Josh R

iTrader: (1)

I was just wondering, since i thought my '86 Camaro Iroc-Z Z/28 had 190 HP and it only has 155, what is the best thing for an easy not really expensive engine upgrade to hop up the HP more.

GuitarJunki17

iTrader: (1)

What Kind of motor is it? 305 or 350? TPI?

I would start with a simple tune up, all the simple essentials. Air filters (K&N never fails), fuel filters (this ones big, and overlooked many a time), oil, pcv valve, new spark plugs, clean distributor cap and rotor (all the metal contacts, make sure they are free of carbon). Start there and see what you feel afterwards.

You can start with "free mods", including gutting airbox, throttle body coolant bypass, ect (do a search on free mods).

Next, you can ditch the stock exhaust manifolds and step up to a set of shorties, which in many cases will bolt in with no modifications to anything else. Step up to an aftermarket Y-Pipe (You'd crap yourself if you realized how restrictive these actually are...Something to this effect:


and catback system as well. Youll get about 25HP that way, maybe more.


You can also opt for getting a custom chip burned from a place such as PCMforless.com , or the like. Not one of those Hypertech or Jet chips, they are garbage. But you might want to wait until you do more to your motor to get one of these, as you would have to recalibrate it for a major upgrade like heads, intake or cam to get it where you want it to be in terms of performance.


Anything else in terms of motor upgrades would cost you a little more, and are more intricate in terms of doing the work yourself. Elaborate a little more such as how much you are willing to spend and what kind of driver this is to get a better response.

Josh R

iTrader: (1)

Its a 305 and not a TPI. Unfortunately. Thanks for the tips. The car still has got a massive amount of torque but seeing the numbers 155 as my HP seems lame. haha. What do i know. Thanks again. Oh and i don't believe they do but have you seen any forms of forced aspiration like turbos or superchargers?

GuitarJunki17

iTrader: (1)

Carb'd then? Reason I ask is because if you are running a TBI setup, these are the numbers I'd expect. Don't know too much, but you might be in need of a carb tuning if thats the case here. Someone else who knows them better can chime in and help here.

rik89gta

Yep, You've got the lame Lg4... It's fun to launch that motor but after a second or 2.... the fun quickly fades away before it shifts. If it's bone stock, I would definitely start with a tune up, and then progress to a catback exhaust. After that... A set of shorty headers and a high flow cat matched with an Edelbrock intake will really wake that little 305 up. But I would really recomend performance parts that would get the car movin quicker without diggin into the little, old engine. Some better gears, and a bigger torque converter matched with headers and an exhaust would be perfect for the car. It's not worth digging into the engine with mods like better heads and a bigger cam if the 305 has some miles on it. You definitely wanna work around the engine to make the car faster! That way when it comes time for a rebuild... You have parts that will completely compliment a fresh rebuilt motor, or will make the best of a 350 swap for example...

Josh R

iTrader: (1)

It doesn't even have 50,000 miles on it but it was sitting since 1990. According to some website it said that it was 155 hp out of the factory. Im not really in the position right now for an engine swap, even though i would love to. The car still needs body work and some cleaning up. It runs great for sitting so long, but unfortuantely is not in perfect condition.

Josh R

iTrader: (1)

Would it be worth getting bored out and are there any performance camshafts that can help it out?

Josh R

iTrader: (1)

Would it be worth getting bored out and are there any performance camshafts that can help it out?

Josh R

iTrader: (1)

If anyone else seems to have the same issue, please let me know what you did to resolve it.

Sonix

iTrader: (1)

not worth boring out a 305. specially not one with 50,000 miles.

Yep, a cam would help, but it's not your main power bottle neck now. Get rid of the bottle necks first, headers, exhaust, cold air intake. That sorta stuff. The hard stuff like a cam can come later.


Hey guitarjunky, is that your flowtech y-pipe in that picture? sketchy !

Randy82WS7

no it snot really worth it unless you are bored and like ot burn $$ and have alot of it to burn

anything you do to this engine will make more power in a larger engine,

i really reccomend getting a larger engine, preferably a 350 or 400 or at least a good old 327, or something, can find good running 350 engines for dirt cheap, and they have larger pistons than their stroke and are good torque producers and are dirt cheap to hop up, nice little cam, some good springs, headers, dont need much more than that

just my $.02


good luck

GuitarJunki17

iTrader: (1)

No no, that is just a representation of what the stock Y-pipe looks like at the connecting point. This was a random picture I pulled off the web. The flowtec one is 100% as open as can be where the two pipes meet.

rik89gta

Well... while Your doing body work, the best mods are prolly steeper gears and a full exhaust. You can probably acomplish these 2 mods for less than a grand. They should both combine effectively to knock close to a second off Your quarter mile ET if complimented with a full tune up and some good tires and carb tuning. You should also look into either building or finding a dual snorkel air cleaner. It will definitely wake up Your throttle response in a heartbeat!

sqzbox

All the HP raitings today are NET HP. Thats what you get when your headlights are on A/C on and all acc. are on. With them all off, your probably closer to 170.
A good open element (like 14 or 15 in.) air cleaner (about 30 bucks) and a simple 3" bolt in cat back exaust (2 to 3 hundred bucks) should get you close to the 190 your looking for. If you have smog checks in your state, these two mod's will give you some improvement and keep you out of trouble with the MAN! if you know what I mean.

JamesC

iTrader: (5)

Here what I did to my old LG4: Summit cam, Edelbrock intake, L69 dual snorkel with K$N filter, carb tweeks (air valve tension, DR rods and G hanger, IIRC) and a complete L69 exhaust to include exhaust manifolds, y-pipe, cat, and cat back. Truly awoke the car. In the end, I thought it was pretty much the equivilant of an L69 without the 3.73's. By the way, should you be interested in the dual snorkel (aix box only), please PM me.

JamesC

sofakingdom

iTrader: (1)

No, that's not true.

"Accessories", when mentioned in HP "ratings", refers to emissions devices. It has nothing whatsoever to do with A/C, power seats, radio, and so forth. In other words, you start out with 155 HP or whatever; and it goes down from there as you add other loads to the engine.

The advice about exhaust is right on the money. I'd add, that when you change it out, get the complete exhaust all at one time, all the way from the heads to the bumper, and make sure NONE of it, NOT ONE PIECE, is designed for the LG4. The reason being, if it fits to the factory stuff AT ALL, it will preserve the small Y-pipe size. Buy the parts for a TPI or HO motor, which will have the larger Y-pipe, cat, and intermediate pipe.

A cam also helps out that engine. It has the smallest cam Chevrolet ever put in a small block. People get good results with the Comp XE256 in a mostly stock car (stock converter and gears); with improved gears such as 3.42 or 3.73, and a higher-stall converter like around 2200-2500 RPM or a 5-speed, the XE262 works well.

The L69 air cleaner is also a great addition.

JamesC

iTrader: (5)

Note the difference in an LG4 Y vs. the L69:

https://www.thirdgen.org/forums/atta...tion-ypipe.jpg

JamesC

Josh R

iTrader: (1)

Thanks guys. Ill make a list of the best things you say i could use.

84L69TA

Why? Are you gonna rebuild it and change the pistons?

GuitarJunki17

iTrader: (1)

Bottomline here, is the setup you have is a bad foundation for a powerplant. Ideally you'd want at least a 350 to start, but you can make it with a 305.

To kick things off youd want a new carb/intake combo, along with either a new set of higher flowing heads, or a killer port job on the ones you currently have. Then you'd have to compliment that package with a cam to wrap it all up, and THEN youd be making a respectable 300+HP depending on your combination....at over $2000 later. Right now you can tinker with bolt ons and maybe reach 200hp, and if that is all you are looking for, then great, you have all the info you need thus far, and can do it for under $1000. But if you are going to want to go further, you are starting off with the wrong foundation, and I would suggest starting with a fresh crate motor. At least then you are guaranteed to be starting off where you want to be.

_Clark

84L69TA

Id stay away from a crate motor. I havent seen a GM crate motor yet (small block) that has impressed me. A couple of years back, a friend of mine gave me a ZZ4 with 20,000 miles on it. That was the biggest disappointment. What an overrated pile of garbage. Basically a carbed L98 with a mild cam. The 350HO isnt anything either. Theres always the Goodwrench 350 which is a decent short block to start with...but by the time you replace all the garbage (pistons, head, cam), youre into it for so much money you can just pick up a good builder short block and go through it. Heads and cam is where its at, and making the right combination work. So unless you want to be stuck in the 13's at best, be prepared to spend some money any way you look at it. Most of the aftermarket providers of crate engines offer some pretty good packages, but are pricey compared to GM. Its all about how much you want to spend, and what you want the final product to be.

JamesC

iTrader: (5)

I chucked when I saw this thread and asked myself when the suggestion of a 350 would creep in (it always does at some point--for good reason, I suspect). I had a modded LG4 for some time; I enjoyed the car and learned a lot. All worth while. I now enjoy at GM crate, a 350HO Deluxe, which in spite of 84L69TA's disapproval, I get an immense kick out of.



JamesC

84L69TA

I dont have to approve or disapprove of anything. Its your money, spend it how you want. All Im saying is it didnt impress me one bit, just like the ZZ4 didnt. Im a build it rather than buy it kind of person. I want to be able to choose what pistons, what cam, what heads, and what intake goes into my engine....and for less than half the price at times, while matching or exceeding he performance level of the crate engine. If you guys want to go spend $3,500+ on a crate small block and run 13's at best...be my guest. Take a look at the Chevelle in my sig and see what it runs, (with a 3900lb race weight). I have $900 into that engine including the $50 I paid for it. Its a Gen VI 454 out of a 2001 3500. Its running those times N/A because I researched and got my combination right. Everyone is so quick to run out and buy a crate motor...but if they do their homework, they soon realize it is not the way to go in most cases. And I know someone will chime in and say "I dont know how to build a motor, Ive never done it". What better way to learn than to read, research, and do it.

JamesC

iTrader: (5)

Cool. Let us know how it goes.

JamesC

1991L98G92

To recommend a CAT back exhaust system and an open element air cleaner will improve performance would be from a salesman point of view. The CAT is the highest restriction of the exhaust system. You should not have any backpressure past the CAT. If you do, you have a restricted muffler. An open element air cleaner will be taking in underhood engine temp air, which will lead to less fuel on computer controlled cars. Just because the exhaust is louder, and you can hear the air going into the intake, doesn't mean it's performing better.

GuitarJunki17

iTrader: (1)

This is pretty much wrong to say the least. Sure, converters are restrictive, but only by a small margin compared to the choking exhaust manifolds, crappily put together Y-pipe (see pic above and tell me thats not restrictive) small diameter intermediate pipe, non mandrel bent piping, and restrictive muffler combined. Headerback systems are dyno proven, and he WILL pick up a solid number with it. If your motor can get rid of that exhaust gas more efficiently by addressing said restrictions, then you will see noticeable power gains.

1991L98G92

The exhaust manifolds, and Y pipe are before the CAT. If you read my quote, I'm talking about just replacing after the CAT (CAT back) and before the throttle body (CAI - but I can't see calling it a cold air intake when you're getting underhood temp air). You should have no more that 3 psi of back pressure before the CAT. Any backpressure after the CAT, then there is a restriction. Sure, maybe at 5000 RPM you may have some backpressure, but unless this is a "race only" car, there isn't going to be any noticable change for the amount of money thrown away at it.

sqzbox

I put a JC/wit. 3" cat back on my 305 formy and felt a difference right away.
better throttle responce, and acceleration in the bottom end. It wasn't no big power gain but the differance was noticable. I am only going to tell the guy what I have experianced and nothing more because that's all I've done along with the open element. He wanted a little for a little $'s. Now it's turned into a big debate on what works and what doesn't! BTW I'm not a salesman!

izcain

I have a flowmaster cat back for sale in the parts section if your interested. Just throwing that out there ;-)

Dizturbed One

dont mess with the motor itself aside from tuneup parts, if it runs well i'd only do a few things... spark plugs, fuel filter, oil filter and 5 fresh quarts, PCV valve, get a new filter and fluid in the transmission, and check the vacuum lines and replace any worn pieces. it won't give you any power, but will undoubtedly smooth things out a bit. then crawl under there and squirt grease into any zerk fitting you can find. these are things that tend to go from just sitting around and not using the car.

for what YOU seem to be looking for, i'd do all the free mods first, then do these in this order

open element air cleaner
exhaust (hi-flow catalytic converter and some 3" pipe with a good muffler)
get some 3.73's or 4.10's with positraction for the rear

you can get all that done for about 1000 bucks, and if you do it a piece at a time it doesn't hurt your wallet so bad.

if you still want more after that, get a shiftkit, higher stall converter, ignition box w/coil & good wires, and headers with Y-pipe. thats about another 1200 to 1500 bucks right there. less if you buy right.

if after all of this you still want more power (or are just getting obsessed with improving your car) THEN think about putting together a 350 over the course of a few months, researching and slowly piecing it together right. or else you'll spend alot of money on a 305 and get alot less power than the same money would have gotten you on a 350.

and all of the work that you did before that will still be good parts that will go well with your fresh 350.

i wouldn't touch the motor on that car. with only 50,000 miles it will probably be very reliable and give you alot of miles in the time to come while you can focus on the rest of it. by the time it's ready to go you won't have 100 other things to address on it while trying to get the motor up and running at the same time.

sqzbox

Hey sofakindom. Are you telling me that detroit is advertising HP as gross now instead of net? Back in the 70's, a 300 hp motor was only rated at advertised 280 hp net. This was a ploy by detroit to lower ins. rates. I didn't think anyone advertised or sold hp with gross #'s anymore. I would have figured that a 155 hp
engine would be closer to 175 gross. That's what I was basing my reply on. I guess things change huh?

Apeiron

No, they're still advertising net horsepower, although SAE has recently made slight changes to the test specifications.

The old "gross" ratings used to be with the engine on the dyno, no water pump, no alternator, no emissions equipment, timing tweaked, etc. The "net" ratings are with the engine as it's delivered to the customer in the car.

sofakingdom

iTrader: (1)

I don't know about all this "gross" and "net"; the truth of the matter is somewhat simpler.

Before about 71, all of the HP "ratings" that the mfrs claimed, were nothing but ad copy and other forms of monkey-spank. They had essentially no connection whatsoever with a dyno. NONE of them are remotely believable in any way. They were simply concocted and manipulated as necessary to serve a variety of masters; marketing, product liability insurance, racing sanctioning organizations, etc. Quoting those old 60s numbers is a sure-fire way to lose touch with reality. As a great example, if you were to actually build a "350 HP 327" right now, part number for part number, in the condition it came in when you bought a car with it, and put it on an engine stand, you'd be MIGHTY LUCKY to get more than 275 HP out of it. People have been falling for that "350 HP" line for 40 years now and buying that crappy cam, and then wondering why everything over the years from a stock 307 2-barrel 71 Nova to a 2006 Nissan Altima will drill them in the real world.

After 71, the "ratings" are somewhat more concrete. They are called "net", and refer to the HP produced at the crankshaft with the motor installed in the chassis it's being "rated" for, with all "accessories" "installed and operating". "Installed in the chassis" means with the air intake system, exhaust system, and actual engine attachments such as water pump and alternator present in their normal configuration. As I stated, "accessories operating" means emissions control devices (EGR, AIR, computer control, and so forth), and not A/C or power door locks or rear window defoggers or power steering with the wheels cranked all the way to one side. Problem with that is, there's basically no practical way to directly measure HP that way; those "ratings" are still estimates, being based on rear wheel horsepower which IS directly measurable, and from which crank HP can be approximated (with a healthy variation from one vehicle to a supposedly identical other one, I might add); but at least they have some basis in physical fact, as opposed to a bunch of people sitting around a table in a back room somewhere plucking a number from the air that all of their various stakeholders would be happy with. Like, every 283 HP 283 Vette made exactly 283 HP. Yeah right....

Given that there's no kind of "standard" or otherwise repeatable methodology for coming up with whatever it is that people are talking about when they say "gross" HP, I suppose one could say that the 155 HP LG4 made 175 "gross" HP. In fact, I suppose one could claim that it actually produced 255 "gross" HP, since nobody can disprove it. "Gross" HP is just a bunch of meaningless empty drivel.

Apeiron

There was SAE J245 describing how one "should" measure gross horsepower back in the day, as meaningless and perverted as it was made by marketing departments. SAE J1349 defined net horsepower, but again it could be abused. It was just updated recently to remove some ambiguity in the test conditions though. SAE J2723 now defines requirements for "certified" horsepower, and specifies things like verification by independent third-party witnesses.

sqzbox

Back in 75 I bought a 65 2+2, catalina that had 3-2's, muncie close ratio, w/ 3:42:1 posi in the rear that came from the fact. w/a 421 that had forged rod's and crank. The engine was rated at 376 hp and even Hot Rod mag. claimed that that was a consearvative #. On their test track, 0-60mph test runs went down under 5 sec. consistantly. I also met a guy that had BUILT his 440 GTX and after dyno showed me his pull #'s and was putting right at 400 hp to the rear wheels. The race was on! The next night, I beat him 3 times in a row and afterwards I pulled up to see him kicking the sheet out of his bumper because his 400hp car had been beaten by a pontiac! I told him my car was stock at 376hp and I thought somebody had lied to him about his figures. Turns out, the 421 was a little more than detroit had advertised.
You have to take into consideration that back then, they still had 102 premium at the local stations and San Diego was as close to sea level as you can get without getting your tires wet! The only reason I don't have the car today is someone offered me 10 times the 300 bucks I bought it for from a sailor that was building an MG with a small block chevy in it. The 2+2 had sat for 6 mo. and needed a battery and a rebuild kit in the center carb.

Damon

Start with a COMPLETE exhaust, including headers, y-pipe, high flow cat (or straight pipe if emissions aren't a concern) plus a complete 3" cat-back system.

THE ENTIRE LG-4 EXHAUST SYSTEM IS JUNK AND WON'T FLOW ENOUGH AIR TO FEED A BIRD. All of it must go. That's the very first thing I'd do after a good tune-up. You can't even put in a bigger/more powerful motor until you've done the exhaust becuase it won't be able to breathe through the stock exhaust. So you need it whether you want to hop up your LG-4 or just drop in a bigger motor later. This is where you'll spend the most money.

The LG-4 in 1986 isn't really too bad. At least it has the higher 9.5:1 compression just like the higher output L-69 and it uses the same heads. Really, it IS the basic hardware of the L-69 HO motor but with a smaller cam and the afore-mentioned restrictive exhaust system. Beyond that the remaining differences are in the carb jetting (easily changed), the ignition advance curve programmed in the chip (also easily changed) and the air cleaner (also easily changed).

Full exhaust system, Summit 1102 cam, DR rods in the carb secondaries, better air cleaner, a chip change or bump the timing and you're going FASTER than a factory L-69 HO car by a fair bit.

five7kid

iTrader: (14)

Gads, people, all the "make 305 faster" stuff is discussed in the 305 thread on the FAQ forum. Why are we reinventing the wheel?

Once you're tired of that, you do what's in my sig. Basically, I did to the 305 what's recommended in the FAQ thread, then did the 4" bore kit.

The 305 mods took a second off of the "free" mod'd 305 1/4 mile times, and the bore kit took off another 1.25 sec.

Dizturbed One

it's not really "what's everything i can do to make my 305 faster" though

it's more like "what is a good plan to to make my 305 faster on a budget"

anyone can get a motor and start doing anything to it. if you're on a budget you need to plan it out well, or you might be stuck with a half done project and no motivation.

five7kid

iTrader: (14)

I would argue that the FAQ thread is the "budget" approach. Max'd out 305 is not what you'll get if you follow those recommendations, but you will have a very streetable (and emissions legal, if necessary), much improved ride.

Of course, one person's "budget" is another person's "fortune". $1000 for exhaust (of the emissions-legal variety) isn't the conventional defination of "budget", but without it, nothing else you do is going to help much.

In my opinion, spending money on the wrong things is never part of "budget" (for instance, an Edelbrock carb, without doing anything else). That's the "carefully planned" part, which again the FAQ thread addresses.

Dizturbed One

i agree with you completely

which is why, in my post above, you see i started out with the cheaper stuff that tends to bottleneck the other stuff first. that way, if he's happy, he can stop. if not, nothing has been wasted. and when it's all said and done, all of that money has went into parts that he can still use on a 350 later in life. Also, with all of those parts, you wouldn't need to build a 350 beyond stock smogger specs to have a very peppy car that would be reliable as hell.

if he catches the bug down the line, chances are he won't be happy with the 305 in any case. this way, he'll know if he wants a 350 before he puts money into the 305 itself. money that will be thrown away (or get very little return) when (if) that 305 goes out the window.