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View Full Version : i found a TBI 4.3vortec yes you read it right!



whitelightnin92
05-02-2009, 11:11 PM
didnt know they made them but i found one in a late 90s c1500. must heve been an export truck or something. i think it was a W/T

DV2000NJ
05-02-2009, 11:12 PM
I thought all the TBI 4.3s had the Vortec heads?

g9m3c
05-02-2009, 11:12 PM
4.3's have been called "Vortec" since 1986.

FordeatinZ71
05-02-2009, 11:40 PM
http://www.73-87.com/7387info/ads_GM/84_vortec.jpg

yep, all the 4.3s were called Vortecs

tippmann243
05-03-2009, 02:46 PM
some of the late model 4.3's came with the L35 (cpi) heads instead of the LB4 heads. the l35 heads flow better then the LB4 heads. i know in the s-10s gm also topped most of them with the plastic covers that say vortec on them

CandyBowtie91
05-03-2009, 06:22 PM
My 91 c1500 has a vortec 4.3 :dunno:

98GreenMachine
05-04-2009, 01:13 AM
didnt know they made them but i found one in a late 90s c1500. must heve been an export truck or something. i think it was a W/T

As stated, the 4.3 has been called Vortec since the mid-80's.

My dads last truck was a 1994 K1500 W/T with a TBI 4.3 and the valve covers both said Vortec on them. Its just the "brand" name of the engine, it has nothing to do with the heads/injection being Vortec heads etc.

98GreenMachine
05-04-2009, 01:17 AM
some of the late model 4.3's came with the L35 (cpi) heads instead of the LB4 heads. the l35 heads flow better then the LB4 heads. i know in the s-10s gm also topped most of them with the plastic covers that say vortec on them

The CPI 4.3's were only offered from 92-95 on S10 Blazers and Astro vans(and their GMC equivalents).

The CPI 4.3 looks like this:

http://hooverae.com/upload/files/CPI.jpg

JoshTheCanadian
05-04-2009, 01:43 AM
So much miss information in this thread.

V6's have been called Vortec since the 80's but in 1992 they got L35 CPI HEADS but kept the TBI system.

Pre 1992 they were just 4.3Ls with the vortec name

1992-1995 CPI Vortec heads are used, they heads add something in the range of 5-10 horsepower and ARE a vortec head, just a early style one.(1992 was also first year for Balance shaft)

1996+ are "True" 90* intake bolt style heads and flow better the early CPI vortec heads.

So, any TBI truck in a fullsize truck that has Vortec Composite valve covers should have CPI heads that are early vortec heads.

Any with the centerbolt metal covers are TBI heads.

EDIT: fixed some of my wording it came out wrong.

g9m3c
05-04-2009, 01:45 AM
So much miss information in this thread.

V6's have been called Vortec since 1992




1986, as mentioned earlier. :D

98GreenMachine
05-04-2009, 01:50 AM
So much miss information in this thread.

V6's have been called Vortec since 1992 when they got L35 CPI HEADS but kept the TBI system.

Wrong :read:

I'm too tired to correct the rest of your thread, I will do so later.

JoshTheCanadian
05-04-2009, 01:55 AM
I ment to say they have had vortec heads since 1992.

Here is a pic of my 1994 LB4, Z code engine that came FACTORY with L35 CPI heads.

Any truck with the plastic covers should have these heads and a balance shaft.
Notice the eyebrows on the ports.

http://photos-f.ak.fbcdn.net/photos-ak-snc1/v318/105/95/593480251/n593480251_4351501_2606.jpg

reesez
05-04-2009, 02:09 AM
i gotta side with orangette here. vortec v6 heads were introduced on the cpi in 92, before then it was just a name, kinda like the cortec 305 in the late 80's. the vortec heads in fact flow better than regular tbi heads in 92-95 trucks. in 96 all v6's were vortec but were not tbi.

98GreenMachine
05-04-2009, 11:05 AM
V6's have been called Vortec since the 80's but in 1992 they got L35 CPI HEADS but kept the TBI system.
Correction, in 92 Central Port Injection was introduced and a new head was designed for it. TBI and CPI was offered simultaneously on 4.3's up through 95. TBI's did not use CPI heads until 94, more info later on this.


Pre 1992 they were just 4.3Ls with the vortec name
correct


1992-1995 CPI Vortec heads are used, they heads add something in the range of 5-10 horsepower and ARE a vortec head, just a early style one.(1992 was also first year for Balance shaft)
I dont know where you pulled the 5-10 HP number out of but the CPI setup added ~35 HP & ~25 TQ over a TBI system in the same vehicle, same year.


1996+ are "True" 90* intake bolt style heads and flow better the early CPI vortec heads.
Correct, in 96 the true Vortec head was launched.


So, any TBI truck in a fullsize truck that has Vortec Composite valve covers should have CPI heads that are early vortec heads.
Your generalization is wrong here. From 92-93 the CPI and the TBI heads were different. The intake ports were different as were the valve angles. From 94-95 the TBI systems used the came head as the CPI systems. This is why your 94 heads pictured have the eyebrow on the intake port.


Any with the centerbolt metal covers are TBI heads.
I would suggest you take a long hard read over this article, it will clarify alot of your questions with actual facts:
http://forums.s-series.org/viewtopic.php?t=41520

trans_am78_01
05-04-2009, 01:57 PM
[QUOTE=98GreenMachine]The CPI 4.3's were only offered from 92-95 on S10 Blazers and Astro vans(and their GMC equivalents).

I would have to disagree with that statement. I had a 94 ex cab s-10 with CPI a few years back. I know that it was CPI because we liked to never found a replacement engine for it

FordeatinZ71
05-04-2009, 02:11 PM
yep, it was an option on the S10 and Sonoma too. the S10 SS used that motor before the 96 Vortecs were introduced.

g9m3c
05-04-2009, 05:36 PM
OK already! Geez!























:lol:

tippmann243
05-04-2009, 05:57 PM
So much miss information in this thread.

V6's have been called Vortec since the 80's but in 1992 they got L35 CPI HEADS but kept the TBI system.

Pre 1992 they were just 4.3Ls with the vortec name

1992-1995 CPI Vortec heads are used, they heads add something in the range of 5-10 horsepower and ARE a vortec head, just a early style one.(1992 was also first year for Balance shaft)

1996+ are "True" 90* intake bolt style heads and flow better the early CPI vortec heads.

So, any TBI truck in a fullsize truck that has Vortec Composite valve covers should have CPI heads that are early vortec heads.

Any with the centerbolt metal covers are TBI heads.

EDIT: fixed some of my wording it came out wrong.

gm put the metal centerbolt covers on the L35 heads in the cpi and the tbi motors.

my 93 sonoma had l35 heads and metal covers. it was kind of a bastard child of gm. 4.3/m5 non balanced shaft with l35 heads. i think it was built with left over parts lol

JoshTheCanadian
05-04-2009, 06:12 PM
Correction, in 92 Central Port Injection was introduced and a new head was designed for it. TBI and CPI was offered simultaneously on 4.3's up through 95. TBI's did not use CPI heads until 94, more info later on this.


correct


I dont know where you pulled the 5-10 HP number out of but the CPI setup added ~35 HP & ~25 TQ over a TBI system in the same vehicle, same year.


Correct, in 96 the true Vortec head was launched.


Your generalization is wrong here. From 92-93 the CPI and the TBI heads were different. The intake ports were different as were the valve angles. From 94-95 the TBI systems used the came head as the CPI systems. This is why your 94 heads pictured have the eyebrow on the intake port.


I would suggest you take a long hard read over this article, it will clarify alot of your questions with actual facts:
http://forums.s-series.org/viewtopic.php?t=41520
1. Yes I was wrong on the year, I was thinking about it at school today

2. Since FSCs only used the heads they only added 5HP, the whole system added as much as you stated.

3. I realize the differences in the heads, and don't know what u think I meant?

Toadz
05-14-2009, 11:11 PM
Those CPI 4.3's were also in the Olds Bravada. Awesome engine, especially when matched up with the AWD system of the Bravada. You'd swear it had a V8 in it except we could easily pull 20 mpg out of it with normal city/highway driving.

NEUMANNZZ
05-15-2009, 01:04 PM
So much miss information in this thread.

V6's have been called Vortec since the 80's but in 1992 they got L35 CPI HEADS but kept the TBI system.

Pre 1992 they were just 4.3Ls with the vortec name

1992-1995 CPI Vortec heads are used, they heads add something in the range of 5-10 horsepower and ARE a vortec head, just a early style one.(1992 was also first year for Balance shaft)

1996+ are "True" 90* intake bolt style heads and flow better the early CPI vortec heads.

So, any TBI truck in a fullsize truck that has Vortec Composite valve covers should have CPI heads that are early vortec heads.

Any with the centerbolt metal covers are TBI heads.

EDIT: fixed some of my wording it came out wrong.

when did they start using roller cams?

98GreenMachine
05-15-2009, 02:26 PM
when did they start using roller cams?

87 was the first year for roller cams in the 4.3, specifically the VIN Z engines of the S10/S15 platforms.