im new to the third gen life i just got a 1985 camaro z28 with 110,000 miles with a 5 speed but its the lg4 for 1400 dollars. was this a good price? all it has is a flowmaster exhaust and a k&n airfilter and i want to to be able to run low 14s or high 13s in the 1/4 what ill i have to do to my car to make it happen

 

with an LG4, you have a good base to start with, but you're going to need a cam for sure and either new heads or some serious port work on them stockers. headers along with a good intake like a performer will assist in geting the air in and out. if i had to guess you probably have the 3.23 gear which insn't bad, but does leave some room for improvement and if you don't have a limited slip or locker i'd recomend one of them. that's a good starting point.... others????

 

As far as the price, that would depend on the condition. If it's in really good shape, great paint, clean interior, low miles, etc., then that's OK.

That car is a high-15s car at best, as it comes. You're talking about knocking 2 seconds off of it. That's a pretty tall order.

Do the obvious, tune-up and fluid change (use synthetic gear lube in the rear end and trans), etc. Make sure the car is running as good as it can for what it is, first.

The weaknesses in that car are, in order of importance: exhaust from heads to street; air cleaner; cam; gears; engine cooling fan; head porting; intake manifold. Notice, nowhere on the list will you find a carb or a distributor. Resist the temptation to just un-blot and re-bolt things that sit on top of the motor where everybody can see them; just because there's big new shiny things sitting there, won't make the car go one bit faster. The correct way to mod a car is to identify the one part that's holding it back the most (i.e. the cars limiting part); upgrade it; find the next such part, and upgrade it; and so on. It is NOT to waste money on stuff just because "everybody else does", or because it "looks" cool. The only way that will make the car go faster, is by being lighter; namely, the driver's wallet won't weigh as much.

It needs a good quality chassis-specific set of headers, a high-flow cat, and a cat-back; BUT NOT FOR LG4. Getting ANY piece that will fit to ANYTHING that it came with, will preserve the bottleneck, which is the tiny little Y-pipe and all of the other pieces of that size. I'd suggest getting the stuff to fit a 350 TPI car.

It's easy to get too much cam, especially in the low-compression version of htat motor that you have. I'd recommend the Comp XE256, or the equivalent from Crane or Lunati or Crower or some other top-tier cam mfr. Look for one with about 210° intake and 220° exhaust duration at .050", as little "advertised" duration as possible (steep ramps), and as much lift as possible. You should be able to end up in the .450" - .460" range.

The best air cleaner setup is the HO dual-snorkel cold-air system. Those are beginning to get hard to find though. But even an open element is better than what's there.

Gears need to be 3.42 or 3.73. That makes a HUGE difference to how the car accelerates.

I'd recommend a ZZ4 intake, which you can pick up cheap on ebay or the classifieds on this site. Typical stock replacements like the Edelbrock Performer will do just about nothing. Just because it's new and shiny doesn't help. Waste of money as far as going faster.

Head porting speaks for itself. The main things you should do, are to clean up the bowls behind the valves, and smooth the valve guides. Resist the temptation to do a bunch of hilljack "hogging out". They don't need that. Remember, you're not trying to make them bigger, you're trying to make them flow better; smoothing, streamlining, uniform cross-section with as little turbulence a spossible, that's the goal.

If you do all of that right, you'll be at low-mid 14s. From there, you'll just have to lighten the car.... get rid of anything that you don't need for going down the track, that you can put back. Take out seats, spare tires, junk that's accumulated in the back well, etc. etc. I'd recommend against devaluing the car by hacking off the A/C or any pollution gear.

Then, start saving for a 350.

 

Alight first do what RB83L69 said and make sure the car is running perfect. Then go with headers a high flow cat and a cat back. Then go pick up some corvette Aluminum L98 heads and have them milled to pick your compression up to 10:1. Then get an edlebrocke performer RPM intake, comp cams XE262 cam, have your carb tuned, get at least 3.42 gears or better, and build your suspension. Then your set. I realize by the fact that you bought the car that your probably not rich and this sounds like alot. Well it is. Not many people can just go out and by these parts all at once. So start with the exhaust and save and work your way up. I am just trying to give you a setup that will run the times you want. Good Luck.

 

Why get aluminum L98 heads, his 416's are better.

 

How are his 416's better? Stock for stock the l98s flow way better.Now if he was going to port them that would be a different story, but I was just throwing out a head that will work well with a 305 without porting. Also the Lg4 has crappy compression he can get higher compression and still use pump gas with the L98's. Either idea is good it just depends on weather or not he wants to port his 416's.

 

IIRC, the L98 heads (casting 083) have a 64cc chamber versus the 416's ~58cc. That would mean he lowers his compression with L98s.

 

Flow-wise, L98 heads are not much better than 416s at all!

They both need porting and polishing. But from a dollars spent for hp gained point of view, the 416s blow the L98s into the weeds, aluminum Corvette pedigree and all.

Follow the link at the end of my sig.

 

Hey Sitting Bull,

I know this is kind of random, but I was wondering if you put 300 HP to the wheels or if that is just a flywheel measurement?

I am planning to build something very similar to your setup when I start modding my LG4 and I was beginning to wonder if it was realistic to see numbers above 250HP with this 305.

Also, what kind of suspension mods do you have?

Thanks again!

 

Im talking aluminum vette heads which should have 58cc, but I said he should mill them to get at least 10:1 compression. Also stock for stock the aluminum L98s flow a good amount better. I am not talking about the cast iron l98's. But of coarse if he is willing to port them he can get them to flow better for cheaper. I am just throwing this idea out there if he doesnt want to port.

 

The aluminun L98 heads don't flow more then the 416's, ok maybe a minute amount. But then you have to pay for the milling, to keep the "compression" the same. Aluminum transfers heat better then cast iron, so really your not gaining anything. Power is energy, which is heat.

 

So your telling me that the aluminum L98 heads which are the same heads used on the zz4 crate motor barely out flow 416's? Im not trying to sound like a jerk or anything I am actually using the 416's on my current engine, but if they flow so well then why do people even bother with the L98's? The 416's flow like 195 cfm @ .500 right? Well I thought the vette heads flowed at least 215 @ .500. I know this isnt alot of air flow to gain by ported the 416's but stock for stock thats a pretty big difference especially for someon who doesnt want to port the heads and can get the l98s used for a decent price. Oh and I know what your saying about compression but 10:1 on aluminum heads is way better than 8:5:1 on cast iron heads. No matter what heads he gets they need to be milled because that low of compression will kill any combo.

 

Hey Nate86!

That is just my best guess for flywheel hp. Never had it on a dyno, just calculated it using Desktop Dyno 2000 and 2003. Both said I was much higher than 305 hp but I didn't believe it and settled for one hp/ci. I have no suspension mods other than front and rear sway bars from Apeiron's 84 Z28, in place of the smaller F41 originals. Apeiron's a good lad--he gave me a fair number of freebies including the bare 601 castings I ported and polished in the thread

 

Why people drop so much coin on L98 heads is a mystery to most of us, too! Any of the 416s, 601s or 081s are almost at the L98 level of flow as cast but when you port and polish them, and enlarge the intake valve out to 1.94", they can be made to outflow Vortecs. Talk to F-Bird'88 about his 416s that he has flowing 238 cfm, which is significantly more than Vortecs

 

i am new as well and am wondering how much weight is one saving if they wanted to go with aluminum heads?

 

With a good port job, I doubt the flow differences between the 2 kinds of heads are significant enough to matter on a 305.

There's no sense whatsoever in spending that much money to replace one set of 58cc heads with another set of 58cc heads of approximately equal flow characteristics, when the 2nd set of 58cc heads needs to be milled further to get the desired compression. Basically you spend money, then you have to spend more money just to get back to where you were before you spent the first money. That's just stupid money like you see on ebay buying "Vortec rockers" as if they're something magical.

I would not recomend wasting money on the 113 castings; not because they're no good, but merely because in this application, they're an EXTREMELY high $$$$/HP proposition. The cost is all out of proportion to the benefit. Porting the existing heads is entirely adequate. But even that is a little ways on down the road from where you are now; you can take care of the tune-up, exhaust, gears, converter, air cleaner, and fan, without ever even popping off a valve cover. That's probably a full second off your 1320 right there. Then when time for the cam comes, pull the heads and work them up while that part of the car is apart.

One thing I didn't mention is suspension work.... these cars, like about any stock cars, can use help getting better traction. The more power you can produce, the bigger of a problem it becomes. The things that do the most good for the least amount of money there, are a poly trans mount ($18), poly torque arm mount ($12), lower control arm relocation brackets ($65), and lower control arms ($85). Those things will make a MASSIVE improvement in how hard you can make the car launch, for very little $$$$.

It's all about bang for the buck, spending your money where it gets the most results. Save the big expensive things for later, if they won't do you the most good now, and what you already have is still working. Not on aluminum heads that will do almost nothing to your motor as it now sits. Not on a bunch of chrome, not on big shiny pieces for your friends to oooh and aaaah over when you pop your hood, not on magazine article buzzwords. The right way is to identify the thing that's limiting you car's performance, and cure it; then identify the next limit, and upgrade that one; and so on.

 

Incidentally, you save about 40-50 lbs with aluminum heads compared to cast iron.

 

you are joking right? yes, heat is energy, its a result of the non-ideal combustion reaction in which about 70% of the energy made is going to heat and 30% is going towards moving that piston. heat is NOT power, it's a waste by product of the combustion reaction which is why we want to get rid of it and have a cooling system. A cooler engine 1) runs better, 2) lasts longer, 3) won't detonate as easy, 4) can run more compression and make more power. Aluminum heads promote better cooling. In the real world, aluminum heads will make more power than a similar spec cast iron one because of this, especially with C/Rs over 9.5:1, it won't be a big difference, but when conditions are thrown into the mix, they will make more power. keep in mind I don't defend getting L98 heads, I think if you're going to spend money on heads at least get some that are worth a **** like AFRs, Dart, Brodix, or Motowns, but I wouldn't bother sticking those heads on a 305, hell most of them have valves too large for the 305 anyways. Remember peak flow levels don't mean crap. it's like some idiot with a honduh braggin about his civic putting down 300 WHP for a 100 rpm spike between 9900 and 10000 rpm while from 3000-9899 rpm he's only putting down about 150 HP. it's not useable and won't matter much for anything in reality. Take a good look at the flow graph for the heads you want to get. if the curve is a gentle slope rather than a steep one, peaky one. it will make more power than one that spikes high at a high lift, even if the peak flows a bit less. Peak cam lift is only experienced for a very short time.

195@.350, 205@.450, 210@.500 will make more power than 165@.350, 195@.450, 225@.500 because more air will be moving into the cylinder during the time the valve is open with the prior example than the latter. Don't get me wrong more flow on whole is better, but what good will bragging about flow numbers at .600 lift or whatever when your cam is .420 and the flow numbers are junk at that lower lifts compared to another set of heads?

I'll also add onto RBs suggestion for suspension, it's a must. These cars can't hook worth a crap on stock suspension and street tires. I could never get any traction with my stock L98 IROC and the rubber on back. LCAs even in the factory location made a HUGE difference, helped put power to the ground even when I was doing a 3000 rpm stall launch with my new converter. Also, things like drag radials can't hurt either. NIttos are pretty damn nice for a 14-12 second car. Just make sure you heat them up really well.

 

Thanks for the info!

By the way, if you ever get your car dyno'ed, let me know .

 

I'd like to see a dyno run on that too SB.... it would be interesting to see how close DD and all those comes to the real value. I've had mine dyno'ed, and I suspect it has more flow than yours, and the numbers aren't what you're claiming; so I'd like to see. Of course that's as installed in the chassis, with the exhaust and air cleaner, emissions, etc.

Incidentally, for all of those among us who didn't pay evey close attention in high school physics, an internal combustion engine is one form of a "heat engine". It converts heat energy into mechanical energy by allowing hot gas to expand. An engine of the design like ours (and pretty much all other 4-stroke gasoline engines) manages to convert about 30-35% of the total heat energy produced by combustion into mechanical work. The rest either goes into the cooling system or out the exhaust. Between 2/3 and 3/4 of what goes into the cooling system, gets there through the heads. Cast iron is a poorer conductor of heat and therefore less heat transfers through it into the cooling system than through aluminum. This fact not only allows, but also requires, an aluminum-headed engine to have higher static compression, in order to achieve the same thermal efficiency as a casat-iron-head one.

 

What have you done to your car, RB? And what kind of numbers are you pulling?

If you prefer not to say, I understand.

 

Rebuilt short block (I know, I was in California at the time, and didn't know whether they'd check the block casting #) with some lightening here and there; double-hump heads with a little mild port work; a Comp XR264HR cam (retro) with 1.6 rockers; ZZ4 intake; SLP 1¾" coated headers. Stock L69 carb, dist, programming, emissions eqpt. In a word, nothing; but more than Sitting Bull has I do believe.

237 RWHP @ 5100 RPM, 267 RW ft-lbs @3800 RPM. So that's probably 290/325 or so at the crank. Pretty weenie; but I guess for a 305 that passes California emissions, you can't really expect alot.

 

One word: N2O.

 

Hey, that's pretty beefy compared to the stock figures, though! And it still passes emissions. That's pretty nice.

Anything you would have changed/modded had you not had to pass emissions testing?

 

About 130 cubic inches, to start with.

No nitrous.

 

We usually like to distinguish the two, as the usable kinetic energy and unusable, thermal energy. they are one in the same definitively. thats a stout 305, sorry ya live in CA but you can always say your car is 100% street legal anywhere you go.

 

RB,

Yeah, I'd say some of your parts are more choice than mine.

When I say 305 hp I'm figuring at the flywheel but I should have mentioned that my estimate is according to DD2000's way of estimating. That is to say on an engine stand without the accessories running. I've sat down and estimated its rear wheel hp like this:

- 305 hp gross
- minus 30 hp for accessories
- minus 20% for drivetrain losses

which = 305-30=275
275-20% (55)=220 hp at the rear wheels, which I think is reasonable.

But you're right, you'd probably kick my butt in a drag race

 

THat's probably realistic; but still, it would be great to have a measurement. Without that, it's all just a guess.

Actually I don't live in California any more; but I built the motor when I did. I got transferred to Ohio. Been here about 2 years now I guess. But I have this brand-new motor in my car that cranks up and drives off absolutely every time I hit the key without fail, and doesn't leak or otherwise consume a drop of oil or other fluids, and gets great gas mileage, and still manages to be a little fun to drive; so it hasn't been real urgent to replace it just yet.

 

Yes, that's the way I feel about my engine, too. It runs great, gets great mileage and (other than a persistent choke anomaly) starts great. So the 350 is just gonna have to wait until old reliable bites it

 

This is the beginning of a series that has some good info.
http://chevyhiperformance.com/projectbuild/48158/
It's right down your alley (LG4) but it has a slushbox instead of a stick.

 

I really enjoyed those my generation camaro articles when they first came out. It was very interesting reading, but I wouldnt pay to much attention to it. Most 305 builds would have turned out much better. They used a car that had to many miles on the ticker and didnt use the right heads/cam combo in the end. The only thing that is informative in those articles is the gains they made with the bolt ons other wise the guys who built that car really screwed up. If they would have had a low mileage motor and the right cam/head combo they could have gone 13's for $5000 no problem with out nitrous. Go ahead and read them and get ideas but I wouldnt base any major decisions on that build up if I were you. Good Luck.