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09-28-2004, 02:45 PM
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#1 | | Moderator
Join Date: Mar 2000 Location: Littleton, CO USA
Posts: 26,852
Car: 82 Berlinetta(2)/57 Bel Air Engine: 86 LG4-> ZZ3(LS1)/mild 396 Transmission: TH700(T56)/TH400 Axle/Gears: 3.23(4.10)/3.73 | Differences between 305 engines, performance tips
There was only one engine called "HO" in 3rd gens - the L69 (VIN code "G") from '83-'86. There seems to be a lot of confusion over what made it "HO", so here are some basics.
At least in 3rd gens, LG4 (VIN code "H") and L69 used the same head castings, 416 from 1982-1986, and 081 for 1987 LG4's and '87-up LB9's (VIN code "F"). The '85 & '86 LB9 also used the 416 casting. The chamber size (at least as far as the factory is concerned) is determined by the casting. Therefore, LG4, L69 and LB9 will all have the same size chambers.
The '82-'84 3rd gen LG4's had lower compression because they had dished pistons in them, which, when combined with the 58cc chamber 416 heads, produced 8.5:1 compression ratio. The L69's and '85-'86 LG4's & LB9's had flat top pistons with 4 valve reliefs that, when combined with the 58cc chamber 416 heads, produced 9.5:1 compression ratio. '87-up used a slight dish piston with 4 valve reliefs that reduced compression to 9.3:1. The factory typically used steel shim head gaskets, although they have also used composition in later years. And, for the record, 3rd gen LG4's, L69's, and LB9's all used 1.84" intake and 1.50" exhaust valves.
The L69 had a better cam, larger exhaust manifolds and exhaust all the way back, different PROM tuning, knock sensor ('85-up all 305's have knock sensor), different carb calibration, dual snorkel air cleaner for Camaro, cowl induction for Firebird, and electric radiator fan ('86-up all 305's have electric radiator fan).
If you want to improve the performance of an LG4, you do the following: Replace all of the exhaust with headers, y-pipe with 2-1/2" downpipes to 3" at the cat, 3" cat, and 3" cat back to 3" inlet muffler (single 3" outlet or 2 x 2-1/2" outlets is your choice). Replace the cam with something with a little duration and lift (the Crane 2050 worked well in mine). Replace the valve springs with something that can handle the lift of the cam. Upgrade the ignition coil and module with aftermarket pieces. Replace the single-snorkel air cleaner with a dual snorkel unit, either a factory type (Camaros), or fabricated one (see the tech articles on the Board home page, or Link to Home Made Dual Snorkel Post (Home-Made Dual Snorkel - $10 and a few hours work) for the latter). If you want, further improvements can be obtained by having the heads reworked for 1.94" intake valves, and cleaning up the port bowl area (do a search for porting, you'll find out what is required). Pinning the rocker studs or having the heads machined for screw-in studs is a very good idea with an upgraded cam & springs. If you want, you can put an aftermarket performance intake on it such as the Weiand Action+ or GMPP q-jet intake manifold. Most of this will also help an L69 or LB9.
If you have an LO3 TBI or LU5 cross-fire - well, those are special cases and you're on your own...
jk, check out the TBI forum "Important/Useful" stickies.
__________________
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 14.32/95.5 @ 5800' Bandimere (13.28/102.8 @ sea level).
82 Berlinetta #2. 301k orig LG4 California car. Beautiful condition. Will be recipient of 2000 SS LS1/T56 soon.
57 Bel Air, my 1st car. '66 396, mild rebuild, self-ported heads, XS282 cam, Holley/Proform/QFT 750DP, RPM AG, dual-snorkel cool-air inlet, Hedders. Runs E85. TH400 w/3500 stall. 8.2" 10-bolt w/3.73 & Powertrax. Best 13.15/101.54 @ 5800' Bandimere (12.23/109.4).
Last edited by five7kid : 12-13-2005 at 06:19 PM.
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09-29-2004, 12:26 AM
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#3 | | Moderator
Join Date: Mar 2000 Location: Littleton, CO USA
Posts: 26,852
Car: 82 Berlinetta(2)/57 Bel Air Engine: 86 LG4-> ZZ3(LS1)/mild 396 Transmission: TH700(T56)/TH400 Axle/Gears: 3.23(4.10)/3.73 | Thanks for posting all those links!
I could have added a few other things, like:
All US-delivered carb'd V8 3rd gens were computer controlled (along with the distributor).
All US-delivered carb'd V8 3rd gens had an aluminum intake manifold - and they were the same part whether LG4 or L69 (except the '87 LG4, which had the center two mount bolts on each side at a different angle than the rest - '86-earlier were all the same angle).
LG4's originally delivered to Canada typically were not computer controlled (I believe they finally were in the later years - but don't hold me to that) and had a cast iron intake manifold. However, their L69's were computer controlled and had the aluminum intake. | |
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06-01-2005, 08:23 PM
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#4 | | Senior Member
Join Date: May 2005 Location: Pasadena
Posts: 329
Car: 87 Z28 Engine: uh does the name give u a hint Transmission: 700r4 Axle/Gears: 2.73 | i hv carbed 305 whats the cam measurements u suggest? | |
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08-02-2005, 12:51 PM
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#5 | | Moderator
Join Date: Mar 2000 Location: Littleton, CO USA
Posts: 26,852
Car: 82 Berlinetta(2)/57 Bel Air Engine: 86 LG4-> ZZ3(LS1)/mild 396 Transmission: TH700(T56)/TH400 Axle/Gears: 3.23(4.10)/3.73 | If you retain the computer controls, you should consider a computer-compatible cam. Comp, Crane, Lunati, all carry cams that meet that description. The Crane 2050 cam I referenced is such a cam. It requires a good exhaust and higher stall torque converter (if auto tranny). | |
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08-09-2005, 08:27 PM
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#6 | | Senior Member
Join Date: Mar 2004 Location: San Antonio, Tx
Posts: 404
Car: 86 Camaro Z28/ 87 Camaro IROC Engine: 5.0L TPI LB9 / 5.7 TPI w/cam Transmission: 700R4 w/ TCI Racing Parts/ Transcat Axle/Gears: 2.73 Highway Haulers/ 3.23 | Did the LB9 camaros have different exhaust manifolds than the L69 camaros?
I had heard once that the L69 camaros had better exhaust manifolds and i ran across one at the junk yard, i should have pulled them off but i ran out of time ! (my dad has the LG4 car and i have an LB9).
__________________ ~Lucid is a state of mind~
Boxed Panhard Rod and LCA's
KYB Struts and Shocks
K&N Airfilters / TB Bypass
3" Catalytic Convertor/Borla Exhaust
140 Amp CS144 Alternator
Ramchargers Dual Fans 2500CFM  http://SA3GO.tripod.com | |
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08-18-2005, 01:33 PM
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#7 | | Moderator
Join Date: Mar 2000 Location: Littleton, CO USA
Posts: 26,852
Car: 82 Berlinetta(2)/57 Bel Air Engine: 86 LG4-> ZZ3(LS1)/mild 396 Transmission: TH700(T56)/TH400 Axle/Gears: 3.23(4.10)/3.73 | LB9 and L69 are different, but fairly equal performance-wise.
The L69 has the EFE valve while the LB9 does not. The L69 EFE valve is bigger than the LG4 valve, so you can't put the L69 manifolds on with the LG4 valve. | |
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08-31-2005, 02:44 AM
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#8 | | Senior Member
Join Date: Jul 2005 Location: Manchester: UK
Posts: 463
Car: Was 3rd Gen now MustangGT Engine: 302 Transmission: Auto Axle/Gears: 3:73:1 | Pardon my ignorance but where should the G be in the Vin code?
ie: mine starts 1G2AW so does that make it an HO?
The reason i ask is it had an HO transfer on the back of the car which was obviously aftermarket. | |
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08-31-2005, 07:45 AM
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#9 | | Moderator
Join Date: Mar 2000 Location: Littleton, CO USA
Posts: 26,852
Car: 82 Berlinetta(2)/57 Bel Air Engine: 86 LG4-> ZZ3(LS1)/mild 396 Transmission: TH700(T56)/TH400 Axle/Gears: 3.23(4.10)/3.73 | 8th character of the VIN. | |
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08-31-2005, 08:47 AM
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#10 | | Senior Member
Join Date: Jul 2005 Location: Manchester: UK
Posts: 463
Car: Was 3rd Gen now MustangGT Engine: 302 Transmission: Auto Axle/Gears: 3:73:1 | Thanks again, mines an LG4 then and seems people buy and fit any old stickers.
Now where did i put those 600ci Supercharged stickers............  | |
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05-08-2006, 05:45 PM
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#11 | | Junior Member
Join Date: May 2006
Posts: 8
| are there any aftermarked snorkel kits sold? or just factory/custom ones? | |
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05-08-2006, 09:35 PM
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#12 | | Moderator
Join Date: Mar 2000 Location: Littleton, CO USA
Posts: 26,852
Car: 82 Berlinetta(2)/57 Bel Air Engine: 86 LG4-> ZZ3(LS1)/mild 396 Transmission: TH700(T56)/TH400 Axle/Gears: 3.23(4.10)/3.73 | Ramair. Goggle it.
Last edited by five7kid : 05-08-2006 at 10:28 PM.
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05-09-2006, 07:21 PM
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#13 | | Member
Join Date: Apr 2006
Posts: 110
| carbs diffrent?
am i correct in thinking that L69s had 650 Q-jets. if so what did the LG4s have? i always thought the carbs were diffrent. Engine Specs
i'm basing my info on this site, seems to be a very reliable site with good information. | |
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05-09-2006, 07:30 PM
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#14 | | Member
Join Date: Apr 2006
Posts: 110
| sorry about the long obnoxious post, i dont know what happend there, just coppied the link and pasted it in my post. it wasn't that big when i copied it | |
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05-09-2006, 08:24 PM
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#15 | | Moderator
Join Date: Mar 2000 Location: Littleton, CO USA
Posts: 26,852
Car: 82 Berlinetta(2)/57 Bel Air Engine: 86 LG4-> ZZ3(LS1)/mild 396 Transmission: TH700(T56)/TH400 Axle/Gears: 3.23(4.10)/3.73 | The carbs are basically the same but tuned differently. The LG4 had a cast-in "tab" that kept the AV from opening fully (on some LG4's, not all - mine wasn't). The primary jets and secondary rods/hanger were typically different L69 to LG4.
Both carbs have the same capability, basically.
(BTW, don't try to copy a page into a post. Go ahead and copy the URL and put it in your post. Not-so-good things happen when you try to copy content into a post.) | |
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05-12-2006, 07:30 AM
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#16 | | Member
Join Date: Apr 2006
Posts: 110
| ok, that makes sence, so basically what you find in the "tuning Q-jets" tech article is the only diffrence from the Lg4 carb to the L69. and you're saying that some LG4s have 650s?? | |
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05-12-2006, 08:01 AM
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#17 | | Moderator
Join Date: Mar 2000 Location: Littleton, CO USA
Posts: 26,852
Car: 82 Berlinetta(2)/57 Bel Air Engine: 86 LG4-> ZZ3(LS1)/mild 396 Transmission: TH700(T56)/TH400 Axle/Gears: 3.23(4.10)/3.73 | They flow, or have the capability of flowing, in the 750 to 800 CFM range. | |
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08-20-2006, 11:39 PM
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#18 | | Junior Member
Join Date: Aug 2006
Posts: 20
| mines a 88 h.o? we talkin bout High Output? | |
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08-21-2006, 06:59 AM
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#19 | | Moderator
Join Date: Mar 2000 Location: Littleton, CO USA
Posts: 26,852
Car: 82 Berlinetta(2)/57 Bel Air Engine: 86 LG4-> ZZ3(LS1)/mild 396 Transmission: TH700(T56)/TH400 Axle/Gears: 3.23(4.10)/3.73 | Officially, "H.O." designations were only from 1983 to 1986 model years, and were only on cars with the L69 carb'd engines VIN code G. If you have an '88, it isn't "H.O.". Some people refer to the LB9 as the "H.O." engine, but technically, it isn't. | |
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08-21-2006, 01:02 PM
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#20 | | Junior Member
Join Date: Aug 2006
Posts: 20
| ooo thats weird my hood says5.0 h.o and those are the orig stickers.. i will look at my build sheet i bought it off my dads cousin who bought it new in 88 its only got 55 thousand on it
but im assuming ur right maybes its just one of those weird things | |
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08-21-2006, 06:47 PM
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#21 | | Junior Member
Join Date: Aug 2006
Posts: 20
| yeppp sure enough MY BADDD was thinkin of somehting else | |
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09-02-2006, 03:55 PM
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#22 | | Member
Join Date: Apr 2006 Location: Cape Breton N.S
Posts: 133
Car: 84 Z28 Engine: 305HO Transmission: Borg Warner T5 Axle/Gears: 3:73 | Quote:
Originally Posted by five7kid  There was only one engine called "HO" in 3rd gens - the L69 (VIN code "G") from '83-'86. There seems to be a lot of confusion over what made it "HO", so here are some basics.
At least in 3rd gens, LG4 (VIN code "H") and L69 used the same head castings, 416 from 1982-1986, and 081 for 1987 LG4's and '87-up LB9's (VIN code "F"). The '85 & '86 LB9 also used the 416 casting. The chamber size (at least as far as the factory is concerned) is determined by the casting. Therefore, LG4, L69 and LB9 will all have the same size chambers.
The '82-'84 3rd gen LG4's had lower compression because they had dished pistons in them, which, when combined with the 58cc chamber 416 heads, produced 8.5:1 compression ratio. The L69's and '85-'86 LG4's & LB9's had flat top pistons with 4 valve reliefs that, when combined with the 58cc chamber 416 heads, produced 9.5:1 compression ratio. '87-up used a slight dish piston with 4 valve reliefs that reduced compression to 9.3:1. The factory typically used steel shim head gaskets, although they have also used composition in later years. And, for the record, 3rd gen LG4's, L69's, and LB9's all used 1.84" intake and 1.50" exhaust valves.
The L69 had a better cam, larger exhaust manifolds and exhaust all the way back, different PROM tuning, knock sensor ('85-up all 305's have knock sensor), different carb calibration, dual snorkel air cleaner for Camaro, cowl induction for Firebird, and electric radiator fan ('86-up all 305's have electric radiator fan).
If you want to improve the performance of an LG4, you do the following: Replace all of the exhaust with headers, y-pipe with 2-1/2" downpipes to 3" at the cat, 3" cat, and 3" cat back to 3" inlet muffler (single 3" outlet or 2 x 2-1/2" outlets is your choice). Replace the cam with something with a little duration and lift (the Crane 2050 worked well in mine). Replace the valve springs with something that can handle the lift of the cam. Upgrade the ignition coil and module with aftermarket pieces. Replace the single-snorkel air cleaner with a dual snorkel unit, either a factory type (Camaros), or fabricated one (see the tech articles on the Board home page, or Link to Home Made Dual Snorkel Post (Home-Made Dual Snorkel - $10 and a few hours work) for the latter). If you want, further improvements can be obtained by having the heads reworked for 1.94" intake valves, and cleaning up the port bowl area (do a search for porting, you'll find out what is required). Pinning the rocker studs or having the heads machined for screw-in studs is a very good idea with an upgraded cam & springs. If you want, you can put an aftermarket performance intake on it such as the Weiand Action+ or GMPP q-jet intake manifold. Most of this will also help an L69 or LB9.
If you have an LO3 TBI or LU5 cross-fire - well, those are special cases and you're on your own...
jk, check out the TBI forum "Important/Useful" stickies. |
so what your saying is: do these mods to your car and it will just be as good as a L69?
Last edited by Z28er : 09-02-2006 at 03:57 PM.
Reason: wrong engine code
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09-03-2006, 02:03 AM
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#23 | | Moderator
Join Date: Mar 2000 Location: Littleton, CO USA
Posts: 26,852
Car: 82 Berlinetta(2)/57 Bel Air Engine: 86 LG4-> ZZ3(LS1)/mild 396 Transmission: TH700(T56)/TH400 Axle/Gears: 3.23(4.10)/3.73 | That's right.
The L69 cars did have the AC line routed slightly differently to stay out of the way of the passenger side snorkel, but I haven't had any problems with the LG4 line & L69 snorkel. | |
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12-12-2006, 10:17 PM
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#24 | | Junior Member
Join Date: Feb 2004
Posts: 49
| the 8th letter in my vin is a E what kind of engine is this does anyone know | |
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12-12-2006, 10:20 PM
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#25 | | Senior Member
Join Date: Jul 2002 Location: Burnaby, BC
Posts: 548
Car: Custom 1992 Camaro Z28 25th Anniversary Ed. Engine: 5.7L V8 350 L98 TPI | Quote:
Originally Posted by freestylin the 8th letter in my vin is a E what kind of engine is this does anyone know | Enter your VIN : http://www.camarosource.ca/php/camar...year=2002&tm=1 | |
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12-12-2006, 10:42 PM
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#26 | | Moderator
Join Date: Mar 2000 Location: Littleton, CO USA
Posts: 26,852
Car: 82 Berlinetta(2)/57 Bel Air Engine: 86 LG4-> ZZ3(LS1)/mild 396 Transmission: TH700(T56)/TH400 Axle/Gears: 3.23(4.10)/3.73 | (Edit: try this again)E = LO3 305 TBI.
Last edited by five7kid : 12-13-2006 at 07:06 AM.
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12-12-2006, 11:49 PM
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#27 | | Junior Member
Join Date: Feb 2004
Posts: 49
| i entered in the vin online and it says its a v8 305 tbi i just wanted to know ifit was ho or lb9 or what it is its a firebird btw | |
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12-13-2006, 12:11 AM
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#28 | | Junior Member
Join Date: Feb 2004
Posts: 49
| okay i got it its a LO3 anyone got any info on these engines | | | | | |
