Whats the difference between a 2.8 firebird and a 2.8 H.O. firebird. I'm thought that it was just one was Carb and one was F.I. But I also know that F.I. was not to great in the early 80's so dose that mean that my 83 w/Carb is the H.O. or is it the F.I. From what I heard was the Carb had 107hp and the F.I. had 135hp which was supose to be the H.O. motor, But Carbs were the faster car for that year, even on the 305's and 350's.

Rob

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Chevy 2.8L, k&n filter lid, Headers Soon!!!
http://www.geocities.com/fiream/RobsCarArtPa.html?994187591828

 

both 2.8's came with 2bbl carbs that year. there was no fuel injection until 1985. the non h.o. 2.8 was rated at 107 hp. the 2.8 h.o. was rated at 125 hp.

 

the 2.8L H/O was basially the same block, but was apparenty made to create more power from the same cubic inches. Not sure from where, but most likely in larger valves (maybe). I believe that the 1985 model cars got a 2.8L H/O also, but that HO was FI, and would explain the extra 5lbs. of T.Q. 165 vs. 160...

 

Even though my VIN says that I don't have an H.O. I think my car has more power then 107hp, maybe it's because of the flowmaster and the custom open element I made with the K&N airfilter lid.

Rob

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Chevy 2.8L, k&n filter lid, Headers Soon!!!
http://www.geocities.com/fiream/RobsCarArtPa.html?994187591828

 

sounds like a good start to a fast firebird!
If you want ideas to make your 2.8 more powerful i have a 2.8 power recipe i can write to you because i have a 1982 firebird with a 2.8 in it so i know a lot about them.

 

yeah what can I do to beef up my 2.8, oh yeah i also put in bosch plat +4 too and I have a set of headers that are going on soon.

Rob

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Chevy 2.8L, k&n filter lid, Headers Soon!!!
http://www.geocities.com/fiream/RobsCarArtPa.html?994187591828

 

ho is 1.72 int 1.42 ext stock 1.70 1.40
ho stands for 1.72 int valves 1.42 ext.

 

here is so stuff i am going to do to my 1984 2.8 engine. the first 4 things i found in jc whitney. complete engine rebuild kit $199.98 have this done at your local machine shop bored .030 over,port,polish heads,3 degree valve angle job,rebuild heads. pushrod & rockerarm kit $49.99,high volume oil pump $63.99,double roller timing chain $89.95.
I'll get back to you with the rest from summit!

 

The 83 Firebirds with an HO V6 had to have a computer and an electronic carb. The normal V6s didn't need one but could have one.

The other big changes for the HO V6 were bigger valves (as mentioned above), a stronger cam (from the X-11), and a bigger exhaust - 2 1/4" I believe. The cam and exhaust give the engine a different sound, kinda lopey with a growl that some of the later V6 GM cars picked up.

All of the above changes were used in the FI engines later on. The FI really smoothed out the cam and makes a much better driver than the carb. GM used the stock air cleaner assembly which is far more restrictive than the X-11 piece and is why it's only rated for 125 HP. Flipping the lid helped the engine pull harder on the top end and shaved off about 1 second.

I know this because in 1982 I ordered a Firebird S/E with an HO V6 and the WS6 option (4 wheel disc brakes and 3.73 posi rear end). I still have it in the garage, never drove it in winter and it has less the 25 000 miles on the clock. I'm hoping to have more time when I retire to put in subframe connectors and maybe a 3.4 longblock under the hood. Sigh...

Cheers,

Duane

 

hi. im back with the rest of my 2.8 power recipe. from summit you can get a edelbrock performer intake manifold base #edl-3785 $137.95,edelbrock 4bbl intake manifold top #edl-3789 $86.95,crane fireball HI-6S ignition box #crn-6000-6300 $135.95,dearle oil cooler #der-15502 $63.95,edelbrock chrome valve covers #edl-4488 $63.95. The gm performance catalog has performer valve springs #12363215 $4.97 each,performer retainers #12363216 $2.74 each. Go to your local advance auto or autozone and get 4bbl carb spacer,chrome oil pan,performance water pump, my complete tune-up - accel super stock plug wires,accel super stock coil,accel cap & rotor,K&N air & oil filter,oil change,fuel filter,pvc filter. If i can think of any more mods i will write to you again!

 

V6camaroman, can you give a quick $$ sum to that recipie of yours?
And after all them $$$ spent does it really make a noticable difference in performance and all?

 

my total was about $1400.00 I have my engine completed but its not in the car. I hope those mods make it run in the low to mid 15's. my friend rebuilt his 2.8 mpfi engine in his firebird and did some of my mods and his will run 15.9 - 16 flat. my friends car kicks A$$. that car will put you in the back of your seat. i hope mine does when i get it completed!!

 

I would say if you really want to know how to make a 2.8 Fast I would frequent the Fiero boards. Some of those guys are running pretty strong!


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89 Trans Am Turbo 3.8L All stock 43,000 miles #1053 of 1555

Past Thirdgen:
86 Trans Am w/ built 355TPI with SLP goodies and too much other stuff to List. One sweet *** car, wish I would have had a good enough Job to pay insurance on three cars so I could keep it, but for a 89 Turbo Trans Am w/ Low miles, I think I made the right choice!