3.4 History

[synistershadows]

ok im pretty sure most of us here know the history but some prob dont i found this write-up from a guy on cardomain i cant remember who though anyways heres the info its quite long but its worth the read for thoes who dont know much about the engine or want to know more about it.

 

 

 

3.4L DOHC 24-VALVE GM V-6

 

The 3.4 was concepted as a V6 version of the Olds 2.3L "quad 4". The quad motor went into production in 1988, and that also marked the start of the V6 design program. The 3.4L DOHC was actually the forerunner of many current motors. The Cadillac Northstar 4.6L 32 Valve V8, and later the Aroura 4.0L 32-Valve V8, were sons of the V6 program. Now we have expanded into the 3.5L V6 and to a degree, the OHC Truck V8 small-block. Most of us wouldnt put that as important, but the lessons learned on the Quad 4 went into improvements for the 3.4 V6, and subsequently, the Northstar and Aroura.

 

The 3.4L DOHC motor was designed with a CHEVY name, and was slated to go into the W-10 body cars, namely the Lumina, Grand Prix, and Cutlass. Buick opted to go with their 3800 Series I V6. Target date was 91 model year, as Lumina Z34's, Grand Prix GTP's, and Cutlass Supreme Internationals. In that order. A funny thing happened on the way to the assembly line....When it was orginally concepted , the little Quad was pushing almost 200hp on 4 Jugs. So the V6 needed to have some more power. Now GM at that time was not know for a good FWD Transmission. Even the rocket 180 HP quads in N-body cars came with 5spds only. No auto was offered as HI-PERF, quite frankly because they wouldnt live behind the motor (remember we have to warranty the car if it breaks). Well, the GM engine gurus went to their counterparts at GM Hydramatic, with a challenge. Build a FWD auto trans, that will take 275 HP. You have 2 years to be in production. In a car. Warranty and all. Hydramatic said, "no problem". Meanwhile, the 2.8L V6 had grown to a 3.1L and was currently in use in the W-10 cars. The 3.1L was redesigned as an overstroke version using a cast iron block. To this went the best that GM had to offer, remember we're building a 275HP FWD muscle car. Forged crankshaft, forged rods, forged pistons, balanced lower end. Revamped oiling system with high volume pump. An oil cooler. On top, a pair of computer designed 4 valve per chamber aluminum heads, with hemispherical combustion chambers. Cross-Flow intake and exhaust ports, designed for maximum flow at high RPM. Next, add FOUR, count 'em FOUR camshafts, each controlling 6 sodium-filled lightweight valves. Dual dampner springs rest under a "bucket"type cam lifters, for instant and precise valve timing. The cams were supported by 4 journals each, providing durability along with the least amount of valvetrain mass. The cams were driven by a cogged belt, further reducing mechanical drag of the motor. The exhaust was cast iron manifolds, large by any standards, with a single high flow catalytic converter using 3inch downpipes. All 3.4L cars used a dual muffler system, which not by coincidence, is mathematically perferct in diameter and distance for performance applications. The intake was a tuned tunnel ram, with the early builds using NO mass air flow sensor, and 94 and later ones using one. Add to this combination Fuel injection, digital EGR, and it was by far, the BEST motor that GM engineers could build for its application. Emission certification verifed an honest 281HP on the sheets. Emission 7000RPM screamer. This was in early 1990, January I believe. Transmission? Anyone? Hydramatic had its own challenges to conquer. The THM125 3 speed was being redesigned every year, to combat the next weakest link in the unit. The THM 440T-4 four speed auto debuted a few years earlier, but was prone to valve body and erratic shifting problems. The 440T-4 also had this quirk of self-destructing if the owner happend to get stuck in snow. Not much to build from...Hydramatic had its hands full on this job. An all new FWD O/D trans was needed. Many prototypes were tested at GM proving grounds, in believe it or not, a V8 FWD Camaro. Each version had uncovered problems, aka "The next weakest link". Time was fast running out. When it came clear that the all-new trans wouldn't be ready for production by mid-1990, there was only one thing to do. Redesign the 440-T4 as best as they could. Hydramatic went to the market with their finished product just days before the deadline. Will it take 275HP? NO! Will it take 250HP? NO! How bout 225Hp? Maybe. GM engine ground was peeved! All this effort, just to be cut down at the flywheel....225HP? I want 275! Well, the rest is corporate decision making at its worst. Cut the horsepower of the 3.4L to 200 with an automatic. You can have 210 on a stick. Makes a guy want to cry, don't it? Well, warranty concerns led the list of "why" and there's no way around it. The redesigned THM 440-T4 was designated the THM 4T60E, with an early RPO code of MXO. Internals were beefed up, a heavier drive chai, a better pump, and best of all, Electronic shifting! Now, instead of finicky hydraulic valve body, all shifts and timing ere controlled by the ECM. The same one used by the motor. Big, beefy driveshafts were installed into the W cars to take the power. (on a side note, I have never heard of one breaking) By this time, tooling up was underway for the '91 model year. While there were a supply of motors, the trans were still being built a few at a time. Delco electrionics solved the horsepower problem by cutting the fuel delivery and spark advance curves of the motor. This weakened it to a 6250 shift point, and 6500 rev limiter. Free-reving was limited at 3000RPM. The first 3.4L DOHC engines were spoken for by CHEVY. After all, it was their project. Stick models didnt get orders, as most dealers preferred the auto trans models because of sales. Add to the problem, af HEFTY price tag on the motor combination, adn they were a tough sell as lot inventory at the dealers. The trans shortage had eased by Feb. of '91, and finally some units were released to Pontiac for production. These facts conclude that '91 models are scarce, some Z-34's, a lot less GP's, and virtually no Cutlass. 1992 was a carryover year for the 3.4L option. Pontiac changed wheel cap centes. This was the only visual change from the '91 cars, save the VIN of cours.

 

The engine used a speed-density program for the ECM/fuel injection. This consisted of a MAP sensor, a BARO sensor, ambient air sensor, throttleposition ensor, and of course RPM. Cubic inch displacement X rpm, barometric pressure, and air tempurature divided by the throttleposition and engine vacum (load). Witout fail, the computer (ECM) will deliver the same amount of fuel for a given set of input parameters from the sensors. There is no substitute. Spark timing was calculated the same way (an algorithm) based on sensor input. This is very handy to understand when you want to modify your DOHC to do more. The 3.4L works on a multiport injector arrangement. Early year 3.4's did not have a cam sensor in the front valve cover. These are MFI cars. The injectors are fired three at a time, with the logic that one of the intake valves will be open. The other two will puddle the fuel on top of the valve until opens. Starting in 1994, most 3.4's went to SFI. This reduced emissions and allowed for even learn injector rates, atmoization was improved. SFI bascially means that the charge of fuel is fired at an OPENING intake valve, so that air flow will charge the fuel as a vaport. SFI cars are a little touchier to injector rates then MFI cars. The distributorless ignition system firs added/waste spart method. It would take a volume of reference to cover it fully, but just know that it is operated from input from the crank and cam sensors. Picture two companion cylinders (one coil pair) spark leaves the coil on one tower towards the weak cylinder, (the one on the exhaust stroke). The spark jumps the plug gap from center to ground and then travels through the engine block ot its companion, (which is on the power stroke) and jumps the plug gap from ground electrode to center electrode, then back to the coil tower, completing the circuit. A big circle. It reverses every crank revolution too. Spark timing is controlled by the ECM, whcih calculates which coil pair to fire, and how much timing advance or retard is needed at the moment. The intake manifold shape changed every year after 1992. Why the different manifolds? The early ones howled at 2100 RPM in drive, the later ones changed for size constraints in the car, and there was the switch to the Mass Air Flow system, whcih added another variant. All will bolt to the lower intake, but not all will accept the other various equipment needed. Exhaust manifolds are pretty good for cast units. I cant even imaging fitting headers to this beast, but you dont need to. I have run backpressure gauage on my car, and found no significant problem save the converter itself. Al converters are restricitive, but the exhaust is low on the list of places to get more zip from a 3.4. And now that the background is covered, its time you get teh mechanicals of the DOHC 3.4L "Hemi" Hope your not too bored yet.

 

Think of it as a MG Midget...maintance, maintance, and more maintance. I cannot stress enought that this is NOT a car to give the kids going to college. The 3.4L takes frequent, extensive maintanence to assure its durability. All strange noises should be investigated immediately, as you may soon be walking. Maybe you arent mechanically inclined. That's ok, as long as youu can work with assistance. But if your're the type who doesnt want to spend money on frequent maintance, sell the car. It will bite you!!!Last I checked a motor from GM cost $4600.00. Used start at $1500.00. If you can find one. Oil changes....complex and incredibly long oiling system of the 3.4 is very touchy about dirt. Aluminum cam carriers, valve lifter buckets with only .010 margin, and about 6500RPM thing, you gotta change the oil and filter often. I use and recommend a FULLY SYNTHETIC OIL for this engine. Yes, it cost 5.00 a 1/4. Think about the price of a motor. That makes it better. The long oiling system is the reason why the oil pressure flucates so much while driving. GM says 15psi at 1600 RPM is acceptable, that aint alot, but consider it has a lot to do. Typical readings are 40 PSI at 1600RPM, and 15-20psi at idle when hot. Use a 5W-30 grade. There is no benefit to heavier oils, and they may be harmful if oil pressure gets too high. Fuel filters need to be changed at least once a year. Forget the 30,000 mile thing. One bad tank of gas will plug it. GM fuel injection systems are recirclating, meaning the fuel passes through the filter faster then it is used by the motor, with the excess diverted back to the tank. Nominal pressure is 47PSi. A partial restricted fuel filter will casue odd power loss and it will harm that pricey fuel pump in the gas tank. Change it 15-20,000 miles, or once a year, whichever comes first. Air filtes are critical. Since the early units are speed/density engines, their is restricated air flow. Clean the filter at every oil change, or insist that the kid at speede-lube to do it for you. K&N is ok, just make sure you dont install it and forget about cleaning and oiling. Its ok to buy cheap air filters too, just change them more ofter. Coolant and hoses need good car too. Being a bi-metal engine, glycol type coolant tends to become acidic with age. This then eats aluminum, head gaskets, and causes localized overheating, which leads to cracked cylinder heads. Hoses to be concerned with are those at the oil cooler, which get oiled everytime the oil filter is changed, and the coolant pipe that runs down the RH frame. These pipes are exposed to road spray, and will rust and leak within a few years. Check near the attaching brackets for bubbling rust. When replacing this pipe, use spray undercoating for a lasting repair. Spark plugs and wires are the weak link in any GM ignition system. Due to the variable dwell circuit of GM HEI, excess resistance in the secondary ignition ciruct will fry ign coils and modules. Thes problems usually start as a buck or miss felt in high gear at low speeds, say in OD at 45 accelerating uphill without a trans downshift. I use split tip spark plugs in my DOHC, NGK, Splitfire and others have such a plug. It is a performance advantage with this type of ignition system. OE wires are ok, as long as tey aer in good shape. Powered looking "mooneyes" along with the wires where they pass near a piece of metal indicates the insulation is getting weak, and its time to change them. That brittle split loom that covers the wires is important too, if it cant be reused, go buy some more and use it. Throttlebody, throttle blade, and intake system cleaning should not be ignored. A coating of oily "fuzz" builds up on the surfaces, adn can caue problems with stalling, and even in bad cases a check engine light. I use a throttlebody cleaner spray on the inlet, and GM top engine cleaner on the internals. (Do not spray the MAF, or you will be buying a new one) On MFI cars, this is especially critical to use a liquid cleaner injested while the engine is running to break up and clean the intake valves. Excess carbon build-up will soak up the fuel sprayed at it by the injector, and cause a lean condition. Keeping the back side of teh intake valves clean promote fuel distribution and is a major performance tip. Timing Belts. Priced one lately? I told you this was an expensive motor to maintain. This is one area where it gets REALLY expensive if you dont. Timing belt arrangement uses two idlers, a tension/idler, the 4 cam sprockets, and the drive sprocket. Unless you are pretty good with a wrench, I wouldnt recommend you try to change one. There is reason they want 500.00 to do it at the garage. Bad news is, when they go, you stop. There are many DO NOTS to the timing belt setup. I add these so you dont make an uniformed mistake. Anybody with a 8mm socket can inspect the timing belt for extreme wear. Just take off one of the plastic cam covers and look. If there is any fraying of the belt, or a bunch of black hair inside the cover, change the belt NOW. If you do it yourself, under no circumstances remove the bots from the camshaft sprockets. These sprockets are not keyed, and cam timing is lost to the tune of 700.00 and a tow to the Pontiac dealership. More so, the factory timing marks are done in yellow paint pen. It can and does wear off, leaving no reference marks to time the cams with. This then requires removing the intank manifold, valve covers, etc., and some nifty GM special tools to reset the deal. The idler pulleys are wear items as well. It is a plastic pulley, and is usually what caused the belt to fail. The replacement ones from GM are a bunch better then the OE ones were. Replace them once, probably won't have to do it twice. And about that belt...it is a highly saturated nitrile belt. Don't get a cheap one either, go to GM or Gates for this one. Around 50.00 is right price, but here's another tip. Due to the lenght of the belt, and the way it drives the cams, it does stretch a little with high mileage. This means that while cam timing on the front two cams is close, the timing of the back two cams will be off. The performance edge is noticeable between 20,000 timing belt and a new one. Cam timing, it is very important. I am a tech by trade, so changing the timing belt every 20,000miles is what I do. They sure wont go the 60,000 the factory recommends. If you race your 3.4L, or expect tip-top performance it can deliver, keep a fresh belt on it. One final work, while the 3.4L is not designed as an interference engine, it has happened that when the timing belt breaks or slips, the pistons can hit the valves. ther is only .010" designed clearance between the valve at full lift and the piston at top dead center. That is how my GP was when I got it. 6 bent valves, timing belt broken. That God I didnt have to pay the labor on that mess...One more area to inspect often is the oil pump drive. This is located on the rear (LH) of the motor, under the throttlebody. While almost impossible to see from up top, if it starts leaking oil it will leak oil VERY FAST!!! The oil pump drive is a leftover from the 2.8/3.1 design. It is where the Distributor use to go. With the advent of DIS, the dist is gone, but the gears and oil pump remain. This is sealed with an O-ring along. On the other side, is a pressureized gallery. When (not if) the O-ring breaks, engine oil will leake under whatever oil pressure is available. In extreme cases, a quart every 100 miles is possible. More bad news. to replace the .29 O-ring, the upper half of the motor must come off. Replacement requires cylinder head removal. Only good part is if this happens, you can replace a bunch of other parts with virtually no labor...its already apart. And the final think on the subject of maintaince, the transmission. I have put a few hundred passes on my 4T60E on the dragstrip. I race SCCA autocross regularly. I drive at high speeds. I live to beat someone from a stoplight or leave them halfway around the on-ramp. My GP gets driven hard, if not harder then it was intended. It now has 174,000 miles and will run with any 3.4L out there. The trans has never been apart. I am a firm believer in changing the trans fluid and filter every 20,000 miles. Flush it if needed. The biggest enemy of the 4T60E is dirt and oxidized fluid. The tans and filter/cooling system is sufficient to take road racing and autocross. It will not take neglect. I can sympathize with anyone who hates to spend money on a car. I ain't rich either, but I do know that a few dollars of maintance is worth a thousand saved in major repairs. I have had my GP for about three years. I like to drive, and have put 100K on the car. I have no fears that the car will fail me, even though the high mileage would send most into a comma. Bottom line is, that if you do own one of these cars, you have something that can last, can be driven hard, raced, and still get the groceries on Friday. It can be done. I am doing it.

[ManicMechanic]

These facts conclude that '91 models are scarce, some Z-34's, a lot less GP's, and virtually no Cutlass.

 

To be honest...I think that's bs...I've seen a lot more 1991 DOHC CSs than I have GPs or Z34s...

[slick]

Fuel and spark are NOT the only things that are different.

[BXX]

Yeah, and the theory you gave on the wasted spark is so horribly inaccurate.. The spark does not flow through one side to the other... They both fire at the same time, through the wire, through the center electrode to ground. Think of it as exactly what it is, once coil with two connected outputs.

[synistershadows]

well i didnt write it like i said i found it from thisone guy on cardomain just cant remember who he is JJ or something

[BXX]

Ahhh, Ok...

[synistershadows]

yeah but some of it is right

[Hairdo12]

Its a copy and paste from here:

 

http://www.angelfire.com/ca2/34Performance/dohc.html

[synistershadows]

yes thats it i couldent remember where i got it from but thats it

[goolash1991]

i have a 91 chevy lumina z34 and my timing belt snapped and need to get a new belt hydraulic tensioner but now i need the plate and the bushing the plate comes with but its discontinued any advice on how or where i can find it??? my email is goolash1204@AOL.COM

[RobertISaar]

can we lock this thread or at least put a big FAIL tag in front of it? almost 100% of the original post is false or misleading.

[goolash1991]

i have a 91 chevy lumina z34 and my timing belt snapped and need to get a new belt hydraulic tensioner but now i need the plate and the bushing the plate comes with but its discontinued any advice on how or where i can find it??? my email is goolash1204@AOL.COM

[pshojo]

What is the true story? I alway think i've heard version close to this.

[1988PhantomFE3]

I already knew all this, do you think I'm stupid?

[RobertISaar]

What is the true story? I alway think i've heard version close to this.

 

GM modded the LH0 block to become DOHC instead of OHV(because racecar), ran lower compression to run on regular gasoline(because $$$), installed in W-bodies(because LULZ), end of story.

 

anything beyond that is either speculation or is info directly from GM. good luck finding out which is which.

[Schurkey]

ok im pretty sure most of us here know the history but some prob dont i found this write-up from a guy on cardomain i cant remember who though anyways heres the info its quite long but its worth the read for thoes who dont know much about the engine or want to know more about it.

There's a "Sticky" post at 60*V6 about this.

http://60degreev6.com/forum/showthread.php/28369-Anyone-hear-of-the-3-4dohc-having-275hp-originally

They don't have much good to say about the 275-horsepower theory or the author.

 

I wasn't there when it happened, I have no opinion.

 

Picture two companion cylinders (one coil pair) spark leaves the coil on one tower towards the weak cylinder, (the one on the exhaust stroke). The spark jumps the plug gap from center to ground and then travels through the engine block ot its companion, (which is on the power stroke) and jumps the plug gap from ground electrode to center electrode, then back to the coil tower, completing the circuit. A big circle.

 

It reverses every crank revolution too.

 

Yeah, and the theory you gave on the wasted spark is so horribly inaccurate.. The spark does not flow through one side to the other... They both fire at the same time, through the wire, through the center electrode to ground. Think of it as exactly what it is, once coil with two connected outputs.

The first part of his statement about the path of the electrons is reasonably but not completely accurate, BXX's description is wrong. One spark plug of the two companion cylinders fires from coil terminal to plug wire to center electrode to side electrode, the voltage pulse conducts through the engine to the other (companion) plug, which fires from side electrode to center electrode. The voltage pulse travels up the second plug wire to complete the circuit at the second ignition coil tower. It REALLY IS a big circle from coil tower to coil tower, the spark pulse travels at nearly the speed of light. With any kind of automotive-grade test equipment, it would show as "instantaneous". There's no timing variation on the companion cylinders because the speed of electricity is so much faster than the speed of piston motion or crankshaft rotation.

 

Where the other post is wrong is that the spark pulse DOES NOT REVERSE DIRECTION, therefore the plug on the exhaust stroke is NOT guaranteed to fire from center to side electrode. The same plug ALWAYS fires center-to-side electrode, and the other plug ALWAYS fires side-to-center electrode. Firing from side electrode to center electrode (reverse polarity or "negative firing" versus "positive firing") is not as efficient, it requires more voltage when that cylinder has compression--thus the very high voltage rating of those coilpacks.

 

Is it possible to reverse the direction of the spark path? SURE! Swap the two plug wires at the coil pack. The spark plug that WAS firing from center electrode to side electrode is now firing from side to center--and will continue to do so until you reverse the wires again.

 

This is, by the way, the same waste-spark ignition philosophy as employed by a bazillion Japanese four-cylinder motorcycles starting about 1969. Of course no parts interchange with our W bodies. It was actually quite clever. Having no distributor cut costs. The system allows a very precise crankshaft trigger rather than a less-precise camshaft trigger and an expensive distributor. Maximum parts duplication employing two completely separate--but identical--ignition systems on each four-popper motorcycle. The Jap bikes got a reputation for having marginal spark at higher RPM, so an aftermarket motorcycle ignition industry was born.

Edited May 24, 2012 by Schurkey

[Z34guy]

On a somewhat related note, what's the safest you can have LQ1 heads resurfaced to without making it an interference motor?

[Jssuper]

I have a question...

 

Is the power output of these engines capable of making 275-280HP as it stated in the OP? 200-210hp to me isn't worth the added difficulty of working on this engine vs say a 175hp 3100/3400. But if it can be easily made to put out that kind of power, then maybe! Though I have never owned a LQ, it might be a fun learning experience anyway. The problem I have is.. well the car list I already have screams "maintenance" enough.

[RobertISaar]

good question. i imagine the 91-95 and 96-97 will have different answers, but the "easy" way to determine this would be to get some putty (or is it clay?), stuff it on top of the pistons into the valve reliefs, assemble the top end, rotate the cylinder you put the putty into to TDC, then rotate the cam around a few times, see how much of a surface is left in the putty at the thinnest point, then that's the amount of static clearance you currently have.

[RobertISaar]

I have a question...

 

Is the power output of these engines capable of making 275-280HP as it stated in the OP? 200-210hp to me isn't worth the added difficulty of working on this engine vs say a 175hp 3100/3400. But if it can be easily made to put out that kind of power, then maybe! Though I have never owned a LQ, it might be a fun learning experience anyway. The problem I have is.. well the car list I already have screams "maintenance" enough.

 

as-is, no, not possible without changing parts out. headers, retimed(or better yet, reground) cams, 96-97 intake/heads, higher compression, boost, etc.... they'll all go a long way to making it there. there are quite a few 400+ LQ1 builds on 60V6 using only factory parts + boost of some form.

[Z34guy]

good question. i imagine the 91-95 and 96-97 will have different answers, but the "easy" way to determine this would be to get some putty (or is it clay?), stuff it on top of the pistons into the valve reliefs, assemble the top end, rotate the cylinder you put the putty into to TDC, then rotate the cam around a few times, see how much of a surface is left in the putty at the thinnest point, then that's the amount of static clearance you currently have.

kind of looking for a definitive answer. lol. As stated before, I'm swapping 92 Lumina Z34 5 speed heads on my 95 MC Z34 as there are bent valves. Matt recommended having them resurfaced before installation and I haven't torn apart my Z34 at the moment.

[Galaxie500XL]

Having owned an LQ1 for 3 years now, I really don't think they're all THAT bad to work on, if you're patient, and have some experience.

 

As far as maintenence goes, I'm not really doing anything different to my LQ1 than I do to any of my cars, but I AM a stickler for careful preventative maintenence.

 

What they won't tolerate is abuse---but this is true for pretty much ANY engine.

 

Part of the disconnect, I think is that people forget what sort of engines the LQ1 was competing against at the time---no one then would have anticipated 500 HP Corvettes, or 200 HP Hondas to be available from the factory-EVER. So, to 21st century enthusiasts, 210 horsepower seems kind of "puny".

 

Keep in mind, the Thunderbird "Super Coupe" of the early 90's was rated at only 210 horsepower WITH SUPERCHARGING and intercooling..and greater displacement than the LQ1.

 

Having driven both 3.1 and LQ1 Cutlasses, I personally prefer the way the LQ1 moves the car. The 3.1 feels a bit stronger in my opinion for about the first 60 feet due to a lower torque curve...but there's nothing like mashing the pedal on an LQ1, say at around 60 MPH, and watching the needles climb, and hearing the sound the LQ1 makes around 5,000-6,000 RPM.

 

I have a question...

 

Is the power output of these engines capable of making 275-280HP as it stated in the OP? 200-210hp to me isn't worth the added difficulty of working on this engine vs say a 175hp 3100/3400. But if it can be easily made to put out that kind of power, then maybe! Though I have never owned a LQ, it might be a fun learning experience anyway. The problem I have is.. well the car list I already have screams "maintenance" enough.

[emb1230]

Keep in mind, the Thunderbird "Super Coupe" of the early 90's was rated at only 210 horsepower WITH SUPERCHARGING and intercooling..and greater displacement than the LQ1.

 

Having driven both 3.1 and LQ1 Cutlasses, I personally prefer the way the LQ1 moves the car. The 3.1 feels a bit stronger in my opinion for about the first 60 feet due to a lower torque curve...but there's nothing like mashing the pedal on an LQ1, say at around 60 MPH, and watching the needles climb, and hearing the sound the LQ1 makes around 5,000-6,000 RPM.

 

But the T-Bird SC cranked out a whopping 315 ft. lbs of tq, later year ones, (94-95) were up to 230 hp and 330 ft. tq.. I've heard ppl call the T-Bird SC (and 89-90 Cougar XR-7 ) the Ford version of the Buick Regal Grand National. 210 hp was indeed not much considering by the late 90's both the Buick and Ford N/A 3.8's were putting out 200hp. Might catch hell for this, but I had a 1990 Taurus SHO, they too had gobs of high end hp, loved how it kept pulling and pulling, lol.

Edited May 24, 2012 by emb1230

[Galaxie500XL]

A couple of things...the LQ1 was designed a full decade before those "late 90's" cars...and Ford didn't even build the engine they put in the SHO--Yamaha designed and built it for Ford...

Edited May 24, 2012 by Galaxie500XL

[55trucker]

Hmmmmmmmm.......the LQ1 was originally intended as the performance option engine that was to be installed into the 1989-90 Fiero. This didn't happen because 88 was the last year for the Fiero. Pontiac was forced to pulled the plug on the car because the *new* design outperformed the Corvette and Chevy stood in the way of letting the car into production seeing as they were not going to be outdone by a two seater V6 mid engine rival. Since there now was no Fiero for the engine to go into....guess where it ended up?

The original DOHC was a 3.2 (not 3.4), there is one preproduction model of the Fiero GTA that makes the show circuit, I last saw it at the 2008 Fiero 25th anniversary in Detroit, I imagine that it will be at the 30th anniversary which is to be held at Indianapolis.

 

 

 

Edited May 24, 2012 by 55trucker