So I'm thinking of swapping a new motor into my V6 after I get the body work in order. Ok,so I KNOW I'm swapping in a new motor but that's besides the point ! lol,anyway so here's the setup I'm going for....I'm going after a turbo or twin turbo(most likely a junkyard twin). And I was thinking a 305 instead of a 350. Simply cause they are alot alike in alot of ways just that the 305 has well less displacement and NO bottom end/low end power in anyway shape or form. But I figured since I was going to slap a turbo on in would it just be cheaper to build up a 305 and slap a nice cam,heads ,with the turbo I'm gonna use instead or spending the extra money for a 350. I'm trying to make this build as cheap as possible for my bird. but I need some input from the experts to see what you guys think. So any input will be GREATLY appriciated ! ~BB~

you will spend as much on the 305 as you would a 350, and get much better results from the 350. hell about the only parts that aren't interchangeable are the pistons. when it comes to serious power, there is no comparison between large and small bore engines...and 305 engines have very decent low end torque, it is higher up where they drop off...

I agree. The only reason you would want a 305 is um.... oh there are no reasons.

And by the way - 305 and 350 blocks are NOT interchangable.

who said the blocks were interchangeable? if you misunderstood my comment, i was under the assumption that everyone already knew that...

i agree. you are going to spend the same amount on parts between the 2. get the 350 so you start out with more power. no point in swapping the 305 in. theres a reason why they stopped making them...

Last time I heard they were still making the 305 and 350 for that matter. I believe they are still used in the chevy vans the non Express ones. I know that the boat manufacturers (Mercruiser & Volvo Penta) are still building them and using them. I believe the reason that GM made the new engines is that the aftermarket could make parts for them cheaper than GM could, not to mention if you build an engine that doesn't last as long, people will have to buy new cars more often. The reason to use a 305 is that most 80s 305s will outlast 350s. Mine has 160,000 miles on it and still has the crosshatch in the bore (known to be originol with no rebuild)

they dont outlast the 350s....thats far from the truth. and no they dont make 305s any more. all the new engines arnt even 5.7s anymore, they 6 and 5.4s and stuff like that. chevys new v8 in the trucks is a 294 or some odd number like that.

Thanks,

See I was asking becuase well I wasn't really sure since they were alot alike in some ways but yet so different in others.

~BB~

aren't LS1's technically 347 c.i.?

348 in pretty sure. same with lt1s

we're both wrong...at least according to this post. 346 ci

http://www.thirdgen.org/techbb2/show...hreadid=157243

hmmm im still pretty sure its a 348. ill ask the guy at the dyno place when i go in 20 days

LS1 is 346ci... the LT1 though, is still a 350. Its got a 4" bore, 3.48" stroke, just like the 350s made for 30 years before it.

The LT5 (ZR1 motor) has the same bore/stroke as the LS1 i think, so it too is 346ci.

Twin turbo and cheap don't mix. To do it right you are going to want a forged bottom end to hold up to any kind of significant boost, and forged parts are expensive. If you want a cheap but semi powerful engine to replace your V6 I'd suggest you consider a normally aspirated 350 with decent heads and cam.

Oh no,

Cheap and turbo do indeed mix and it has been done before. Besides I have a friend who owns a machine shop and he's good with helping me out on this one. I pretty much have the turbos so you know it's not all that hard. But anyway it's just a matter of doing in and buying the annoying stuff !

~BB~

Kontrax
Where are you basing that 305 don't outlast 350s. I have talked to many fleet mechanics and most prefer 305s because they have almost the same power and have fewer problems. Go to the junkyard and look around. I have seen many 350s with no cross hatch in the bores where most 305s still have a decent if not great cross hatch. I have seen 2 brand new 350s burn oil. In fact that said 350 has 50,000 miles on it and is in my dads 1997 1/2 ton. I also have a 350 crate that is already burning oil @ 10,000 miles in my 1980 1/2 ton truck. Both burn a quart every 1,000 miles. My 305 with 255,000 miles on it burns 1 pt. every 3,000 miles. This is hauling my 1983 G20 van around. It has always pulled heavy trailers and been pretty abused. It probably spends 15% of its time at or near WOT. It also got HOT one time (driven 2 miles with a gash in the upper radiator hose). That happened at under 100,000 miles. Still goes strong. TOUGH little motor if you ask me. I have also found that the little 305 has only 7% leakdown in the worst cylinder (thats better than most brand new engines.) Don't start this 350s last longer without proof. In my experience 305s outlast 350s in almost every case.

I also disagree about a 305 having no low-end power. In fact it is just the opposite. 305s have good low and midrange torque and moderate top end horsepower. I have enough torque to pull the van along @ 70 mph and 1,900 rpm and still have 13 in/hg of vacuum.

I do agree there is no CHEAP to a twin turbo setup. You might be able to get the turbos cheap and the labor cheap, but you will still need a beefy block and engine components to support the turbos and the boost.

engines are luck of the draw sometimes. you get one that runs great, or one that needs everything. do a search, ive talked with many people who have over 200k on their 350 and never had a motor rebuild. its how you take care of them. plus, when you have a 350 in a sports car, most people are like "wow a 350 lets beat on it" and they whip the SH!T outta it. so dont go saying 305s are this and that compared to 350s. and people prefer different things. hell, go to honda and ask them what they prefer, i bet they say their v6. does that mean you'll prefer a v6 now? no, people have their own oppinions. i just say a 305 is a waste of time to swap when you can just throw the 350 in and have more power. please dont start the old "305 v 350 in power" convo. im not bashin 305s at all, ive owned 5 305 cars and they were all great. im just saying its not worth the time or money to swap a 305 when you can get the 350 for the same or close to the same price. and please dont think im talkin to you with disrepect, not trying to T you off man. some people mistake what i say as bashing sometimes... anyways those are my thoughts on that

1 more thing, if 305s were so wonderful, then they would continue making them. not to get nitty gritty, but all these things you say about 350s leaking and this and that could have to do with the fact that they are making more power and torque. i dont know any power engine that will run without problems after a while...

well i think that 305's are pretty damn good i have had one in my camaro and i pound the f*** out of it daily and i have over 170k on it and still no leaks. it burns oil but not noticeable and infact my 305 auto keeps up beats most 350 5 speeds by at least a car lenght i get a really good launch off of most cars and they start to come back but i pull on them in 2nd and 3rd
but there is only so much you can do to a 305 so im looking for a 350 or a 400
(im not an expert on turbos but i thought they work better at higher rpms so wouldnt you want a 305 cuz they wind up quick but i dont know much about them)
but 350's have more hp stock so you already have an advantage...i have had nothing but good from both 350 and 305 so im not gonna dis either but like i said you can only get so much out of a 305.
personaly i would do some work and spend a nice amount of cash and pack a 454 or 502 in the there

beats 350 with a 5 speed? i hope your not talkin stock form because there was no 350 5 speed cars unless some1 swapped it...

no there swapped 3 of my friends have 350s with a richmond 5 speed tranny and few engine mods and my car walks on one and hangs right next to or infront of the other 2

if what you say is true, then your 305 is far from stock. either that or you have a 350. i notice the ? next to your engine spec. do you even know what you have?

richmond makes a 5 speed? always thought they were 6 speeds...

:yourock: :hail:

Sounds good !

~BB~

all new 2004 GM Engines

Ecotec 2.2
Vortec 2800 2.8 inline 4
Vortec 3500 3.5 inline 5
Vortec 4800 4.8 V8
Vortec 5300 5.3 V8
Vortec 6000 6.0 V8
Vortec 8100 8.1 V8
Duramax 6.6


no more 5.7 or 4.3

350 was dropped years ago its 347 now

well the 364 is the 6.0 and the 347 you mention cannot be the 5.3... but i am positive the 364 is the 6.0

Wasn't the 305 a bit more fuel efficient at least? That was some of the goals with the engine design anyway...

I am not here to bash anyone but my opinon is that if you have a 305 in your car that runs decent why not use it. I got a 305 for free so guess what, I am going to use it.

Just looked up the 350s demise. The 350 also 305 were last used in the 2003 non express vans. Dropped after the 2003 model year. That means that the 2004 vans have the 5.3 as stated or the 4.3 which is still used there.

no i have a 305 not stock theres i have put a pretty penny into it and im far from done
but yeah richmond makes the 6 speed a 5 speed and a the super t-10 4 speed

don't forget to add to that:

5.7 ~ 347 LS1 LS6 V-8
4.3 ~ 262 V-6
3.8 ~ 232 V-6

to find the liter equivalance of any engine simply multiply the number or cubic inches by .0165

Example: (LS1) 347*.0165= 5.7225 or a 5.7 (5700cc's)
(LT1) 350*.0165= 5.775 also a 5.7 (5700cc) engine

The converse to this formula would be to divide the liters by the same # (.0165) although the numbers will be only approximate rather than exact

(5.3L) 5.3/.0165= 321.2121 although we know that the 5.3 liter is a 324 cubic inch block

I never knew that....you learn something new everyday !
~BB~

You forgot to add 3.1 and 3.4 V6 which are based on the old 2.8.

i'm sure i'm forgetting quite a few engines it's pretty hard to keep track anymore

Don't matter as long as we remeber the "important ones !"

~BB~

my 305(310 )ci motor walks alot of stuff and yes some 350s is what it walk. but the whole thing is it's all in how much your willing to spend. if you have got a lot of cash anything can be fast.

A lot more potential in a 350 hands down then you will ever get out of a 305. Go with anything but the 305 and you will be a lot happier down the road.

true, but its easier to make power with bigger motors

Yeah, cause that brings it all back to the import VS. Domestic arguement.

~BB~

350 hands down. There is not much you can do with a 305. The Trans Am I just got 6 months ago has one and it is crap. I will soon be putting in a 350 or a 383 with a supercharger.

If a 350 is that much better than a 305, then a 406 would be alot better than a 350 and spank it every day in the week. Why bother with the 350 when you can get the 406?

you shouldnt bad mouth the 305 i produces a good amount of power for it bore.the 350 will produce more power and is more versatile but ilove my 305. now dont get me wrong i love my camaro and the 305 will stay in it and but i'm getting a lighter car for my 350 like a 78 malibu or an 80's regal that'll be may race car.

A 78 Malibu and an 80s regal are lightweight cars?

id take a 350 over a 406. i think you can do much more with a 350 then any other motor. i mean all these FI kits and head and cam packages like the systemax are all for the 350. endless combonations you can do with the 350

the 305 is alot tougher han any 350 i've ever seen. i am at wot about 3-4 times a day, the car runs 14.8 all day long w/ stock exhaust. its an auto too. still running strong at 105k miles and its seen its sare of races and thats more than most.

3.8 V6 is a 231 and the LS1 are 346. ask any 4thgen guy. he'll tell ya its a 346

yeah there are lighter then camaros and you can run dual exhaust cheap

What 80s buick regal are u talking about? Most of them weighed around 3750lbs and the 70s malibu's weighed around 3,300lbs. Not exactly "light" weight cars. And the camaros normally weigh around 3,300lbs as well. So I am having trouble figuring out why the 80s regals and 70s malibu were lightweight cars? I know that they could probably be made lighter but so can the thirdgen fbodies in the same way. A true duals is not needed unless you plan on doing some serious racing and even then its not that important. Its called the cutout.

that is what the car is goning to be for racing my camaro is the daily driver. and the 78 chevy malibu weighs 2900 lbs and the regal i havent found the weight spec on that yet

well i can tell you if its that light then its had things removed. there is no way a full size car weighs less then the 3rd gens. most 3rd gens are between 3-3400 lbs depending on motor, tranny and suspension. but a regal weighs more from the factory then a 3rd gen, no questions asked

Can i just add Fast 305, that you must be running some bad oil, or have some bad luck with your engine. A quart every 1000 miles is alot of oil, you may want to have the checked out. Its not because its a 350. Trust me, they did not run the 350 engine for all this time for nothing. Let alone, has a LS1 and LT1 have close to a 350 spec. Its just because its proven that a 350 is a longer and better runnign engine IMO.

Well,

I'm sure at this point I'm really leaning twards a 350. But I still wanna do this turbo build too. So if the next few days goes accordingly I wont have a problem with that at all.

~BB~

I have a 305 in my car with over 225,000 miles. Im not saying its better then a 350 but I have personally pulled many 350's. Seems to have good low end torque, Also they can take a beaten just rebuilt mine and when I pulled my intake all the ports were clogged well they were almost clogged. Couldnt even fit my pinkie in them and it was still going strong.

I don't think it is bad maintainence or bad oil. I use the same in both. Castrol GTX 10W-30 synthetic. I switched the 305 @ 100,000 miles over to the synthetic. The 350s were switched at the 1st oil changes. They've run the 305 for a long time too. Its next to the same thing. The only difference other than cylinder bore is the rings, pistons, and piston pins and head cc. I don't know why our 350s burn oil as they both run good other than that, so I don't see any reason to pull them apart, yet.
IMO it doesn't really matter in durability both the 305 and 350 will outlast most cars, I have just had better luck with the 305 in HD apps.