Best way to make fast 305

I think its awesome that you decided to build a 305. Don't listen to these guys that just whine about cubic inches and how much a 350 is this and a 350 is that. Go with some trick flow 305 aluminum heads for starters. They have 170 cc runners which will give you extemely good low end response and Ive used many of dyno simulators and a 200 cc runner wont make much of a difference. They also have 56cc chambers so it'll boost your compression ration a bit. If your 305 is like the early models you'll have 58cc chabers from the factory so putting some 66 chambers will drop your power hard. You shouldn't need anything more than a 650 cfm carb for that thing. I'd go for a 575 or 650 speed demon from barry grant. Get some 1 5/8 primary tubes going into a long tube header with a 3 inch collector and 3 ich exhaust all the way back. None of that 2 1/2 inch baby exhaust. I would strongly suggest getting painted headers and heat wrapping them rather than getting the ceramic coating, anything close to your headers will melt quick even with the ceramic but not with heat wrap. I mean real heat wrap not jackets. Part number 893-12003K on jegs is what I mean. Get some catco high flow cats for cheap and maxflow mufflers. keep your cats unboltable so you only have to use them for emissions purposes so you can keep them a long time. Go on summit and get a hyperutetic  rotating assembly and reuse your stock crank if its good. A cast crank will take a lot. Get a weiand stealth air strike manifold its way better the the rpm from edelbrock. Talk to lunati about a good camshaft for your application so you don't end up with a cam that you don't like. Get some self aligning full roller rockers, you could upgrade to 1.6 ratio but check your clearances first.  Try some specs around .45 lift at 1.5  114 lobe center angle, 113 intake center line 235 intake duration 230 exhaust at .05 timing And with the 305s low compression you can crank the balls out of the timing. I'd go with the lowest spring kit available with 14 to 18 initial. As for ignition go with MSD all the way. The distributor doesn't matter as much as the box and coil so find that last. Pick up a 6a or 6al on craigslist and an HVC 2 blue coil. Thats about it and you should make around 350 hp and 350 tq qith a pretty flat curve.  

Yeah, don't listen to us. Myself and everyone else on here is just plain stupid for thinking that 305's are dogs. I know you're the one who should be giving all the advice...

Wait a second. A 200cc port on a 'street' 305? I take that back everyone should be ignoring you!

Using cams ground on a 114° lobe separation is just asking to lose power. You have to be worried A LOT about vacuum and or part-throttle to even consider a lobe separation that wide...

Also, you know there is no significant difference between a Edelbrock Performer RPM and that Weiand intake. Test after test after test over the past 5-6 years has proven that the Performer RPM is a GREAT manifold. I don't doubt that Weiand (Holley) can produce manifolds that will make similiar power but I can safely say there will be little to no gains to be had, so saying that they are "way better" is just false.  

I said a 170cc port not 200 you moron. And edelbrock manifolds don't operate under the true dual plane qualifications because the divider is like an inch below mounting face so you're not getting what you pay for unlike the weiand. Just because you like a company that makes junk carburetors doesn't mean you have to spread you're stupidity to others. There are plenty of cams with 114 and 115 lobe separation that have good idle and vacuum and create broad torque curves but relatively mild hp curves, but hes gonna need torque to get that pickup moving not a bunch of high rpm horsepower nonsense. The RPM, just like the Torker 2, is an overrated manifold. I'd suggest a Z-manifold but they're impossible to find. If you're going to buy a dual plane manifold you're going to want one thats actually a dual plane with separated runners.

Popular knowledge is usually the worst knowledge out there because its unfiltered with rumors and speculation and long held beliefs. The 305 is a great engine if you know what your doing and do your research. That engine is practically indestructible. I've run mine at 310 degrees with 5 psi oil pressure  with 8 degrees BTDC initial timing and 38 total advance at 2800 and she was running like normal with out even a hint of pinging. Hell I drove her with no oil pressure and I used to drive around all day running at 220 for 5 months. I drove it with 1 1/2 qts of oil in it for a few days. Ans it has 200,000 miles on it and the valves are almost completely encrusted with carbon. Its lost complete compression on 1 maybe 2 cylinders. The 305 is bar-none the most reliable engine I've ever seen.  People don't like 305s because they don't know anything about the 305 but its just like any of the other off beat engines made by the big 3 but its a little smaller.  

yo electric wize i feel you and i got your back.  and don't worry about t that as-shole gibtg it took me a week to stop arguing with him about various things,.  don't let yourself fall into the same trap.  he is some little biatch rich kid who just believes that he is the only one right. i love the 305 and i will see if i can bring the other one up i think it was about anti-ballooning converters at first and he turned the whole thing into a whining fest.  im not denying any involvement i got caught in it too. just don't let your self.  

electricwizard:
I said a 170cc port not 200 you moron. And edelbrock manifolds don't operate under the true dual plane qualifications because the divider is like an inch below mounting face so you're not getting what you pay for unlike the weiand. Just because you like a company that makes junk carburetors doesn't mean you have to spread you're stupidity to others. There are plenty of cams with 114 and 115 lobe separation that have good idle and vacuum and create broad torque curves but relatively mild hp curves, but hes gonna need torque to get that pickup moving not a bunch of high rpm horsepower nonsense. The RPM, just like the Torker 2, is an overrated manifold. I'd suggest a Z-manifold but they're impossible to find. If you're going to buy a dual plane manifold you're going to want one thats actually a dual plane with separated runners.

Popular knowledge is usually the worst knowledge out there because its unfiltered with rumors and speculation and long held beliefs. The 305 is a great engine if you know what your doing and do your research. That engine is practically indestructible. I've run mine at 310 degrees with 5 psi oil pressure  with 8 degrees BTDC initial timing and 38 total advance at 2800 and she was running like normal with out even a hint of pinging. Hell I drove her with no oil pressure and I used to drive around all day running at 220 for 5 months. I drove it with 1 1/2 qts of oil in it for a few days. Ans it has 200,000 miles on it and the valves are almost completely encrusted with carbon. Its lost complete compression on 1 maybe 2 cylinders. The 305 is bar-none the most reliable engine I've ever seen.  People don't like 305s because they don't know anything about the 305 but its just like any of the other off beat engines made by the big 3 but its a little smaller.

I had no idea I was talking to someone that didn't know how to read. You said,"I've run plenty of online dynos and a 200cc port shouldn't make much difference."

Popular knowledge is unfiltered? Listen to the BS stories you're feeding me, that's unfiltered! 310° coolant temp? No oil pressure? I don't know why you're wasting your breath, nobody is going to believe you.

By the way, GM produced engines in the muscle car era with FORGED rotating components and you're going to tell me a 305 is indestructible? You're just some backyard joe who thinks so much of himself that you can't accept higher quality research.

Go back to testing your true dual plane intakes with 115° LDA cams on your butt dyno or cheap software dyno so you can get some results that only pertain to you...  

I'll go make a sound byte of my coolant boiling if you feel like it. Yeah it would blow apart if you put 250 shot of NOS through the stock rotating assembly  but you can't do much to a 305 that would break it under normal circumstances you're taking things out of context. I meant that a 200 cc runner will give no big gains on a 305 over a 170 cc runner on an overall basis and  if you have a streetable cam.  I bought the car with 1 1/2  qts of oil in it and drove it for a few days. When my 300 degrees temp gauge was pegged the oil pressure was falling like a bronco down a mineshaft. When I got home I could hear my intake manifold boiling. Then I drove around for a few weeks with the same oil in it and then got 1 qt of water in it and drove on that for a day and it still runs perfectly fine. The clearances on that engine are so sloppy its ridiculous.  When I changed my intake there was a chunk of carbon about the size of 2 golf balls just resting against the pushrods. I've never had a mechanical issue other than the freeze plugs rotting out on me.  

You can't get much more hypocritical! And I'm afraid you don't even realize it...

"Normal circumstances, unless you're taking things "Out of context," Oh so now performance enthusiasts are building performance engines that are meant to survive at jacket temps of 310°! No engine should ever be subjected to that kind of heat, you're a fool to do so and the engine SHOULDN'T stay together at those kinds of temps.

It just amazes me that there are so many people that come out of the woodwork to defend how great of a performance engine the 305 was. I swear it's just because so many people think they're junk and so many ignorant rednecks want to prove all these rich kids wrong...  

Below is an excerpt from Power Secrets by Smokey Yunick and if you don't know who he is and what hes done then you shouldn't be giving advice on this website. I would really suggest everyone read this book, you can get it ordered from Autozone for about $20.

Under normal circumstances of 200 degrees temp readings from the stock location it can be upwards of 350 degrees in certain areas of the cylinder head. And you called me a fool for making my engine get to 300 degrees? What do you think I just woke up and decided to clog my radiator and try and destroy my engine? I also never said that the 305 was a great performance engine I said it was a reliable engine that you could build for mild power. I'm not the guy saying he should get a 7000 rpm 900 hp rated rotating assembly and put twin turbos on it I answered his question just like he would have wanted to have it answered. He wanted to know what he could do to make his 305 make around 300 hp, thats not a ridiculous race car hp number its just power to have fun with. And a lot of you are telling him to just buy a crate engine rather then go through a great learning experience and get the sense of pride in workmanship that comes with assembling your own engine. He didn't ask whats the easiest way to make 300 hp he asked whats the best way to make a fast 305 and most of you blatantly ignored him because you think your few years of experience means you get to dictate what people should spend their money on rather than helping them do something creative and original that they wanted to do in the first place. What kind of advice is telling someone to buy a crate engine rather than build one?

The 305 is not a powerhouse engine, it doesn't blow the doors off of supercars but does it have the potential to..... yes. Everything has the potential to be something great, it just depends on how much work you are willing to spend making it all it can be. But the 305 could with very little work make 300 hp or close to it and thats all he was asking, not if a 305 is a good race car engine but what you can do to make it slightly better.



 

i tried to warn you about arguing with this guy.  he will just keep on going with you.  he is a di ck.  he is probably some little teenager who has no idea how do do anything in life but argue.   he needs to be run off the sight.  

At the very least I do know how to use the English language (like spelling, grammar, and punctuation for example).

But I can't say the same about you...  

You surely are not going to sway me with quotes from Smokey Yunick...

I appreciate what Smokey did for his sport. His dedication was tremendous but that doesn't mean that all of his research should be taken for fact! Need I bring up the "flow-cone" theory. How about using the longest connecting rod possible?

Now, since that's covered, back to you looking like a fool...

So, since your gauge read 310° 'globally' then your engine had "hot-spots" of approximately 410-460° F according to Smokey's thinking. I don't think your near-stock 305 would qualify as having a highly-efficient cooling system so why shouldn't this be correct if Smokey is a God? I can say one thing, that 400°+  had to be great conditions for oil film strength, ring expansion, and induction temperatures <sarcasm>.

Your last comment is at the center of the entire debate. A 350 has MORE potential than a 305, it's just that simple.

I don't recall recommending a crate engine myself but since you brought it up I will say that I favor it heavily...

I don't know how many performance 305's you've built (if it's more than 0, then it's more than me!) but building any performance engine is not for the faint of heart! It's incredibly time-consuming, complex, and expensive. Budgets get blown out of proportion in many cases and 'parts' just don't fit together as they always should. Then, you go through all the trouble of assembling YOUR engine and one mishap can make it all go away (most crate engines will even have warranties!). How about one poorly adjusted valve on a flat tappet engine during break-in, the chances of that lobe going flat increase tremendously. Using a roller? Still, this is a highly complex and interrelated system of parts, it's not bolting parts onto your 305 in the backyard.  

The 305 is a good economical motor and will run forever but its not meant for performance I ended up getting a 400 small block to replace it.  Which between the two theres no comparison between them.  

Finally something we agree on! Making the bore 3/8" larger and adding 95 cubic inches sure does help!  

I currently run in a 305 spec class and yes 300 horse out of a 305 is not hard to do. Stock heads 601 castings will come in around 53 to 55 cc. 450 castings are 58 cc. With the 601 you would be looking at about a 10-1 compression ratio the 450 a 9-1/2-1 ratio. Going 60 over with a set of KB pistons a 3.480 stroke crank .041 head gasket will put you about 315 cubic inch put a Air gap rpm intake on it with a 600 HOLLEY A decent ignition of your choice ie (MSD,Pertronics,Accel,) Good set of Headers, 450 to 480 lift hydralic cam and you should be there. We put 60 to 80 race nights on our motors with out much problem. Most of our stuff is bottom of the line race componets such as scat i beams about 200 a set scat 9000 cast cranks 190 apiece, KB pistons 300 for the forged so if a 305 is what ya want to build BUILD IT yes a 350 is a better performance engine But a 305 is reliable and will take a lot of abuse. One thing I will say Running a 305 class my racing budget goes a hell of a lot further that it use to with a lot less stress. Hence the fun factor has went up in my racing tremendously.  

the meanest 305 that I have ever seen in my life was just a 305 with stock 350 heads and a 350 two barrel holley carb on top of a high rise 350 intake manifold. You have to adjust the manifold bolts to the right angle but that can be done with a die grinder. It would also be wise to add a 112 degree cam. All of these parts can be bought at any kind of auto parts store and if you are on a budget you will find that big headers and high flow exhaust will make her have a little more unmph  while making it sound good. If you are looking to spend a bit then you could just buy the parts that they tell you too.  Or you can jump a limb and listen to an old head at the local coffee shop down town and he will know what you want. The guys here are just a bunch of young bucks all wanting to be the hero. So just talk to a local old man at the auto parts store and he will do you right. Unless this world has all gone and died since the fifties. as far as the rebuild goes just keep her clean and make sure the hone on the block is good and you will do just fine.