five7kid

iTrader: (14)

I wish they were more reliable. They were typically published prior to production, and often had errors, especially at the beginning or end of a run.

The testimony of members who have had these engines apart tends to support the 3rd gen database. But, these cars are basically 30 years old now, so unless one is the original owner of an LU5 and knows for a fact that it wasn't taken apart before, it's going to be hard to provide concrete evidence.

Do your old service manuals happen to have a horsepower rating? It is interesting that the TGO database shows the '82 as 165 HP, and '83 as 175 HP.

screaminformula

yes.

Guest

Not to fan the flames, but this has been niggling me for a bit, and this morning I think it's because I seem to remember seeing an HO designation on an LB9 / T5 Formula.
And 230 HP is definitely high output for it's day, well past the L69.
But I feel it best that we let the L69 be the one known as the H.O.

screaminformula

eh, i don't agree there (about letting the L69 be known as THE H.O.)...GM themselves put "5.0 Liter H.O." on MANY LB9 Trans Ams (at least, haven't noticed that on Formulas, Z28s or IROC's) made from about 85-88...so those, too, are High Output engines...the General built them, so i think it's up to them to decide what's High Output and what's not. :-)

Guest

I know I'm not the most normal man, but it looks to me like you've gone from confrontational to conversational, and for that I thank you, and do wish to discuss the 305s more.
The hard material I have is yellowed and literally falling apart, and I really don't have any ready access to a scanner, but I see no reason to lie.
Moving on, my own reasoning cannot be evidence, but it makes sense to me that the '82 being 8.6:1, then the '83 being 9.5:1, could and would go a long way toward explaining the '83 gaining another 10 HP and another 10 ft-lbs.
The .260/.273 cam is the old 3896929 cam from the LM1 350, and the L48, and the L65, and the L30. It was certainly never used in any LG3 or LG4.
The LG3 cam was a modified 929, with a 189 degree intake lobe. I've driven an LG3, and it's a good cam for surprising acceleration with a 2000 stall, a TH350, a 3.08:1 axle, and 235/70R15 tires. The LG4 got the bigger valves so they could shrink the cam without losing HP.
Also I found that Elgin is offering close-enough replacements for both the LG3 and L69 cams. Part numbers are 1127 and 860S, respectively.

Lucid

iTrader: (4)

Can anyone elaborate on how the L69 and LG4 carbs are tuned differently? I know the LG4 and L69 had different secondary rods and hangers (DR rods on a K hanger).

Are the primary jets different sizes? Most of the guys I know in the thirdgen scene put in Holleys because they wont spend the time to tune the Qjet.

Ozz1967

iTrader: (4)

To my knowledge there is no difference in the primaries.

The main difference between the L69 and LG4 were the Cams. Just about everything else was the same.

sonjaab

The L-69 had MANY differences from the lg-4:
9.5 vs. 8.6 compression, different heads, larger valves, bigger 795 cfm Q-jet, special aluminum alloy intake, bigger 2.75 inch exhaust and Corvette style wide mouth monolithic catalytic converter, in tank and block fuel pumps,
dual snorkel air cleaner...................

five7kid

iTrader: (14)

He was talking about the engine itself. Only the '82-'84 LG4's had lower compression.

All the other stuff has already been covered.

Miami350

My eighth letter is an f in a 88 formula do i have the better engine

jjcuff1

if I look up the RPO code for the LB( the descriptions says 50L TPI HO
so it is a HO option. Maybe local dealers did COPO and added HO stickers on the 87-89? Either way it is technically HO option

jjcuff1

The F means you have the LB9. Not to flame which one is better TBI (L03) or TPI but yes you have the TPI option which has more power stock.

I owned both and I like the TPI better for stock-mild setups comparing apples-apples. Heavily modded anyone's game. But the TBI is no slouch either tuned and easier and more reliable.

Miami350

Thanks its pretty fast it has the entire slp package ive always had 50 mustangs and my 88 form might take it

jjcuff1

Your saying compared to your previous 5.0 experience you think the LB9 with exhaust is faster or close?

Miami350

Please dont get me wrong i love my low milage formula its fast it handles much better i had 3 mustangs 89 91 92 my 91 had just bolt ons and an e cam and 5sp and did middle to high 13 s all day im trying to get my formula there any advice would be helpful

jjcuff1

I am in same boat like to be strong 14 flat at least

Miami350

The total slp package makes a diff mine was put on from the dealership plus 5sp 342 gears hoping to just get into the 14 s i know these cars r heavy maybe a 100 shot

jjcuff1

I have the stock motor all original but with 2.73 and 700r4 peanut cam. So I far behind you. I just want good sound, little lope at idle, and seat of pants torque, pin you back. Actual speed at the end of the strip is not as important but I don't want all show and no go. Meaning I punch it and I am screaming yet corolla is walking on my as I try to enter highway. i want something I can get out in front of cars when I need to to be safe and sometimes to show off ;-)

jjcuff1

I had TBI 305 in past and puts lots into it and it was a strong 14.5 car all motor t-5 with 3.73 on street tires. Based on the MPH at 100 I should have been low 14 but hard to hook up and this was with before home ECM tuning was not possible and not in my budget back in 94. On gas it ran 13.8-13.7

It was reliable and fun and on the street a real sleeper especially in 1-2 but by 2-3 LT1 stock walked away easily.

The TPI I hope is much different form a throttle response and mid range perspective. And will respond to mods alittle better. After the TBI I told myself after spending $4000 on engine and labor stuff that the value wasnt there.

I am going to try to stick to that and if the TPI runs well just be happy with simple bolt ons and tuning and if it blows or I need more go gas or go to 355.

Without opening up the heads/cam the big gain will be headers and exhaust. Then gears. Sounds like you have both. I don think the TPI airflow is much of a bottleneck on the 305 vs 350. So without bigger cam, tune, and really good port on heads you can keep your stock TPI stock, maybe home polish and port. The intake base is the biggest bottleneck I read. So maybe that on stock heads

Then a good tune and fuel pressure you can dial in some better power and mpg.


I am looking at keeping stock tran now, clean paint, and tune engine up. If all goes as planns I will tune, do free mods, ignition, bump fuel, headers (already cat delete and magnaflow on it) and maybe 1.6RR and new springs.

and just drive. After that if things go bad or feel I want to spend more I might pull heads port polish match everything bump compression and go with as close to 490-500 lift and 2200-2400 stall with 3.42

that should be a solid 14 or 13 sec car for sure.

Miami350

That sounds like high 13 s to me im like u my formula is pristine and just want the power for the street light to light and beat a mustang once in awhile lol and car shows

jjcuff1

Not sure what the TPI will do but from memory I know time slips aside, the 305 TBI was a blast to drive on the street and torque pinned you back. I do remember in friends stock lt1 they had more of SOTP feel. And LT1 with headers and cam really pinned you back hard.

Recently being inthe import scene the 4banger and even small v6 turbo like 300zx all were fast maybe faster then the tpi for sure on street and street but even my new M35 is probably faster mid 14sec car but it doesnt pin you back much.

all those HP numbers are hoigh 300 at 6500rpm and at most 270ft-lbs at 4400 I like the 270 or hopefully 300+ft-lbs at a low 2000 on my TPI to be reality.

jfl1960

That is how my 1982 Canadian Edition Camaro Z28 came, non-computer controlled and cast iron intake. I have to rebuild my motor anyway, crank failed and cylinder bores need over-sizing (30 over), I suspect I can just manually adjust timing by +2 degrees or so to compensate if I upgrade to L69 components during the rebuild, to the best of my knowledge there are no knock sensor on my motor. Want to keep the 305 just for matching numbers, wish 350 came in 82 but wasn't available.

1986BANDIT

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