hartsmike

Hey guys, what is the difference(s) between the two?

Thanks

AmorgetRS

iTrader: (6)

In what year?

hartsmike

I guess any/all years. My favorite year is 86.

AmorgetRS

iTrader: (6)

I am not sure in 86 what engines got the HO designation, however earlier models it meant the L69 motor and in the later models it meant the 305 TPI (LB9) motor

mjdavis68

iTrader: (1)

I don't think he's referring to the TPI motors,I think its a "given" that any TPI was a high output engine,However if i was to ask this question, i would be asking about the actual one's that where labeled H.O. on the badging or on the air filter.Also these where carb'd motors too.

AmorgetRS

iTrader: (6)

I am really not 100% sure what he is asking.

Here is another thread on 5.0 "HO" motors:

https://www.thirdgen.org/forums/hist...-0-ho-5-a.html

scottmoyer

The TPI engines are not considered HO. You had the 305 LG4 V8 and the 305 L69 HO V8. He's asking about those. There weren't many in '86, so you are probably looking for details on the '83-85 carbed L69 HO. You will probably find more information from a search on this forum. Is there anything in particular that you are looking to get answered?

gt4373

I Would Say The Main Difference Is The L69 Having A Higher Compression Ratio And Higher Lift Cam Than The LG4,Here's Some General Data.

hartsmike

That's it>what is the difference in the L69 versus the LG4? Both are 305's, correct? The H.O. a TPI?

hartsmike

I remember back in the mid to late 80's the selling ads of these cars would really promote the "H. O." option!

AmorgetRS

iTrader: (6)

They are both 305s and both carbed.

I believe the only difference by 86 was the different camshafts, slightly better exhaust system and maybe different computer tuning.

Earlier years the LG4 had lower compression, no knock sensor and a mechanical fan. By 86 all those differences had gone away.

https://www.thirdgen.org/forums/faq-...5-engines.html

AmorgetRS

iTrader: (6)

By the late 80s the L69 was gone, 86 was the last model year for it. So those aren't the "HO"'s that were being promoted.

Confuzed1

iTrader: (4)

TPI 305's are not considered an "HO" engine and never were. So if a TPI engine...it's just that...a TPI.

I've seen so many over the last few years talk about their HO TPI 305 engine....laughable...those cars never had a HO designation...ever.

The true HO cars are CCC Q-Jet controlled. First came out in mid-year of '83. Pretty sure they lasted through 85...I've never actually seen a 86 HO.

They were built for one real purpose...Mustangs were handing Camaros their *ss at the time, so that's what GM came up with to compete. And they did....for a couple years till Ford upped the HP again.

I actually thought this was an old thread since this topic has been covered in detail so much.

sofakingdom

iTrader: (1)

Right: the ONLY time that designation was ever "official" in these cars, was in reference to the L69.

Mostly it gets tossed around as a buzzword nowadays.

The ones that are REALLY laughable are the TBI owners that think they have a "HO" TBI.

okfoz

The HO was offered from 1983 - 1985, and only a handful in 1986, most of which went to Canada.

From what I have seen the L69 "HO" differences:
1) Higher Compression pistons
2) Better heads
3) Hotter cam - same as CFI in 83 and same as TPI in 85 & 86
4) Higher flow air cleaner
5) Better exhaust manifolds, probably slightly better exhaust too.
6) Taller axle gear ratio 3.73

From 1987 - 1992 there was not technically an "HO" however I have seen the L03 sold as being an "HO" all too often which is laughable what people will claim. the LB9 (TPI) would technically be the HO 5.0 motors from 87+, but it was not marketed as such very well, meaning that they may have it in some literature as the High Output 5.0 Engine, but GM usually went with the TPI route when advertising, even badging on the cars were typically "Tuned Port Injection" "Fuel Injection" 5.0 F.I., etc. Which can be confusing as the Formula for example had 5.0 Litre F.I. on all L03 and LB9 hoods from 1988-1990...

the L69 & LG4 both used the same intake manifold according to IPC replacement parts... Whether or not they were the same in production I do not know... IIRC my 87 LG4 had an aluminum intake from the factory.

JT

iTrader: (1)

This reminded me of a sales ad that did appear to blend the HO and TPI together:

gt4373

Even They Worded It Wrong.

dmccain

iTrader: (2)

LG4 had maybe 155hp vs 190 hp in the L69 H.O. The HO cars also came with the 373 gear ratio which really woke the cars up. Id see stock LG4's turning 15.7's and L69's running 14.7's back in the day. The old L69 with 5spd would run neck to neck with the TPI 350. The TPI 305's never got recognized as an HO even though i think they went right on up to 220HP or so with the manual cars in their last few years.

The_Wraith

The L69 and LG4 are night and day difference just in driving alone. My 84 t/a with iffy compression in one cylinder still fishtails and lays rubber when you stomp on it. Not even my old L98 z28 was as fun to drive. The "pull" on these L69 engines with functional cowl/qjet makes an all around fun car around the city (for a stocker)

okfoz

I put a 3.73 gears behind my LG4 powered car, and it seriously changed the car on how it performed. Adding that 1.00 in ratio made an amazing change and the fun factor just exploded... The car has been changed to TPI and a ton of mods, cam, increased compression, headers, cat-back, under-drive pulley done to it and it really performs now...

Really if anyone does a rear gear, installing an under-drive pulley is a good idea because it keeps the components from spinning up to high when going down the road.

Sorry to be off topic.

Fast355

iTrader: (2)

I had a canadian LE9 305 in my old G20 van that I could spin the tires and fish tail around corners. I too was surprised how punchy the little 305 was. It was rated about 170 HP, but removing the factory pellet style cat and advancing the timing woke it right up.

The 1985 L69 and LB9 were the SAME exact engine, only one had a Q-Jet and the other TPI.

86 LB9 engines had the LG4 peanut cam in them rather than the HO cam