Beretta.net

Friend and I are going to try and swap a 3800SC from a 95 riviera into a 96 bonny. does anyone know if the subframes are different or would the 95 motor mount right up into the 96 bonnie?


Thanks in advance.

Considering the Bonneville I believe had options for a 3800SC a time or two, it should. But no idea for certain.

Should bolt right up. Bonneville had an SC option with the 3800 called SSei. Should be a direct swap.

I know for a fact in '95 Bonneville and Riveria shared the SAME SC'd motor. Should swap right into a '96 as well.

The SC option doesn't change the engine mount style used. Just the belt routing/heads/intake manifold. You should be fine.

Thanks Everyone for the info.

Beware that you car swapping a OBD1 engine into a OBD2 car. There may be some slight changes to deal with

Barry wrote:Beware that you car swapping a OBD1 engine into a OBD2 car. There may be some slight changes to deal with

I don't want to call everyone else who replied to this "wrong", but you all are, sorry...

The 95 Riviera's are what we call "OBD1.5". It uses for the most part OBD1 programming except for the ability to jumper terminals and self-diagnose. And they DO use OBD2 connectors, however an OBD2 code reader can't read from it.

Your also swapping a series 1 engine into a series 2 car... People say the Riviera engine is OBD2 compliant, and the engine electronics appear to be the same or similar sensor-wise, but some of the plugs may be shaped different as well as the location of some plugs are in slightly different spots. The PCM and wiring harness is different enough to make you scream and throw things...

Also the engine mounting is completely different and afaik the mounting on the engine blocks are different and cannot be swapped easily or at all... The water pump, belt system, alternator mounting, exhaust manifolds and routing is all different as well!

So, do yourself a favor and get the correct series 2 engine! If you feel like tons of headaches and wasting tone of time and money, go ahead, but I wouldn't recommend it!

BTW, you're welcome

The engine blocks and heads are the same. The 90* V-6 changed very little over the years. You can swap just the long block in and use year correct sensors.

Also, the mouning points ARE the same.

SuzukiGhostRider wrote:The engine blocks and heads are the same. The 90* V-6 changed very little over the years. You can swap just the long block in and use year correct sensors.

Also, the mounting points ARE the same.

The Series II is quite a different engine. Although the stroke for the 3.8 L engine remained at 3.4 in (86 mm), and the bore remained at 3.8 in (97 mm), the engine architecture was vastly changed. The deck height is shorter than the Series I, reducing weight and total engine package size. This required that the piston connecting rods be shortened 1 in (25 mm), and the crankshaft was also redesigned. A new intake manifold improved breathing while a redesigned cylinder head featured larger valves and a higher compression ratio.

The series 1 supercharged engine in the 1995 Riviera has all different engine and transmission mounts compared to the 1996 Bonneville SSEI Series 2 and I'm almost positive the mounting points are different as well... But what difference does that make anyway if the long block is different...!?

Useless pictures for fun!

Series 1 1995 Riviera Supercharged


Series 2 1996 Bonneville SSEI


You can bicker with me if you want, but I'm done. KTHNXBAI

oooooh i'm impressed we can quote wikipedia.....

the series 1 and series 2 3800 both have similar block mounting points.

but i would probably try to get a series 2 to swap into the 96. "moar" power and easier in the long run

scd88ga wrote:

Barry wrote:Beware that you car swapping a OBD1 engine into a OBD2 car. There may be some slight changes to deal with

I don't want to call everyone else who replied to this "wrong", but you all are, sorry...

The 95 Riviera's are what we call "OBD1.5". It uses for the most part OBD1 programming except for the ability to jumper terminals and self-diagnose. And they DO use OBD2 connectors, however an OBD2 code reader can't read from it.

Your also swapping a series 1 engine into a series 2 car... People say the Riviera engine is OBD2 compliant, and the engine electronics appear to be the same or similar sensor-wise, but some of the plugs may be shaped different as well as the location of some plugs are in slightly different spots. The PCM and wiring harness is different enough to make you scream and throw things...

Also the engine mounting is completely different and afaik the mounting on the engine blocks are different and cannot be swapped easily or at all... The water pump, belt system, alternator mounting, exhaust manifolds and routing is all different as well!

So, do yourself a favor and get the correct series 2 engine! If you feel like tons of headaches and wasting tone of time and money, go ahead, but I wouldn't recommend it!

BTW, you're welcome

OBDI.5 does not use an OBDII connector. It uses OBDII flash technology vs a removable chip but still has the same ALDL connector and language as OBDI. I have an OBDI tool that read my Beretta's 95 ECM which was OBDI.5.

Mount wise I wont argue, that could be completely different as I do not know that part... and the big thing to worry about which you did mention, is some of the OBDI.5 engines did not have all of the same sensors, or even provisions to install a specific OBDII sensor so you would lack the ability to fully equip some OBDI.5 engines with all the necessary items for OBDII.

I never look at just the sensor plug, because if the location is there to mount the sensor and the part is provisioned to be read then you can typically use the newer sensor in that location. One example is I'm running a 2005 Cam sensor from a 3500 in my 3400 thats using a 97 ECM, works fine and SFI works as it should.

the mount locations vary however they share the same "mount bore" holes on the block and heads. So either way the mounts will bolts up

^^ Exactly ^^

spacecadetz26 wrote:oooooh i'm impressed we can quote wikipedia.....

I knew off-hand that the heads, block, and internal parts were different, but I didn't know the specific numbers, so I looked them up and copied them, what's your point, at least it's correct info which is what the OP wants I would assume.........

SuzukiGhostRider wrote:^^ Exactly ^^

Congrats, you got 1 thing correct out of like 5! Make sure to print that out and put it on your fridge...

3X00-Modified wrote:OBDI.5 does not use an OBDII connector. It uses OBDII flash technology vs a removable chip but still has the same ALDL connector and language as OBDI. I have an OBDI tool that read my Beretta's 95 ECM which was OBDI.5.

You sir are incorrect, a 1995 Buick Riviera HAS a OBD2 style diagnostic port/plug NOT OBD1!

TEAMZGTZ11 wrote:the mount locations vary however they share the same "mount bore" holes on the block and heads. So either way the mounts will bolts up

Thank you VERY much for the clarification on that because I was unsure which is why I said "I'm almost positive and AFAIK"... Posting tech info without being 100% sure that it's correct is a pet peeve of mine when other people do it and I'm sorry that I did it myself... My bad...

Regardless of all this, I don't think the OP needs 100 different reasons why he shouldn't attempt this swap! It doesn't much matter if the bolts line up if nothing else is going to work and there is nothing "direct" about it besides that!

So, we're all wrong and you know it all? STFU, and go back to where ever it is you've been with everyone's money you stole from them.

And, I got everything I said CORRECT. Google all you want. I know what I'm talking about.