94Camaro

Hi there. My name is Russell and I have been here a while, just havent posted much cause I usually only post when I feel that I have information to contribute. This is such a time...

I have owned a 3.4L Chevy Camaro since 1996 and have been on a "quest for more power" since I bought it. It's peppy enough from the get go with a manual transmission but the automatic is lacking a little bit. Even with the manual, it still has issues putting out enough power to push the massive 3250lbs that is the car itself. When you add speakers or anything else this becomes a serious hinderance to the car in terms of performance.

I have seen posts regarding the 3.4L engine, and I have seen both facts and fiction on this motor thrown around in an attempt to sway people one way or the other. Thats not what I'm trying to accomplish here. Here is my honest opinion about the 3.4L OHV (204ci) RWD engine that comes in the 1993-1995 F-body (Camaro/Firebird). Most of you will be like "oh great whatever". Those of you that know that I have been here and most often won't post in a thread unless I have something important to voice on the matter will stop and read this. And a few of you will be genuinely curious to know what it is I'm trying to convey. Pull up something to drink and some popcorn, this promises to be a long thread.
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I have done my share of research on this engine. I even contacted GM and asked them for any information they had on the car. They promptly sent me the GM Rebuild Kit for the 1994 Chevrolet Camaro. It didn't cost me a thing and this little packet included every bit of information, original brochures from 1994, a full detailed listing of all options and factory information on every part of the engine, car, chassis, etc.

It was here that I began, studying and calculating and realizing the first thing about the motor. GM Lied. It wasn't a big lie. The motor is advertised at 207 Cubic Inches, but using valid formulas for calculating CID I came up short at only 204. I rechecked several times and came to the conclusion that GM rounded up the engine size because in reality, the "3.4L" engine is really only 3.35 Liters. Now .05 Liters isnt a huge deal..but when you start with so little, every bit counts.

Armed with this information I began signing up to different boards and clubs with the hopes of finding people who had begun to modify the car and make it work better. I came across a lot of owners who were frustrated because they hadn't found anything created by the aftermarket and had given up and advised me to do the same. My Camaro, is honestly my first car. It's the first car I ever purchased and still runs strong to this day. I didn't let anyone's dismay sway me from my goal of making my car work better for me, and not go out and try to win any awards for the most horsepower or torque or anything like that. When I discovered RKSport and their aftermarket products for the 3.4L, my hopes perked up because I realized that if I saved up enough money I could make my car work better. I began to research different engine shops in the area and stumbled across Norris Racing Tech (NRT) with their 3500 package which promised to make the engine a 3.5 Liter and give you the best performance you could get. But at 3000.00 for the engine package + shipping/handling I wrote that off.

Now I have to digress a little because I realize I skipped a very important point. Most 3.4L owners try too hard. You think that you can take your 3.4L V6 and run out and make it faster than any car on the road. That’s not going to happen. There will always be, whether you own a 3.4L v6 - a 3.8L v6 - a LT1 - LS1 – Vette – Viper – Porsche – Ferrari, a car faster than yours. The thing I realized that if I built the car for me, if I did things I wanted and questioned the conventional wisdom of “that won’t work” I would stumble across the magical mod that would give me a massive boost in the right direction. I stayed on these boards for years, watching people come on and ask, “what’s the best intake, what’s the best exhaust...” and all those things. I watched people rise and get incredible gains and saw people I knew push the limits of the engine and develop supercharger and turbocharger kits for the 3.4L, as well as take and add nitrous to it. There were a couple of “loch ness” stories about a mythical 3.4L out there running 9’s in the ¼ mile, but that person never signed up to this board or any others that I have visited, so that person remains a mystery as to whether or not they really exist.

Getting back to my topic – When I realized that I would have to work harder and think more because the things that people were doing weren’t really accomplishing much, I turned to the actual engine design and I looked at several options. I then realized, in 1999, that Pontiac’s Grand Am GT was making 175hp/205tq from a 3.4L OHV FWD motor. I did research into this engine and found that GM had worked a different path on this motor and it was better than the 3.4 RWD. I did more research into engine design and found that runner lengths help determine how much power and torque the engine gets. I looked at the plenum and runner design on the “3400” engine as well as the 3.4 RWD and realized that the RWD runners were jokes. At only 2” long and without any type of airflow acceleration present, they looked like all they served was a means to get the air from the Y shaped plenum, which once I saw a cross section – laughed at, to the cylinders. That was when I decided then and there that the plenum and air intake system was the 3.4L’s weak point. GM had spent money into making the 3.4 into a “Race style” motor. At 60 degrees the Angle of the V shape is natural. EXACTLY replicating the letter V, the angle between cylinders is 60*. The crankshaft in a six cylinder v-type engine has three throws of 120 degrees. With this combination, it makes the engine perfectly internally balanced. No bad vibrations, hence the lack of balance shaft that the 90 degree 3.8 or 3800 series II engine needs to employ to keep the motor from rubbing things the wrong way.

With that in mind, I kept looking into what I could do to increase the natural power of the engine. And I realized that the FWD heads and intake manifold were direct bolt-on parts. The holes all lined up, and they were aluminum which would shave weight off of the engine. Combined with their increased flow (I had no idea how much at the time) they would add a lot of power to an engine that was struggling. So I did more research and found that the iron heads that came with the RWD engine had been used since the original 2.8L engine came out. No changes had been made by GM. Not till they tried to use the 3.4L as a viable engine for the FWD cars did GM even consider making the 3.4L into a “performance” engine. Because of that the 3.4L has become the laughing stock of the F-body world. Many people have tried to make this engine perform better and succeeded, and many more have failed. Simply because they aren’t thinking before they throw parts at the motor. Most people think, “I can get an exhaust or intake and it’ll make the car work great!” This isn’t always the case. Most often it requires planning to increase the airflow of the engine to efficiently use such parts. Why? Because the 3.4L is anemic to begin with – GM thought that they could simply increase the bore and stroke of the engine and throw a “performance cam” into it and it would work fine. This isn’t the case because the plenum and air intake and exhaust systems are so poorly designed that it suffocates the motor without anyone giving it a second thought. While everyone is putting bigger throttle bodies and porting and polishing heads, they are neglecting the most important idea – “you engine only flows as well as the worst bottleneck.” With that in mind, ponder this thought: I asked James Montigny for his flowbench data from Norris Racing Tech on his heads. And then I asked a good friend of mine who specializes in the FWD 60 degree motor for a stock flowbench of the “3100” heads I had pulled from a 1996 3.1L engine and put on my car.

The results shocked me. The stock heads from a 1996 FWD 3.1L engine flowed as good as the heads that were bolted to Tiago’s car (many of you know him as the one who developed a turbocharger for the 3.4L and pushed it to the edge). Tiago had gotten his heads from James Montigny previously and James had the NRT engine package. I went to NRT’s site to learn that the full engine package came with the 900.00 option full port/polish and valve job. You can digest that for a minute before carrying on. GM had managed to work the heads on the FWD engines so perfectly that they flowed as well as taking a set of the iron heads and paying someone to R&D a perfect portjob on them. 900.00. Using the aluminum heads means you have 900.00 to use elsewhere.

The first bottleneck is the plenum. While it looks pretty decent, being that the outer size is 3 inches wide by 2.5 inches tall (or somewhere around there – I forget) where the inside is really only like 1.5 – 1.75 inches wide x one inch tall! The plenum has an incredibly thick construction (why I have no idea, its not like you are boosting the motor from the factory) and it makes for very little space for the air to travel inside. Then on top of that the airflow has to split, make two 45 degree turns in order to get to one more 45 degree turn down into the engine. This equates to a lot of bad sharp angles that the airflow has to navigate – effectively slowing it down. The fact that the runners are super short makes for more problems being that there is no way the engine is capable of any top end power, hence the problem with the engine “dying” at 4500 rpm. Ask any 3.4L owner and they will tell you that the engine seems to top out around 4500 rpm. While most people are ok with this, the tachometer shows that the engine has a rev potential of 5500 rpm and a redline of 7k. This is due to the forged steel connecting rods in the engine that can take more abuse than most. The other thing GM didn’t think of – fuel supply. While 16lb injectors come stock on the 2.8-3.4L engine, they are only capable of supplying the engine with enough fuel for a max of 160 hp. (sound familiar?) After you go past 160 hp, the injectors begin to become less and less efficient, costing the driver more in terms of gas mileage and not really working to their full potential. Putting larger injectors helps a good deal.

All this said, it seems to be that the 3.4L engine is a stout powerplant with untapped potential. I proved this when I bolted the aluminum heads to the block itself. Using a stock 3.4L RWD engine block I mated the Gen III aluminum heads and 3100 intake (1996 model year) along with the fuel rails and larger injectors, the stock 3400 throttle body (50mm, just like the RWD stock tb) and adding RKSport headers (due to the fact that nothing else fit that would work in the RWD engine bay, pacesetter headers would work just as well) I realized a gain in the form of 27RWHP and 30RWTQ. (thats from 140rwhp -> 167rwhp and 183rwtq -> 203 rwtq). Once I took the cutout plate off to open the exhaust fully, it gave me another 3 horsepower and 3 torque (both rearwheel) taking me to 170RWHP and 207RWTQ. That’s a 30 RWHP gain and 24 RWTQ gain. Factor in 15% drivetrain loss and that comes to 200 horsepower at the engine. Now when I started, stock engine save for the 3” catback exhaust and K&N FIPK – I had dynoed at 140RWHP and 183RWTQ – that’s 164 HP and 215 TQ at the crank. Just updating the heads and intake from the restrictive version that GM put on there in 1993-1995 to the ones they were currently using in 1996 gave me an increase of 36 hp and 30 tq (170rw=>200c / 207rw=>245c) over what came from the factory. Then I decided to upgrade to the “3400” parts. I made sure I got a set of heads used on the 1999+ Grand Am GT, which featured bigger valves and roller rocker arms built in, as well as larger runners and ports on the plenum as well as an increased plenum size. I still haven’t dynoed the current setup that I’m running, but it’s enough that to date I have beaten a 1996 Convertible Z28 that was going all out to catch up to me and couldn’t until I decided to let off the gas a little. A 3.4L with parts from GM’s factory shelves, complete with casting flaws – keeping the car from being caught by a stock 1996 Z28. To me that’s a major achievement. I can get the owner of the Z28 to come on here and back me up if you need proof, I’m sure he would help me out. He’s one of the members of my car club.

I guess the point of all this is that I’m tired of people giving up on this engine. Its got a lot of potential but it is a challenge. You can’t just slap parts on it like you can with the V8. Even the 3.8 is a challenge but the 3.4 has so many design flaws that it comes across as a failure when it simply needs to be “woken up”. I’m tired of hearing that making the 3.4L perform is impossible – it isn’t. If it was then neither myself or Tiago would have gotten any results from our testing and working so hard. It is a challenge though. And it’s not an easy one at that. Lots of time and effort have to be put into it. So if you think you are up to the challenge of making something cool and custom, then stay with the 3.4 and realize your own personalized car at the end. If you want an easy way out, sell your car and buy a V8. I really don’t care either way. But sooner or later everyone will realize that the 3.4 isn’t as bad as they think. If GM had put a little more thought into the 3.4L like they did with the 3800 Series II – then the 3.4 would have been rated in the top 10 engines of all time. 200 hp is achievable in “stock” form. I’ve done it. Can you?

91greenbird

iTrader: (4)

ever think about getting 3400 heads & intake and selling one that will fit on the rwd motor?? Also i heard on here before that the heads for the fwd motor will make are compression jump to 12:1??

rx7speed

this is old


I have read it before somewhere else

The_Raven

Did you read the original post?

Anyway....


I have also swapped to the 3100 top end in my Jimmy, but with less displacement, at 3.2L (.030" over 2.8 block, with a 3.1 crank)

With injectors that were too small, I managed to lay down 218 HP and 270 FT/lbs at the rear wheels (about 250 and 310 at the crank), oh yeah, I also had a turbo that was too small.

Anyway, I too am swapping to the 3400 top end, but will be modifying the intake in search of a few extra ponies. I'm upgrading the turbo, injectors and will be performing some ECM tuning as well.

A couple things I just wanted to point out:

Yep, many people have figured this out, no big deal, but look at ANY other engine, they are all rounded off in displacment.

This is incorrect, the original heads had smaller valves and the porting was slightly less. The "HO" heads that were offered a year or two later, are the same as what was used from '85.5 to the demise of the iron head 660 in '96.

Yep, but really not so surprising when you compare the the heads side by side. The raised ports of the genIII heads, more open, and and splayed valves, heart shaped combustion chambers that are also smaller (28cc as compared to 56cc) all make it pretty obvious they will be an improvment over the iron head design.

Sorry, but this is blatently false. I have a GM power manual from 1987, that has a pretty extensive build up on the 660, using iron heads, that mentions the use of aluminium heads, at the time the genII design was being introduced, but unfortunatly not much info was given, due to not enough experimentation with it at the time. GM probably also didn't see the need to make huge changes to the design, considering where it was used and fell into the line up of vehicles they were offereing at the time.
The 660 was being used in midget cars and hydroplanes, several aftermarket intakes were available at the time, unfortunatly, they are no longer found.

GM has thought about this and the reason for this is, the way the car will be driven MOST of it's life, by MOST people. Meaning low throttle, low RPM cruise, with mild half throttle or slightly more acceleration, which if you stay low in the RPM, even at WOT, will not max out the injectors. Only at higher RPM, where more power is being made, and subsiquentily, more fuel is needed, will the injectors run out of steam. "So they could have used larger injectors and tuned the PCM differently" you say? True, I will not disagree with that at all, but a larger injector will have a harder time metering a low amount of fuel to hold a steay idle, or smooth RPM increase. Using a smaller injector that can be held open a little longer to meter the exact amount of fuel easier works best. The injector drivers would have a hard time switching on and off to control a large injector. Even electronics have an amount of time that is needed, to go from an "off" to an "on" state and visa versa. Called slew rate.

This is incorrect, the 3400 TB is 56mm. The 3100 TB is 52mm.

Agreed, 110%, but also applies to the smaller siblings too, being the 2.8 and 3.1.