possible to make a 305 fast?
305 and 350 are same stroke (3.48")
1bdbrd is right, the small bore is only good for so much (great daily driver)
$ for $ you just won't get the results out of a 305
if you really had to you could use the 305's crank and rods and accessories to save some cash
get a 350 or 400 block (377 w/ stock bore and 3.48" stroke) and some pistons and good heads and cam of choice and be happy
-OR-
try to find some of world products '305 Torquer' heads (had em on my '86 305 TPI Z28) and a mild cam and a performer intake, small carb and good exhaust . . .make about 300 hp and have a great driver . . . .but not a great racer
it just doesn't seem worthwhile to try for 500+HP with the small bore motor
I'd rather have a 283 that'll rev to the moon if I was gonna go small bore motor
honestly, I'd just suck it up and build a fun driver and look for/build a bad motor in the meantime
FWIW the 305 H.O. was rated @ 190 in the f-body and monte SS
I forget what the LG4 was rated at, but it's lame (great mileage lol)
good luck
1bdbrd is right, the small bore is only good for so much (great daily driver)
$ for $ you just won't get the results out of a 305
if you really had to you could use the 305's crank and rods and accessories to save some cash
get a 350 or 400 block (377 w/ stock bore and 3.48" stroke) and some pistons and good heads and cam of choice and be happy
-OR-
try to find some of world products '305 Torquer' heads (had em on my '86 305 TPI Z28) and a mild cam and a performer intake, small carb and good exhaust . . .make about 300 hp and have a great driver . . . .but not a great racer
it just doesn't seem worthwhile to try for 500+HP with the small bore motor
I'd rather have a 283 that'll rev to the moon if I was gonna go small bore motor
honestly, I'd just suck it up and build a fun driver and look for/build a bad motor in the meantime
FWIW the 305 H.O. was rated @ 190 in the f-body and monte SS
I forget what the LG4 was rated at, but it's lame (great mileage lol)
good luck
Back in the early 90s I built a 305 just to see what we could get and to my surprize we made 382 hp and 346 torque. What was done was a 305 block and a 350 crank which if I remember right makes it a 315 cu.in. Pistons were 10.1 flat tops with reliefs (hyper.) and used a Comp 280 cam. 1.6 fulcrum rockers. Heads were brand new untouched except springs Corvette 58ccs., and the intake was a Edelbrock RPM with there 650 carb. This engine had a killer idle, and I sold it to a guy that put it in a 71 Nova and that thing screamed. Nobody believed us that it was a 305 or should I say 315. If I'd do over i'd just stick to the larger cu.in. to gain even more but it was fun to do.
I do not think a streetable 500-600hp NA 305 is going to be easy to build. My bench-racer calculator says more displacement every time I think about it. I imagine it is possible, I just don't see how. Without some form of forced induction, you just cannot get enough air/fuel through that chamber. You will save a TON of cash building up a 350, though the 500hp - 600hp you mentioned are still not going to be cheap. A 400hp 350 wouldn't be too expensive, but the money starts to grow exponentially past that point.
Launching!
Joined: Jan 2003
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From: Saginaw, MI
Im lookin to get like min 500-600 hp. = $$$$$$$
Someone's 305 was that fast I'm sure. You’re not going to get there. The above recipe is about 350rwhp or a lot of suspension/weight work. Bet you can’t get there either but I like the set-up and 250rwhp is twice what you have now.
The heads can’t support high horse power! You will need a base with larger cubes or better heads and rpm for the hp level you said. I think you need to modify your hp level/goal. Your whole drivetrain, suspension and frame would need to be modified to handle that kind if power. IT WOULD BE CHEAPER TO BUY A MODDED LS1 THEN BUILD YOURS!
Someone's 305 was that fast I'm sure. You’re not going to get there. The above recipe is about 350rwhp or a lot of suspension/weight work. Bet you can’t get there either but I like the set-up and 250rwhp is twice what you have now.
The heads can’t support high horse power! You will need a base with larger cubes or better heads and rpm for the hp level you said. I think you need to modify your hp level/goal. Your whole drivetrain, suspension and frame would need to be modified to handle that kind if power. IT WOULD BE CHEAPER TO BUY A MODDED LS1 THEN BUILD YOURS!
Originally Posted by alconk
Back in the early 90s I built a 305 just to see what we could get and to my surprize we made 382 hp and 346 torque. What was done was a 305 block and a 350 crank which if I remember right makes it a 315 cu.in.
305 and 350 are same crank, 3.48" stroke, the difference is the bore
the 334 is made the same as a 383, by using the 3.75" stroke 400 crank and a slight overbore
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I forget which mag did a 305 build that made near 400 and was very simple . They simply used Vortec heads with appropiate manifold , cam , rockers , and exhaust . All the parts could be switched to a 350 in the future . It was either Car Craft or Hot Rod . I want a 3rd gen but I'd go big atleast 400+ cubes , I really want a big block .
Still don't see a cheap or easy way to extract 500hp from a 305. Hell, it isn't all that cheap to get 500hp from a 350! For what he is asking for, he really needs to look at more displacement. The 305 is a great engine for what it was intended, but the cost of building it past 350-400hp is very prohibitive, and would most likely be unstreetable. He could buy a built 383 crate for a lot less money than he is looking at spending...
The Valves are a big limiter to what he wants to do, they are tiny! 1.94 intake just isn't going to flow enough (even with a perfect head) to support 500hp NA. IT is a shame to waste the shortblock he bought, I do understand that, but that is the price of hotrodding. Look at a lot of the small block crate motors available now. You don't see much in the 500hp range. THere are 425-450 hp ZZ4 combos out there that would move that F-bodya round sharply though.
The Valves are a big limiter to what he wants to do, they are tiny! 1.94 intake just isn't going to flow enough (even with a perfect head) to support 500hp NA. IT is a shame to waste the shortblock he bought, I do understand that, but that is the price of hotrodding. Look at a lot of the small block crate motors available now. You don't see much in the 500hp range. THere are 425-450 hp ZZ4 combos out there that would move that F-bodya round sharply though.
Last edited by 67rsss; Jul 25, 2007 at 10:13 AM.
Originally Posted by v8pwr
I forget which mag did a 305 build that made near 400 and was very simple . They simply used Vortec heads with appropiate manifold , cam , rockers , and exhaust . All the parts could be switched to a 350 in the future . It was either Car Craft or Hot Rod . I want a 3rd gen but I'd go big atleast 400+ cubes , I really want a big block .
If you take enough time and spend enough sure you can make a 305 make power, if that's what you want to do.
305's are not the ideal choice but if you really want 500-600 hp out of it stroke to make a 331 or 335 or whatever it is with the 4 inch stroke, make sure it's forged. Build it for spray. Get the best heads, you can and a good cam for spray. Spray it with say a 300 shot.
I think you can get 600 that way.
3rd Gen's just beg for an LS1 instead of a 305...
305's are not the ideal choice but if you really want 500-600 hp out of it stroke to make a 331 or 335 or whatever it is with the 4 inch stroke, make sure it's forged. Build it for spray. Get the best heads, you can and a good cam for spray. Spray it with say a 300 shot.
I think you can get 600 that way.
3rd Gen's just beg for an LS1 instead of a 305...
On The Tree
Joined: Jul 2005
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From: Old Bridge "Raceway Park" N.J.
Originally Posted by 94lt1m6
I am going to build this **** out of it, but is 305ci just to little to get lots of power, or not a problem.
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From: Joplin, Missouri
Hey since no one is posting in my other thread i'll rectify this one. I am taking your guys advice.
I can buy a 400sb for 250 or a 454bb for 300 what should i buy. personally i want the big block but i can be persuaded to a high reving small block
I can buy a 400sb for 250 or a 454bb for 300 what should i buy. personally i want the big block but i can be persuaded to a high reving small block
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I would go big block, they are cheap as small blocks and 500-600 hp can be done with mostly stock parts. I know the feeling of high reving sb, but there is nothing like tipping into the throttle of a BB and roasting the hides at a rolling 30 mph.
A 454, with the stock oval port heads, an intake, a carb, and 10.1 pistons, a lumpy cam, and a tourgue converter will yeild 400+rwhp. But your limitied to a 6500 redline.
Building a high reving SB will yeild the power you need, but above 7000, you will eat valve springs like toliet paper in a ladies room. Unless you buy revkits ($400 with no power added)
I have built plenty of nasty 305's and they ran like a raped ape, but 475hp is usally the most out of a 305, you have to remember 305 blocks are 2 bolt and the caps walk like a 3 legged dog.
Big Blocks can produce 600hp without breathing hard, a small block you have to wind it to the moon to get 600hp.
Just my opinion.
A 454, with the stock oval port heads, an intake, a carb, and 10.1 pistons, a lumpy cam, and a tourgue converter will yeild 400+rwhp. But your limitied to a 6500 redline.
Building a high reving SB will yeild the power you need, but above 7000, you will eat valve springs like toliet paper in a ladies room. Unless you buy revkits ($400 with no power added)
I have built plenty of nasty 305's and they ran like a raped ape, but 475hp is usally the most out of a 305, you have to remember 305 blocks are 2 bolt and the caps walk like a 3 legged dog.
Big Blocks can produce 600hp without breathing hard, a small block you have to wind it to the moon to get 600hp.
Just my opinion.
if you wanna spend some money on the 305 to make it go fast, it isnt worth it. Just go with a LSx engine, if thats too much for you(its good since its also light and compact) but if its too much, I woulndt go with a 305. I in fact have a 305 in my drontyard, painted orange. It has a cracked cylinder and can be resleeved. I would never use it in a car though... 305s all around arent good from what Ive seen. I dont know if its identical to a regula SBC, just teh block itself, but from what my understanding is... it isnt.
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I really think a big block is what i want. I found a kit to make an all forged 540CI for 2k. I can have all machining done for free. What does that sound like? I can have a forged 540 for 2,300 incluiding cost of engine, parts, and labor(by me). And then i was thinking about buying a 6speed from an lt1 car and throwin in a 12 bolt, or a 9 inch with 4.10s