Car Craft
Click here to find out more!

what can i do to make my 305 pull like a train?

  
Car Craft
1 |  2 |  3 |  Next   | Last 
Item Posts    Sort Order

what can i do to make my 305 pull like a train?

 
HunterT HunterT
New User | Posts: 41 | Joined: 09/07
Posted: 11/03/07
08:39 AM

I have a firebird with a chevy 305 in it. I felt like the engine was way underpowered for the car so I was going to do a 350 engine swap but then decided against it because i want to keep the numbers matching. what could I do to this engine to make 300+ hp. can it be bored to a 350? Strocker kit maybe?  

monte7108 monte7108
New User | Posts: 7 | Joined: 10/07
Posted: 11/03/07
10:00 AM

why dont you save the motor if you want number matching put a 350 in anyway, you can always swap back, I was always told that the 305 wasnt worth the hassle and expense of building up when you can so easily jump to a 350 with more power right off the bat  

GibTG GibTG
Guru | Posts: 931 | Joined: 08/03
Posted: 11/03/07
10:21 AM

If you want it to pull like a train, I recommend chaining it to a train. If this doesn't work for you the least you could do is park on the tracks and hope that a train will come by and take it off your hands...

Numbers matching? Are you joking? A 305 Firebird will never be valuable. Don't waste your time with making it numbers matching. If you want a performance engine a 305 is simply not an option. It was never meant to be a performance engine and it never will be short of completely re-engineering it.

A 305 has a bore of approximately 3.74". This more than a quarter of an inch smaller than a 350 so it can't be bored that far. Putting a stroker kit in a 305 is also just shifting the power band even farther down. An engine like this with a stock induction will probably top out at 4000 rpm. This kits are also not very cheap because they require components that aren't readily available.  
~Gibs

Mavman72 Mavman72
User | Posts: 187 | Joined: 04/07
Posted: 11/03/07
05:50 PM

You can build em up a bit.Cam/headers,better induction system but in the long run you wont be happy.Throwing money at a 305 is akin to casting pearls before swine(sorry) but its true.Your cars engine is just an air pump(like any other)and due to its small bore,small ports,small valves it just wont move enough air to make an apperciable amount of power per dollar spent.You really are better off building a 350 for it and moth-balling your 305 for when it does become valuable(if ever)but you never know.If I knew 25 years ago what I know now,I would have kept my boss 429 70 mustang along with a few others I got rid of.  
Power is bliss Torque devine

HunterT HunterT
New User | Posts: 41 | Joined: 09/07
Posted: 11/03/07
08:00 PM

Ok 350, LT1? Would a 2nd gen lt1 bolt in. What would i need for this swap. Just an lt1 longblock?  

powerdreams powerdreams
User | Posts: 87 | Joined: 11/07
Posted: 11/04/07
07:26 AM

Your dilemma depends on how much you can afford? 300hp easy from a 305! stock heads, call comp. cams tech line. At a guess on pump gas, I would say something like a sig erson TQ30 and 625 cfm carb.But you have injection, if its a ac delco or motec computer ,chances are a good cam company will sell you a cam and computer chip package. Providing your injectors are rated for 300hp. IF this is'nt feasable ,the ezy way go would be 2500 to 3000 high stall converter if auto a lower diff ratio with maual.I'm guessing you have something like a 3:1 final drive ratio.I would go to 3.3:1 or 3.5:1. these mods will take alot of the initial load away from the motor and will give greater acceleration and stump pulling power on tap. Any route that you choose will use more fuel.It would greatly help if you know the compression of your motor for 300hp you need at least 9.5:1.Also are you auto or manual trans? whats your current diff ratio and gross vehicle weight would also help if it was known! or buy a junkyard 360 mopar cheap as and forget all your problems ,only kidding! I recently visited a web site for 3.8supercharged v6 buick engines with stock internals and a 14psi pulley kit producing over 300 rear wheel horsepower with ease! and on pump gas!thats like 410-20 flyweel real power and more efficient than a normally aspirated v8 of the same power equivalent. If you can find a 302 chev or 327, they would kill a 350! why cause they rev harder and would swallow 300hp at 3500 rpm with the right cam and flowed heads(u want high velocity ports) this will deliver greater low end torque and a 7000rpm capbility.Properly worked these engines will eat GEN 1,2 and 3's why much tougher and more reliable oiling system.In OZ GM had alot of complaints and engine troubles with their 300kw and 260kw GEN II and III's (400hp & 350hp) no good cosidering the price of the car.  

HunterT HunterT
New User | Posts: 41 | Joined: 09/07
Posted: 11/04/07
09:03 AM

Its an auto with a sport shifter, its got stock gear ratios. So some people say 350 and some say 305???? I also want to go the affordable route?  

HunterT HunterT
New User | Posts: 41 | Joined: 09/07
Posted: 11/04/07
09:12 AM

oh and its a 1980 no fuel injection.  

powerdreams powerdreams
User | Posts: 87 | Joined: 11/07
Posted: 11/04/07
09:45 AM

Hunter awesome! call summit or paw cam and lifter kits are cheap $200, 625cfm carb even secondnand and new timing chain . Do you know someone that can fit the cam cheap. I'd say around $600 all up. I had a similar problem. I went from a 2.92 to a 3.23 diff cost $400 all up. I used a non noisy 2nd hand diff with 3.23 from same car family (theres usually a metal tag) underneath saying what it is.WOW! it flew with a 200hp engine only. acceleration improved remarkably from that single diff change. I guess it also depends how worn the 305 is.  

HunterT HunterT
New User | Posts: 41 | Joined: 09/07
Posted: 11/04/07
09:53 AM

Yeah thats a good idea. Now i have been playing around with the idea of a tunnel ram on my car. It already has the hole for the shaker so it would be easly done. What are the pros and cons of this.  

CSIROC CSIROC
Guru | Posts: 793 | Joined: 11/05
Posted: 11/04/07
10:01 AM

As someone who's tried to defy the "305's are junk" crowd...take it from me...they are right.  I dumped a ton of money into my 305 for no noticeable gains what-so-ever.  While a cam would certainly wake it up some...its still a complete dog.  Really not worth the time or money.  Replace it.

If you are worried about its value in the future...modding the engine will decrease its value.  You'd want to replace it anyway and just keep everything to drop in at a later date.  
____________________

Casey McCall:What happened to your values?
Dan Rydell: I find that maintaining them is a lot of work. I take a day off every now and then.
Casey McCall: You take a vacation from doing the right thing?
Dan Rydell: Yeah. I don't loot storefronts or anything, but once in a while, when I consider the effort it takes to diligently adhere to a moral compass, I take myself out of the lineup and I rest up for the next game.
Casey McCall: I swear, you could run for Congress and win.

TheSilverBuick TheSilverBuick
Guru | Posts: 1225 | Joined: 02/06
Posted: 11/04/07
12:11 PM

Icon QuoteHunterT:
Yeah thats a good idea. Now i have been playing around with the idea of a tunnel ram on my car. It already has the hole for the shaker so it would be easly done. What are the pros and cons of this.

The Tunnel ram intake will kill the low rpm performance, give lazy throttle response in normal driving situations and I don't think a 305 will flow enough air to remotely take advantage of the benefits of more air.

The benefits are all in the upper rpm range (4,000+rpms?) where velocities are high and the engine requires lots of air.  
-
The Silver Buick- '77 Skylark coupe w/ a Fuel Injected Buick 455&TKO-600, '72 Centurion Conv't - 455w/TH400, '67 T-bird 4Dr (suicide) w/428&C6. '69 Firebird replaced!

http://www.bangshift.com/forum/index.php?topic=6189.0

GibTG GibTG
Guru | Posts: 931 | Joined: 08/03
Posted: 11/05/07
09:02 AM

Icon Quotepowerdreams:
Your dilemma depends on how much you can afford? 300hp easy from a 305! stock heads, call comp. cams tech line. At a guess on pump gas, I would say something like a sig erson TQ30 and 625 cfm carb.But you have injection, if its a ac delco or motec computer ,chances are a good cam company will sell you a cam and computer chip package. Providing your injectors are rated for 300hp. IF this is'nt feasable ,the ezy way go would be 2500 to 3000 high stall converter if auto a lower diff ratio with maual.I'm guessing you have something like a 3:1 final drive ratio.I would go to 3.3:1 or 3.5:1. these mods will take alot of the initial load away from the motor and will give greater acceleration and stump pulling power on tap. Any route that you choose will use more fuel.It would greatly help if you know the compression of your motor for 300hp you need at least 9.5:1.Also are you auto or manual trans? whats your current diff ratio and gross vehicle weight would also help if it was known! or buy a junkyard 360 mopar cheap as and forget all your problems ,only kidding! I recently visited a web site for 3.8supercharged v6 buick engines with stock internals and a 14psi pulley kit producing over 300 rear wheel horsepower with ease! and on pump gas!thats like 410-20 flyweel real power and more efficient than a normally aspirated v8 of the same power equivalent. If you can find a 302 chev or 327, they would kill a 350! why cause they rev harder and would swallow 300hp at 3500 rpm with the right cam and flowed heads(u want high velocity ports) this will deliver greater low end torque and a 7000rpm capbility.Properly worked these engines will eat GEN 1,2 and 3's why much tougher and more reliable oiling system.In OZ GM had alot of complaints and engine troubles with their 300kw and 260kw GEN II and III's (400hp & 350hp) no good cosidering the price of the car.

That is really a newsflash to me, that 302's and 327's would kill a 350. So that's why GM stopped producing those smaller engines 35+ years ago. I don't care how you look at it. More displacement with more induction volume equals more power. If you can feed the added displacement it will make more power. There's no way an engine that has a 45 cubic inch DISADVANTAGE can outperform another engine just because it's stroke is smaller. I would also like to know how a 302 with "high velocity ports" would make great low-end power, I sure hope you don't mean more than a 350 because that is not true...

Would you please inform us what exactly how fast is a high velocity port and how this is so special to power production...

Now back to the topic. I second the advice to STAY AWAY from a tunnel ram. This type of manifold is by far overkill to the rest of the induction system. The small valves and tiny port cross-sectional areas would limit the engine speed to the point of completely eliminating any benefit the tunnel ram would have and only exaggerating it's deficiencies (such as low-speed power in this case). A 305  just isn't meant to see the RPM's to use the large volume of a tunnel ram and dual carburetors.

I suggest to the original poster to do some research into this topic. Study some builds done by Car Craft or Hot Rod magazine and realize that everything we speak of here with performance engines is a highly interrelated system. Changing any one thing effects many others and everything MUST work together to achieve a balanced combination. Once you think of where the engine will work best make sure that the car applies the proper mechanical advantage to make the engine's power most useful. The best efficiency is achieved by making sure everything is in sync, so to speak...  
~Gibs

powerdreams powerdreams
User | Posts: 87 | Joined: 11/07
Posted: 11/06/07
07:46 AM

GibTG, you seriously should learn more about head flowing. Yeah,you can have big heads, valves etc BUT!!! this usually means BIG CAM! As I see it , it usually means real power and torque begins at or above 3000rpm and up. And yeah a 350 can be made to produce alot more power given the extra cubes. Dont underestimate the 302 and 327. I've seen many big doller 350's humiliated by these engines on many occaisions. OUR 305 man wants 300hp without giong radical.That means good torque off idle. In any book 305 ci should be more than sufficient to produce 300 flywheel horses.................................AND GibTG I dont know if you have any stockers laying about. If you do, put smaller heads and inlets on a 327 or 350.No cam change and youll pick up Significant low down torque off idle and the engine WILL WITHOUT ANY DOUBT rev harder.Yes gross Hp will be down.On the street the power range will be greater in a dynamic sense.i.e from idle to an extra 500 to 1000rpm up top(stiffer valve springs recommended or you may get valve bounce)which is more enjoyable to drive................................... I've seen and experienced this first hand and on more than one brand of engine chevs ,fords and chrysler.That is FACT!And port velocity is critical if you want a "STREET" dynamic engine. OR do we all want 400hp 420ftlbs that is so overdone these days . Wow! listen to my lumpy idle man! and my expensive box and diff,to live with the engine day in day out,Been there,done that!  

TheSilverBuick TheSilverBuick
Guru | Posts: 1225 | Joined: 02/06
Posted: 11/06/07
09:46 AM

GibTG might come off a bit rough but I'd put money on him being right, especially about air flow and cam variables.  
-
The Silver Buick- '77 Skylark coupe w/ a Fuel Injected Buick 455&TKO-600, '72 Centurion Conv't - 455w/TH400, '67 T-bird 4Dr (suicide) w/428&C6. '69 Firebird replaced!

http://www.bangshift.com/forum/index.php?topic=6189.0

1 |  2 |  3 |  Next   | Last