S!MON

I really like 1/4 mile runs, but racing on a cicuit is the real thing. so I think I don't need hundreds of horsepower (ok, a few of them would be nice ) and much more torque!
so what's to do, to make this engine ready for, hmmm, let me say 7000rpm??

what kind of cam do I need (is a LT1 even with chip tuning to small)? what can I do against unbalance, do I need special heads (afr should always be good) , what is a good manifold for that, aftermarket tbi etc.etc.

I'm looking forward for your replies.
greetz

S!MON

Dewey316

why are you planning on spinngin to 7k?

just gear accordingly based on your HP peaks, and it will get around a road course just fine. do the normal buildups for power.

S!MON

mhh, I just like the idea!

and I also know a guy with a third gen bird. he's got a mean 435 in it and has the rev limiter anywhere at 7500! on a meeting in switzerland he has blown a big block gto and cars like that (on the mile), and he says that's just because he can rev that much. when the others had to shift he was able to pull away...

that's his page: www.trans-am.de

so what do you think? when I do a "normal" build up, what is a "normal" rpm then? anywhere at 6k?

S!MON

Mark305TBI

The 305 doesn't make the best rev motor with it's long stroke and small bore.

kevm14

Nope. I would recommend a 400 block with a 350 crank. Big bore, short stroke. That's a 377.5 including 0.030" over on the block.

kevm14

Whoops, double post...

MrDude_1

leaving out the entire "305s are poorly designed for making power"


you would have to take apart the entire motor and have it balanced. THEN you would have to bring the valvetrain upto snuff to take it... and install a cam that can breath there.. and that would mean either major work on thoes heads, or new heads....



so, you would have to rebuild teh entire engine to make it rev that high and have it make power.

MrDude_1

brings up a small point...

if you totally rebuild and modify a l03, is it still a l03?

kevm14

If you MUST have a high revving 5 liter, then make it a 302. 4x3 bore and stroke. Doing this or using my short stroke 377.5 idea, is fine - but a 305 really isn't up to the challenge. Like someone suggested, you will need to have everything balanced to pretty high standards and you might even have to use special light weight components. And in the end, you have an engine that makes the same HP at 7500rpm that a 350 (or even a 377.5) could make at, say, 6000rpm.

brodyscamaro

Nope, makes it a 305 with TBI

Z28GEN3

302 is supposedly a better block. but why would you want to rev that high in a 5 liter? like one guy said reving at 7500rpms your still making the same power that a 5.7 liter makes at 6000rpms at least with a 350ci you can gain more power but a 400ci is better. Iknow a fella who has a 700HP+ 3rdgen who pulls 10's with a 400ci block. hell i have 1969SS 327ci engine thats got a max RPM range of 5000 and makes well over 400HP and TQ long before it ever gets to 5000rpm's.

Mark305TBI

It's alot easier on parts having big cubes and low revs, too. A 7000 rpm sbc would have to have a stout *** bottom end.

kfoley

If you want to rev a motor high that means you'll need to invest in good parts. All forged bottom end, Callais light weight billet crank, Manley 4340 I beam rods (to recuce reciprocating weight) and some good SRP/JE lightweight pistons. The whole assembly needs to be balanced as close as possible. Valvetrain will also need to be top notch. You'll need a solid cam, 4130 steel pushrods, shaft rockers are reccomended, large springs to keep the valves under control at 7.5k. The heads will need to flow like mad to make lots of power up high. You'll need to run a large cam to be making max power at 7k, so don't plan on it having a stock idle or having great street manners. If you want to run to 7500, you're going to have to spend some money on high quality parts if you want it to stay together. Personally I don't know why you would want ot rev it that high unless you were a serious racer (like professional, sponsored). You could spend a whole lot less money and only take it up to 6k, plus you would have plenty of low end which is what makes the SBC great. Of course you don't have to have all the parts listed above to have a motor that revs to 7500, but that's the way to make it last if you plan on revving it that high more than a few times.

S!MON

that's what I also thougt! a lot of high quality parts...

hmm, as you said, a traditional build up with 6k in the end should also work. I think that's a good compromise!
I also think, that the big cam would be the biggest problem for a daily driver.
ok, let's see what I will do.

first of all, I will start this winter with the good ol' hot rodding: in words-full exhaust!
greetz

S!MON

kfoley

Full exhaust will help a bunch...

Mark305TBI

I agree. Headers & cat-back, and/or posi & 3.73s (3.42's at least) will make your car feel totally different. Well worth the money. Then later on, when you've got the money, build yourself a new motor with big cubes.

M1tch

not true, read some articles where you can have 324 horsepower for $1500. Its somewhere in here.

They took heads, cam, and intake and created 324 horsepower from a 305 tbi.

Fast355

iTrader: (2)

I am also leaving out the whole 305-350 debate for this one. But I can say that I turn my 312 to 6,500 rpm @ WOT 1-2 upshifts. That is where it shifts with my foot on the floor. It takes a Very PRECISELY balanced bottem end, 4 bolt mains, (Studed mains and rods would be a good idea), forged crank, X-rods, Forged pistons (mine had everything but the Forged Pistons), good valve springs, hardened pushrods, guideplates, light weight valvetrain components, throw out the exhaust valve rotator, lighter valves, heavily ported 305 TPI or carb castings, a good cam with healthy lift, a 454 TBI, and the least restrictive intake and exhaust setup you can find. It can be done and has been done. Peak RWHP on my setup is at 5,500 RPM, but the engine is still pulling HARD at 6,500. 6,400 is about as high as you can accurately control the injector as the TBI injector firings become way to closely paired. It takes a BIG injector to spin the engine to high RPMs. Think 68 lb/hr @ 32 PSI big.

MrDude_1

thank you for bringing up a 3 year old thread just to quote some incorrect info where, once more, someone mistakes a destroked 4" bore 305 for a production 305.

and even if it is a production 305, with the amount of work you have to do to get there, its unimpressive and foolish.

Fast355

iTrader: (2)

If its the article I am thinking of they used a STOCK LG4 305 with bolt-ons to achieve 325 FWHP. All they did was stab in a comp xtreme energy 262, mill down some vortecs, and use a single plane intake for vortec heads, and headers.

Building the same engine, I would port the milled vortecs some, use a Comp Extreme energy 268 or 274 cam, and use a dual plane manifold such as the RPM for Vortec heads. That would give you more HP and more torque.

BronYrAur

iTrader: (1)

Why are all these old-*** thread getting brought up to say some comment like this:

Please don't do that, don't bring back a 3 year old thread to say something like that. He probably read either a stroker site or that stupid "goingfaster" site. Anybody that tells you 305's are built for making power is either lying to you or he's a fool. Simple as that. Rebuilding a 305 is possibly the worst idea of anyone working on SBCs when you can build a larger bore motor for probably less money, including the purchase of a block.

Seems like a lot of "I read somewheres" going on here lately. I dont care much for magazine buildups and how much power they made, I don't put any stock in them which is why I don't read them.

M1tch

I never said 305s are for making power. BUT they can just like any other engine.

Fast355

iTrader: (2)

A 1.8 Honda doesn't make any power stock, but I have seen one make 325 RWHP on the dyno naturally aspirated at 10,000 rpm. Took alot of money but it was done. I have seen one put out over 650 RWHP on the dyno with a turbo.

I have also seen a 305 put out over 400 RWHP Naturally aspirated on the dyno with "stock"(undercover acid ported) 601 head castings, flat-tappet cam, Brezenski preped GM Q-Jet manifold and an 800 Q-Jet.

BronYrAur

iTrader: (1)

That's just great, but its never the "smart" thing to do, to build a 305 up. I never said you can't make power with one, obviously you can, its an engine with bad heads and cam stock, of course you can make more power with different parts. Personally, I think trying to make that kind of power out of a Honda is even dumber, which explains my dislike for r!cers.

My point was not that it could be done, but most people on this forum are on budgets. If you want the most power possible for the least amount of money, a larger bore motor is the best way to go.

Fast355

iTrader: (2)

My point is that GM 350 engines don't grow on trees and almost every TBI thirdgen I can think of came with a 305 from the General. I find it cheaper to build what you have then to pay $400.00 for a 350 core. Then you factor in that it will cost you ALOT more fuel over the life of the engine. I think the key to making power in a 305 is to make the heads flow, a good cam, and then spin the snoot out of it.

That being said, I know you can only go so far with a 305. I am stuck at 15.45 @ 94.08 and a 2.15 second 60 foot, with mine right now. I have a bigger bore, much longer stroke engine going togather on my engine stand built to swallow some juice. Think 450 FWHP 396 smallblock with a 150 shot. Hopefully 13s N/A and 12s on the Juice. I would use the nitrous on the current 305, but I think the 700r4 would blow to pieces. I am swapping to a piggy back PCM run 4L80E when the 396 goes into place. Still going to be TBI.

Apeiron

350s might not grow on trees, but that doesn't matter, they're more common than dirt. For $400 do they at least use vaseline? I don't know where you're buying your 350 cores, but I've had entire running used 350 engines for $250 CDN. I just bought two good used short blocks not long ago for $50 CDN each.

If price is your major concern, then there's nothing wrong with building what you've got, as long as all the parts you have are reusable. When you start replacing rotating assembly parts it quickly becomes comparable to the cost of building a 350. If you're more worried about power, don't even bother with a 305, and get your hands on the biggest displacement block you can find.

Fast355

iTrader: (2)

Double

S!MON

btw as thread starter:

It was a long way from this thread to the actual engine.

https://www.thirdgen.org/techbb2/sho...hreadid=315210

way better now good for low 13s so far maybe less with more tuning and a better exhaust.

greetings

Simon

MrDude_1

no. they cant.

the damn bore is too small.. its a huge disadvantage.

take a 302 (4" bore, shorter stroke), a 327 (still 4" bore), a 350(4") or even a 377/383....

they all flow ALOT more air then 305s.

the aftermarket heads that flow even more air, fit on them.

305s are at a distinct disadvantage. their tiny bore.

thank you.
you're either telling me you're full of ****, or that you're naive and easily mislead.

but 350 cores are VERY plentiful... they made SEVERAL MILLION of them, and they're still making them.
every TBI thirdgen came with a 305 POS motor. every part of that motor must be replaced to have something resembling performance.

really? because by the time you do all of the extra work required to make your 305 as fast as a basic 350, you will have spent FAR MORE then $400

fuel is used when you make power. yes, if you make more power, you'll use more fuel.
this is probly the stupidest argument ive ever heard... if you want to get into fuel consumed per unit of power output... well, you're on the losing end with that motor... the same bottlenecks and inefficiency's that make it a crappy performance motor, also make it have a low BSFC.....



nice thoughts, but lets recap what you just said.
heads flow.. well they're going to suck on the bore, and you cant swap most of the cheap aftermarket heads on it... but lets pretend you have magic ported heads that fit.
cam.. well, they're all the same price, doesnt matter if its a mild grind or extreme.. only real cost diff is roller or non roller.

spin the snot out of it?! HA!!!
you need new rods, crank, and of course a good valvetrain... in other words, you'll have to rebuild the entire shortblock....
you have just lost your cost savings of building the 305 over the 4" bore block.


so even you know that the 305 is a POS and you're going to replace it... why argue about its "performance aspects" ?!

91ChevyRS

I don't think you have any right to say that a 305 motor is a POS...just because you have a damn LS1 powered horsepower hog doesn't mean you can be a wise *** and start snooting around and talk down to 305s. Yeah ok, you proved your point, without spending the moolah you won't get any real power out of the 305, but the engine is rock solid and you can still get some decent gains from minor mods...


All I have to say is wow....the ignorance of some people

EDIT: And I for one have to say that, I am not gonna be looking at the 305 as a 300hp goal kinda thing...I wanna set my standards low for this car, if I can achieve 200-230rwhp then I'll be a solid guy. If I wanted anything more I'll go buy myself an LT1 car and already stock I am faster than a 305. But again, before you start talking down and spitting on people with those that have 305s...and do NOT have the 4-5k dollars for an LS1 engine, why don't you take a look on the TBI boards and see what some of those guys are running with their built cars....some of these guys are running low to mid 14s all day long with just a mild cam, intake and full exhaust...that's it.

You have also got to understand the 305 came out of the factory RESTRICTIVE, so stupid minor mods like an open element, full exhaust will make an enormous difference in power and acceleration. It's not unheard of....I plan on making my car a very low 14 1/4 mile car, if I can't do that well it sucks for me, atleast i still have a 15 second car and while thats not all that fast its still decent enough...and oh yes one more thing you literally responded to everything Fast355 said about his engine and what not. Look at what he's driving there fellow, its not a thirdgen car its a 4000lbs Chevrolet G20 van, thats right a van...he built his engine to make it to a 15.4, 1/4 mile, and his rear wheel horsepower is 272hp...what did he start out with? A POS 305 as you so eloquently put it, just imagine if he had that built 305 in a thirdgen Camaro or Firebird, yeah that thing is definitely a 14 second car, maybe high 13s...

mrpopo573

Perfectly Said.

MrDude_1

psst.

what do you think was in my RS for years before i finally saved up enough to change motors?

i have every right to state any opinion i want about the motor, having done more with them then the far majority of other people on this site.
i didnt go as far as a few other specific people, but i think low 15s was damn good for a car with a 2.0 sixty....

that said..
the motor is still a boat anchor that is better off scrapped then rebuilt, when it comes time to rebuild....


edit:
dont take it as a personal insult just because you have one. i hated the POS when i had it in my car as well... just because you own it doesnt make it any better, step back and look at it from the full outside perspective.
sure, you probably cant afford to replace it. i sure as hell couldnt afford to break anything on my car for the first few years i owned it.. i bearly had enough money for the open element.. lol.
that doesnt mean its any better then when you have all the cash in the world to replace it.
just because i saved for a year (driving a fuggin TERCEL at that to save money) to buy a better motor, doesnt mean im "above you" and it doesnt mean i lost the knowledge i gained while owning the 305.

Dewey316

Exactly. There is "Faster than it was stock" . . . Then there is "Fast".

You are never going to be fast with a 305. With the deluge of 500hp cars coming out of the factory's, a 305 just won't cut it. For the small fortune you could spend trying to get a 305 into the 12's NA, you could be solidly in the 11's or 10's with a 4" bore motor.

91ChevyRS

Again, I am not trying to see if my car is going to make it to 500hp...and although I considered it awhile back, I am not one of those people who will throw away a perfectly good motor to replace it with another...

I mean if my motor is crapping out and exploding on sight then yeah ok, I'll get a 350 or slap in an LT1 but its not doing any of that stuff. My car has been through alot, and hearing the past adventures of it makes me love the engine even more.

I figured if I am gonna get an LT1, I am gonna get a car that was made for the LT1, i.e. 4th gen Z28s/Trans Ams

I am saving a few of my dollars for one, but in the same process am doing some modifications to my car.

Dewey316

91ChevyRS

Funny how the guys who plan to do stuff, stick up for the 305's.

The guys who you quote as running low-mid 14's all day. Are the guys telling people to go with a big-bore motor. Those of us who have put in the effort, who are making the numbers you talk about, are the first to tell you to go with a 350. You don't even want to think about the number of hours I have put into this motor, in sheer effort, trying to make it run right, and get the numbers out of it.

MrDude_1

ah, so what you're saying is you have a illogical emotional attachment to your motor, and thats why you're all offended when something insulting about it comes along.
that somewhat makes sense.


btw, if you're considering later model motor swaps, you should really look at the LS1 setups... the price is about the same as LT1s were a couple years ago.. and you'll be able to expand into the modern performance era... not to say that the LT1 isnt a great upgrade, but theres not as many vendors backing it anymore.. its going to become the oddball motor between gen I and genIII+

MrDude_1

you know what just occured to me?

look at my first post in this thread:
"305s are poorly designed for making power"

mmk, that was posted in 2003.

in 2003, i had the L03 still in my car... and that was right around its "peak" time where it was running its fastest.
yet i still just stuck to the facts back then.... so i dont see how me owning a better motor now makes my opinion any less valuable.
atleast ive DONE it. you're still at the "planning" stage, and you're telling me...... lol.

Fast355

iTrader: (2)

I have built one and you still tell me off.
A damn 6.0 Vortec Express with a 4L65E and 3.73s, granted it is a little heavier is over a full second behind me in the 1/4 mile.

MrDude_1

yea well, you said alot of things i dont agree with. lol

Fast355

iTrader: (2)

Because you couldn't get 275 RWHP from a 305 TBI?

BTW, My G20 is closer to 5,500 lbs with me in it.

MrDude_1

no.
because you think its worth the effort to get 275hp from a 305.

Fast355

iTrader: (2)

Well lets just say that with a 350 you should have 315 HP to the wheels.

Getting 275 RWHP out of the 305 wasn't that tough!

What I don't understand is why you think the LS1 is a worthwhile swap! I am building a 450 FWHP 396 small block that will surely cost less than your LS1 swap and surely alot less headaches.

Oh, and I honestly don't think an LS1 would fit!

MrDude_1

then you honestly need to do ALOT more research.

btw, the LS1 is smaller then the SBC.....


and i only have ~3k in my entire swap... thats about the same full cost as a very basic SBC rebuild.


but whatever, you obviously arnt informed about it, and you obviously arnt going to try to learn from me, so go do your thing, i'll do mine...

Fast355

iTrader: (2)

Lets see factory LS1 vs. Built 396. With the 450 HP I stated, it will be around 550 ft/lbs! Built to swallow a 150 shot or a blower at that. What else is there to learn.

A very basic SBC rebuild is much less that 3K. I can go buy a GM goodwrench 250 HP 350 for about $1,600, swap to vortecs, upgrade the cam, buy an intake, sell the factory stuff on Ebay, and will be 350-400 FWHP for $2,000.

I have about $900.00 into a FULL rebuild on my 305.

The top-end of a LS1 is WIDER than a standard small block, I have done research. It required hacking on the heater-A/C box to get one in a friends Monte Carlo SS. I would be hacking on the frame and dog house area=NOT GOOD. The LS1 is as wide if not wider than a Big Block up top. Look up the measurements, I am sure they are on the net somewhere. Then lets not even get into the Fact the A/C would be smacking the Cross Member.

MrDude_1

its wider until you relocate the coil packs, or put truck coils on, then its the same...
as for the rest... ok. sure.

then i'll stab a cam in mine with basic bolt ons, have the same HP and torque, and snag 30mpg highway.

but quick question.

have you DONE it yet? no.
go finish yours.
i'll finish mine.
PM me when you're done.

Fast355

iTrader: (2)

I am still working on it, the main thing stopping me is the 4L80E swap and the wiring/PCM to run it. The 700r4 would shatter behind the torque. I could have the engine built in a couple of weeks, if I wanted to. I am still working out the cam specs. I am actually building this engine very similar to a LT1 that a friend built, tuned, and ran on the dyno. It made 485 FWHP @ 5,800 and 560 ft/lbs @ 4,500. I am using better flowing heads, with a slightly smaller port, and a slightly smaller cam (really just a tighter lobe seperation angle for a wider powerband), and about 1 point less compression.

I would love to see you pull 550 ft/lbs of torque at 4,000 rpm from only basic bolt-ons and a cam, I seriously DOUBT it will happen. I can see you getting 450 FWHP and I can buy 30 MPG. I am shooting for 18 MPG in a Van, I will probably get it because the 396 will have alot more torque and keep the converter locked and the transmission in OD vs. the 305.

Like I said my goal is low 13s NA and mid 12s with the 150 shot. In a fullsize van. LOL.

Fast355

iTrader: (2)

Originally posted by MrDude_1

Are you telling me I wasn't standing there while we were TUNING this 305 SPEC DIRT TRACK car with a 8,000 RPM 310 that made over 400 RWHP. 437 @ 7,300 RPM to be exact




I never said the 305 was a piece, I just want to beat sports cars in a VAN and that takes more cubes and lots more torque!

The 305 is going into a car or on my engine stand, NOT the JUNK pile.

FWIW, my 305 was cammed and setup for a peak torque of around 3,500 and peak hp around 5,500. It actually made peak torque at 3,350 and peak HP at 5,500. It wasn't a super high RPM build, but the head flow and cam kept the HP strong all the way to the REV LIMITER @ 6,500 RPM (I was afraid the valves would float). Not to mention the H-rated tires were spinning at almost 150 MPH in 3rd gear and were beginning to ballon out. Also nobody has driven a van fast enough to know where the critical driveshaft speed is???

DM91RS

This does not translate into anything worthwhile for anyone to do for their street car which is what I thought was the subject at hand.

Fast355

iTrader: (2)

It does however relate to his saying that a 305 has NO potential. It CAN run.

swerve-driver

S!imon: See all this arguing you started here? You should be ashamed of yourself! Kidding--

I checked out your engine- it looks awesome.

I don't know if they make a muffler short enough to fit between the real muffler and the tips (outlet) of the pipes? Like two small mufflers where the tails currently are? jUst a thought. Otherwise, I can only think to stash one in where the cat. conv. used to be.

Looks great-
S-D