I'm new here just joined, I'm looking to get about 300hp out of my 305tbi, I know most will say go with a 350 and I agree I have a 350 with a 4 bolt main that I want to stroke to a 383 and throw in my Camaro but I want it to be a monster and don't have the money for a full build yet.(hopefully tax time will change that) I'm just about ready to paint my car and I want some power to add to the looks. So I figure a mild build on the 305 will have to do for now. I have all ready rebuilt my 700r4 added a shift kit and boost valves for the vette. But I'm pretty new to the Chevy seen I've had my Camaro since I was 18 and just drove it and enjoyed as a slow cruser. I'm more of a tuner guy any ways I could tell you anything about nissans, so hate away lol. Getting to the point I'm only looking to spend around 500$ to gain the power I'm looking for, I have a full exhaust straight pipe with stainless long tube headers. I'm going to delete the a/c no need really in a vert. I herd an lt1 cam is cheap and good for the power I'm looking for and I can get an eddlebrock tbi intake for around 200$ witch will also work for when I'm ready for my 350 but the problem I'm having is finding heads for a good price for the power I'm looking for. What are your seggestions? Can I just get some bigger valves for the 305 heads? And advance the timing? I have a set of cast iron sbc 400 heads from a 70's motor can anything be done with those? Or are there any cars that came stock with 350 aluminum heads that I could find in a junk yard or cheap used on line. Any other advice for other things I can add to get the power I'm looking for? My tbi 305 has about 100k stock miles on it burns a little oil, any thing I should replace on that to make sure it will be good with more power. Thanks for any advice.

 

sofa!!....help! I don't have the patience to explain it....again.
Can you copy and paste your comprehensive explanation that you've posted countless times?
Seriously

 

Sorry I'm sure I'm asking something that's been asked many times before but I've done hours of searching and cannot find anything that answers my question. Other than buy a set of heads for 800$. Witch to me kinda sounds insane to make 300hp with a 5.0 liter v8. My i4 2.0 liter makes well over 300hp with just bolt ons and a flashed ecu.

 

Put some 22's on that SLAB!

 

The simple answer is you are not going to get 300 HP out of a 305 for $500.00.

You can't compare the way a more modern car can get much higher HP gains for less money to what it takes to get higher horsepower out of a smog era Chevy V8. Today's fuel systems and electronic controls are light years ahead of what was available in the '80s and '90s.

 

We're talking 5 years apart my Camaro is an 89 and my 240 is a 95 to be techinacal my Jdm engine is a 94. Now I do have a lot of money invested in that, but I've built cars around the same years and 3rd gen goes in to early 90's that I have gotten 280hp n/a all motor off eBay and junk yard parts with 4 bangers using basicly the same technology. So I am comparing apples and oranges here but not in your sense, in the sense that I have had have the engine to work with.

 

Lol your 240 makes 300 N/A? Got any dyno numbers?

 

300hp to the imagination maybe

 

My 240 is f/I 327whp at 20 psi and i have not tuned it yet, I was referring to a motor me and my friend built b18c1 it was over 300 to the fly and I forgot it had adjustible cam gears but if you compair the too it's still the same cuz you can't adjust timing with the distributer like u can on an sbc. And if you want to talk **** and your close to the buffalo area come race me in the spring time I'm sure my 240 weights less than your muscle tank so better hope your over 800hp hahahaha and a standalone is bolt on just so u kno. All I'm looking for is where can I get cheap aluminum heads that will work for this I'm sure if I advanced the timing with ported heads ill be around where I want to be.

 

Lol "800hp" to beat a 327 whp Nissan 240, lmfao yeah right

 

Yeah it's called power to weight ratio and Ill be way over that after my tune. You don't know much about racing do you, let's do some simple math a car that weights about 4000lbs and has 800hp and a car that weights 2000lbs and has 400hp well be a close race.

 

You need to work on your attitude a little bit. You're coming into a group and a scene you know nothing about, asking for advice, and then insulting everyone for not explaining things to you that are honestly pretty involved and complicated to actually explain.

The short answer is, as mentioned, $500 will get you maybe 15hp. These are cars designed and built as the american performance car industry was crawling its way out of the dark ages. By the time we figured out how to REALLY make power (and make no mistake, these cars were the start of it. They went from late 70's 200hp big blocks to 250hp smallblocks in a matter of 10 years, then by the mid 90s they were at 350hp, and you know where they are now...) these cars were already out of their warranty periods.

You've got two things working against you for big hp. NA a smallblock chevy of any sort will always have more potential than a smaller displacement engine. The problem is that even though you have an 89, these cars were designed in 1980, they were sold with engines that have roots in the 1950's. They only go fast when you put parts on them that were designed and refined in the past 20 years.

These cars are very well balanced. Every single thing in the power train is a bottleneck above the stock power level. That means everything from intake to heads to camshaft to exhaust manifolds and catback to transmission to rear axle will need to be addressed to put down serious power. It's a long road. $500 isn't going to do it. It hurts when you have to buy TWO cylinder heads instead of one, and the cylinder heads themselves have a lot more crap going on than a simpler OHC setup does. Lots of things have to go around and through each other to work.

The other problem is the 305 is a terrible platform to start. Anything that works well on a 305 will NOT work well on a 350 or 383 because of compression ratio issues.

HOWEVER... $500 MIGHT get you an LT1. Which will bolt in place. A nice roller cam and some new valvesprings can get an LT1 to 400hp for less than $1k if you're smart with your money.

See, the LT1 is almost entirely identical to the smallblock chevy you have, but it was designed much more recently, with modern insights into fluid dynamics and efficiencies. It's ultra high compression, so throwing a big cam in it will actually work well. The intake flows at high RPM too so you can actually spin it up and take advantage of all that compression and big cam. The cylinder heads are even decent. And you can do it cheap.

Those 400 heads you have are junk. Anything smallblock chevy before 1988 is garbage for the most part. They flow like crap. You can buy some 58cc chamber Trickflow heads for your 305, but they wont work too hot on your 383, so you'll be wasting your money. And the heads on that 305 are HORRIBLE. They are fuel economy heads and they were used in trucks to get a lot of idle torque. They suit the TBI system. The TBI system itself can barely support 300-350hp.

The smallblock chevy doesn't truly begin to shine until you dump $5k into them. The sky is the limit almost when it comes to horsepower, but there's a reason everyone who can afford it is jumping to an LS1 setup.

Which is another option. the 4.8, 5.3 and 6.0 iron block truck engines can be had fairly cheaply, ESPECIALLY the 4.8 and 5.3, and they can support ~1000hp in stock form with boost. So if you can build turbo manifolds, go with a $500 truck Vortec 5.3, boost the hell out of it and run it. But you will need new engine mounts and a new transmission to fit. You run into the same cost wall.

I would, however, suggest that if you truly intend to build a 383, dont waste your time with factory heads. You get something, even something on the cheap side of awesome, like Profilers, can be had for $1000 or so and make big power with it.

The main advantage of being a hot rodder with these cars isnt that they were good from the factory or that they are cheap to make fast (they are not). It's that they are blank slates you can do nearly anything to. You can make an autocross car, a drag race car, or even a drift car, or a road race car ,etc, with these. They can do everything surprisingly well. And you can do it with a big block or a smallblock or an LS-whatever, and you can do it with a modern six speed manual or you can do it with a 2 speed powerglide. These cars tread that line between old and new and you can make power old school or new school, but its going to cost you money either way.

And trust me, I like 240's a lot. Unfortunately it seems they are the 3rd gen camaros of the import world. Cheap, cobbled up, trashed, and then bought by people who cant afford to maintain them. They do have a weight advantage, but my car is only 3250 lbs. Heavy compared to a fox body and a 240 and a Miata, but compared to anything modern that's pretty light. Add in any F-body with an LS whatever and you can cut another 100 lbs off that. There are many of us down to 3000 lbs . I dont know where you get 4000 lbs from. I know some of the Pontiacs with all the creature comforts creep up past the 3500 mark, but these are the lightest generation of F-body around.

1. $500 isnt enough.
2. No cheap aluminum heads besides the Corvette 87+ heads. 113 castings. They aren't particularly special in any way other than just being aluminum, however. 128 castings are worse. Dont waste your time. These aren't particularly cheap even.
3. The hp per dollar curve is not linear. You only get all the gains after ALL the bottlenecks are removed.

 

Then he says 20 psi, haha if my "muscle tank" was on 20 psi I would have about 800 hp lol. That's like a 130hp motor with 170hp of boost.

 

To the O/P-Unfortunately for you,you might have to race me at Lancaster.Certainly for more yrs than this thread can handle,I've been in it to win it.

 

I don't mean any disrespect bro but some people here think 300hp out of a 4 banger is crazy or something ive taken down many corvettes and mustang owners who laughed at me when I pulled up to the light and turned down a street after I dusted them most likely in disbelief there are people out there making 1200hp with 4 cylinders I should have not set a price limit just cheap power for the time being till I have enough money for a full build


Thats with a small stock turbo and no tune your car could be on 50psi and not have 100hp more if the turbo was the size of your fist.

 

It was a joke man, I'm not running up to summit with a parts list so I can boost 20 pounds. I'm saying 20psi is a lot, out cars on 20 psi (correct proportioned turbos and all) will most likely make more than 300 hp

 

My car weighs 2980

 

That's what I'm saying! 300 hp on 20lbs of boost?!?! Nothing impressive whatsoever. Put 20lbs of boost on a 3000lb f-body and you won't be able to keep up...

 

Stock '95 240SX weighs around 2700 lb. Stock thirdgens weigh around 3500 lb for a loaded Z or T/A. "Simple math" sure is fun when you're pulling numbers out of your bumhole.

Anyway, on the original topic: If you're saving to build a "monster engine" for your thirdgen, save that five hundred bucks to put towards your build rather than burning it on the boat-anchor 305. Five hundred bucks is almost halfway to a pair of AFR 195 heads, which would go very nicely on a moderate 383 build... or you could throw that money away on a couple bolt-ons for your 305 that might get you another fifteen horsepower (Pro tip: the airflow restriction in these engines isn't going to be solved by slapping a shiny TBI unit on it; the heads and cam are the culprit).

If you're hell-bent on spending that money now, use it on parts that won't be tossed out with the engine... subframe connectors and a steering brace are a night-and-day difference in handling, and SFCs in particular are essential to prevent chassis twist if you're getting traction with a big engine.

 

bottle feed it!

 

When did the 300hp go to 400hp lol

 

You can make 300 horsepower out of a 4 banger all day long. EASILY in this day and age. I mean, it's a freaking walk in the park! Now, take that grocery getter out and run into an 800 horsepower small block powered anything. 800 horsepower is certainly not impossible, numerous people achieve this and some even daily or at least street drive these cars. However, the people I have personally met with 300 hp 4 cylinders, and there hasn't been a lot of them, are almost exclusively the kinds of people who buy a turbo, slap it on, and boost to all hell. Guys I have personally met with 800+ horsepower small block or LS powered cars, have been more technically geared, more precise, cleaner, and more complete with their builds, addressing all aspects. Now, when your 300 horsepower noise maker happens upon one of these power leviathans on the street, there is one, indisputable, carved in stone fact. YOU. WILL. NOT. WIN. It is an 800 horsepower car. They did not build it for ***** and giggles. From a dig, it will go up to stall, it WILL launch, and it will RIP like nothing that 4 cylinder could ever hope to achieve. Now if you want everything based purely on stats, if you have a 3:8 ratio on horsepower, it's going to be something like 1:4 on torque. Sorry guys, I get trolled so easily by these simians, 4 cylinder worship drives me up a wall.

 

You eaither cannot read or do not understand why they are called tuners you have to tune them. I'm running stock fuel maps, no timing changes, no restrictions removed besides speed, and rev limiter. My school has a dyno and I wanted to see where I was at for fun. I did not buy an eBay turbo kit and throw it on my car cuz I wanted to boost the hell out of it and here the blow off valve. My engine is stock f/I. I have thousands of dollars on top knotch parts all HKS, Greddy, tomei, Apexi, and some Jim wolf stuff with a kazza 1.5 way. This **** ain't cheap that's why I have not bought a new turbo yet but that's next with some serious tuning time. My hp and tq is just about matched and I've seen dyno sheets of people running pretty much the Same set up with a gt30r putting down 500whp and 450tq at 15psi.
I've also had my car weight with all the reduction Ive done and I'm under 1 ton. I don't worship 4 cilenders I made my choice on how much power I knew I could make with the amount of money I wanted to spend if I wanted to spend twice what I have in the car I'd have a i6 Rb26dett with an N1 block. Look up the price of parts for Jdm 4 cilenders then look up the cost for usdm v8 the Jdm parts are usually 3x the cost. I also don't drag my car all like that I drift it so I'm not gunna get a huge *** turbo and have 2,500rpms of lag just to get that 500hp, I need quick spool times for techinical tracks. My car is function over form all day built to take turns at high speeds not to go in a straight line. I love you v8 worshipers...love to take y'all down its not hard to get crazy power in a v8 with the right money **** you can have 500hp with an ls1 just with Bolt ons eBay parts and with no tuning. It takes technically minded turners real skill to get big numbers out of small displacement engines. What fun is it to say hey I beat a 4 clynder with my supercharged v8 none at all you got twice the engine. It's more fun to say hey I took down a boosted v8 with my 4 banger, that's besides the point I'm not one minded that's why I own a 3rd gen Camaro and a Nissan 240sx cuz I can respect both ends of the spectrum. Sounds to me like you have seen many tail lights of people running 4 bangers and your just mad about it. Lmfao

 

I have to pull the engine any way to get a nice paint job, that's why I was wondering if I could find better flowing heads in a junk yard and I can get an lt1 cam for like 50$. If I can only get another 20hp out of it this route than your right I'd reather not waste the money. I was going to sitch weld the hole car and make some fender braces. I was also wondering if there are any coil overs for the 3rd gens all I can find is springs and struts. I'd also like to get a posi for it and upgrade to rear disk. All I want out of the 383 build is 1hp per cube with matching tq and have decent fuel Econ like 14-15 mpg. The engine build is my plan for next winter. I'd just wanted to finish the body work, interior and add some power for summer so I have something nice to cruser around in and get some rays lol.

 

You can get coil overs, a couple of my ig friends have um, I gotta find out the brand though.

 

That with a 383 is very doable, my father in law has a 383 in his 84z28 and his is at about 450hp. I think he's running 11.5:1 compression or so.

 

Yeah that's what I here, my teacher told me when I rebuilt my 700r4 I'm good too about 400-500hp so I don't want to get crazy with it. I basically just want it to be my show car/drag now and again. Ive also had it since i was 18 and were both 89's so is like to do it once do it right and have it the rest of my life. And what's everyone's oppionion for a mild 383 build 4bolt main or splined 2 bolt? I have the 4 but idk even kno if its gunna be good when I bore and hone it cuz as of right not the pistons are rusted in to the block.

 

I'll tell you some of what I know about his 383, it's an 80's block, machined for roller cam, Doug Herbert 510 lift(not sure on the rest of the specs), wiseco pistons, 750 Holley..that's all I know off the top of my head, I'll have to ask more about the rotating assembly..I know he has aluminum heads..

 

if it's not a roller block throw it in the garbage. A new core longblock can be had for $200-$500. Machinework costs more than that, and a roller cam will net you a lot more power and streetability. As I said before, these are primitive engines, it takes good parts to get good power out of them and a roller camshaft is a huge help.

I would suggest instead of doing a 383... do an LS swap. Those are not primitive engines. They may have pushrods but their power levels speak for themselves and they're good to 1000 hp with stock rotating assembly parts. Hard to fight that. $5k will do the swap, especially if you go automatic. Or spend a little more for an aluminum block and you can get it below 3000 lbs... althoguh you said yours is a vert... not really the best platform to start out with for power, but there are many here who have done a great job with them.

 

I can get an ls1 for around 1.5k, does the 700r4 bolt right up or is there a bell housing for it? And if I went that route I'd really like to wait and find a crashed ss 4th gen or fire bird so the swap is straight foward you kno. Unless someone makes a wiring kit for the 3rd gen chassis to ls1 motor? Cuz the way I look at it a 383 with decent parts is gunna be at least 3.5k and I'm only looking at 400hp I can get that with Bolt ons with an ls motor. For half the price now that u mention it. But wiring everything by hand is a real painstaking process that would take quite awhile I did that on my 240 and its just a pain in the *** don't really want to do it on a car that's just gunna be my weekend cruser lol.

 

It's your call. You can always run an MSD box and a carburetor. It's a little pricy, but if you just want to toss it together and roll that will work.

700r4 will not work. They 4l60e they use is the same internally as a 700r4 but the bellhousing is different and they need a computer to control the shifting. If you get a T56 you need an LS T56, again, special bellhousing, different than an SBC. The LS T56's tend to cost quite ab it of money and are hard to find NOT attached to an engine. The 4l60e's are damn near everywhere and are cheap. Just have to stay fuel injection so the stock computer can control it.

The swap is actually pretty straight forward in these cars. If you get a T56 from an F-body it will need a new crossmember that relocates the mount two inches back, and everything else can be re-used. Same torque arm, same driveshaft, etc. You'll need to figure out the speedometer, though. The LS will need new conversion engine mounts, but that's stuff that's available relatively cheaply. The main problem is exhaust, because there's no bolt on solution for that. You'll have to get an exhaust setup fabricated (can you do it?). The most common, best headers for an LS available for thirdgens costs $700 or so. Not cheap. Otherwise you can use factory manifolds and run a y-pipe to the stock exhaust routing. The factory manifolds on those are a lot closer to shorty headers than they are manifolds, so you're not losing as much as you might think.

It's extra expense and complication, but the fourth gens are nearly identical to these car from the firewall back, so a LOT of that stuff interchanges fairly painlessly. There's several threads in the LS swap board about it, you may want to read up on them.

A hot 383 with a lot of really smart building and parts investment in all the right places will do 400-450hp. A hot LSanything will do 500+ and get twice the gas mileage and poop out singing unicorns at the same time. They are amazing. You wont regret doing it, it's just a matter of whether it's feasible for you. If you get a 6.0 truck engine (370 cubic inches) with some decent heads and moderate cam and you'll be in some pretty stout territory, and it could be daily driven.