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Discussion Starter #1
i recently bought awhat i was lead to believe was a 5.7 350 , i tore it down and its a 305. i am going to put it in a camaro 1982.
i really was shooting for about 400 hp. any ideas on getting that out of this 305? should i stick with 300hp can it be done? Im not sure i really wanted a 350, but not sure if i should stick with this motor. anu sugestions?
 

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You may be able to get 300 without breaking the bank but the other 100 HP will cost a lot of money. The 82 Camaros were carburated so a good set of heads Dart or World, dual plane intake with a 600 cfm carb, headers, mild cam would get you to 300 mark. The stock heads had small valves so didn't breathe very well. A lot of air must enter the intake and get exhausted thru the valves and exhaust manifolds. That's the reasoning for the after market heads.
 

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305 is not a good choice for a performance motor. You're many many many dollars ahead to get a 350. Why stop there? Do a 383 or a 400 if you're looking for a hot street motor. Cubes make all the difference, and 350's are good motors, but will never make as much power as a similarly built stroker. And for about the same money!

K
 

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My point remains.

THe first article is an almost 11:1 motor running a GIANT cam, and would be aweful to drive on the street.

Second article would have at least 50 more ponies if it was a 350.

I like this quote from the fourth article:

"Why not use a smaller cam? Lunati says it's hard to move air through a small-bore motor with a restricted valve area like the 305. You need a bigger cam to make this small cylinder work, but there are limits due to the small displacement. Fortunately, the relatively long stroke for this displacement engine helps low-end torque, so the engine isn't all that cam sensitive."

Here's another good one from the fourth article:

"Racing gas with a 108-octane level was used for all tests. This gas is not generally available for street cars. Assuming the use of 92- or 93-octane unleaded, you could get by with a true 9:1 to 9.5:1 compression ratio street motor when using cast-iron heads." SOunds great to me. :rolleyes:

I also like how the third article motor that's only putting out 290 horse has A THOUSAND DOLLAR SET of AFR heads on it. AND ALSO PUSHES A REDICULOUS 10:1 TO GET THAT NUMBER?!!

Pathetic. Build a 350.

K

:smash:
 

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Remember the original question.........

i really was shooting for about 400 hp. any ideas on getting that out of this 305?
Article number 1 shows what is needed to get 400 HP from a 305.

THe first article is an almost 11:1 motor running a GIANT cam, and would be awful to drive on the street.
10.6-1 to be exact.....How much compression are you running?

GIANT cam? One grind bigger than the one you run........

Aweful to drive on the street?
"Everyone involved was surprised at the amount of power and the degree of driveability the package displayed."

"This may seem like a bit too much cam for a small engine, and a Victor,Jr. intake manifold also seems out of line, but the engine is really responsive to the combination."




Second article would have at least 50 more ponies if it was a 350.
I would hope so, its a bigger motor.......


I like this quote from the fourth article:
"Why not use a smaller cam? Lunati says it's hard to move air through a small-bore motor with a restricted valve area like the 305. You need a bigger cam to make this small cylinder work, but there are limits due to the small displacement. Fortunately, the relatively long stroke for this displacement engine helps low-end torque, so the engine isn't all that cam sensitive."
This is probably why the first article use a big cam as well. It also says "The engine isn't all that cam sensitive"

"Racing gas with a 108-octane level was used for all tests. This gas is not generally available for street cars. Assuming the use of 92- or 93-octane unleaded, you could get by with a true 9:1 to 9.5:1 compression ratio street motor when using cast-iron heads." SOunds great to me.
You missed this part of the quote.

"The generally accepted rule of thumb is that you lose 12 to 15 hp for each point drop in compression-- so an otherwise identical 9 1/4:1 engine would be down about 15 hp from the results reported here."

A change from the " Lunati used "generic" 305 iron cylinder heads" to a set of 350 heads like the first article used would cover the 15HP loss with ease.

I also like how the third article motor that's only putting out 290 horse has A THOUSAND DOLLAR SET of AFR heads on it. AND ALSO PUSHES A REDICULOUS 10:1 TO GET THAT NUMBER?!!
"RHS was determined to develop a strong-running engine that's also capable of meeting late-model 50-state emissions standards while running successfully in a computer-carburetor application without any software changes, using commonly available 92-octane unleaded gas. This required using only parts classed as a "stock replacement part," or those that carry a specific California Air Ressources Board (CARB) Exemption Order (EO). An individual car builder can install or stack any number of seperate EO components on the same motor and still be smog-legal, provided the vehicle passes the sniffer test."

"RHS used the stock GM HEI distributor with advance, retard, and fuel-curve all controlled by the stock GM computer."

"With the engine installed on the dyno, the fuel curve, total timing, and timing retard under detonation were left pre-programmed with the stock GM computer chip."

WOW, This is a 50 state, smog legal motor that uses a stock GM computer, distributor, and electric carb. And it still made 290 HP. One could only imagine what it would do with an aftermarket chip that optimized the fuel and spark for performance.

The 82' Camaro that camaronewbe has, CAME with a computer controlled Q-Jet.

i am going to put it in a camaro 1982.
should i stick with 300hp can it be done?
Can he reach his power goals with a 305? Yes

Can he reach his goals and still be smog legal? Yes

Will a 350 make more power than a 305? I don't think anybody has ever questioned this. The 350 is bigger than a 305. A bigger motor will always make more power........

Most of these articles are quite old now. More power can be made with todays current cams, intakes, and heads. With the use of soft head technology, and a little port bias, a small bore motor can be made to run quite well..........Dan
 

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My point is bigger bore motors respond better to bolt-on upgrades than do smaller bore motors. Yes its nice that these guys were able to get some decent power out of the little 305, but to be honest, many of those motors have some BIG dollar parts on them, especially the one with the AFR heads thats only making 290 horse for the amount of dollar sunk into the heads.

I don't think you can compare my motor with those in the article. Yes it has a 280 comps (which is NOT one grind smaller than the 292, there are about 3 grinds in between) and considered the 292, but even in my motor which is 83 freaking cubes bigger than a 305, I thought it to be overboard. The high end of that cam stops at like 6500RPM on a 350, more like 6800 on a 305. Start pushing those R's and you need a forged bottom end to handle the stress. We gonna put a forged bottom in this 305 too? Tell you what man, my motor swallowed that 280 like a champ. Really streetable combo, but comparing a big bore stroker smallblock with big cubes to a 305 is like comparing apples to oranges.

Sure, you can make 400 horse with a 305. I've never seen one, and there are reasons for that, but to each his own. The general rules of hotrodding still apply though. You've fewer dollars in and more potential ahead to try to get 400 horse out of a bigger motor. Can you build a 305 to 400? I guess. Does it make sense? No. And any hotrodder worth his salt will tell you that-

I am taking the original question into account. The dude wants 400horse. I'm just saying yeah it can be done with a 305, but it can be done cheaper and with more room for expansion with a bigger cube motor.

K
 

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There was guy at the monteSS site that put Vortec's on a 305 w/ a mild cam and ran retty stout(mid 14s)for a 305.If I remember though it was gutless for torque though as 64cc heads will put you at like 7.8:1or less.
IMO I would just stick a whitebox cam,lifters and springs in w/ a new oil pump and T-chain.Maybe bowl port the heads yourself and have a valvejob done.Bolt an intake and headers on and beat it like a redheaded step child till it dies.
 

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yeah, they're ok and respond to some bolt ons but not really worth the time. I speak from experience on this one and have done everything that can be done to a 305. That said, actually I was kinda impressed with how well it pulled from 2500-5500 RPM (summit cam, bigger valve late model heads etc etc). There's nothing like cubes to give you the snappy response that you want. Cubes MAKE a musclecar feel like a musclecar-

K
 

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Originally posted by killerformula Cubes MAKE a musclecar feel like a musclecar- K
I dunno killer,you may be generaly right,but I'm sure theres a vast number of 69 302 Z28's out there that could make you eat your boot.:D
 

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::chewing presently:: That motor was a big bore high rever though, the poor 305 is stuck with that lousy long stroke that keeps it from winding out, and those small bores that keep it from breathing deep...

k
 

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Discussion Starter #12
new plan

thanks for all the info...after allot of recearch i found the vortec heads the airlift manifold and a compcam, 650 carb I should get about 340hp give or take. doing a simulation we found the horsepower really came out about 5500 rpm's. I was told if you are going to get parts like that put them on a 350....the motor cost me 200 bucks and two days to deassemble, im not feeling real good about the 305...
I really just want a crusier that will not only look good but perform a little, no track just some showing off..
 

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Doesn't seem to make much sense to build a motor for peak power at an RPM which it will rarely see. They weren't exactly meant for upper RPM's.
 

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If your after a cruiser with a little pull to it . . . it can be accomplished with the 305. Just build it up for some low end torque. That will give you a nice seat of the pants feel. Just keep in mind that if your looking to build something with an overall performance profile your going to have to do it with a larger cubed setup.

But like I said . . . a 305 can be built to accomplish what you want out of it (not 400 hp without costing your first born). Btw I consider a 400hp engine as more than something that "perform(s) a little" lol.
 

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Discussion Starter #16
400 hp

yeah I agrre..
The day I posted that a friend had taken me for a ride in his 66 GTO.. somewhere around 500 hp.. And all I can say is WOW!
I was pinned to the seat more then in any car I have ever been in. a porche, aall kinds of vetttes.. I thought set the bar high and then come down a little but realistically that would be to much for what I want , i think your right on the low end side of things, If it will pull out of the hole and go go go to about 60 ill be happy, anymore and ill probably get myself into trouble.
Any suggestions for building toward that kind of motoe?
I have the block ready to be dropped off for the bore and cleaning. I really had quite a buy list going and perhaps I dont need all that!
 
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