3.1 firebird

so our stock injectors are 17#'s right? What # should I go to after I port my heads out?

Dont forget I also have these mods:


------------------
1992 black 3.1 V6, auto, T-tops. dynomax catback,3.4 headers, home-made FIPK,hypertech pulleys,B&M shiftkit,3.73's,crane compucam 2030
16flat@85.6

KED85

Go get Chevy 305's or just find 3.4 injectors.
NEW ONES cost money!!
Don't waste time porting, just reassembly right, tight leak free.
Spend the effort making sure all vacuum lines are leak free and crack free (not the drug!).
Porting these heads ain't worth it.
ADDING THE 3.4 CAM & SPRINGS AND RETAINERS & NEW VAVLE GUIDES is the hot ticket!!
Less money & effort & BETTER RESULTS.
EVEN GM SAYS SO.
Look in the Performance Parts catalog.
Go get a used 3.4 cam from a FWD engine, same thing!
NEW LIFTERS & CHAIN FROM Northern Auto (800-831-0884).
Have fun quicker & cheaper!
Let us know how car sounds at 6500RPM!


------------------
Chat Soon,
KED85
Karl
1985 Firebird 2.8 to 3.4 swap project for Smog Happy LA, CA

Red91Bird

I have to dissagree.... WASTE THE TIME PORTING!!!

These engines respond to flow... The intake and the heads... Do not waste alot of time porting the heads on the intake side, give it a very light makeover, HOWEVER, get down and dirty on the exhaust side of the heads, port and match, they respond nice to that. After you do that BE SURE to port and gasket match your intakes however STAY AWAY from taking any metal from your 3rd (bottom) piece, if you go to far you will go thru the metal and kill the part. They recommend that you take and make the metal flow even only, do not grind at all, only polish on the third piece. The other two are alittle more forgiving however its thin still - make even not grind to hell is the key. Also do not go more then 1/2 to 1 inch into the ports. I am still unsure why you are only running 16 flats bro, i am hoping and have been watching this board to see ya break into the 15's and hoping to see 14.9, its a matter of the heads, intake and the right tuning now - i promace you...

BTW... to not port the heads is to rob you of flow - flow = air and fuel. Air and fuel = power. I am not sure why or where GM says do not do it, all the z24, fiero and firebird/camaro 60 degree builders i have talked to have said that a good porting especially on the exhuast side brings the engine to life. No flames, just what i have heard and witnessed. I do know that GM sells directly a set of heads that have 40% more flow - that maybe why and rightfully that maybe the cheapest way to go. My heads cost 450.00 to get done over, i think GM sells theres for 600 a set or so - dunno, been awhile since i looked. Still thats about 600.00 cheaper then the V8 perfomance heads.




[This message has been edited by Red91Bird (edited July 10, 2001).]

TomP

I agree; a port job on any stock intake will help- especially when you run out of simple mods. I'm not going to have my heads done professionally; I'll have a go at 'em myself- but I'm not going to go too crazy. I'm basically going to gasket-match and smooth down some obstructions. Good call on needing higher injectors after the port job, too... have you thought about an adjustable fuel pressure regulator?


------------------
-Tom P (Hot rodded 1986 Firebird 2.8l) from http://www.f-body.net/mailbag/3rd/3rd_mailbag.html message boards
---Think your car could be pic of the week? Visit http://www.f-body.net for details!

3.1 firebird

hey thanks for all the info everyone. Ked, I;m betting the head porting might give me 5-7hp, but I consider it well worth it. I also plan on decking the heads and getting a nice valve job done. I might even get the larger 3.4 valves.

Red91, good info. I think my 16.0's are off the line traction problems. When I ran the 16.0 my #5 cyliner had half the compression of the rest , so that costed me power. However since I was making less power I was able to launch very well. This year after decking the heads .020 and compression being restored(the head was warped) my 60 foots were horrible. I;m guessing the increased power caused the launching problems. Dont forget I have 3.73's with an open rear end, so it a bitch to get to hook. After the head work, maybe a chip, injectors, and slicks I hope to hit mid 15's.

TomP, I cant find a pressure regulator. I',m going to get some inhjectors instead.

BTW I;m wanting 19# injectors, is that what 305 TPI injectors are? Will they work ok with the computer?

erik-

------------------
1992 black 3.1 V6, auto, T-tops. dynomax catback,3.4 headers, home-made FIPK,hypertech pulleys,B&M shiftkit,3.73's,crane compucam 2030
16flat@85.6

KED85

You already have the same size valves as the 3.4 heads.
OF COURSE porting the exhaust side helps.
WANT TO REALLY HELP!!
PORT THE EXHAUST MANIFOLDS!
I know you're all jumping on me for this, but these little things don't have the flow power to make it worth the effort.
AND THE GAIN IS AT THE TOP RPMS, where ya don't drive on the street. Thus your street performance (light to light) is WEAKENED! You loose bottom end torque.
Put the heads back together correct & tight and enjoy the time & results more.
Add nitrous for the upper RPM & more HP you really desire.
You will have your cake and eat it, too.
The truth.
Flame me all ya want, but, when ya start in on your project, you'll see why I keep recommending this receipe of slap it back together with better springs, new guides & a 30/60/90* valve job.
Milling only raises compression and that equals higher gas requirements (higher octane).
These engines are almost 9, now. UNLESS YOUARE BUILDING A TRUE RACING PURPOE ENGINE, don't spend the time.
WHEN YA GET A NAKED HEAD IN YOUR HAND, you'll understand better. MAKE SURE YOU COMPARE THEM TO A V-8 CASTING FROM THE 70'S and see the diference! That's why ya port & polish old Chevy heads. YA NEED TO!
The "BETTER HEAD" GM SELLS is the cantered valve aluminum head (the FWD version).
THAT DOESN'T FIT OUR North-South engine, anyway!
Look at the GM PERFORMANCE BOOK FOR THE STUFF I MENTION.
EVEN TRY TO FIND THE OLD PERFORMANCE BOOK FROMTHE LATE 80's for GM tips on the HOP UP of the 2.8/3.1
They recommend to use the original 2.8 TRUCK INTAKE (the carb) version AND MAKE A PLATE TO ADAPT THE 500CFM HOLLEY 2-BBl onto that design. OR, the old carb intake IS THAT WELL DESIGNED for performance, already!
I only have read from the GM engineers who designed this stuff for my answers. Not some guy that wants to make money outta your back pocket!

------------------
Chat Soon,
KED85
Karl
1985 Firebird 2.8 to 3.4 swap project for Smog Happy LA, CA

3.1 firebird

Ked, when I had to get my heads planed because of the warpage that caused low compression in #5 cylinder, I had him take .020 off,302 V8 springs, and a good valve job, so as I start to think about this the gains might only be minimal after all. And now you are saying I already have the bigger valves I;m probably not going to do this.

Are you sure we have the same valve size as 3.4's? I thought we had 1.6/1.3 inch valve, and the 3.4's got the 1.72/1.42?

well anyway,I might skip the heads/fuel injectors and just but another slick since I already have one that I got for free. The slicks should give me the traction I need to hit my goal time of a 15.8-9ish.

KED85

Now ya got the idea!
Honest, it's a waste if ya NOT going to always stay in 6500 RPMS.
I'm really bummed, for my 2 small block Chevy heads, I gotta keep 1.94 size for living on the street.
AND I BOUGHT THE MOST PRIMO 2.02 1.6 VALVES YOU CAN GET NEW TRW Undercut Stem valves.
Oh well.
Maybe I'll save those valves for the AFR 190 CFM aluminum heads I'm gonna try to buy, one century!
The samller sized valves you sepak of are the CARB HEADs, Like on my 1985 S-10 Blazer.
Best upgrade I can make is the heads I'm now installing on my S-10 Blazer. The left over from my 1985 2.8 MPFI engine that lived in Jennifer, before I put the Silver dollar hole in piston number 1!
Any carb'd engine has teh smaller sized heads.
Any 2.8/3.1/3.4 has teh same sized valves.
IT's teh springs that make the difference.
I THOUGHT DIFFERENTLY, also.
I check in my 1998 edition of the GM Performance Parts catalog. It says, same.
Confirmed by others here, too.
You already got the good stuff done.
Go to ignition for the more power, next!
Or exhaust or intake, too!
You are definetly on the right track and with your train of thought, you'll be closer to your E.T. goal.
You have invested your money wisely!
What tire ya gonna use?
What wheel?
What size wheel?
Is it from a GM car?
I'm thinking of using one of my 1974 Corvette wheels. 15" x 8".
Hope it fits, I want a BIG tire back there. A big fat drag tire is WAY CHEAPER than installing ProTrax unit for better launch!
ALSO TROW OUT AS MUCH DEAD WEIGHT WHEN RACING.
I do not have anything behind my nose piece. Saves about 150 lbs I hear!

------------------
Chat Soon,
KED85
Karl
1985 Firebird 2.8 to 3.4 swap project for Smog Happy LA, CA

3.1 firebird

Ked, I think I'll use a 15x7 stock firebird or camaro rim. My grandpa has a couple wrecked fbods, so he has the rims, and I can have them for free. BTW the slick I have is a Mickey Thompson ET Street, it fits the stock 15 inch firebird rims and its 10 inches wide! It cleared everything even being as wide as it is. It has some dry rotting, but I;m going to tube it, so I wont have to worry about a blow out or anything.

TomP, red, thanks for the info. If I ever tear the engine apart again I WILL port the heads out, but Ked got me to thinking how much of a hassle it would be for a little extra upper RPM hp.



------------------
1992 black 3.1 V6, auto, T-tops. dynomax catback,3.4 headers, home-made FIPK,hypertech pulleys,B&M shiftkit,3.73's,crane compucam 2030
16flat@85.6

Red91Bird

Food for thought:

Next time ya are sitting at a red light, rev it upto about 2000 to 2200 rpm as the oposite light goes yellow - do this on a raod that you won't launch into a car that is trying to beat a red - Launch hard and try to feather the gas so you do not get wheel hop or spin. Now watch your rpm's climb to about 4500, you should be in first gear at about 35 mph, feel how the car starts to lag as it climbs from 4500 to 5500 to 5700 to shift. The actual time is prolly around 2 to 3 seconds the car flatens out in torque and there is very minimul climb in speed. Its almost like your spooling up to hit 2nd gear. That right there is what will be MAJORLY minimized by better airflow and a strong ignition. The same happens at 2nd to 3rd or at highway speed in OD when ya punch it, it will downshift and take forever to shift up at about 85.... In a 0 to 60 if ya can get your car to spool fast and grab second without (or with a faster shift time) you WILL shave a good 3/4 to 1 full second off your 1/4 mile time. Get some junk heads, get em preped and take a weekend to swap em. Trust me bro - the gains are well worth it and i would say jsut that will get ya 15.5 in the 1/4 OR to put it another way, a dead even race with a 88 LX 5.0 with a AOD.

TomP

3.1, the AFPR's for V8 tpi's are supposed to fit our cars. I think Crane makes the cheapest, then there's also Hypertech, JET, and I think Accel & SLP. There's also a tech article on thirdgen.org that talks about making your own AFPR by modifying the stock one (you add a set screw thru the top and a penny inside), if you want to try that.

Oh & Karl, you told him to port his exhaust manifolds, and get an intake and exhaust- my man Erik's got all that- including headers- and more. He's one of those guys running out of mods, not just starting out. With all his changes to the engine, a port job might be what he needs.

But you're right, it's a crapload of work. Me & my friends had enough of a time scraping off the head gasket from that 2.8 engine (from my friend's car's 2.8/2.8 swap)- and that engine was on a stand! If it was in the car that's a ton of work... plus the downtime for the machine shop.

Also, not as a flame, but you keep comparing our heads to that of a 70's v8. People still port the "brand new" V8 head of the 80's, 90's, and today. (To quote many radio stations, of course!) Hell, people even port brand new $2000 aftermarket heads! I'd be scared to lift those heads out of the box, let alone port them!


------------------
-Tom P (Hot rodded 1986 Firebird 2.8l) from http://www.f-body.net/mailbag/3rd/3rd_mailbag.html message boards
---Think your car could be pic of the week? Visit http://www.f-body.net for details!

KED85

What they are doing to NEW heads is porting them to the engine package they have designed.
They do this on a FLOW BENCH, to test the effects.
Do WE HAVE ACCESS TO A FLOW BENCH?
DO WE WANT TO PAY THE COST TO A FLOW BENCH?
Want to ppay the person with the expert knowledge of how to work the heads for flow bench & track results (or do you own a NASCAR TEAM LIKE JOE GIBBS OR JACK ROUSCH?).
PLUS, what engine size they playing with. LOOK AT THE NUMBER, it's V-8! Like a 383 (stroked 350 engine) or a 502 Chevy or anything that is a V-8, not a small V-6, like what we have.
Our engines are not pushing that much air to cause that great of a change, ESPECIALLY on the street.
AT A TRACK DEDICATED CAR, sure!!
You're looking for that extra .10 or 3-4 mph, hit the heads, etc and other tricks.
On the street, buy a V-8!

Let me offer about the 55MPH & such.
Whenever I hit the gas pedal on my 3.4 swap, I'm close to 90 in a blink of an eye.
WHY?
It's the CAM & ENGINE SIZE ISSUE.
I have a better designed cam and more air being pushed thru the engine, EVEN WITH THE UNPORTED HEAD INTAKE SYSTEM OF THE 2.8 SET UP!
I mean, I am up to 90 in a blink of an eye!
I was stunned the first time I did that! I couldn't believe how much of a difference those extra cubes & cam shaft profile change made.
And all I did was reassemble what I was given (the 3.4), made it tight & leak free!
Make what ya got, leak free, tight, powerful (ignition/gas presure/fuel injector/exhaust/tranny & gear) and go have fun!
When ya reach the wall, go get another car!

------------------
Chat Soon,
KED85
Karl
1985 Firebird 2.8 to 3.4 swap project for Smog Happy LA, CA

TomP

Not to sound like I'm attacking you, but instead, discussing: That's not the point; the point is, they're still porting them for a better design. The 2.8/3.1/3.4 head design is not the ultimate head design; it's got the capability of improvement. You're saying to leave the thing alone, but that's more of a personal decision of yours. Point-blank is, the heads can be ported, and some HP gain will follow. You're arguing against the whole concept of touching the v6's heads, but if the guy wants to, why not? It's not going to hurt (unless ported badly to hurt air flow), and chances are it'll help.

I doubt most of the guys on the V8 board paid someone a ton of cash. Either they've had a machine shop work 'em, or they've done them at home, and they've seen results.

No matter what the size, an engine's still an engine, dude, any way to improve air flow in or out will increase power. I mean, you could say to not put on an aftermarket cat-back, because we only have little V6's... or to not mess with the air filter, because of the engine size. Such could be said about any mod we do to our cars! I'm not saying I want anyone to spend $3000 on heads just for a v6, but instead do a minor "budget" port/polish job.

And 3.1Firebird has a camshaft already, too... with all the work he's done, I'd be trying to keep going, too. Just by itself, adapting the 3.4 headers to the 2.8 was an awesome job!

Imagine if you ported the heads, too! Just playin!

------------------
-Tom P (Hot rodded 1986 Firebird 2.8l) from http://www.f-body.net/mailbag/3rd/3rd_mailbag.html message boards
---Think your car could be pic of the week? Visit http://www.f-body.net for details!

KED85

Tom, I have ported my cylinder head.
The 186 1969 Z-28 head.
It took me ten hours.
I could have ported the V-6 head, easy.
BUT, for the effort, very little personal performance rewards, compared to stuffing the bigger engine under the hood of my Firebird.
One improves the performance of these things with all the tricks mentioned (ignition/exhaust/ etc) those gains really make with ya originally got, worth it.
IF ya wanna pay someone to port & polish, go a head, it's totally your dime.

ALL I'M THROWING OUT IS THE GAIN FOR THE DOLLAR/TIME INVESTMENT will not give ya back what ya expect.
UNLESS YOU ARE BUILDING A DRAG STRIP DEDICATED VEHICLE.
Throw the effort into finding & installing a 3.4 engine and go have more fun, then waiting for this guy to finish spending the money you could have invested into a bigger better engine.
That 3.4 engine has all the hop up stuff you are putting on the smaller engine, from the get go.

Imagine going to 90 MPH faster?
Doubt it.
This is a very well balanced drive train, right now. I am very pleased with the results.
NO, make that IMPRESSED!
Going faster to 90, I'll do it in my Corvette or 1967 Camaro, when my engine is done being built by me.
Find out the cost offered to play with these heads and throw that number back.
I paid $800 for my running 3.4 engine with 40,000 miles.
It's show me the money time.
What is the better dollar investment?
BIGGER ENGINE
or
PORTING POLISHING HEADS and throwing them back on a smaller engine and hoping for a HP gain to equal 165 HP & 200 Foot Pound of torque right away?
ALSO NOT FLAMING, Tom, you are a very intelligent dude, as are 90% of all here, (rest, 10% keep reading and understanding better what to do with what ya got-it's fun to learn).
Me?
I keep asking my machinist what's worth the effort and dollar investment!
My machinist, Phil, raced Craig Breedlove (one of the fastest men alive) and worked with **** Gulsdtrand (Corvette engineer that has raced at Le Mans). Now plays with Honda heads & such (like my lousy projects!!).



------------------
Chat Soon,
KED85
Karl
1985 Firebird 2.8 to 3.4 swap project for Smog Happy LA, CA

Red91Bird

Porting the V6 heads is not a little reward, i have posted time after time on what it does and how to do it. I did it, i got to see and feel the performance. Tom is absolutly correct in saying it maybe a V6 but its a engine and has the same rules as a 350, i.e. - more air/fuel, more hp and torque.

To do the 60 degree heads the correct way:

VERY LIGHT port on the intake side,

FOCUS IN on the exhaust side...

That is it, thats the downfall of the 60 degree engine. The engine is almost a perfect design actually. With 3.1 running headers and a true Y pipe he will feel a BIG increase in the mid range to highend and in the 1/4 mile he will have to travel thru the highend of his engine atleast 2 times. A area that the 3.1L lags out starting at about 4500 RPM. At 16 flat a good port and polish with matched intakes, he is looking at a 1/2 secong to 1 full second in gain. Is changing out the heads a PITA? yes it is, about 8 solid hours of work, but its alot easier then changing out a engine and the cool thing is he can hit the heads and intakes all at the same time.

Sorry, i am seeing him so close to breaking into the 15's and see what he is missing <---is driving me nuts heheheheh

x55Cam

KED85 said
That 3.4 engine has all the hop up stuff you are putting on the smaller engine, from the get go.

No flame intended and I realize where your coming from, but I wish you would back this up with facts instead of opinion and inuendo. All the GM performance books and rebuilds that I have, based on the 60deg motor, explain very implicitly that this motor can benefit greatly with just MILD porting and head work. I'll be happy to show you these quotes if you insist. What I would like to know is where do you get YOUR information from that makes you so sure that it is "a waste if ya NOT going to always stay in 6500 RPMS."? Porting intakes and heads has absolutley nothing to do with runner length! It's volumetric efficiency that we are concerned with.
If your machinest finds that it is,for what ever reason, performance enhancing to work on Honda heads and intake, why shouldn't we feel the same about the V6/60?

DO WE WANT TO PAY THE COST TO A FLOW BENCH?
Want to ppay the person with the expert knowledge of how to work the heads for flow bench & track results (or do you own a NASCAR TEAM LIKE JOE GIBBS OR JACK ROUSCH?).

Yes if it will benefit what I set out to and what the results will be. Air flow is just as important as putting a different cam or adding higher compression pistons.
Yes, I will be doing flow benching to my intake/heads BEFORE and AFTER porting and will post the results on my web as promised in other topics. And to support theory that results from better flow produce more power through the band that is determined trough the runner length and cam configuration, I will also post calculated performance data that will predict HP/TORQUE also using an "Engine Dyno" program that I have from plugging in these Flow Bench figures. This will prove beyond your doubt that it is not a waste of time in producing HP/TORQUE over a wider band than just 6500 as you claim. I will back up my claims with data, charts and statistics. What will you backup you claims on?

3.1 firebird

its traction. My car had better times when the #5 cylinder was shot because it was eaiser to launch. WhenI fixed the cylinder the added power caused me to sping the tire so bad my 60' times went to hell.


I;m still sort of stuck on what to do about the heads. KED has some good points, and so do other people. One thing about doing the heads is that I am pretty sure I will need bigger injectors. I;m still dont know what injectors WILL work without a doubt. I like to look inn scrap yards to get them for 5$! Then I'll have them flow tested to see if they work ok.

So heres my options:

A. buy another slick and hit high 15's

B. do the heads and get another slick possibly seeing mid-low 15's, or possibly no gains with the heads work.

C. Keep on saving for the LT1 camaro!

3.1 firebird

KED, you were right about the valves being 1.72/1.42 on fuel injected 60/V6's. I just measured my spare set of 3.1 fulie heads.

Graeme'sFirebird

Slick

------------------
1989 Firebird
2.8 v6, t5 swapped in

Ram Hi-po clutch, Cold Air, 1.6 rockers,Lakewood LCA's, Lakewood Lift bars, Wonder Bar, 3" y-pipe, Random Tech Cat, 3" I-pipe, Flowmasters, MSd 6a, MSD Coil, Accel 8.8 wires, Auto Meter Gauges (Water, Clock, Fuel Pressure, and 5" Sport Comp Tach)TB Bypass, 4th Gen Seats

Coming for my v6:
Panhard Bar, 4thgen front seats, Nitrous, Line Lock, Posi, Spohn Torque Arm & Subframe connnectors

"I'd rather run last in a full out race, than to NOT have run at all"
#3 Forever

KED85

I can back it up with, that I have installed a larger engine, with all the work everyone is speaking of doing and I only paid $800 for my effort of a better running engine.
The stock 2.8/3.1 cam tends to have a flat spot at certain RPMS.
You're asking the smaller engine to make up for that, by playing with the heads.
When you get the larger flow going of the whole 3.4 engine package, the flat spot is eliminated and more power is achived, all in one tidy installation.
Let's us read from the BOOK OF CHEVY PERFORMANCE. (Fifth edition)
There are two different heads used in the (early 80's) 60*. #327 & #884 are used on the HI-PO LH7 & our MPFI engines. They differ from the heads I got on my 1985 Truck 2.8 (as I had smaller valves).
Both production heads use a 4 angle valve seat contour wihich should be kept during any rebuild or modifications. (46*, 65*, 75*, 82*)
The unique flow of the inlet port was arrived at after considerable testing. It's shape provided a 17% increase over more conventional designs. Basic port work should be limited to enlarging the inlet port to the gasket size at the manifold surface, removal of any casting irregularities on the port wall and blending any steps in the bowl area in order to form a smooth appraoch to the valve seat area.
Any work on the exhaust port should be limited to the bowl area where it should be contoured in such a manner as not to disturb air flow thru the valve seat area by developing a proportional venturi.
The cylinder head casting was developed for production use and as such extra material was not included for further port flow work. ANY MAJOR PORT REWORK SHOULD BE PROCEEDED BY THRU RESEARCH OF THE MATERIAL AVAILABLE AND AFTER EXTENSIVE TESTING IN A SUITABLE FLOWBENCH.
Any milling of the 60* head should be kept to a minimum since it will produce a mismatch both in the inlet port and valve cover sealing areas. With the four bolt cylinder head pattern, milling the head will reduce head gasket clamping and lead to early head gasket failure.
Modification of the cylinder head for extra valve spring space and 7/16" studs rocker arms is covered in the section of springs and valve train.
Crane Rocker number 2F89 is the suggested roller rockers.

Like I've said, if ya got the tools and time, DO IT.
Like I've said, the heads are in excellent shape from the get go, if REBUILT RIGHT, NEW GUIDES, SPRINGS and Roller tip rockers (1.52).
If ya wanna play with them, pay someone big bucks to do it, as they have the knowledge to do them quick and right.
BUT that $1,000 or so can buy, the-
Bigger 3.4, with all machining work done, cam heads, pistons, stroked crank.
AND pay for tires
and exhaust work
and maybe NOS system.
BUT, NOT THE BLOWN TRANNY.
Do the work on the heads, to show the results.
I only installed the better value ($800 for my 3.4 engine), from the beginning and I'm enjoying my results quicker.
Including a ET, when the tranny gets fixed!
AND if I wanna get radical, I can use my larger 3.4 engine as a springboard to go larger.
How much larger can ya go with a 3.1?
Really, ya can't go as large as a 3.4 overbore job.
Spending the money on a 3.4 engine package is just flat out the better value for the dollars spent.

------------------
Chat Soon,
KED85
Karl
1985 Firebird 2.8 to 3.4 swap project for Smog Happy LA, CA

x55Cam

KED85 said
BUT that $1,000 or so can buy, the-
Bigger 3.4, with all machining work done, cam heads, pistons, stroked crank.

Have to disagree with ya there. The only diference between a 3.4L and a 3.1L is the bore size and cam. Heads and crank and everything else is identical (except for casting of the block walls).
If I had a choice between putting a cam in and doing porting over removing the entire motor and searching the junk yards for a motor to just throw in without doing anywork whatsoever to the 3.4L I'd rather keep the 3.1. Less risk involved in going to something unknown.
So your point is that a 'stock' 3.4L will out perform a modified 3.1L (porting/intake work) and a cam, with all else being equal? I'm willing to wager some money on this!

Red91Bird

3.1L modded vs's a stock 3.4L? heheeh, i got one to push 13.98 on NOS. Now i bet a modded 3.4L will do a tad better, maybe afew tenths faster, but not much more. Yeah to take a 135hp 2.8 and goto a 180hp 3.4L is gonna seem like going from a go cart to a 4 banger car. 40hp and 40+ in torque is alot for about the same weight. I suspect the torque curve is abit flatter and i can imagine that it feels alot faster. That said tho a 3.1L can and will hold against a 3.4L easy, maybe not stock for stock, but modded vs stock... in a heartbeat. Its only 18CiD bigger, not alot of room for gobs of torque, hp yes, torque no. Any of these 2.8L to 3.4L engines are hard pushed to make over 240ft/tq no matter waht ya do save NoS or forced induction. Remember HP sells cars, torque wins races....

KED85

I guess so.
I mean, right now, I do not have the means to go drag racing. I need atranny!
But, I still stand by what I've said. For under $1,000, bigger engine, already built, and running, stronger and faster than the others....

That's my SUGGESTION.

I'd still like to see the bills for all this work to be able to outperform a 3.4 from the get go.

------------------
Chat Soon,
KED85
Karl
1985 Firebird 2.8 to 3.4 swap project for Smog Happy LA, CA

TomP

We're not talking about going to a 3.4 in this post. Sure, you've done it, great, but the message asked about porting. Plus, you keep skipping over one thing- 3.1Firebird has already done a ton of work to his 2.8. You keep saying to do intake and exhaust- he's got it!

He's running out of upgrades; and I don't think he's chasing down a 3.4 yet.

You might as well tell us to just drop in a junkyard v8, since they can be had for under $1000, and not bother about touching the heads. But what happens when the v8 runs out of mods- instead of doing head work, do we move up to a big block motor? See what I mean? Heads should be done- but not as the first mod.


And what happens when your 3.4 becomes modded up to the point where headwork would be a good idea? Will you just dump the 3.4 for a 5.7? Granted; you might, that's personal preference, but nobody here wants to do that.

Quote:

<font face="Verdana, Arial" size="2">IF ya wanna pay someone to port & polish, go a head, it's totally your dime.

Again, you mention paying somebody; I never have. I have not once said to pay somebody $1000 for headwork! I say to do it yourself with a grinder. Simple headwork can yield a good result with little work- it's the hardcore headwork that needs flow-bench testing.


------------------
-Tom P (Hot rodded 1986 Firebird 2.8l) from http://www.f-body.net/mailbag/3rd/3rd_mailbag.html message boards
---Think your car could be pic of the week? Visit http://www.f-body.net for details!

KED85

Tom, you certainly have brought up very good points!
BUT, to keep working a 3.1.....
Go get a bigger bottom end, to make the work doing/to do/done really shine!!
Yeah, ya can do the work and I also offered whata the GM engineers offered.
It's ALOT of personal time & work
ALOT.
Again, I put 10 hours into one head. Yet, I am pushign ALOT of cylnder volumn thru those V-8 heads, compared to the V-6's

What gain will you get from V-6 head work?
That's an unknown.
BUT
BUT
THERE IS NO REPLACEMENT FOR DISPLACEMENT.
I still say, upgrade to a 3.4 block and heads. Alot is already done (the better reving springs and retainers).
AND it's well know, the results of going to a bigger engine.
The best would be for doing what ever ya want to the smaller 3.1 package, then testing it. Then getting the bigger engine, later!
See the results SHINE
My thoughts, only.

I know the benefits of the 3.4 package.
I still have a broken tranny to show.
Working up that spare change, still!
Personally, add nitrous and be done with the mission! & competition!

------------------
Chat Soon,
KED85
Karl
1985 Firebird 2.8 to 3.4 swap project for Smog Happy LA, CA