Epro

Has anyone made these engines perform?

__________________


Do you drive a domestic vehicle? Then you my friend, are a misfit.

THE PITS = Home of the misfits!

Stekman

They can be made to perform however you want them to. Namely, for whatever amount you dump into it.

I had an LG4 in my Caprice a year ago:
Ported 416 heads
Comp xe256h cam
ZZ4 intake
Edelbrock 600 cfm carb
Mallory HEI ignition

The thing ran fine for me. Good guts for an LG4 that was a daily driver. In your case, though, if the carb and ignition are still working, probably in your best interest to keep them as they optimize fuel economy.

sofakingdom

No, no one. Ever.

Seriously...

The choke points in that setup are, in the order they should be fixed:

1. Exhaust
2. Cam
3. Air cleaner
4. Electric fan
5. Gears
6. Heads
7. Converter (if it's an auto)

Notice that at NO POINT did I mention the carb, intake, or ignition system; hacking off any emissions eqpt; aftermarket "chips"; add-on ignition boxes; or other typical wastes of money. The reason those are wastes of money, is that THEY ARE NOT THE THINGS LIMITING THE CAR'S PERFORMANCE. Note also that I said "car", not "engine"; as not all of the things that make those slow, are under the hood.

1. Exhaust - needs to be replaced, as an entire unit. Every piece from the heads to the back bumper. The replacement MUST NOT be designed to fit LG4; because if it is, it will PRESERVE the LG4 exhaust bottleneck, namely, the itty bitty Y-pipe. Get one of the quality brands of headers SPECIFICALLY for one of these cars, BUT NOT for the LG4; get the ones for a TPI 350. Get a high-flow cat such as a Catco from Summit, and your choice of cat-back. All of this for something like 89 TPI 350 without G92 (single-cat setup). This will retain emissions legality (except for the EFE valve).

2. Look at cams in the 210 - 215 degree @ .050" range on the intake, with a larger exhaust lobe. Comp's XE256 and XE262 are known to work well. Crane has cams of somewhat similar specs that also give good results; I think it's the Energizer 272 but I could be wrong. Lunati's new Voodoo series is the right design for this, and may have something in the right duration range for it. Whatever cam you pick, avoid choosing it based on "sound"; any cam that "sounds" "good" will probably be too much for the rest of the engine and car. Replace the valve springs and their hardware, and the timing set, along with the cam. DO NOT try to use a modern cam under stock springs; you'll probably break something.

3. Get a dual-snorkel one from L69. This will give several HP over a typical open element, since it will give the motor cold (dense) air instead of hot, thin underhood air.

4. If your car has a clutch fan, it uses a good solid 12 HP just to run the fan. An electric fan will give you back those HP. Watch the classifieds on this site for a used fan setup.

5. Those cars were always the "sacrificial lambs" to CAFE in the V8 F-body product lineup. At the time they were new, the people who bought them were looking for the "image", not the "substance", of performance. Since anybody that was buying a new car and was seriously interested in performance avoided those like the plague, I guess GM figured they could nut them as much as they wanted to get their fuel mileage up, and nobody that bought them would care (might even like them better in fact, if they were cheaper to drive; no matter how slow). So they always got crappy gears. The best they ever got, standard, was 3.23; and most years they got 2.73 or the like. 3.42 or 3.73 makes an AMAZING difference to a 2.73 car. If yours already has 3.23s, it's not quite so urgent; but once you get the motor to breathe, it will benefit from 3.73s. In stock condition though, 3.73s will force the engine RPM so quickly up into a range where the motor has no power, that it won't really be any faster than stock; even though it will feel like it has this huge launch off the line.

6. The heads themselves are fine, entirely adequate for 305; except that they can use some porting, and larger intake valves. There is a great deal of HP available here.

7. This is like gears. The stock converter pins the motor to a very low RPM range, especially from a stop. Once you get it to where the motor has some higher-RPM power, letting it rev up when you punch it will give it a much harder "leave".


I cannot emphasize enough, RESIST THE TEMPTATION to un-bolt and re-bolt big shiny things that sit up there where everybody can see them, on top of the motor. There's an old saying you'll hear at the race track, from the people who WIN: "Chrome don't bring the money home". People who spend their limited cash on "dress-up" are choosing the path to a slow expensive car that loses races.

The parts that produce performance are INVISIBLE. Don't let that discourage you from doing the right thing. Spending your money on things you can "see", will produce little or no results; except maybe, the car will be lighter, because the driver's wallet will be thinner.

Which reminds me of another whole set of things you can do to make the CAR faster; and that is, lose weight. I don't advise hacking stuff off; few things make me puke as bad as all the people who hack off their AC, for example. But, any time you replace something, make an effort to get something lighter in its place. For example, a "mini-starter", a plastic/aluminum radiator instead of copper/brass, an aluminum drive shaft, lighter wheels, lighter flywheel if it's a 5-speed, aluminum bumper support to replace the steel one, the 82-83 "composite" hood, etc. etc. etc. You can shave an easy hundred pounds off of it that way, maybe more.

__________________
Numquam ponenda est pluralitas sine necessitate.
— William of Ockham, from Quaestiones et decisiones in quattuor libros Sententiarum Petri Lombardi

Roughly paraphrased into modern English, and applied to figuring out what's wrong with your car:

The simplest explanation that fits all the facts is probably the right one.

naf

Sofakingdom has some good advice, although I'm not sure if he writes it up on the spur of the moment or does the cut/paste from a library of pre-written advice.

sofakingdom

Good idea!! Maybe I should do that, keep from making my fingers so tired.

__________________
Numquam ponenda est pluralitas sine necessitate.
— William of Ockham, from Quaestiones et decisiones in quattuor libros Sententiarum Petri Lombardi

Roughly paraphrased into modern English, and applied to figuring out what's wrong with your car:

The simplest explanation that fits all the facts is probably the right one.

Fast355

I will add some info to sofakingdom's advice.

A.) If you decide to port the heads, I would pick up a pair of 601s from the wrecking yard. They are like mini 462s in the chamber, have better flowing ports than the 416s stock, and have a 52 cc chamber. That will bring the otherwise stock LG4 from 8.6:1 compression to about 9.2:1. This will add compression and flow, which will increase HP.

B.)The CCQ-Jet is VERY adaptable by changing out mechanical parts and settings. The limiters on the mixture control solenoid can be adjusted to put out the correct air/fuel ratio on the primaries. There are many different primary jet/metering rod combinations from the general. Some cars came with big jets/big rods(V8 4bbls) and some cars cam with smaller jets and smaller rods(V6 2bbl such as the 3.8). Dual Jet metering rods and jets will swap to a Q-Jet. Combine the bigger jets with the smaller rods and viola, more fuel flow on the primaries. Don't worry though as you can set the limiters. The secondary metering rods and jets can be tailored to provide the best WOT power.

C.)If you could find a L-69 chip, they are best for performance and could actually increase the fuel mileage some. Short of a L69 ECM or chip, you might find that boosting the base timing to between 4-6* will add performance and MPG.

five7kid

The '85 & '86 LG4's had 4-relief flat top pistons, bringing compression up to 9.5:1. '87 has slight dish pistons that dropped it back down to 9.3:1. On those engines, 52cc chambers may raise compression too much.

'86 & '87 had the electric radiator fan.

I never had mine on the dyno, but from dragstrip performance it calculated out to around 250 RWHP at sea level. Not bad for a stock bottom end.

Did anyone mention not bothering to rebuild a stock bottom end?

__________________
82 Berlinetta #1, orig V-6 car. '86 LG4 swap. Mods: Rebuilt ZZ3 shortblock, self-ported World S/R 305 heads, roller tip 1.5 rockers. ZZ3/4 intake & cam, dual snorkel. Accel coil & module. Jet Hot coated Hooker 2055 headers, 3" catback, Magnaflow. '83 TH700, 2500 stall, shift kit. 3.23 limited slip. Spohn SFCs. Daily yr-rnd driver. Best 14.20/96.4 @ 5800' Bandimere (13.17/103.8 @ sea level).
82 Berlinetta #2. 301k orig LG4 California car. Beautiful condition. 2000 SS LS1/T56 swap WIP.
57 Bel Air, my 1st car. '66 396, mild rebuild, self-ported heads, XS282 cam, Holley/Proform/QFT 750DP on E85, RPM AG, dual-snorkel cool-air inlet, Hedders. TH400 w/3500 stall. 8.2" 10-bolt w/3.73 & Powertrax. Best 13.15/101.54 @ 5800' Bandimere (12.23/109.4).

85cmroz28

Here's a good thread for getting some performance out of the 305

http://thirdgen.org/techbb2/showthre...hreadid=333467

__________________

----Mods on the way-----
**Looking for a new or reman 350 4 bolt main***, hooker headers, glasspacks, sidepipes

five7kid

There is this one, too http://thirdgen.org/techbb2/showthre...hreadid=261488 .

In FAQ, no less . . .

Fast355

I run 4-relief flat top pistons(-6 cc total), 55 cc chambers(angle milled and CCd 081s), .010 deck height, and a .029 nominal compressed gasket. That is 10.3:1, it runs fine on 93 octane gas with 32* total advance. I am injected however and have a cam that has a fair amount of overlap.

Epro

Exhaust:

Would this product fix the exhaust problem?

http://www.slponline.com/view_product.asp?P=31007

Or would it be necessary to add headers?

(Note: Edited by Moderator to eliminate the long quote, that wasn't even referenced in the next question. Guys, there's no need to "quote" just to reply!)

__________________


Do you drive a domestic vehicle? Then you my friend, are a misfit.

THE PITS = Home of the misfits!

sofakingdom

Yes, that exhaust would be an excellent choice; in conjunction with their 30000C headers, the 30018 "install kit", the 30038 cat adapter, and a 3" slip-fit cat such as this one here. Or, if you think you might ever change to a 350, which would need the larger primary tubes, get headers 30001C instead; all other parts the same.

A cat-back won't do too much to fix the restrictive cast-iron manifolds with undersized outlet ports, or the Y-pipe that's not much bigger than a garden hose. In fact, it's questionable whether the cat-back by itself, would make any noticeable difference at all, by itself; since those bottlenecks in front of it would still be there.

__________________
Numquam ponenda est pluralitas sine necessitate.
— William of Ockham, from Quaestiones et decisiones in quattuor libros Sententiarum Petri Lombardi

Roughly paraphrased into modern English, and applied to figuring out what's wrong with your car:

The simplest explanation that fits all the facts is probably the right one.

Epro

Thanks for the info, I just learned a lot from reading that!

But for all the time/money spent on an LG4, wouldn't it be smarter to just drop one of these in?

http://www.jegs.com/webapp/wcs/store...0763&langId=-1

It comes with headers. Would everything from an LG4 just bolt right in? Because that sounds a little too good to be true

Fast355

It does NOT come with headers!!!! A 350 would be a great start, if you wanted the added expense.

sofakingdom

No that doesn't come with headers.

That's the crappy phone-company-van replacement motor. They might call it "260 HP", and it might actually make somewhere near that, with a big intake and Holley carb and open headers and no accessories; but it made 165 HP when it was installed in cars in the 70s. Yes, the EXACT SAME MOTOR, part number for part number. You got your 993 heads, your 929 cam, your 8.2:1 compression, all right there in a crate, instead of in a 74 Impala. Still the same thing though. Which means, it'll probably make about 165 HP in one of these cars, too.

The L69, or the better TPI 305s, will run circles around that thing.

Yes it can be made better. Yes a magazine did a write-up on it, and eventually got it up to 370 HP or something, with some Vortec heads and a different cam. But by the time you do that (buy a whole motor, take it apart and throw half the parts away, and then buy more parts to replace the ones you threw away), it's not "economically attractive" any more. That is, you can get A WHOLE LOT MORE POWER, for the same or less money, some other way.

And of course, it doesn't address ANY of the problems with the CAR: gears, converter, exhaust, air cleaner. Even if you buy that motor, you still need to change the cam just like you need to change the LG4 cam, and then do all those other EXACT SAME THINGS that you would have to do to the LG4. In other words, it's not some kind of a shortcut to upgrading a LG4 CAR, that replaces doing all those other things.

__________________
Numquam ponenda est pluralitas sine necessitate.
— William of Ockham, from Quaestiones et decisiones in quattuor libros Sententiarum Petri Lombardi

Roughly paraphrased into modern English, and applied to figuring out what's wrong with your car:

The simplest explanation that fits all the facts is probably the right one.

naf

There are long block crate options that are attractive if your current LG4 is tired and high on miles. The 350 HO and ZZ4 come to mind. You can use your current intake, distributor and accessories. With the addition of headers/exhaust you'd have a crate combination "around" 300 hp. You may still want to upgrade the rear-end and tranny.

My camaro has a vortec headed 350 a "mild" performance cam, headers, 2200 stall, transgo shift kit and 3.27 nine bolt. It's fun, but would get tiresome driving it every day. I drive the LG4 trans am to work every day (65 mile round trip). It's a comfortable cruise and averages 23 mpg (mixed). I plan to one day open the exhaust, install an electric fan (mainly for aesthetics) and CAI, but I'll probably leave the 2.73 (original 3.08 died and was replaced) rear end and trans/converter alone-these things will affect mpg and driveability. All depends what you're looking for.

Epro

It says it comes with headers

It produces 260hp and 350 ft/lbs of torque with a 4bbl carb and headers.

Thanks for the info though

I'm not sure if I have that kind of money though. I seen how much those headers were going to cost! Any place to get them cheaper? I really can't justify the cost of those headers...

Epro

http://www.thunderracing.com/catalog...&vid=6&pcid=52


Which the $150 one do any good?

I'm sorry, I'm still trying to learn...

Epro

naf

Try Jeg's, Summit or Scoggins-Dickey. Headers and y-pipe can be had from 250-350 and cat back (w/cat) for around the same.

If you want to go the cheap route you can find some 305/350 TPI logs and y-pipe at a j-yard and hook up an inexpensive cat and cat-back to it. The logs won't get you in tire screaming territory but it's a definite improvement over existing and practically a give away at the yards. Worth the install effort? Let me know.

naf

Missed your earlier reply. Either of those headers will do but you'll have to add a y-pipe (around another $100).

Epro

Hey,

for an air cleaner, would this work?

http://www.hawksthirdgenparts.com/inc/sdetail/2007

Or is there a difference between an air filter and an air cleaner?

Epro

http://www.thunderracing.com/catalog...&vid=6&pcid=51

Which cam?

sofakingdom

It also doesn't say anything about including either the 4-bbl carb OR the headers; they're not in the text, and they're not in the pic. One can assume that it requires gasoline and spark plugs as well, to produce 260 HP; but you gotta buy those extra too.

I'd advise against cheep headers. You'll hate them for every minute you own them. Save up and get good ones.

About the cheepest ones that you would not hate forever, would be the Edelbrock TES. They actually FIT the car (no small matter) as opposed to simply being associated with the car; they fit the stock exhaust, no "custom" work required; and can be bought ceramic coated. Look at the same 350 TPI application for the headers.

Other mfrs of cat-back exhausts may also cost less; but you also won't get stainless steel like the SLP, except from Borla. Edelbrock, Hooker, Slowmaster, Dynomax, etc.

The coating, by the way, is definitely worth every penny. You'll spend that much in replacing other parts under the hood that get scorched by the heat, without it. It will make you money over the long term.

Those cams are all roller cams, which you can't use. Here's the XE256 as an example of a cam known to work well in that motor.

__________________
Numquam ponenda est pluralitas sine necessitate.
— William of Ockham, from Quaestiones et decisiones in quattuor libros Sententiarum Petri Lombardi

Roughly paraphrased into modern English, and applied to figuring out what's wrong with your car:

The simplest explanation that fits all the facts is probably the right one.

Epro

For Headers and Y-pipe, what about hedman?

http://store.summitracing.com/defaul...1&autoview=sku

http://store.summitracing.com/defaul...9&autoview=sku

Combined it'll cost me $350 CAD to have it shipped to my door, and that seems good

That cam is priced really well too

naf