can someone tell me what is the diffrence between the 5.0 FI motor and the 5.0 HO motor. someone told me if it was throttle body injection it was the FI motor, but if it was a tuned port set up then it was the HO motor. Is this right or is there something else to set them apart. and did the 5.0 ho or fi decal ever appear anywhere on a firebird or just the formula.

 

HO had better cam and pistons

some non HO had the flat top pistons also but not the better cam

thats really all thats different

is more compression in the HO

HO was carb usually

L69 for example was carb HO 305

the someone you refer to isnt very knowledgable about chevy v-8 engines



good luck

 

that someone told me that 18 years ago in high school but thank you for the info

 

Uuum didn't the TPI engine replace the 5.0 HO with very similar power numbers? It doesn't make it the actual HO labeled engine but yes the TPI is what replaced the HO and technically is the high output motor for the years the 350 TPI wasn't offered (pre 1987).

 

The "5.0 Liter High Output" motor is the carbed L69 motor. It was basically replaced by the "Tuned Port Induction" line of 305's and 350's starting in 1985, although L69 was still available in 5 speed form, as the early TPI cars were all automatics through 85 and 86. I believe that by 1987, the L69 was gone from the option list, as 5 speed 305 TPI cars took the place of the L69. In 1988, the base motor, which had been the carbed LG4 305 was replaced by a throttle body injected 305. It is an efi mill, too, as was the 82-83 Crossfire 305. So, you have only one "HO" motor, the L69. The efi cars are the Crossfire (called CFI, too.), the Tuned Port, and the TBI ones, in that chronological order. Hope that helps. Oldtimer.

 

^ what he says is the truth ^

the L69 "HO" appeared in mid 83 to counter the anemic engines and the threat from the Mustang 5.0

it was THE car to have at that time

Came with either auto (not as much fun) or the 5 speed with a 3.73 rear axle, so it felt faster than it really was

they had massive problems with them boiling the fuel (vapor lock) and in later 84 started installing an electric fuel pump.

A TSB was issued for all the earlier cars

in 85 & 86 they even included a "squirrel cage" electric fan to blow air at the carb

Those were different for the Firebird vs the Camaro

as stated, they were the only "performance" engine avail with the manual trans until the TPI was "allowed" to have the 5 speed in 87.

Camaro production of the L69 are as follows:

83 3,223 (I think they were ALL 5-speeds)
84 52,457
85 2,497
86 74

HP rating
83 L69 190hp
83 LU5 (Crossfire) 175 hp (automatic ONLY)
83 LG4 (Base 4bbl) 150HP

84 L69 190hp
84 LG4 150hp
no crossfire anymore

85 L69 190hp
85 LG4 165hp
85 LB9 (Tuneport) 215hp

86 L69 190hp
86 LG4 155hp
86 LB9 190hp, DOWN from 85 rating

I still have a copy of the TSB somewhere as my girlfriend had her 84 L69 redone with the recall (it would die all the time in the summer here)

 

The only cars that got the "5.0 Liter HO" decals had the L69 carburated engines, and 1986 was the last model year for that engine. The Formula didn't come out until the 1987 model year. So no, no Formulas got those decals because none ever got that engine.

Some VIN decoders list the 305 TPI engine as "HO," but that wasn't the actual, real HO engine. Why they'd do that, I dunno. Maybe it was a way for the programs to distinguish between the standard and optional engines. But the L69 engine was the one and only, real HO engine.

On '83-'84 TAs, the stickers were on the rocker gfx(below the front fender vents), on the rear bumper cover(driver's side), and on both sides of the hood bulge. On '85-'86 TAs, the stickers were in the same locations, except for the hood. The bulged hood wasn't available in '85 and '86, so if there were engine decals on the new TA hood, I'm thinking they'd have been alongside the hood vents.

When the "5.0 Liter FI" decals came out, the standard engine was carburated. So having those stickers indicated having the optional TPI engine. And with the bulged hood available again in 1987, on Formulas, those stickers were again on the sides of the hood bulge. I'm not sure whether or not the '88+ TBI-engined cars got the FI sticker too, but because it was also a fuel injected engine, I'd be of the belief that they did get the stickers.

 

Yep, they quit making them middle of '86. Like said before due to fuel boiling problems, all of them were 5 speeds of which i think they made 75 in 1986.

 

Technically, TBI is a form of FI, so yes they are both FI motors, but most of us know the difference.

TBI - Fuel mixed with air at the Throttle Body
/
FI
\
TPI - Fuel injected directly into the combustion chamber


I do recall that Pontiac lists the TPI motor as an HO motor in some sales media, I will have to double check mine later, this has somewhat added to the confusion.

 

Hold on a minute..
This may be true for Camaros, but the few 83 HOs that were put into Trans Ams that year, didn't even have GFX, so no decals were their OR on the rear bumper.
The ONLY place for the decals were on either side of the power bulge hood.
Only when the redesign happened in 1985, did they start to put them on the rocker GFX, just below the extractors, due mostly from the lack of the power bulge hood, in those years, and not on the hood.
And there were never any on the rear bumpercover of any years of Firebird.

I too, have seen the LB9 referred to as an "HO", but the L69 is the only one and true HO in my mind!

Also, the L69 was a manual trans ONLY option, in 1983 for the Trans Am.
No automatics until 1984

Leon