Zar

Thinking of Vortec heads on my L03 engine. Can it be emissions lagel? Will it pass emissions? What all needs to be done? Any help is great!

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92 Firebird
305, exhaust, intake
Tbi spacer

Chad91Rs

That's a no no.
The vortecs will lower your compression ratio and you'd see power go out the door.
The stock chambers are 55cc (I think) while the vortecs are 62 or 64 depending on who you ask.
No milling will correct this either.
To my knowledge that is.

Zar

I just saw the same topic on the tbi messageboard, and some one said that you can put vortec heads on a L03(supposed to be the biggist hp gain). If I cant do vortec heads than what can I do head wise?

[This message has been edited by Zar (edited September 13, 2000).]

Tab92bird

uhh why can't you mill the heads?

Mark305TBI

You can mill the Vortec heads. Car Craft did a 305 Vortec build-up and they milled the heads (I don't remember how much) and brought the combustion chambers down from 64cc to 58cc (the stock LO3 volume). Only other thing you have to watch out for on the Vortecs is the dedicated Vortec intake manifold.

-Mark W.
<A HREF="http://www.angelfire.com/al3/thegreycar">'88 SC Camaro w/ 305 TBI</A>

Zar

ok found that Vortec will work. Now, does anybody now if there is a posability that is can pass the emissions testing?

Mongoose

iTrader: (2)

The only catch would be running an EGR valve. You'll have to draw gasses from the exhaust manifold and route it to the valve at the intake. Edelbrock makes a kit to do this with their TES headers. Another thing is an intake manifold that fits the heads AND has provisions for mounting an EGR valve. SDPC should have info on this as well.

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Mongoose-NCTGA-1990 Pontiac Formula/305 TBI-700R4 with Edelbrock Performer TBI intake,TES headers,and STB,K&N,MSD-6AL,Holley laser shot coil,Accel Extreme 9000 wires,Jet Stage 2 chip,TCI shift kit with corvette servo,Richmond 3.73 gear with Auburn 3 series posi,no cat,SLP 3" cat back,Eibach sportline springs,Energy Suspension poly throughout,Lakewood LCA and adjustable panhard bar package,SSM subframe connectors,IROC wonder bar,Tokico 5 way adjustable struts and shocks,Autometer electric fuel pressure gauge,Alpine,JL Audio,MB Quart,92 GTA taillights,92 GTA aero wing and hatch,Steve Spohn LCA relocater kit,MacEwen White face gauges,84 T/A cold air induction air cleaner.

MRZ28HO

Zar, check out this thread. You can use a TBI adapter plate to mount on a carb manifold. I posted two links, one for the intake and EGR, and the other showing that the Vortecs have the required passage for the EGR.

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George P. Lara
1994 Z28 LT1 T56
1984 Z28 High Output
Member: SCCA, SCFB, SC3GFB

Chad91Rs

I was under the impression you can only mill a head so much and going from a 64 chamber to a 55 is a strech.
Someone correct me if I'm wrong.

Birmass

You can mill um .035 and get a good enough compression. It's also a good idea to use a very thin head gasket to get it up higher, but it has been done by many people. The power gains are pretty impressive too.

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88 firebird formula
350 Vortec TBI
Edelbrock headers
SIX-speed
Eating LS1's with a 2.73 open rear and 2 1/4 stock catback

[This message has been edited by Birmass (edited September 14, 2000).]

Keith5

There are also L30 heads which are 305 vortec heads, they would give you the right compression but they cost more.

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1989 Pontiac Firebird Formula LO3 Auto
-180 degree stat
-Hooker Cat-Back
*****Possible summer '01 mods*****
Open Element, Auburn Posi, Keyless Entry, wonder Bar off the IROC, 4th gen seats, T/A tail lights

1985 Camaro IROC-Z LB9 Auto
http://www.geocities.com/krt80/