Sorry to bother you for such a basic question.

I'm wondering what you can tell me about the Pontiac (Not Chevy) 265 engine. I guess it was produced in '80/'81. Is it a low-deck like the 301? I have heard that it has only four main bearings. Is this true, and if so, is the crank 'n' block machined for the fifth bearing, or is it rough cast? Which bearing did they "forget"?

I don't recall ever seeing one of these, and if the 301 isn't popular, the 265 isn't even on the radar.

Thanks, all.

Never heard of a Pontiac 265... They made a 287. The 301 is a one-off engine. Not too many folks put time or effort into the 301's although there are some who have.

I have heard of the 265,not sure how related they are.They are definatly not related to the traditional pontiac motor. I just know what I have heard are @#%#&@! words! http://forums.performanceyears.com/g.../icon_razz.gif

Yes, the 265 is a low deck block like the 301, from about the same era. I don't know about how many main bearings it has. It definitely is a LOW performance engine.

OK.... you guys got my curiosity up now. When did Pontiac build these 265's and what did they put them in??? I guess I learned something new today. http://forums.performanceyears.com/g...icon_smile.gif

If I recall correctly, the 265 was the base engine in the Formula in 1980 or 1981.

Very early 80s.I believe they were optional in the mid size B-O-P cars.Put out a whopping 120hp
That's not bad considering the Olds 260 had about 105hp
My parent had a '79 cutlass salon w/a 231,after alot of engine trouble I found a olds 260 from a '78 cutlass to put in.The front end sat at least 1 inch lower but the car would bark the tires(slightly)This was my first V8 to drive and then I graduated to a 389 in '82 http://forums.performanceyears.com/g...on_biggrin.gif

I think the 265 was a 56 engine.It was a short deck motor,had 2 1/2 mains and 3in stroke.Maybe Steve can verify.Tom

CUBIC INCHES: 265; BORE(inches):3.75000; Stroke(inches):3.0000; Main Dia.(inches):3.000; Rod Dia.(inches): 2.250

It's usually mentioned in the same breath as the 301 and it seems a lot of parts interchanged.

Yes they did make a 265[4.3L]. They came in GP`s also. The only
engine that is more pathetic than the 301.

265-- 80 & 81 only!! Base V-8 engine in the Firebird/ Formula, Optional in the LeMans, GrandPrix, Catalina & Bonneville. 3.75 bore X 3.00 stroke 8.3 to 1 compression, 120 hp @ 4000 rpm, 205 lb ft torque, 5 main bearings.

Want to make a 068 cam sound big? Put it in a 265 with 1.65 rockers! Still no power though. 80-81 only, thankfully.

They make the best Boat anchors! http://pysales.com/images/evil.gif
Not worth the cast iron they were made of!
Drop in a 350-455 and have fun! http://forums.performanceyears.com/g...on_biggrin.gif

Dont bad mouth the little engines. I worked for Pontiac when they were new. No they were not performance engines but they ran well and gave good mileage. Put one it my 1961 Chevy PU when the 389 gave out. It gave me years of dependable service even when pulling a small trailer. Because of the head design they are not worth trying to hop up.

Resurrection time.........the Pontiac 265.

Just saw this on Ebay.

https://www.ebay.com/itm/296340261591

Buddy's parents had tge 265 in a mid-80's car...buick wagon?? Anyways. No replacement for displacement. 301 for the win.

Disclaimer: well i'd never go below 455, maybe 400, okay maybe 350 these days.

As many on this board know,I have built some serious HP with a 301/383 stroker engine.Tom

I recall seeing one in a car back then and did not believe the owner that it was a 265 until I looked at the underhood emissions label and saw that the battery was in fact on the driver's side of the car.

Tom S here's A list of Pontiac production cid motors up to 59 when the 389 came to be.

287

317
347.

I know them well,I used a couple 347 cranks with cut down mains in a couple of my 303 SCCA stroker builds.Tom

Oh that's cool!

370 in 58?

The $187.49 is way too far over the scrap price.

I've heard the comment several times, they are "torquey motors.....", compared to what? Me riding a bicycle up hill???:pound:

I've taken heat here, some, for calling them, NOT real Pontiac engines.
They are the Pontiac engineering departments forced agenda to come up with a better emission better MPG engine. They went a little too far.:Ithink:

I think their first year of production was 1976 and it ended in 1981. I know that firebirds got 305's in the new "F" bodies in 1982. I read speculation and maybe it was mostly hopefulness the the 301's would still be produced after 1981...

Seems as though I've the there was possibly an engineering plan to produce a twin turbo'd 301 for the TA's??? Doesn't sound right.

I remember anxiously awaiting the arrival of the turbo 301 engine. I read back then, in magazines, the the turbo engine was having crankshaft issues.

Someone, here, years ago passed on a story: Back in his early teen days he used to have a friend who's relative owned a salvage yard. The relative would allow them to fiddle with stuff as long as they were not destroying a sale-able part. One if the things they do is, find 2-3 same non running engines, Tear them apart and make one running engine, maybe put in a car and putt around the yard.......

Oh boy, they had found 3 Pontiac 301's that were locked up!!! They were enthusiastic in their endevour. Until they took the oil pans off. All 3 had broken crankshafts,:caked:

Is that a .030 over 301 with 3.75 stroke crank? Are all 301s the same-
block?

The 301 T (turbo) blocks are thicker.

Yes.

If GM’s intended goal with this engine was better fuel economy from less cubic inches, wouldn’t it have been way easier to cast up a 3” rotating assembly and use 350 blocks?

NO!Too much iron in 350 blocks compared to a short deck.301s are 3in main.Tom

To clarify, 3” stroke .

Lighter weight along with a lower overall profile to fit under lower modern hood lines and just plain less cubic inches for both fuel economy and emissions are the reasons for the short deck 301 and 265.

Weakened thin block castings, flimsy non-counterweighted crank lower ends and siamesed intake ports. Yuck.

It’s really no wonder why these engines are less popular to say the least among Pontiac enthusiasts who like the power and torque that Pontiac V8s were famous for. The low-compression 400 Trans Ams of the mid to late ‘70s were already enough of a disappointment and then along came the 301 turbo T/A….. :(

The early 287, 317, 347 and 370 V8s were already bulky and heavy for their cubic inch displacement. Once the 1959 389 appeared on the scene it finally had enough displacement to justify its weight and bulk. Reasons why the 350 and 326 are passed over as well, too big and heavy for their small displacements.

Joe Sherman was not worried about the 301T blocks,it the rest of the engine that gives them a bad rap.Heads intake and crank suck.Making one into a 383 stroker with 400 heads or RA V heads is NOT for the weak of wallet!Tom

The 1981 301 turbo had the highest horsepower and torque ratings for any V8 used in GM passenger cars, even better than the L81 350 in the Corvette.

I've told the story before, but my automotive engineering professor at GMI, Jim Lyons, left the university to head up Pontiac's turbo development. The crankshaft strength limited maximum design output to 280 HP. But the fully dressed engine was 110 pounds lighter than the 350 which helped offset the power drop. And it still produce 340 LbFt of torque. There was interest in offering the engine in the Grand AM as well.

Given what was available at the time, the Turbo T/A was one of the best performers GM had, especially in the handling department with the lighter engine. Jim went on to being lead chassis engineer on the 3rd gen Firebird.

Look at the crankshaft photos!
There's a front counterweight, there's a rear counterweight, and there's a bunch of iron in-between saying "Daddy, when I grow up, can I be a counterweight just like you and Mom?"
https://i.ebayimg.com/images/g/bjgAA...YaY/s-l960.jpg

https://i.ebayimg.com/images/g/WKEAA...YaZ/s-l960.jpg

Not surprising.

Pontiac did the siamesed ports on the "Iron Duke" also. Made a big deal of it in their SAE paper, as if it were a good thing.

I knew they were lighter, but I didn't know they were that much lighter!

The piston and rod assemble would have been UGLY. I am sure Pontiac didn't shorten the deck height and then decide to run a 6.05" rod, but decide on the 6.05" rod and then what deck height would work with it.

Stan

They took weight reduction to a crazy level in these 2 engines, they removed 2 rows of links on the timing chains and narrowed the timing gears in their quest to cut weight.

The conventional timing chain and gears can be substituted without any changes, but think of retooling for thinner timing chains and gears to save a few ounces..............crazy :D

The early blocks (77-79) also had all the nickel removed from the blocks. They were incredibly soft and wore the bores out really quickly. At 60,000 miles you had to cut the ridge out of the blocks just to remove a piston. I've routinely disassembled older Stratostreak engines and even at 150,000 miles you could still remove the pistons without cutting the ridge out of the cylinders. This was the time that all the GM lines cut costs by removing alloys that improved the cast iron for wear resistance. I guess accountants thought no one would realize the engines were wearing out sooner and save 50 cents per car........:third:

This was really when GM lost their market share, and never would regain it...............:eek:

Those efforts GM went to - in order to build a small CID package using as much existing tooling as possible, made for some odd ducks for sure. Olds took the 350 and made the 260 by keeping the crank the same and reducing the bore size to the point where it physically couldnt be made any smaller and end up with an engine capable of being assembled and rotated. 3.5x3.385 isnt gonna impress anybody.

i believe the 265 is to the 301 (non "T") like the 350 to a 400. just a smaller bore. I had a 265 block for a short period. I couldn't give it away. I ended up junking it with a car.

We made 478 HP @6000 with the 383 301.Tom

Tom,
You need to add that the HP had not peaked yet @ 6000 RPM

Stan

In the conversation of lightened blocks, aren’t the last 400 blocks produced the lightweight “windowed” blocks?

The 557 blocks

TomS 301 Build
 

Does someone have a link to the TomS 301 build thread?

Thanks -Kevin

here you go

https://forums.maxperformanceinc.com...d.php?t=710524

Thanks
 

Thanks Tom! Any idea where it is today?

I dont,I built a RAV one also and the Throttle stop I believe has it.Tom