ViciousZ

iTrader: (1)

I'm looking into buying an LG4 car for my daily driver, but I'm kinda disturbed about driving a 16+ second car. So my question is: what made the LG4 suck so bad?!?!? Was it the intake? The carb? Heads or cam??? Or all of the above?
And what could be done to improve upon it's performance?
Right now I've got several spare parts laying around just beggin to be put on an engine. My arsenal consists of: an Edelbrock 600 carb, edelbrock Performer intake, hydraulic cam .442/.465 lift, 214/224 dur, 112 LSA, a set of 76cc 882s (probably not useful) and a set of L98 heads.
These parts may or may not be appropriate...
Tell me what you guys think!
Oh yeah, and what cc are LG4 heads?

Mark A Shields

The cam in it was horrible, known as a peanut cam. The heads didn't flow well. The stock manifolds and y-pipe were restrictive.
The intake wasn't that bad, the q-jet is among the best carbs, just needs to be properly tuned.
If you go with a NON CC carb be sure to get a vacuum advance distributor.

Sitting Bull

The LG4 heads are 58cc, thus the 882s are out of the question. The L98s will work well, though. The other parts will all work very well, even if the .465 lift is a tad too high--.450 or thereabout might be better but I think it will still work OK.

With those parts and headers and 3 inch exhaust, you will have a mid-14s car. Add a 3.42 rear end and 2200 rpm toque converter and you should be veru low into the 14s or maybe even high 13s

ViciousZ

iTrader: (1)

Yeah, I've got a vacuum advance distributor as well, but it's the coil in cap style. I suppose that will not fit, will it?
As for the L98 heads, should I bother milling them, or would it be better/easier to just take the drop in compression? And will the valves be shrouded? What about a 350 head gasket? Can I use it on a 305 if I use L98 heads? Hehe, I'm making this a heck of a budget buildup!

Mark A Shields

I have the coil in cap style.

sleeper

I had the exact parts that you are talking about on my car a few years ago. Only difference is I have a 350.

Here's what I found:

The 882 heads were garbage. They dropped too much compression in my larger 350 bores and couldn't keep up to the headers and larger cam (mine is a 214/224 - same lift - from Weiand). As a result I had no low end torque but it was the fastest the car ever ran (the car would still pull at 170mph). This problem may be less noticable in a 305 because of the smaller bore... however the dished pistons arn't going to help.

Unless you bought an 87 or later intake then the L98 heads won't match up. They aren't that great anyway.

I'd find a set of 305 HO heads and have them rebuilt with new springs - .465 lift on stock springs won't work. These heads have 1.84/1.50 valves, 64cc, and flow pretty well. Whenever I come across them they are about $300 already rebuilt.

You need a standard, coil in cap variety, dist. with vacuum advance.

With your parts, plus the 305HO heads, a 3.42 gear, and a 2600 stall I'd put you at 250hp (80 over stock) and mid to high 14's. It seems like a waste of time to buy the car and do all this given that a L98 has 240HP and runs 14's out of the box.

five7kid

iTrader: (14)

For a daily driver, the LG4 really isn't that bad.

But, it can be made more fun to drive...

The intake and carb are not the problem. Air cleaner is. Exhaust is. Cam is. Heads aren't great, but can be improved.

Keep the CC carb & distributor. Good for driveability and economy. Improve the coil & module, though.

Get a dual snorkel air cleaner. End of that problem.

HEADERS, HIGH-FLOW CAT & CAT-BACK! End of exhaust problem.

Cam. Like said, peanut cam terrible. Crane PowerMax (like 2030 or 2040) or Comp XE (like 256) will wake it up and keep it streetable (even my 2050 is very streetable with the higher stall converter). Is this car an '87? If so, it'll be roller. Keep it roller if possible. The year of the car is also important because '84-earlier LG4's had dished pistons, '85-up had flat top. The latter is better for hopping up. (EDIT - the cam you already have may fill the bill.)

The heads are 58cc (LG4 and HO L69 used the exact same heads). If you use any iron 350 head, it should be 64cc (like L98) then shaved down to 58cc volume. Aluminum 350 heads could be shaved to something like 54 or 52cc, but you could get away with leaving them alone. But, the best choice, if you can afford the down-time, would be to work over the stock heads - 1.94" intake valves, bowl cleanup, port matching, polishing. Do it yourself, great bang-for-buck (well, have the larger valve seats roughed in by a machine shop, do the port work, have the valve job finished). Put on new valve springs to match the cam while you're at it.

You've demonstrated you're willing and able to do the wrenchin' (I still think you stay too clean, though ). Ready to step up to the die grinder?

sleeper

LG4 and HO heads are NOT the same head... when was the last time you saw a reqular 305 with 1.84/1.50 valves? Further they are 64cc from the factory... I had mine surfaced to make sure they were flat and then cc'd them at 63

my 86 LG4 had dished pistons

the edelbrock carbs are far easier to tune than the Q-jets...

rather than shaving heads and buying new/larger valves (which isn't very cheap) why not buy the right part for the job in the first place? You can also raise the compression by using thinner head gaskets

five7kid

iTrader: (14)

Let's not get into a shootin' war here, but...

You sure somebody didn't sneak a 350 into your car? The dished pistons & 64-ish cc chambers sound like 350 info. Did you measure the bore or do anything else to the rings/pistons when you had it apart? Got casting numbers? What type of rear main seal does your engine have? What type of cam/lifters? What type of head gaskets were on it when you took it apart?

All factory 305 heads were 58cc. Some had smaller valves, but all F-body engines got 1.84/1.50" valves. '85-up LG4 got flat top pistons with 4 valve reliefs. The factory used thin steel shim head gaskets.

I had my LG4 apart in November (#'s matching from the donor car, VIN code H, single snorkel air cleaner, 2" exhaust, never been opened up) and confirmed all of the above. 14014416 casting heads, 1.84/1.50" valves, flat-top 4 VR pistons, 3.736" bore, one-piece rear main seal, steel shim head gasket, flat tappet cam.

Now, on the other hand, this '87 LB9 I had intended to use had 3.776" bore, dished pistons with no valve reliefs, .010"-under bearings, one-piece rear main seal, roller lifter cam, two different casting # heads (both were 58cc and had 1.84/1.50" valves, though), composite head gaskets. Obviously, it had been rebuilt at some time (too bad they didn't notice those cracks in the lifter valley).

CC q-jets require some tweaking for best performance, but no tuning after that. I've barely touched mine (idle speed, choke idle speed, choke pull-off, AV tension, rods & hangers). I'll take that to "tuning" an Edelbrock or Holley or whatever non-CC carb any day.

As for buying the "right" parts, just this once, I restrained myself from recommending World Products S/R Torquer 305 heads. Now look what you've gone and made me do...

Again, don't want to start a war here, just don't want inaccurate info to get passed around. Get casting #'s, check mortec.com, check the tech data on this site, whatever. I've got plenty of catsup for the crow I'm willing to eat if proven wrong (tastes like chicken...).

85_ZED28

325 horsepower 305 cid Chevrolet V8
(Built with simple bolt on mods!)

This information is a brief summary of an article that appeared in the March 1999 issue of Car Craft magazine. If you are seriously interested in this build-up, I suggest that you find a copy of that issue.

305 BUILD-UP PART 1.
Car Craft started out with an 80,000 mile (130,000km) 305 LG4 engine from a 1982Camaro. They removed the engine from the Camaro and put it straight on the dyno withheaders, 3" dual pipes to Flowmaster mufflers, and a HEI distributor with 22 deg totaladvance. This gave a baseline dyno result of: 197 HP @ 4,000 rpm. 261 ft/lb torque @ 3,100 rpm.


305 BUILD-UP PART 2.
Added an Edelbrock Performer EGR intake manifold, but with the EGR blocked off. 217 HP @ 4,200 rpm. 285 ft/lb torque @ 3,300 rpm. This is an increase of 20 HP and 24 ft/lbs over stock.


305 BUILD-UP PART 3.
Replaced Edelbrock Performer EGR intake with an Edelbrock Victor Jr single plane intake manifold. Replaced Q-Jet carb with a 750 Holley double pumper. 217 HP @ 4,200 rpm. 285 ft/lb torque @ 3,300 rpm. This resulted in no change from the previous mods, maintaining the increase of 20 HP
and 24 ft/lbs over stock.


305 BUILD-UP PART 4.
Added Comp Cams XE262H-10 "Xtreme Energy" hydraulic flat tappet cam. 218/224 dur @ 0.050, .462/.469 lift, 110 deg LS. Set initial timing to 16 deg BTDC. 270 HP @ 5,100 rpm. 291 ft/lb torque @ 3,800 rpm. The cam change resulted in a huge increase of 53 HP. Torque was up by 6 ft/lbs.


305 BUILD-UP PART 5.
Replaced stock cylinder heads with World Products 305 S/R Torquer heads. 298 HP @ 5,500 rpm. 308 ft/lb torque @ 3,900 rpm. A 28 HP increase over the stock heads, and the 305 engine now has close to 300 HP.


305 BUILD-UP PART 6.
Replaced World Products 305 S/R Torquer heads with '96 - '97 Chevy truck L31 Vortec cast iron heads, GM P/N 12558060. These are available from GM dealers in the USA for US $408 a pair, fully assembled. The Vortec heads require a different intake manifold, and Car Craft chose an Edelbrock Super Victor. They kept the same Holley 750 DP. Car Craft says that these heads are a bolt on for conventional small block Chevy engines. If your engine is earlier than '87, you will also need a set of self aligning rocker arms, and a pair of "center-bolt" valve covers. 325 HP @ 5,800 rpm. 317 ft/lb torque @ 4,800 rpm.


TECH COMMENTS

With peak torque at 4,800 rpm, the 325 HP 305 would definitely need some stiff rear end gears (I'd suggest a minimum of 3.7 ratio) plus a high stall converter if the car had auto trans. In my opinion the WP Torquer heads are the better choice for a street engine. I think that a 300HP 305 with 308 ft/lbs at 3,900 rpm, would be a nice street /
strip combination.

sleeper

It seems this post has strayed pretty far from what Vicious Z wanted... I'm tempted to let it go but I don't like looking like an idjit...

The part number for the HO heads is 14014416... these are the heads I watched my engine guy rebuild... he then cc'd them at 63. Given GM's "creative" production methods from year to year there may be a difference. I don't have my GM shop manual here so I can't look up the separate years. Mortec is a third party and does not have all the part numbers so I don't think they should be seen as omnipotent.

Five7... You are the luckiest man in Qjet history if you can just slap on carbs with no adjustments. Most require rejetting, tuning, hanger rods, etc... based on elevation, car weight, camshaft, etc... check this site...

http://www.dapa.org/frazier.htm

I'm on my 4th Qjet and I've gotten pretty good at playing with them... after I watched my friend spend 10 minutes adjusting his Edelbrock vs 1 hour on my qjet I just can't say they are a friendly carb for the aftermarket. They require too much learning before you can get good results.

The 305 I was refering to has long since been sent to the scrap heap...I'm now left wondering if Canada put dished pistons in 305's vs flat tops in the US engines... it had definitely not been rebuilt.

five7kid

iTrader: (14)

I agree, it's strayed from the original question (somewhat) - sorry, Vicious. It is only relevant to the original question in that you need to understand what parts you've got and what will work well together. I left it overnight to see if anyone else ventured; no, so I'll take one last stab at it.

Ah, Canada! I didn't figure that, with a location "Clearwater, FL" under your name. Very definately things were different between what was delivered there vs. in the US. With no CC controls, no knock sensor; no knock sensor, less compression (dished pistons). Makes sense, anyway, haven't heard anybody say anything like that in the past. That's the same casting # as the heads I took off my LG4. Did your machinist do anything else to them? I agree, Mortec is not omniscient, a lot of details missing, and I saw at least one outright error. Still doesn't explain the chamber cc's you observed.

As far as the q-jet, I've had a bunch of them over the years. This is the first CC q-jet I've had, and is by far the best of any of them (including the new Edelbrock Performer q-jets - have two of them). If I'm just lucky, then I'll accept that as well (I prefer "blessed"). Staying CC, though, should be one's first choice for cost (if you're buying new non-CC stuff, anyway), performance, and economy (feedback system more efficient, TCC lockup still works, etc.).

Bottom line: For performance, the LG4 heads are part of the limitation as delivered from the factory. Either work them over good, or get another type of head that is taylored to work on a 305. 76cc 350 heads are NOT the way to go, no matter what!

GreenProStreet

Just wanted to add,

The 305 is a high stroke to bore relationship, like a 383. This tend to move the power band down to street only situations. Like I said in another post, Et is all about top Hp, so the Et for a 305 doesn't do the engine justice, because it is not using it true powerband or area.

five7kid

iTrader: (14)

She's building a daily driver, just wants more spunk. For that, a 305 is just fine.

Okay, I can't shut up. Sorry, everybody. You've got L98 heads sitting around - have them ported, shaved to 58cc (about .040" off), get the intake shaved to match, bolt 'em on along with the other improvements & go.

FWIW, for a daily driver, TPI makes a little more sense than carb. But, carb will be cheaper to buy, that's for sure.

ViciousZ

iTrader: (1)

Thanks for all the input guys, but I think I'm gonna pass on this car and wait for a better deal. Anything with less than 200 hp is a big no-no for me. But as far as money goes, I'd rather pour it into my Z, which is now transmissionless, I might add.

Sitting Bull

It is simplicity itself to get a 305 over the 200 hp mark. Read the mods in my sig and go for it!

five7kid

iTrader: (14)

Bull, just curious: Do you know whether or not you have dished pistons? (Just can't let go, don't 'cha know...)

Zepher

iTrader: (1)

I have dished pistons in mine. I saw them when I took the LG4 heads off and replaced them with LB9 heads.

This is my Edelbrock topped LG4 from last year.

199RWHP and 275RWTQ.

five7kid

iTrader: (14)

Can you describe what the top of your pistons looked like? Are you absolutely sure it had not been rebuilt and dished pistons used? (I picked up an '87 LB9, turned out that's what had happened to it - NO LB9's ever got dished pistons from the factory, and certainly not .040" over...)

It is possible a dished piston engine got into your car. Do you have any idea of the car's original country of delivery (like Canada)? Are you sure it is an '86 engine?

I'm not trying to nit-pick or defend myself, I'd truly like to know what's out there when people ask what to do to their car. One point of compression made a 10 hp difference as stated by the factory, the difference becomes more pronounced as other improvements are made.

Zepher

iTrader: (1)

My pistons look like they have 2 half moons on the top.
Maybe I have domed, don't know what mine are called, I just know that they aren't flat.

Sitting Bull

I haven't had the heads off yet. But the 86 is supposed to have 9.5:1 compression and 160 hp, so that would dictate a flat top piston.

Zepher,

Valve notches don't count as dished pistons. They sound like flat tops. Dished pistons look like a dinner plate on top, they really are dished.

Zepher

iTrader: (1)

Oh, ok. I guess mine are flat top.
I am still learning engine fundamentals.

ViciousZ

iTrader: (1)

Oops. Looks like I started a war here.
Valve notches, better known as valve reliefs.

Originally posted by Sitting Bull:
Yeah, I know. I took my 305 TPI camaro from about 185 to 250 without ever lifting a valve cover. But I'm not wanting to mod my daily driver too much. I just want a car that RUNS. Can I have a car that runs? Please? Please?!?! (still pouting over the tranny)...

Originally posted by Five7Kid:
I was repacking my wheel bearings this weekend (by hand) and I almost thought to take a picture for ya!

Sitting Bull

My mods give you an excellent daily driver. They are basically dumping every little bit of polution gear (is deputy Festus gonna give you a ticket for that?), adding headers, 3 inch exhaust and good aftermarket intake. All of this will tranfer straight over to a 350 when that time comes.

sleeper

all right... I have the answer to this head question now. I should have seen it before but I was obviously not paying attention

Part number 14014416 is not the HO casting number. I should have seen the "441" and picked it out immediately. It is the stock 305 head just like the "882" casting is the stock 350 head. Notice the relationship between the numbers.

The HO head casting number is 14014440... Mortec incorrectly states that they were only available in 1980 but they were actually available from 80 to 86. They are a 64cc head. Now that I have the proper number I'm going to see if I can find flow numbers somewhere for comparision.

84Camaro305

85_ZED28:
Any idea what kind of gas mileage that car got? Doing a few of those mods to my car sounds like a good idea since I'm rebuilding the engine anyway. It'll save some money on reworking some parts.