Ok guys my question is this why does everybody hate the 305 from my understandng they can still be built into respectable motors.I know everyone says go 350 its 45 extra cubes an costs the same to build I understand that but I mean really I don't see ppl down talking the 350 and saying go 383 or go 400 I only see this when it comes to the 305 I'm not obsessed with the 305 I just see ppl bashing it all the time and wonder why ppl get so mad when someone says hey I'm shooting for a 400 hp 305 9 out of 10 ppl say go 350 throw the 305 away why the bashing? I don't know this has just been bothering me hopefully we can get it all in the open on one thread...

 

IMO it's because smaller displacement builds are usually used for high reving, low torque purposes. The 305 is not built well enough to last under that kind of stress. It also doesn't have a lot of aftermarket support which means getting good power will take a lot more than just bolt ons and more money usually.

 

You can get 325+HP out of a 305 with bolt-ons, how much power do you need? You can't hardly put that kind of power to the ground without breaking the tires loose constantly anyway.

 

Makes sense I guess another thing that bugs me is why in the hell does everyone wanna be just like the next guy and build 350's 383's etc. Why don't more guys wanna take the road less traveled and have something truly impressive rather than popping the hood and having a 350 just like everyone and there mom... I guess it would be awesome to see more out of the ordinary builds 305 335 327 or hell even the smaller motors what are they 286 or something I mean just imagine running a 383 down and he says what ya got in there and u say a 305 he would **** his pants... I know I would. I personally have a 350 in my iroc but my next build I think is gonna be a 335 tpi with a nice little nitrous set up

 

I didn't say you couldn't get power. Check out this guys:

http://www.cardomain.com/ride/2496232

I'm just saying that to get equal results with a 350, the arguments are always that the 305 will cost more.

 

BTW, I have a 305 and am happy with my performance. I am going to add nitrous just because I like playing at the strip sometimes and right now all my friends with new Challengers and Camaros are making me look dumb for trying. I would just say that if you are going to build an engine, have some purpose other than... "I want to be different". Personally if I was going to build a smaller displacement engine I would go with something lighter than the 305. That would be the whole point of going smaller, right?

 

I wasn't defending the 350, I was just trying to answer his question with the most common answers that I see on here summed up.

 

350 block is more easy to upgrade

 

Ok i read through this and only seen negative stuff lol no one stuck up for it really so here i go. I bought a camaro guy told me it was a 383 stroker bah yeah right. The motor had no low end power my 60 ft was slower than that of a go cart lol. BUT even with a retarded crappy 60 foot it still ran a 14.94 i put a 3200 stall in it. It ran a 13.27. with 2.77 gears and a th350. This motor would rev like no other all the way up to 7400 rpms strongly would turn 8000 but came out with slower times. the motor blew i took it apart. It was a 305 with stock heads NOT EVEN MATCHING both had a 48cc combustion chamber when measured some mild porting look to be homemade nothing professional and a hug cam it was stock bore with dish pistons that appeared to be stock. SO for people saying you cant make a 305 fast without it being exspensive im looking at it like this. 100$ cam 12$ for porting tools 40$ for head gaskets 20$ for intake gaskets. 100$ for a 650 edelbrock carb used and 190$ for a new rpm performer intake or a used one for cheaper. and 75$ for head milling which im assuming was done since the heads were originally 54cc combustion chamber, and a 3200 stall for 190$ . Thats 727$ for a low 13 car probally better considering i didn't empty my car and i weigh 387 :S no shift kit nothing. That i would say is a worth every penny.

 

i have a 305 in my car an a 350 four bolt on a stand and i have no intentions of swaping it in there there is no real advantage anything you can get for a 350 can be had for a 305, anybody who has ever built motors themselfes know this

 

the only difference between a 305 and 350 short blocks is the size of the pistons, so all this 350 blocks are more upgradable is bs

 

Why would anybody want to build a fuel mileage engine when you can get 45 cubes for free, cubic inches always = horsepower, not being smart just old and been down the road before.

 

From what I know, the 305 was a smog motor that GM used to address emissions and fuel economy issues at the time. But it was soon dropped for the Vortec/LT1 when these issues were resolved. It was never a performance engine like the Ford 5.0 but I've read that the 305 was improved upon in the latter years of the Thirdgen.

IMO, the 350 is a better platform to build from especially considering cost/performance. Also, you can build a 383 out of a 350 whereas doing so with a 305 doesn't even get you to where you would have been otherwise. Most people are looking to build something faster for the least amount of money and the 350 is often the best choice.

I would build a 305 though if I had a mint or collectible Thirdgen because IMO it would be worth it to keep it stock but still have enough power to enjoy it. I've always wondered though how collectible something with all of that emissions equipment in the engine bay (as does the mid eighties would be), but the TPI is pretty cool though.

 

It depends what your goals are. If you want to build a lot of power, the easiest way is with cubic inches. A typical performance build can make any engine with 1 HP per CID. Since you use the same parts to build up a 305 as a 350, you're automatically going to get 45 more HP. Yes, there are high HP 305's but if the same components were installed on a 350, it would make even more power.

A naturally aspirated engine is an air pump. The amount of power it can make depends on how much air/fuel it can suck into the cylinders. The 305 has a small bore. That limits head choices. With the larger 350 bore, you can install bigger valves which, with a bigger cam, can get more air/fuel into the cylinders and make more power.

 

you talk about 45 free cubes and 45hp more, but if the person doesnt have a 350 but a good problem free 305, they would have to BUY a 350 to put into the car and spend money on getting that 350 and rebuilding it where they could have used that money to put into the 305 and get that 45hp,

i own a 267cu chevy a 262cu chevy that came out of a monza and a pontiac 350, `ive driven all of them, and that 267 is a real good motor and even that uses the same crank as a 350 would i want to build a 267 insted of a 350 NO but if you have a good 305 i see no point in throwing it away for 45 measily cubes

if somebody had a stroker 383 or a 400 then i would say go for it but all that to gain 45 i see it as pointless,

hell anybody wanna buy a virgin 4 bolt 350 or trade something for it

 

There is nothing wrong with 305s and modifying them but if you want to build a ridiculous engine the 350 or larger becomes the better choice. The anti 305 people seldom look at the whole picture.

 

It all depends how much power you want, and how much you're spending to get it. If you want to put some bolt-ons on a 305 to make it faster, that's great. As you do more the additional cost of a larger, better-breathing block becomes less significant compared to the rest of your expenses, and the benefits of that block become greater.

If you have a 305 that costs nothing, and it'd cost say $250 for a running used 350 to put in that's 15% larger, then on a percentage basis you're spending infinitely more than the cost of the 305 to get the 350. However if you're doing a build from scratch and you're about to put $1000 in machine work and moving parts into the 305 block, then spending $150 for an empty 350 core means you'd be spending 15% more money for %15 more displacement.

Take it a step further though... if you're replacing the rotating parts, put a 383 crank in the 350 block for the same price as a 350 crank, and get 26% more displacement for only 15% more money to buy the block.

 

I've never owned a 305 and so many younger drivers who have only driven 4 cylinders or V6's are amazed at how much power a simple 305 V8 produces. They've never really experienced a 350+ engine.

You should be able to go to your local parts store or GM dealer and buy a stock replacement 350 for under $1000. It's not a super powerhouse but all the machine work is done and doing the simple add-ons like intake, cam etc can make a good engine for far less than building one yourself. Finding a junkyard 350 and building it up will cost a lot more than most people realize. It all depends exactly what you want to do with it. Finding a running junkyard 350 and dropping it in where a 305 once sat isn't that expensive.

 

The discussion for what ever reason always goes back to full high dollar forged rebuilds which is completely out of the scope of what 90% of us do with our cars. You don't need all that for a big power street car. Stock bottom end is just fine and has been proven over and over again.

The common belief is the 350 is the right choice so in order to appear consistent and right you have to repeat it.

If you are building for certain power at a certain RPM with a certain investment you are over thinking it IMO. Just work on your motor and make it fast as you dare and have fun with it. Being broke completely changed my point of view on what's right for me. I don't live in a void where 305's are on the left, 350's on right, choose one. I take what comes to me and is economical at the time.

You can use big valves on a 305 it's been done. It's well documented on TGO 2.02in 1.6ex @ .533 lift on a .030 over bore 305. Running mid 12's all motor is nice if you ask me and he didn't even notch the block like he should have.

 

Bluntly speaking I think most 305 bashing comes from a lack of knowledge on both sides. On one hand you have the guys who seem to regard 350s as if they were made of gold (and like you mention also conveniently seem to forget about all the even larger motors available). I dont care if the original poster has a original 50k mile 305 and just wants a little more pep you will still have people saying dont waist your money on a 305 swap to a 350 bla bla bla. This dosnt really make sense and its clear that if the people responding really knew what they were talking about rather than just regurgitating what they've heard they would see that there's no reason to swap to a 350 if someone only wants a bit more kick than stock (300 or less) if the motor they have is in good shape. Now on the flip side you also have a lot of justified 305 "bashing" (mind you although this isnt really bashing its more the hard reality of things and its perceived as 305 bashing). This is because there are a lot of unknowledgeable 305 owners wanting 400+ hp 305 for their daily driver and thats just not practical. Not only would that motor have to be so radical its probably not something you would want in a street driven car but it also may be cheaper to swap to a 350 anyways. You also have situations where people are talking about swapping or replacing a bad motor and unless someone was given a 305 or got a really good deal on a good 305 its costs pretty much the same amount to go to the 350 so people suggest that route instead. Again this isnt really bashing just making a suggestion based on fact you could get more performance for the about the same amount of money. Then you have the other situation the group that wants to be unique. This is common source of 305 bashing and this is sort of the fault on both sides. On one hand you have thoes that want to do something different. They like the idea of a challenge even if its going to (and it will) cost more money to get less results in terms of performance though may score a few points for the wow factor. On the other hand you have thoes that will always see the futility in such goals. You may be able to get 500 hp out of a 305 and thats cool and all but that same thing could be accomplished or better for less with a larger motor so whats the point? Just to be different? Theres some truth to both side. If you wanted to try and build a car and utilize the latest technology to see whats the best that can be done there is a lot of value to this. This is how you make progress its called research and development. This is how GM went from producing 200 hp 350s to over 400 hp while getting better fuel economy and meeting streetability, and emissions goals. On the flip side though if its just to be cool its kinda silly reminiscent of guys who would dump $10k into economy cars run with stock third gens. Kinda cool for a moment that they did it but at the same time pretty much pointless when you look at the big picture so there will be some bashing here. Now I say pretty much pointless because there is still the satisfaction of knowing you did it(and really what the owner thinks of his own car is most important) but this thread isnt about justifying your build or judging whats right and whats pointless its about why 305s get bashed.

 

As has already been stated, the big roadblock to 305 power is the bore that is smaller than even a 283 (the 305 has a 350's 3.48" stroke). This limits your valve size and causes problems.

When Chevy wanted a high performance 5.0 litre engine, they used the 327/350 4" bore size so that they could get decent sized valves in the cylinders- an "oversquare" engine, the bore is larger than the stroke. And a legend, the 1967-69 Z28 was born- to qualify the Camaro for Trans Am 5.0 litre series racing.

When they wanted a smog/mileage motor to propagandize the government and the consumers, they built the 305 as a small engine that had some torque to make you feel like it (the smaller engine) still had some power from off idle to moderate speeds.

305's can be made to run OK, but you'd be much better off putting the same effort into a 350. That's just the facts.

If you want to work on your 305, enjoy yourself. You can make it run better than it does now and if that makes you happy, go for it.

But the same money and effort put into a 350 will always yield better results, like I said, it's just plain fact.

 

its like saying that people that own 396bb chevys should throw them away because there not going to make what a 454 does, anymotor can run its all in what u want out of it but when somebody wants to build the motor they have and it happends to be a 305 everybody tells them to get rid of it and get a 350 is stupid

 

Well, I don't think it's that people are hating on the 305. We're talking about a desing from the late 70's and early 80's that was during the non performance era.

You will see comments because folks with the 305 will ask questions such as "how do I get to 300HP" etc etc etc.

It's no different than v6 owners of Mustangs (pre 2011) or 4th gen Camaro six banger owners that ask "how do I supercharge or get more performance"?

When you ask that question, and are looking for larger displacement or new technology type performance, then that's when the responses move toward engine swaps, and rightfully so.

Personally, I already own 2 performance cars and am rebuilding an 89 for resale purposes and I've always liked the 3rd gen style so I'm trying one. I'm not looking for a 13 second car. I'm restoring the car so it will get another 50k-100k miles on the motor and the 305 in it runs, has good compression but I'm going to rebuild it myself rather than buy someone's 350 for $1k with unknown internals. Again, my goal is reliability vs power and with a platfom on hand, I know my direction (but if I find a decent priced rebuilt motor I could be pursuaded to not do the work of rebuilding)

 

The 396/454 argument is not as valid as the 305/350 argument. 396's were a performance engine and had room in the bores for some decent size valves, thus- they were sold as high performance engines, not EPA fuel mileage/emissions fooler dogs.
The only reason that stock 305's in Camaros seemed to be somewhat quick, was because of the low first gear ratios in the 700R4's and sticks, with overdrive to milk out the top speed at the other end.

I'd always rather have a 396 than a 454 but I'd spend some time and effort on a 396 if I had a free one. Espeically since that engine could enhance the value of a collectible car, a car that was meant to be a beast to begin with.

Not so much on a free 305. But like I said before, you can make a 305 run a bit better than it does now and if you're happy with that, the world will see a grinning guy.

But the world will probably see a LOT more guys with bigger grins that have done the same things to 350's. There's usually a reason that one idea is much more popular than another, it just works better. That doesn't mean that the other deal is wrong, but it certainly will have less of a following than the proven hot setup.

 

Nicely said.

JamesC

 

Just saying "that's a fact" doesn't make anything a fact. That is still just opinion.

Misinformation like being spread here is a good reason people don't like these motors. Also peoples opinion come from stock/stock comparisons and most fools mistaken dump truck power for racing power and in reality they are both garbage stock.

A 12 second NA SBC nice regardless of the displacement and there are plenty of 305's out there doing this and doing it just like your dream 350 does good heads, cam, ect.

 

I have also been wondering about this, i've owned my rs for just over a year now and even with all the neglected maintance issues i have had to fix the 305 tbi has been a respectfully dependable engine. I would like to dream about having the money to dump an awsome 350 into it but i dont expect to see that kind of cash in the near future, being honest im thinking about just doing a rebuild of the engine that is in it.....few aftermarket addons to get some more power of course.

 

if you want decent MPGs ,and have no intention of racing.and just want to enjoy driving the car, a 305 is for you. however if you are one of those "competitave" types.where nothing is ever enough,AND you dont mind passing everything EXCEPT a gas station.then by all means go bigger.hell you may even enjoy one of those " LS " thingys. there isnt anything wrong with the 305.its just what goals do you have in mind?

 

 

What counts is that you're happy with the engine your car has. In the end, they all good SBC to suit every drivers needs!

 

If someone told me they already have a 350 and want to build a 305 then imo thats stupid

It cost the same thing to build the 350 and those 45 :measly "cubes" do quite a bit.

Think its more people trying to say spend the money once and get more thats all.

305 revving to 8000 I have to see this parts list.
Pray tell whats in it?

 

dang this is an old thread,

but i wanted to say to the member that recently posted, i have two 305 thirdgens, my RS has been with me since i was 17 years old, I love this car to death, the TBI motor has been more than fair to me, but i wouldn't spend a dime on anything performance wise on this motor that would not bolt up and help a 350, as long as it can be swapped over, its not wasted money, and it makes the 305 that much more fun to drive

eventually the RS will be LS swapped, although i may go to a old school 350 for kicks while i build the LS


My IROC will remain an LB9 for the rest of its life, that car will be restored to original with no intentions of racing or beating on it at all

I say if you never plan to pull the motor anyway, then have fun a slap parts on the 305, but if you plan to swap "eventually" then make sure the parts you put on will work with the next build, if the 305 ever needs a serious rebuild, you might as well rebuild a junkyard 350 and throw the 305 away

 

My take is a car making 0HP is slower than any running 305. People get this idea in their heads that they want to do engine swaps, etc. and it all costs both time and money and don't realize the potential for snowballing and issues. There is also this idea that a 350 is automagically better. I'd rather have a Vortec 305 or a dual cat TPI 305 than say a smogger flat tappet 350 any day. The lowest HP V8 'vette actually had 165HP, which is lower than the "california" 305 'vettes at 180hp. By doing a 305 that's in car with bolt ons you can get tangible power gains, protect your investment with a 350 (or bigger) option down the road and enjoy your vehicle now.

Building is another beast entirely, but my question to the "get a 350" people is if you're going to the trouble of yanking the engine why not do a 383, or even better still an LS series engine? They have better heads, valvetrain, intake options, are automatically a roller block, bolt up to a stock trans, there's a ton of aftermarket for them and the list goes on.

There are other forms of racing besides straight line. If you look at what people do in Autocross it's not all about HP. Driver, suspension etc. can have a way more profound effect. The idea that you can have a straight line car that can smoke a ZR1 is fun, but at the same time it's not a requirement to have fun. There will always be someone faster right? Then again some people do absolutely no racing and have fun with their cars.

 

For a DD, I basicly installed some bolt ons and a 3.42 w/Eaton Posi in a 305 and am very happy.
I did not have to touch the engine internals at all.

I had to laugh the other day when I said to a guy that it had a 5.0 in it. He laughed then said that someday I might put a V-8 in it.

 

Trick question!!!!


Ummm.....



Because it's a POS?

E-mail me my cookie for the correct answer please

 

I wouldn't call the 305 a p.o.s. If it were such a messed up junk engine, then why is my original 1987 LG4 still running with excellent compression and trouble free after over 27 years?

 

Its definitely a work horse.
Like I said I'm OK with what I've got.
If I had my preference I would have picked a 350 to begin with but all I did at the time was count the plug wires. They came to 8 so I bought it for $500.00.
Almost $9,000.00 later (none inside the engine).
Someday when this engine decides to go it will get a 350 .
Heres my little 5.0 =