I thot that I would run this by you guys to see what you thought. I have the LO3 stock engine. I have these parts from another motor with 2000 miles on them. Vortec heads with good springs, Performer Vortec intake, LT4 cam and 1.6 roller rockers. How well do you think this set up would work even with the dreaded by many compression loss? PS; I will be the guinea pig for this. I have a scanner and burn my own chips. Lets see, will my wife bitch if I buy a chassis dyno? LOL Let's hear what you think.

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91 RS 5.0 TBI....Edel. TES headers .. 3" exhaust ..... 5spd 3.08

someone said they saw a LG4 with those running high 13s even with the low compression of 8. something because of the heads.

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-Tas
'89 Formula WS-6

305, TBI, auto, 14x3 chrome flat based open element with K&N, Milodon 160* thermo, functional Formula hood, cross-flow Flowmaster, '99z28 rear pipes and tips....

To be installed eventually far far far into the future: Yours if the price is right and I don't have to ship :
Hooker 1-5/8" 50 state legal headers, Dynomax 3" I pipe (PN 44063 and 43248), Catco 3" cat, and injector spacer.

Super GRK_Taz World
F-Body Dual Exaust
EFI & Intake Options
AOL IM: superGRtaz

The only post that I seen was on Sept 2,01 by Brent about an LG4 running around 99mph in the 1/4. Either way these seem like good numbers for the money spent.

Why don't you just get them milled down a tad so you don't lose compression?

Hey you have my car!!!!!!!! I have the same setup and love it. I am in the process of setting up my 670cfm TBI now. With 3.73 gears I can tell you its a STRONG Performer. I did however mill down my heads.


Brian

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1989 Camaro RS

305 .030 over Hydro Pistons
Vortech heads milled to 58cc...Performer RPM intake....LT4 cam..Crane Gold rockers...FastChip custom chip...ALum. Driveshaft...3.73 gears with Posi...underdrive pullys...Rebuilt 700R4 with Vette Servo and B&M shift Kit...MSD ignition...A/C Delete No SMOG junk....1997 SS leather interior...B&M Shifter... Ultimate TBI mods...14X3 K&N open Element Non-Drop...Hooker headers....3" exhaust with Flowmaster Cross flow 16X8 Wheels from 97 RS Spohn LCA's Spohn Panhard Bar..LETS PLAY FORD!!

www.geocities.com/feltsb

I may decide to get them milled but other than that they are ready to bolt on and do not have to be diassembled. How much did you get them milled to get them to 58cc? I wished that I had gotten an RPM intake too. Yes our cars will be very similar. Crane gold 1.6's...alum drive shaft...lightweight GMPP's nodular iron flywheel...no a/c...no smog junk...no rear seats...ult TBI mod's...adj. pressure reg...K&N1500 1" taller filter...non-drop base...4" cold air duct...underdrive pulley's...Accell super coil...sub-frame connectors...strut tower brace...6-point rollbar...Sabelt 4-point harness...custom chip(only spd limiter removed at this time)...parts sitting waiting to be installed...3:42 GM gears...Torsen H.D. diff...1LE front brakes...rear alum drums...plus what we're talking about

https://www.thirdgen.org/messgboard/...ML/002387.html

See this Post. If you read mine near the bottom you'll get my opinion as well as many others.

Search the board for L31 and you'll find a ton of posts about theses heads

-Lars

heh ya get the drilled and put a blower on them

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-Tas
'89 Formula WS-6

305, TBI, auto, 14x3 chrome flat based open element with K&N, Milodon 160* thermo, functional Formula hood, cross-flow Flowmaster, '99z28 rear pipes and tips....

To be installed eventually far far far into the future: Yours if the price is right and I don't have to ship :
Hooker 1-5/8" 50 state legal headers, Dynomax 3" I pipe (PN 44063 and 43248), Catco 3" cat, and injector spacer.

Super GRK_Taz World
F-Body Dual Exaust
EFI & Intake Options
AOL IM: superGRtaz

Thanks for the reply's. I'll let you know the results.

The power loss to compression drop is overrated. Your CR will drop what, a half a point? If you look at the curves for CR vs torque (and power) increase, you'll find that it's a very small change unless you go from something like 8:1 to 13:1 or higher. You'll be going from 9 to maybe 8.5, and that's not worth chasing. Save your money, skip the milling operation.

You probably should go with better (non-stock) valvesprings, because the stock ones will bind, nevermind that they aren't designed to cope with .480" lift from the 1.6 rockers you have in mind. You should also install screw-in rocker studs now as a precaution.

There is at least one Bcar person I know who has put Vortecs on a 305 and his car runs great even with the stock LO3 cam. The LT4 cam, in a Fcar that's 300-400+ lbs lighter than a Bcar, with the Vortecs will run great.

You should be seeing peak 290 fwhp at minimum with that combo, because the heads will flow better on the 305 than on the 350 (13% less demand by engine volume), and in spite of any shrouding. I'd also expect 310+ fw ftlbs torque, so those numbers will almost equal the power (or torque) to weight ratio for a 4th gen Fcar with LT4... so you can expect to run numbers similar to a 4th gen LT4 Fcar, and probably a bit better than a stock 4th gen LT1 Fcar.

This also assumes, btw, that you will be able to supply the fuel to satisfy 290+ fwhp @ 5800 rpm. You'll need the biggest injectors you can muster and you'll also need some combo of fuel pressure increase (fixed, or using the vFPR), and/or ECM. You don't need the big throttle body for 290 hp, but you do need more fuel than from a LO3 ECM fuel table.

The bolt-on parts (heads, cam) will be easy, and the car will run great with the stock tuning up to around 3400 rpm at WOT.... but then you will lean out. You could lean out enough to damage your engine, so make sure you do SOMETHING to add fuel after you do those mods. The vFPR is probably a quick/easy approach but you'll need to tweak it to get it right. The custom ECM is the best approach. Either way, you will need at minimum the 9C1 LO5 copcar TBI injectors AND a fuel pressure increase, and probably an increase to the injector duty cycle.

Thanks for the info kdrolt. I've been reading up articles on C/R's and agree with you on that. I will not be milling and the heads are ready to mount. I will be using GM .028 composition head gaskets. I've already upgraded the springs and clearance's for over.500" lift. I have LO5 injectors to install and will be burning my own proms for this. I don't see how you could tune for anything but minor mods without program changes. I'm glad to see that this will produce some good power.

http://www.nethirdgen.org/ubb/Forum1/HTML/007060.html

Scroll down to Checkeye's post. I saw him make those runs.

You might consider Felpro head gaskets. I believe they have some real thin .015 gaskets.

damn 99mph. He should be in 13s with some decent traction. hmm... I have enough to do vortec heads

------------------
-Tas
'89 Formula WS-6

305, TBI, auto, 14x3 chrome flat based open element with K&N, Milodon 160* thermo, functional Formula hood, cross-flow Flowmaster, '99z28 rear pipes and tips....

To be installed eventually far far far into the future: Yours if the price is right and I don't have to ship :
Hooker 1-5/8" 50 state legal headers, Dynomax 3" I pipe (PN 44063 and 43248), Catco 3" cat, and injector spacer.

Super GRK_Taz World
F-Body Dual Exaust
EFI & Intake Options
AOL IM: superGRtaz

[This message has been edited by Tas (edited September 27, 2001).]

Thanks for the link. Interesting reading. I already have a set of those .015 Fel-Pro rubber embossed gaskets that I originally bought for a 305. I do not know how well those seal however and was leary of using them. It says on the package both surfaces have to be very smooth. The heads are almost new but the block won't be. Think some sealer would work and if so what brand?

Yeah I agree, with traction it would really kick butt for a 305!

I'd call Felpro or a local race shop and see what they have to say.

Calling might be a good idea. If they don't know who will?

I want some fekkin' heads! ARGH!

First, though, one needs money.

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1992 Camaro RS (Auto) 5.0L TBI
-
Performance mods
NOS (125 HP shot)
Dynomax cat-back exhaust
Hedman headers
K & N open element/ X-Stream lid
MSD 6A ignition
MSD 8.5mm plug wires
LT1 camshaft
Soon to be installed:
Edelbrock intake manifold
B & M 2400 RPM stall torque converter
Trans Go shift kit
World Products Torquer heads

Audio
Sony Xplod CDX-M610 head unit
Pioneer 2-way 4x6 front speakers
Pioneer 3-way 6x9 rear speakers
12 inch Pioneer VCCS PRO subwoofer
QLogic sealed box
Kicker ZR360 amplifier
Lightning Audio 1 farad capacitor

Other
Macewen White Faced Gauges/Shift overlay
A-pillar gauges (Phantom oil pressure, Air/Fuel)
180* thermostat
Window Tint

BahamutRS have you made your mind up what heads you are going to use? How did the LT1 cam affect your cars performance?

Just an FYI I am using the .015 Felpro gaskets on my truck with no problems thus far. Mating surfaces must be very flat. I had my heads machined to fit the block and you can't have any imperfections around the water jacket holes. I did ad a slight amount of silicon around water jacket holes.

Thanks for the info br! I don't think I'll use the .015's but instead will use the GM .028 composition gaskets. It can't be more than a couple of tenth's of a point of c/r differance.

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91 RS 5.0 TBI....Edel. TES headers .. 3" exhaust ...Dynomax muffler...5spd... 3.08...underdrive pulleys...cold air K&N flat bottom breather...strut tower brace...6-point rollbar...sub-frame connectors...Koni shocks and struts...16" Black GTA wheels...Autometer guages...custom chip...Grant steering wheel...a/c delete...smog delete...rear seat delete...ultimate TBI mods...afpr...36mm front and 25mm rear swaybars with poly bushings...