Why the 305?

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clutchdust

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Something I've always wondered is why GM ever put any money into the 305. And also, why was it such a lack luster motor?
First, if you compare the 305 Chevy to the 302 Ford, engines of generally the same displacement, there simply is no contest. Sadly, the Ford engine outclasses the gutless 305 in about any category you can think of. In fact, the 302 (more accurately a 4.9L) is far more competitive with the 350 than any production 305.
Second, why was the 305 such a turd mechanically? I mean why couldn't Chevy have just downsized the 350 if they were looking for less displacement? Architecturally, it's almost identical to the small block Chevy that made it's mark around the word, except for where it counts. They're notoriously weak in the mains and as I understand it the crank had smaller journals so cast cranks weren't particularly strong either. They didn't save any appreciable weight over a 350 and weren't as sturdy as the short lived 307, which was no prize either. Hell, the 327 was far and away a better engine, not to mention the venerable 350.
So what was the purpose in the 305? It was weaker than the 350, didn't weigh any less, didn't use some of the same hard parts. If it came out today I would swear it was just a Chinese knock off of a good Chevy motor.
Thoughts?
 
Want my honest opinion?? I think the company had then, and has now, many internal enemies....levels of 'management' that really do not have the best interests of the company at heart....:eek::surrender:
 
GENE, that makes about as much sense as anything else I can figure out. I mean, if they just wanted a smaller displacement motor for economy, why would they not just destroke or debore the 350? The architecture is already there and it's a proven platform. The 305 really was the answer to a question nobody asked. But given that, do you think the engineers responsible for designing it intentionally gave it the weaknesses that made it such a mediocre motor? I can understand higher-ups doing stupid things in the name of politics but I can't imagine the engineer that wants to be known for designing the 305.
 
It was designed for just that level of performance and nothing more. They didn't make it stronger because it was not required for that level.
 
I don't think the 302 was that impressive compared to the 305. What was the highest rating of the 302 225hp? In 1985 the 302 h.o had what 210hp and the 305 tpi had 215 hp. The GM gave the 305's the peanut cam from what 86-89?

In 90-92 gm had the what was some rpo that added dual cat exhaust hotter cam and the 305 TPI made 230hp ?

The 302 had a better flowing intake, dual exhaust, generally lower gears, lighter weight .... Had GM allowed shorty headers, true duals, and a better intake I think the 305 could have easily matched the 302 in every way.
 
AS I RECALL, all that shit got started from the 283 and 327 daze.....take a 283 and put in a 327 crank make 305? take a 327 put in a 283 crank with 327 heads and wind the living crap outta that short stroke bastard....
turned heads with the power....I forget the type of racing, but it was a CI limited class to 5 liters....now why the 305? better small displacement lower torque curves because longer stroke milder cam.....for heavier cars to get the silly EPA shit up to specs and so back when, get a MPG rating, keep some modicum of stoplight performance .....

the 70's were a tough time for all car companies, what with EGR, EPA, MPG, and increased weight that lead to the dropping of them B body cars '75 being last year, except for the Caddy's and then they even got some A body parts and thinner frames like the sharks were purported to get later on....

ME, corp/ mgmt?? simple....350 all the way baby.....

GOD knows GM went hog wild with ever stupid experiment in the world, I think what finally ended the madness was that Caddy HT4100 disaster, I"m told it was IRON HEADS and aluminum open jacket blocks with head bolts about 6' long....some such stupid shit a Caddy mechanic described to me once years ago....which stuck my as YGTBFSM.......


:surrender::hissyfit::eek::crap:
 
It's my understanding that the 305 was built strictly for its (better) ability to meet EPA emissions standards. IIRC, given the crude engine control technology available at the time, a small bore-long stroke engine is easier to clean up than a large bore-short stroke engine.

Had a 305 in my '87 Monte Carlo SS. Easily the biggest POS motor I ever owned.
 
mrvette said:
GOD knows GM went hog wild with ever stupid experiment in the world, I think what finally ended the madness was that Caddy HT4100 disaster, I"m told it was IRON HEADS and aluminum open jacket blocks with head bolts about 6' long....some such stupid shit a Caddy mechanic described to me once years ago....which stuck my as YGTBFSM.......


:surrender::hissyfit::eek::crap:
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Yes sir. I had an 81 "Bustleback" Caddy with HT4100. Threw a rod bearing, ate the journal. Had an alum block with iron sleeves "O-Ringed" into the block. Totally unrebuildable. Sold it off to a guy with a spare engine. Sweet ride though. Land yacht. Dayton factory real wire wheels. Gold striped tires.Kids still talk about that car. Took 8 to their prom night in it.:D
 
big2bird said:
mrvette said:
GOD knows GM went hog wild with ever stupid experiment in the world, I think what finally ended the madness was that Caddy HT4100 disaster, I"m told it was IRON HEADS and aluminum open jacket blocks with head bolts about 6' long....some such stupid shit a Caddy mechanic described to me once years ago....which stuck my as YGTBFSM.......


:surrender::hissyfit::eek::crap:
Click to expand...

Yes sir. I had an 81 "Bustleback" Caddy with HT4100. Threw a rod bearing, ate the journal. Had an alum block with iron sleeves "O-Ringed" into the block. Totally unrebuildable. Sold it off to a guy with a spare engine. Sweet ride though. Land yacht. Dayton factory real wire wheels. Gold striped tires.Kids still talk about that car. Took 8 to their prom night in it.:D
Click to expand...

TimAT seen it, I had a '79? DPFI caddy 425 engine control computer/injectors and t-body on a Pontiac dual plane manifold...highly modded up....on my '70 Lemand/GTO convertible....published in HPPontiac mag Feb '95 issue....Injected Madness....they gave the rong guy credit for the induction build....totally misread my missive.....The TIG expert followed what I wanted....not the short block builder....



:crutches::club:
 
The 305 SBC was released in the mid-seventies as part of an engine family denoted as “economy V8’s”. The 305 has a 265 cid bore and 350 cid stroke (3.75”/3.48”). Other new displacements in the family were the 262 cid & 267 cid. GM’s thought pattern here was to streamline its multi-brands of engines to one family, and the 305 was intended as the ‘center’ of the family as the “all purpose” engine. It was intended to have better has mileage than the 350, with more power & torque than the 6 cyl family.
This was a time of oil embargos & tighter emissions, so this change was also GM’s attempt to raise fuel economy & reduce emissions.

Hence the Chevy engines started appearing in Oldsmobiles, etc… unannounced. I always thought they were trying to get away with something at the expense of the customer with that stunt.

By the 1980’s the 305 was Chevy’s corporate engine, meaning that it would be used in multiple GM brands. For Chevy, it took the place of the 350 as the main performance engine in F bodies & the ‘80 Vette.

My ’86 GMC pickup had a 305 & 700 auto trans. It was one of the worst drivetrain combo’s I’ve ever driven. The engine was a slug, and the gearing ratios in the trans was configured by some 5th grader. All that truck did was bounce and shift. I would’ve been better off raising a sail above the cab!:push:
 
But see, that kind of goes to my question. They had a perfectly good foundation with the 350. If they just wanted a smaller displacement, why not just cast it with thicker cylinders or something? Why reinvent the wheel with a worse wheel? I mean, there really wasn't anything particularly new or inventive in the architecture. Used the same timing chain, rods, cam, distributor, water pump, etc. etc. It's almost like someone said, "hey, the 350 is a pretty good engine. Let's take the things about it that make it great and see if we can screw them up." And that's what they did.
Now I could understand it if it were an attempt at making a new, revolutionary engine and it failed. I'm struggling for an example but the closest I can think of is the LT1, which is by no means a failure (maybe Optispark, but otherwise it's a fine engine). So look at the LT1. If you compare it to the Gen1 SBC, it's obvious that they were attempting to improve or fix known deficiencies. And with the previously stated Optispark, I think they did a pretty good job. But nobody can look at the 305 and say, "yeah, except for this, it's a pretty good engine". That would be a pretty long list of exceptions.
Don't get me wrong, I don't think the 305 is a rotten engine. It was perfectly fine for moving the average 3500lb. passenger car from point A to point B. But I think pretty much any miniscule fuel advantage it had over the 350 it gave up in durability and performance.
 
clutchdust said:
But see, that kind of goes to my question. They had a perfectly good foundation with the 350. If they just wanted a smaller displacement, why not just cast it with thicker cylinders or something? Why reinvent the wheel with a worse wheel? I mean, there really wasn't anything particularly new or inventive in the architecture. Used the same timing chain, rods, cam, distributor, water pump, etc. etc. It's almost like someone said, "hey, the 350 is a pretty good engine. Let's take the things about it that make it great and see if we can screw them up." And that's what they did.
Now I could understand it if it were an attempt at making a new, revolutionary engine and it failed. I'm struggling for an example but the closest I can think of is the LT1, which is by no means a failure (maybe Optispark, but otherwise it's a fine engine). So look at the LT1. If you compare it to the Gen1 SBC, it's obvious that they were attempting to improve or fix known deficiencies. And with the previously stated Optispark, I think they did a pretty good job. But nobody can look at the 305 and say, "yeah, except for this, it's a pretty good engine". That would be a pretty long list of exceptions.
Don't get me wrong, I don't think the 305 is a rotten engine. It was perfectly fine for moving the average 3500lb. passenger car from point A to point B. But I think pretty much any miniscule fuel advantage it had over the 350 it gave up in durability and performance.
Click to expand...

BUT the feds didn't give a crap about quality, they cared about a number..CAFE.....they cared about 'pollution'.....EPA bullshit.....

which is high time the American public started ignoring EN MASSE the entire fed power structure, ie...make cars that RUN, screw the EPA crapola, start ignoring stupid court rulings, sorta the common sense version of all the hippy riot crap of the 60-70's....turn Alinsky right on their heads.....

judge orders water cut off to San Juakean? valley....tell the idiot to do it himself, the water flows on because WE NEED FOOD and the 40k FARMERS need to grow it, IDIOT.....but no, we all follow along like idiots following some pie eyed piper or other.....

time for common sense to take over from the idiots.....:crap:
 
@ Clutchdust - I'm not defending GM here, cause I think the 305 was a lame attempt. But after working in automotive design-engineering for years, I have a good feel for how some things are done. This is just my take on it.
The 305 was just basically a down-bored 350. There was no new wheel invented here. They most likely were in a mad scramble to meet some date lines & criteria, and made the simplest changes to what was already on the shelf. Designing a completely new engine would mean mega (lead) time and mucho bucks. Sometimes that's not possible. Lead time was much longer & more expensive prior to the 'digital age'.
And keeping thicker cyl walls meant the use of more retained material ($$$) and more end product weight.

I think the whole thing was based on the clock. If you then look back @ the time line in SBC development, by 1980 they had developed the C4 system (computer controlled catalytic converter). Which morphed into the C3 system (computer command control) soon after. The more exacting electronic controls were the ticket they needed to meet the criteria of increased fuel economy and reduced emmisions.

With the C.I.D. changes to the SBC family already enacted, it turned out to be the 'other' added ticket that helped them meet the demands and stay current for years.
I see it as 'happenstance', or as a result of.

If you think that whole time line was goofy enough, then let's move fwd and laugh some more.
In the 80's GM was prepping to do away with it's V8's almost completely. Almost all of their car lines were 4's & 6's. By the early 90's, (thanks to big time truck & SUV sales) GM had fired off development of the LT1, and the V8 revamp was back, working it's way up to the LS engine line.
:goodnight:
 
Rod75 said:
In the 80's GM was prepping to do away with it's V8's almost completely. Almost all of their car lines were 4's & 6's. By the early 90's, (thanks to big time truck & SUV sales) GM had fired off development of the LT1, and the V8 revamp was back, working it's way up to the LS engine line.
:goodnight:
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I find this one of the scariest bullets dodged by the buying public. For those that never read Dave McClellan's book "Corvette From the Inside", he recounts a meeting he had with GM brass during the development stage of the c4 (I think they were in beta testing or close to it). He was going over some of the new features and this thing and that thing when some nameless suit stood up and asked him if they could fit a 4 cylinder in it! :twitch:
 
clutchdust said:
Rod75 said:
In the 80's GM was prepping to do away with it's V8's almost completely. Almost all of their car lines were 4's & 6's. By the early 90's, (thanks to big time truck & SUV sales) GM had fired off development of the LT1, and the V8 revamp was back, working it's way up to the LS engine line.
:goodnight:
Click to expand...
I find this one of the scariest bullets dodged by the buying public. For those that never read Dave McClellan's book "Corvette From the Inside", he recounts a meeting he had with GM brass during the development stage of the c4 (I think they were in beta testing or close to it). He was going over some of the new features and this thing and that thing when some nameless suit stood up and asked him if they could fit a 4 cylinder in it! :twitch:
Click to expand...

The thought has crossed my mind as to fitting something else in my '72 here....

just a concept, something more fuel efficient, maybe smaller than the LS, like the Honda engine in a neighbors Murano....I bet available for almost nothing....junkyard style...:smash:
 
Am I the only person here that liked the 305. It served its purpose it provided sufficient power and most of the low end torque of the 350 with better CAFE numbers.In March of 84 I was finally able to buy my first new car I had allready done my homework and knew exactly what I wanted, but for fun I took a 84 Corvette for a test drive. What a underperforming pig ! I was totally dissapointed with the performance. I ordered a Z-28 with the 5 speed and L-69 305 HO this thing put a grin on my face a mile wide it was dam near as fast as my 70 Corvette 350-350 was stock ! I ran a 14.92 at the drag strip stock , and it would hit 140 mph any time you put it to the floor . With shorty hedders and advancing the stock cam 6 degrees it went 14.39 @ 97.5 mph on street tires, there was more in it but I was afraid of launching it to hard or power shifting , I was afraid of breaking the wimpy T-5 and rear axle. And the ride and handling were way better than my 70. I see alot of you guys that have 72-84s callin a 305 a turd but nothin built in that time period would even come close to it stock . OK rant over :D oh by the way the brakes sucked .
 
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I never said I didn't like the 305, I just think it was an answer to a question none of us asked. At the time, the 305 was almost as good as the 350. The only difference is the 350 could be made into a lot more than it was. The 305, on the other hand was almost tapped out in "HO" trim.
 
sssuch said:
Am I the only person here that liked the 305. It served its purpose it provided sufficient power and most of the low end torque of the 350 with better CAFE numbers.In March of 84 I was finally able to buy my first new car I had allready done my homework and knew exactly what I wanted, but for fun I took a 84 Corvette for a test drive. What a underperforming pig ! I was totally dissapointed with the performance. I ordered a Z-28 with the 5 speed and L-69 305 HO this thing put a grin on my face a mile wide it was dam near as fast as my 70 Corvette 350-350 was stock ! I ran a 14.92 at the drag strip stock , and it would hit 140 mph any time you put it to the floor . With shorty hedders and advancing the stock cam 6 degrees it went 14.39 @ 97.5 mph on street tires, there was more in it but I was afraid of launching it to hard or power shifting , I was afraid of breaking the wimpy T-5 and rear axle. And the ride and handling were way better than my 70. I see alot of you guys that have 72-84s callin a 305 a turd but nothin built in that time period would even come close to it stock . OK rant over :D oh by the way the brakes sucked .
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No wonder you liked your 305, as it was in special trim that yr with the Z/28 option. Not your 'run-of-the-mill' 305.
The threat of 5.0 litre Mustangs was giving GM headaches, so this was their attempt to compete at the time. The L69 was their substitute for the cross-fire.

Your '84 Z/28 L69 305 H.O. was rated @ 190hp @ 4800rpm, 240 torque @ 3200rpm, 9.5:1 comp, heads from the LU5 engine sporting larger valves, a more aggressive cam (non-roller), aluminum intake & flywheel, a special prom with more aggressive spark curve & knock sensor to match, special exhaust & converter, H.O. fuel pump, higher stall converter, 3.73 diff (man) & 3.42 diff (auto).
It ran well due to the decent trans/diff gearing setup, and of course your mods.
These engine specs should have been std fare for all 305's, but unfortunately was far from it due to the EPA/CAFE stds of the day.

The std 305 combustion chamber by design were known to create excessive detonation/spark knock. Compounded with a sensitive knock sensor and emissions friendly spark curve and M/C solenoid carbs you can well imagine the lack-of performance curve std 305's suffered with. Hence the reputation...
:bonkers:

You're right about the brakes. Having worked in Chevy dealers in that era, we had a bunch of campaigns and procedural changes to brake replacement/service that were constantly added/changing. It was crazy...
 
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