Chevy 3.8 v6 aftermarket

I'm looking at an old Monza Wagon on Ebay and it has a carbed 3.8 v6. I'm assuming its the same as the first year Grand National motor. Is there a robust aftermarket for the motor and where does one start looking? I'm looking for the typical bolt ons and cam stuff or even alum blocks.

Also would 300ish HP be possible out of a NA 3.8 ( bored and stroked to what ever)?

The Chevy 3.8 (229) shares nothing with any Buick engine.

Nothing. Not even the bellhousing.

It would not be wrong to say that it's a 305 with two cylinders taken out of the middle. It's also an odd-firing engine, which I personally see as an advantage.

I looked into the engine, because I had a chance to acquire one for free. It's a dog, basically. Cams and intake manifolds ARE available for it, but there's only so much valve you can stuff into the small bore. 305 pistons will work, but they are expensive for low-moderate compression pistons, and VERY expensive for high compression units. SBC rods will work with modification.

Best bet is to throw it away and install a 262 (4.3) V6, which is also a dog but it's at least a better dog, since you can use 350 parts in it.

300ish HP is possible with the 262. Hot Rod did a 500hp 4.3 writeup a while back, it's on their website.

Would that 4.3 be a newer motor out of the S10 and F-bodies? It's not the same as the FWD Impalas, Bonnevilles etc?

The Chevy (90 degree) V6s were never used in a front drive application. They were only used in RWD cars and trucks. The last time they were used in F-bodies was around 1981. (Maaaaybe the first of the 3rd-gens used them as well, but by the mid-80s the V6 was the 60-degree)

The only 90-degree V6s used in a FWD application were Buick-based.

(hmm, I wonder now if the Intrigue's 3.5l was 60 or 90 degree)

Just read up on the Hot Rod build. Thats pretty much what I want to accomplish.

Thanks for the info. I now have a starting point.

ThePhranc wrote: I'm looking at an old Monza Wagon on Ebay and it has a carbed 3.8 v6. I'm assuming its the same as the first year Grand National motor. Is there a robust aftermarket for the motor and where does one start looking? I'm looking for the typical bolt ons and cam stuff or even alum blocks. Also would 300ish HP be possible out of a NA 3.8 ( bored and stroked to what ever)?

is it a Buick 3.8- distributor in front- or Chevy 3.8- distributor in back? if it's a Chevy motor, then a 350 is a drop in swap with Monza motor mounts and monza oil pan..

if it's a Buick motor, then, yes, you could bolt in an 83-87 GN motor.. or you could find an 81-84 Buick 4.1 that was essentially a 3.8 with a bigger bore and put that in there.. you'd need to find out if it's an odd fire or even fire engine that's in the car now to figure otu what all you'd need to swap to get it done- a little google fu will help you with that..

yes, find out whats in it first. Then LSX or Ecotech turbo.

3rd option would be a 60 degree build up. That narrow engine would be a better fit (2.8 / 3.1 / 3.4). The 90 degree motors are tight in there.

the Intrigue 3.5 is a different animal altogether. That's the short Aurora motor IIRC.

The Chevy motor, 229cid is crap. Take it out and replace it. However, I'm 90% certain that the Monza came with the Buick motor, 231cid. That motor has potential and used to have pretty strong aftermarket support. It's been a long time since I have owned one so you are going to have to do some digging.

Toyman01 wrote: The Chevy motor, 229cid is crap. Take it out and replace it. However, I'm 90% certain that the Monza came with the Buick motor, 231cid. That motor has potential and used to have pretty strong aftermarket support. It's been a long time since I have owned one so you are going to have to do some digging.

some Monzas came with Buicks, some came with Chevies. i've seen them both ways, but Monzas usually had Chevy engines in them, with the other cars (Buick Skyhawk, Pontiac Sunbird, Olds Starfire) getting the Buick V6. and they are all 30+ years old, so things may have been swapped..

one swap that would be pretty cool in one of these cars is a modern 3.8. you can pick up driving parts car Bonnevilles or LeSabres with supercharged engines for $500.. then you just need a rwd trans for a 60 degree V6 (2.8/3.1 powered S trucks and 3rd gen F bodies are good donors..) and a little bit of fab work..

It's a Buick motor.

I want to avoid fab work as much as possible. A swap to Chevy from BOP would be a min amount of work.

I would like to keep it carbed V6. Something period correct-ish. Not really looking for tire blistering power, much more interested in handling. Not that it would ever really handle great.

if you want easy power and good toque from a stockish looking Buick V6, then start with a 4.1.. put in some flat top pistons, swap in a later model roller cam, and top it with a set of heads from an 89-early 90's fwd 3.8 (these were used on the 89 Turbo Trans Am) with an Edelbrock intake with a quadrajet carb. headers are available, but you will need to rework them to work with the different port layout on the later model heads. should be easy to hit close to 300hp and a similar number of torques without giving up much if any driveability and torque.

regarding the handling- they can be made to turn but it's not as easy as most other GM rwd cars.. you can swap in G body spindles and S10 axle shafts with a little work to improve the brakes and open up wheel selection.

novaderrik wrote: if you want easy power and good toque from a stockish looking Buick V6, then start with a 4.1.. put in some flat top pistons, swap in a later model roller cam,

If you do this, you need to machine a groove into one of the cam journals. IIRC it's the frontmost one.

Early Buick engines, including the 4.1, had a grooved cam to get oil to the left bank's lifter journal. Later engines, excluding the 4.1, had a grooved block. Late cam in early block means the left bank lifters don't pump up.

Yeah, found this out the fun way. In most applications IMO, the "109" 3.8 block is better than the 4.1 block since the 109 is stronger. Plus the 4.1 block is pretty rare, not too many were made and they were only made for a couple years, so in 2012 it's "take what you can get".

I'm fairly sure that the valve order got switched up at some point. but the nice thing about Buick V6s is that a few healthy Grand National racing series means that there are a bunch of cranks/rods/heads available.

Downside is, aftermarket GN parts are expensive. That's the downside of a small but fervent community that plays with 25 year old cars that are still worth $20k or so...

...another downside is that a lot of it is forced induction biased. Granted, a 1000hp turbomotor is pretty fun, but you can't use it on the street.

Say, didja know that they used these engines in NASCAR? Busch Grand National series, where Darth Vader's Buick got its name, saw them raced in N/A trim. Parts sometimes turn up on eBay.

In reply to mguar:

Forged stroker cranks are available for Buicks, stroker pistons are off the shelf items, too.

As far as "the factory cam is the best cam" mentality, you're kidding right? We're talking about an engine that makes roughly 110hp from 3.8l (Chevy or Buick) and is out of breath by 3500 rpm. These are the kind of engines that turned people away from American cars during the 70s. You're seriously going to think that this is sufficient cam and going more will just ruin things?

In many cases, a hotter cam will INCREASE low-end and midrange because the factory cam was made for smoothness and reducing emissions with the first- and second-generation emissions controls in place. Over all costs. Power was NOT a consideration at all, if more power was desired then a V8 was checked off on the option sheet.

Knurled wrote: In reply to mguar: Forged stroker cranks are available for Buicks, stroker pistons are off the shelf items, too. As far as "the factory cam is the best cam" mentality, you're kidding right? We're talking about an engine that makes roughly 110hp from 3.8l (Chevy or Buick) and is out of breath by *3500* rpm. These are the kind of engines that turned people away from American cars during the 70s. You're seriously going to think that this is sufficient cam and going more will just ruin things? In many cases, a hotter cam will INCREASE low-end and midrange because the factory cam was made for smoothness and reducing emissions with the first- and second-generation emissions controls in place. Over all costs. Power was NOT a consideration at all, if more power was desired then a V8 was checked off on the option sheet.

^^what he said^^

it's almost impossible NOT to increase the performance of the late 70's/early 80's GM engines, especially the small displacement ones. they weren't built for performance- they were built to comply with emissions standards and move the car around well enough for the average consumer.

the only real problem with boring and stroking a 231 Buick from this era is that all the good parts are designed around either force induction- which means 8:1 compression- or all out naturally aspirated drag engines- whiuch means 11:1 or higher compression. they are pretty set in their ways in that world and are convinced that even 9:1 compression is too much for a boosted application, and i almost got laughed off www.turbobuick.com for suggesting they try a reverse dome piston with the more modern fwd heads with better chambers to get a usable 10:1 motor that wouldn't complain about 20# of boost..

the only real way to get pistons to get a decent- but not crazy high- compression ratio with off the shelf pistons is to build a 4.1 with flat top pistons. i don't think anyone sells a 10:1 flat top piston for a 3.8- they all either have big inefficient dishes for boost or big domes for high compression in a naturally aspirated drag motor. there really is no middle ground with the 3.8 without getting custom pistons, and that's too bad. but someone did figure out how to put factory early 90's roller cam parts in one with minimal work, and all the other problems with this engine family has been fixed if you know what parts to order.

I've spent a good part of the last 2 days researching and it is limited but there are solutions. Much of it in the GM parts bin some of it machining work.

Good stuff.

I must say I did not know Chevy made a 3.8 V6.

novaderrik wrote: they are pretty set in their ways in that world and are convinced that even 9:1 compression is too much for a boosted application, and i almost got laughed off www.turbobuick.com for suggesting they try a reverse dome piston with the more modern fwd heads with better chambers to get a usable 10:1 motor that wouldn't complain about 20# of boost..

The problems are multifold - the manifolding for the FWD heads is even rarer than GN stuff. That being the biggie.

We do build engines in the 9:1 range.

But mainly, when what works works, there's little incentive to go further. There's a class of racing that requires stock unported heads, stock unported intake manifold, and a stock turbine housing. People still make over 900hp. Some of the numbers did make me cringe, like exhaust manifold pressures in the 90-100psi range.

Another (kinda interesting) thing... almost all aftermarket components are designed around the stock amenities. Keep your A/C, keep your full interior, keep power everything, go fast with class.

My point is, going with non-stock form factor components is introducing variables that take away from the stock vehicle vibe, and that takes away from the class. Heck, lots of GNs run chip-tuned factory computers. (They do work awfully well, to be honest)

No matter what you do, the limitation is going to be the block and/or the head gasket seal. So why get fancy?

Knurled wrote:

novaderrik wrote: they are pretty set in their ways in that world and are convinced that even 9:1 compression is too much for a boosted application, and i almost got laughed off www.turbobuick.com for suggesting they try a reverse dome piston with the more modern fwd heads with better chambers to get a usable 10:1 motor that wouldn't complain about 20# of boost..

The problems are multifold - the manifolding for the FWD heads is even rarer than GN stuff. That being the biggie. We do build engines in the 9:1 range. But mainly, when what works works, there's little incentive to go further. There's a class of racing that requires stock unported heads, stock unported intake manifold, and a stock turbine housing. *People still make over 900hp*. Some of the numbers did make me cringe, like exhaust manifold pressures in the 90-100psi range. Another (kinda interesting) thing... almost all aftermarket components are designed around the stock amenities. Keep your A/C, keep your full interior, keep power everything, go fast with class. My point is, going with non-stock form factor components is introducing variables that take away from the stock vehicle vibe, and that takes away from the class. Heck, lots of GNs run chip-tuned factory computers. (They do work awfully well, to be honest) No matter what you do, the limitation is going to be the block and/or the head gasket seal. So why get fancy?

the exhaust flange bolt pattern is different, but the intakes bolt right up.. the 89 Turbo Trans Am used the fwd heads with only different exhaust manifolds. my point is that if you want to build a better mouse trap, you've gotta think outside the box- and most turbo Buick builders aren't really thinking outside the box any more.. you are right, they found parts that work and they don't like trying new things for whatever reason- these are the same people that think that there is no way a turbocharger and work with a manual trans, simply because a few people tried it 20 years ago and weren't happy with the results and gave up before figuring out how to make it work.. but tell me that a 10:1 motor running on E85 with 20 pounds of boost wouldn't be an excellent street/strip engine. the extra compression would help with low end torque and driveability when off the boost, and help it make more power when on the boost. and having access to cheaper off the shelf pistons for those builds would help people that want to build the same engine but without boost..

novaderrik wrote: the exhaust flange bolt pattern is different, but the intakes bolt right up.. the 89 Turbo Trans Am used the fwd heads with only different exhaust manifolds.

Yep. And good luck finding those manifolds. I've had a hard enough time finding GN manifolds!

my point is that if you want to build a better mouse trap, you've gotta think outside the box- and most turbo Buick builders aren't really thinking outside the box any more..

You have no idea. Some of the people in the field will not touch or even consider a vehicle that has things not done "their way". Some of the stories I could tell...

Part of this is because of pragmatism, a lot of it is because, like any other automotive sphere of influence that's been around for a while, there are people who figured out what works a long time ago, and as time passes they get more set in their ways because they've seen a whole lot of new ideas fail, giving them more conviction that they're right. (A large number of these people are considered to be a-holes because of this. I tend to ignore the attitude that they get from having to deal with snotty upstart punks for the last 20-30 years and just consider the tech info)

And the rest of it is because, and let's be honest here, expensive older cars are driven by richer older guys. Not-rich older guys can't afford to get into GNs and rich younger guys mostly don't care about big dumb American iron - for the money, they could have big dumb newer Japanese iron like MkIV Supras.

these are the same people that think that there is no way a turbocharger and work with a manual trans, simply because a few people tried it 20 years ago and weren't happy with the results and gave up before figuring out how to make it work..

Have you SEEN a Grand National at the dragstrip, on a test-n-tune night? It's like watching a bracket race except the tree comes down evenly. Buick sits at the line for three or four more seconds, patiently waiting for the turbo to finally get spooled against the converter, THEN it launches

but tell me that a 10:1 motor running on E85 with 20 pounds of boost wouldn't be an excellent street/strip engine. the extra compression would help with low end torque and driveability when off the boost, and help it make more power when on the boost. and having access to cheaper off the shelf pistons for those builds would help people that want to build the same engine but without boost..

Well, okay, I'll play that side of the fence for a moment. I've never driven a GN that felt poor off-boost. Even a stock GN setup is probably more powerful off-boost than a Regal with a carb 3.8 - same compression, better intake and exhaust even with the pinwheel in the way. (Forgive me if I'm unfamiliar with the cam specs at the moment) And thanks to the magic of the automatic transmission, even if the trans does not kick down, you can still build boost fairly quickly thanks to the torque converter. That is one place where a lot of GNs I've seen do have things wrong. A lot of them have converters too tight (controlling top-end slip maybe?) which really hurts boost onset. Hurting, in this case, means you roll into it and the boost starts out at 7psi for a while until it builds up more steam, instead of flashing right to 10-11psi.

The rest of it - cheaper off the shelf pistons for N/A builds? Sounds like there may be some bias here (There's a guy/crackpot on Speedtalk who is forever pissed that Chevy did not make a one-year transitional engine with a SBC/LT1 bottom end and LS1 cylinder heads - never mind that it would be pointless, very expensive, and impossible given the head bolt geometry, he wants LS1 heads on an old SBC and it's their fault he can't have it!)

And in any event, they do already exist. 24cc dish pistons plus decking the heads down to 40cc will get you there. Summit lists 24cc dish pistons and 40cc is not a problem.

I wonder what the cylinder pressure curve is on a higher compression alky engine vs. a lower compression gasoline engine. Gotta mind the head gaskets.

Knurled wrote: The rest of it - cheaper off the shelf pistons for N/A builds? Sounds like there may be some bias here (There's a guy/crackpot on Speedtalk who is forever pissed that Chevy did not make a one-year transitional engine with a SBC/LT1 bottom end and LS1 cylinder heads - never mind that it would be pointless, very expensive, and impossible given the head bolt geometry, he wants LS1 heads on an old SBC and it's their fault he can't have it!)

i think i know who that guy was -PDQ67.. he thought the world was out to get him and he got booted off 2 other boards i go to because of some rather inflammatory statements.. but yeah, he wanted someone to try to put LS heads on a small block and wouldn't shut up about it for like a year, and World Products finally came out with a block that lets you do that- for a price.. i think it would be easier to put the LS heads on a small block Ford..

but back to the Buick thing- it isn't just "rich" people that own them.. my T Type is a GN with blue paint and interior, and i'm almost the exact opposite of "rich".. you can buy driving 86-87 GN's for $5k from time to time, with most drivers being in the $10k range as long as you don't do something stupid like buy one from a dealer.

i've had this idea in my head for making adapters to run the later fwd heads with stock 3.8 manifolds for a while, but i need to get a set of those heads and the core engine to build the high compression 4" bore/roller cam 4.1 that i want to build for my car, and it would be cool if i could swing a 5 speed manual trans like a TKO behind it, too- as quick and consistent as my car is, i always think it would be so much better with a third pedal and a shift lever poking out of the floor..

Ah, T-types... I've never seen one, so I can't comment. The nice thing about GNs is that they are all rust free since they were recognized as collector items when they were new. (I often wonder how many GNXs were whisked directly from dealerships to storage, never to be driven on the roads!) Given the local climate, cars that last this long are either immaculate and therefore not cheap, or they rusted away long ago.

I've heard tell of magical lands where people drive RX-2s and 510s and other mythical vehicles as daily drivers, and even IH Scouts exist, but until I see it, i won't believe it. Although, I have seen a 240Z in person once, and not in some history book Had some funny lookin' black and gold license plate on it.

I'm personally biased against manual transmissions for over-3l engines, but hey, it's your car, right? My Buick thoughts turned to finding a 4th-gen F-body's 3800 block and transmission as a drivetrain starter point. The Series II block looks immensely stout compared to the old 231, and it's narrower to boot. I had some crazy thought about using two FWD rear-bank exhaust manifolds as turbo headers after eliminating the crossover dongles and welding Audi K24/26 flanges onto the outlets... NOT a G-body application, of course.

How hard would it be to use the 4gen F body 3.8 as a power plant in an older car?

ThePhranc wrote: How hard would it be to use the 4gen F body 3.8 as a power plant in an older car?

not too bad.. there are GN guys that are claiming to run 9 second 1/4 miles and getting close to 30mpg with the AC blowing cold to and from the track with those engines. they also claim that they are running untouched long blocks out of crashed Camaros to do it..

check the googles- there are people that are using the easier to find supercharged 3800's out of fwd Bonnevilles and what not in rwd applications with a very minimal amount of work.

I must be the odd man out because my dad and I built an 80 Malibu with the Chevy 3.8 V6. Put in a built turbo 350 transmission, some used BGN internals, heads and intake, along with a Holley 4 bbl, true duals with cherry bomb mufflers. With the highway gears in the rear end my 0-60 wasn't the best but at speeds 90 plus, she couldn't be touched. A couple of Missouri State 5.0 Mustangs might have found that out the hard way. Everything was used racing parts that were rebuilt and reconditioned by my dad and myself. It turned out much better than I anticipated considering my dad traded my 75 Gremlin in on it after he threw a rod. Took close to 30 years to get over that...  I gave my dad the idea for the build from one that was a Hot Rod cover car with a blower.

Knurled said:

Ah, T-types... I've never seen one, so I can't comment.

I think not being seen may be the point of the T Type.