One thing that people overlook and is the reason the VQ is stronger than the HV is because it has 4 valves. When people compare OHC vs. pushrod they are comparing 2v vs. 4v engines but over look that point.

The 3v 3.9L HV is expected to put out over 270HP

 

Not sure what defines great, but it was a very powerful 4-cylinder engine for a north american company. Its output was 180 HP, displaced at 2.3L at the time when most japanese 4-cylinders were in the neighbourhood of 127 - 160, and 190 HP for the prelude a couple of years LATER.

It was fairly reliable, although a number of people had head gasket problems at some point. I had mine up to 125K miles and not a single problem, and it was driven spiritedly. Maybe it didn't sound as refined as a sowing machine, a refinement typical of japanese engines, but it surely held its ground and even won a number of races against other imports.

 

I learned to drive on a '91 Grand Am SE 5 speed with the 180hp H.O. Quad 4. Yes, it was noisy. And yes, we did crack a head around 81k miles.

However, with 165k on the clock my uncle recently donated the car to Big Brothers, Big Sisters and the motor was still cranking down the road. I get in too many p!ssing contests with redzed over other things, so I figured I'd leave this one alone.

Considering the power it made during the time it was produced, the H.O. Quad 4 was a fantastic engine. Aside from the obvious flaw of head gaskets and cracked heads, it was a reliable engine. I have taken in on trade 3 Quad 4s with over 200k, and all of them ran well. Their respective owners were quite happy with their peformance, reliability and MPG over the years...

But indeed, they were a loud motor, with many suffering that one, significant issue of blown head gaskets. But to get 180hp and 30+ MPG in 1991, in my mind, makes it a damn fine motor in certain respects...I miss not winding my dad's old one out to the 6,800 RPM redline and barking the tires HARD on the 1-2 shift Ahhh...memories...

 

Yes, the old 3.4l DOHC was a 60 degree, just like the 2.8l in the Citation. But the Northstar wasn't based on it. If anything, the Northstar would have been loosely based on the old HT4100, though that thing had Iron 2 valve heads (and aluminum block) if I recall correctly.

Someone else posted that the new HFV6 is a clean sheet, and that matches what I know about it. I remember an Automotive News article back in 1997 that mentioned that GM had considered an inline 6 for their cars, but they ultimately decided to go with the V6, presumably for packaging reasons.

GM liked the fact that the DOHC inline engines had 1/2 the number of camshafts, with the attendent benefits in reduced friction, complexity and cost. They believed that it wasn't worth going from one to four for DOHC, but it was worth going from one to two. The same article mentioned that there would be two V6 families, "high value" and "high feature", which the HF family being used in markets where the engine specification itself was important (valve/camshaft counting buyers). It all came to pass six years later.

With the 3.5l and 3.9l sixty degree HV V6s, I wonder how many years the 3800 has left?

 

i think even GM itself has stopped asking this question a long time ago. i'm sure it'll go on for several more years while the cars it's in are killed off.

 

The 3800 in the Grand Prix, for whatever reason, is not as raucous as it is in the F bodies. Mine is really quite smooth. It isn't a Camry over 4,500, but it isn't bad at all. Further, never has a customer ever complained to me about the 3800 being loud. Frankly, smoothness in normal operating ranges is what people tend to like the most about them. I doubt your typical GP, or Maxima, owner really cares what their engine sounds like over 5k. Performance-oriented owners like many on the board here may pay attention...but the masses really do not. Hence, why GM stays with OHV engines in the first place

They may be old, but they do work...and they are bulletproof. I don't plan on needing repairs on mine for a long, long time

 

The engine was in 1990 Beretta GTZ, so even earlier than that! I remember running my 91 GTZ with a 5.0L AUTO Mustang... Sure he pulled ahead bit by bit, but only after 60 - 70 mph. Took the car to the track, and it ran 15.80 on my first try, completely stock, save K&N cone filter.

edit: another issue with the motor is its lack of response to mods. GMHTP tried modding one (port and polish, etc..) and got squat. Appears that they were maxed out from the factory, which somewhat explains the noise. A certain club member spent about 3 K on his Quad4 engine in his Beretta, only to run 15.7x. Needless to say, he was extremely disappointed when his car was pitted against mine

 

You're exactly right, and the same concept has been successfully used by Volvo. An Inline-6 can work in transverse engined FWD cars, but it makes for a wider turning circle. Not unsurprisingly, Americans don't give much thought their car's turning circle. GM intended to use the I-6 in North American version of the Epsilion platform cars, but not the European ones.

 

So what makes for a wider turning circle, I6 or the fact that it's transversely mounted?

The tightest turning circle I've experienced is in Audis. Original 5000 I used to have and the current A6 are just incredible, and both have engines longitudinally mounted, with AWD.

 

What I6? The only I6 GM has is the Atlas which wouldn't fit in any GM car that I know of except for maybe the B-bodies which aren't made any more. Also wouldn't the Atalas I6 4.2 be a little to powerfull for any FWD application?

 

Back in 1997 when the HF V6 and HV V6 plans were cemented (resulting in today's 3.6l HF V6 and 3.5l HV V6 and tomorrow 3.9l HV V6, etc.) they considered an inline 6 instead of one or perhaps both of the V6 engines.

I think the problem was packaging. You need a special transmission if you have a transverse I6, due to the width of the engine. It can't just hang off the end. Also, to limit engine length, you have to limit the bore size, which limits displacement. I believe that's why BMW is limited to the 3l in their volume I6 engines. Even their 3l I6 is a long stroke engine. If it had the same bore as the Nissan 3.5l, it would be nearly 3" longer just due to bore size.

 

In theory, the longer size of an I6 engine when mounted transversely means less room for the wheels to turn inside the wheel wells. In practice, the I6 Volvos are not much worse than their competitors.

 

I know that my 91 Regal has 220K miles on it and the old Series II "Tune Port Injected" 3.8 V6 still runs real strong and uses NO oil. And this car has had the snot beat out of it for the last 50K miles(my mom drove like granny for the first 170K). And I've ridden in a 3.8 S/C Grand Prix, that motor has enough torque to break the tires loose at 30 MPH, and I'd take it any day of the week over Nissian's 3.5 V6 simply because its real easy to get power out of. I wish GM would continue to supercharge their new engines, such as have the 3.5 V6 HV and bolt a supercharger onto it for the increased power(get rid of the 3.9 V6). Then have the 3.6 HF V6 and bolt a supercharger onto it.

 

But the I6 Volvo has to use a GM supplied 4 speed auto that sits under the engine, whereas the other Volvos use a 5 speed which makes better use of the power. The I5 S80 is not much slower than the I6 S80, but it gets quite a bit better mileage.

The other I6 FWD is the Daewoo (Suzuki) sedan. I don't think it a coincidence that it's only a 2.5l.

Still, I really like inline six engines, especially the big ones. I say go ahead and add the inches to the front end. Then add an efficient turbo installation next to it and watch the fun. RWD, of course.

I'm a fan of the Falcon XR6.

 

While GM is at it---put in a great 5 speed/6 speed manual trans. If I were in the market for a mid sized car---a manual trans is a must.