FAQ: Why a Series II SC engine for modding purposes?

If you're thinking about modifying a Riviera, but have not yet purchased it, there are a few things you may want to check before you buy. Most important is to determine whether or not it has a supercharged engine. An easy way to check this is to inspect the passenger side of the trunk lid for the "supercharged" badge. Also, look under the hood. If the engine cover says "supercharged", and you see a blower snout protruding from the passenger side of the engine, you're in business.

Also worth noting is the model year. For the purposes of modding, it is more desirable to have a '96 or newer car. One reason for this is that 1996 was the first year to receive the Series II L67 engine. There is a bigger performance market for this engine, so try to get the Series II if you can. Also, 1996 was the year all vehicles became OBDII compliant, meaning you can use a common scanner to see how your car is running, troubleshoot problems, tune for performance, etc.

Buick made improvements for each year the Riviera was produced. Suspension upgrades, steering improvement, a beefier transmission, and more available options are some examples of these improvements. Generally speaking, the newer the car, the better off you'll be.

There were two versions of the supercharged engine, the Series I and the Series II. To tell the difference, pop the hood and read the engine cover. It will say "3800 Supercharged" on '95 models, while '96 and up models say "3800 Series II Supercharged". Another way is to measure the SC (supercharger) pulley, located on the blower snout. The Series II stock SC pulley measures 3.8" in diameter. The Series I is smaller at 2.85" diameter stock.

If you already own a Series I supercharged Riviera ('95 models), you can still modify the engine, but the Series I used a different blower (the M62 instead of the Series II's M90) so it has a different sized SC pulley. The Series I is also different in other ways, and performance parts are fewer and harder to find.

Hey Aaron,
I find myself straying to the Series II section more because you seem to offer more info there...I'm confused. You mention the SC pulley for 96 and above is 3.8 and 95 is slightly smaller. But, when I go to the Pulley Boys site, they show Series I stock pulley to be 2.85 and recommend 2.5 pulley for upgrading Series I M62 SC. Am I reading something wrong? I don't want to buy the wrong pulley.

I'll try to add more to the Series I section soon. Much of the info we have only applies to the Series II engine.

I said the Series I pulley is "a bit" smaller. Maybe I should have said "a lot" smaller. Thanks for the info. I'll edit the above to be more specific.

AA the Series I does not display Series I. It simply says 3800 supercharged. Come to think about it, why would GM stamp series one on the first motor in the series? They didnt know that they would have to come out with the series II at that point in time. Jax95, you are right, the '95s have smaller pulleys. We can drop to a 2.5 with proper thermo and plugs. I'm hate to say that we will wear out our superchargers faster, for they are spinning far faster then the Series II, but I priced a Series I charger @ $599. Not so bad. Don't feel bad for having a '94-95, we don't have to crack out our engine mount to change the belts!

Quote :

we don't have to crack out our engine mount to change the belts!

Thanks for the info, River. I'll make the change.

quote: "Don't feel bad for having a '94-95..."

94?

Don't bang on the 94 model year...lol... it got great reviews on carsurvey.org....

AA wrote:

Thanks for the info, River. I'll make the change.

quote: "Don't feel bad for having a '94-95..."

94?

X2

haha as i wwas reading this i knew i had to say something about the 94 mistake haha So y did they not mkae a rivi in 94???

Nope.

I was thinking, would it be worth it to upgrade to a newer riviera with the series II? i hear that with the Series I im limited to the variety of mods i can do.

Christman wrote:

Alright thanks, also i was thinking, would it be worth it to upgrade to a newer riviera with the series II? i hear that with the Series I im limited to the variety of mods i can do.

If modding it what you want to do it would be worth it. Rivman swapped in a series II into his 95. You don't NEED to get a new Riv you could swap in a series 2 engine/trans. If moneys not a factor or you don't have the knowledge or patience (thats probably more important than anything else ) then you could just grab a newer Riv.