A 165 hp 305 with a electronic Q jet. There was a 190 “HO” 5.0 that year, with better cam and exhaust.

No real ROI with any of the usual tricks. Tubular exhaust system offered by Edelbrock for that engine/chassis opened it up to about 180, but you just coudn’t get much farther than that, even with the “HO” cam. The Q-jet flowed plenty.

The heads didn’t.

Hot Rod magazine tried upgrading the 305 TPI (a port injected 305) and quickly realized the same thing.

They swapped in a 350.
Car craft also tried it, here's what their results were with cheap aftermarket heads.
 

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Back then when you bought an Olds, Buick or Pontiac you didn't know what engine GM was going to put in it. Many 305's and 350's ended up in other cars than Chevy's.
That was ‘77 to ‘79 when GM lost a lawsuit over the non-disclosure.

After that, they had to disclose if the engine didn’t match the marque.

So, by the ‘84 model year - you knew if you were getting a Chevy in an Olds, but honestly I didn’t think Olds was shipping anything with a Chevy engine by ‘84.

If @Jimmy_Russells was in Canada in 1984, that would explain the Chevy engine in an Olds.
 
I tend to not put faith in magazine articles. H E U I on the Powerstroke engine as well as Turbochargers are high foam producers.
 
That was ‘77 to ‘79 when GM lost a lawsuit over the non-disclosure.

After that, they had to disclose if the engine didn’t match the marque.

So, by the ‘84 model year - you knew if you were getting a Chevy in an Olds, but honestly I didn’t think Olds was shipping anything with a Chevy engine by ‘84.

If @Jimmy_Russells was in Canada in 1984, that would explain the Chevy engine in an Olds.
Every gas v8 g body (Cutlass, Regal, monte Carlo, grand prix) built and sold in Canada from 81 to 87 (except 442 but they weren't built in Canada, just sold here AFAIK) had a Chevy 305. An 87 Caprice could have a 307 Olds, a station wagon Caprice 87-90 would have an old 307, and every olds or Buick b Body from 81-90 had an olds 307. Complicated and doesn't really make sense but that's what it was.
My 87 305 actually worked pretty good once I put 3.73 gears in. Other than that it had a shift kit, dual exhaust, timing played with and it ran high 15's in the 1/4 at 87mph still with the stock camshaft. That year was a roller cam with 165hp stock. Not fast by today standard but felt fast compared to the 3.8 v6 83 grand prix I had before it.
 
It could have been Car Craft, it was a long time ago…

Thanks!
There were a few articles like that one I remember reading back in my younger days when I still had a 305.
I personally knew one guy with a 305 Cutlass that sprayed a 210 shot of nitrous bringing it from a 16.4 in the quarter to a 13.8. His intention was to blow the motor up before swapping in the 383 stroker but he ran out of nitrous and swapped it anyway. They were tough engines.
 
The narrower bore forced some pretty small valve sizes. 350s had something like a 2.02 and 1.60 valves, but the 305 was limited to something like 1.84 and 1.50. Since the annulus (the valve open area) was a function of radius squared and lift, those smaller valves, and the low lift cams of the time, killed the 305 ability to breathe.

Even a big carb, headers, or higher lift cam, couldn’t overcome those little valves. They couldn’t be any bigger on that narrower bore.
Pretty sure 1.94/1.60 fit. Best factory heads used those sizes.
 
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