Thread: Engine swap questions need help.

so i plan on swapping out my N/a motor for a supercharged one and i have a few questions on what ill need for this
First of all i have the supercharged motor and hd tranny from a car that i got from a friend that was rearendedd the motor did not consist of the wiring harness pcm or drive axles due to them being lost on the way to me. So to make things simpler for me could i just buy the entire engine and trannt harness with the pcm for my car and plug in all the sensors on the motor and tranny then just drop the engine in after pulling my motor tranny and ahrness out. where does the wrirnig harness all connect to ? the pcm obviously and the fuse box right OR is there any where else it goes besides this? i havent seen one out and i have only ever messed with small block chevys. also ill need the passenger side axle from a gtp right? is there any things that i am missing?
Thank you all in advance.

So basically i just need to know how the wiring harness coneects to everything. Might sound dumb but i just want to double check evrything as this swap has to happen very quickly for me with no snags

It would help if we knew the year of your car and year/make of what the motor came from. Reason for that is.. a Bonneville/PA/Riv is going to have a different rear exhaust manifold and a couple other small things that aren't the same as what you'd see in a GP.

Harness:

IIRC it's like you said plug a couple connections.
PCM
Fuse box (under hood)
Rear O2 sensor (routed through heat shield down tunnel under car)
Maybe a connector to the PS rack (where the column comes out of the firewall behind teh trans)

I think that's it. Might be one or two other little stragglers like the AC pressure switch. (driverside engine bay by trans)

If you haven't bought the harness, you can use yours relatively easy by adding the BCS (boost control) if you wanted and changing the map sensor connector.

PCM: You'll need one programmed for the engine/trans, probably with the codes for high speed fuel pump relay removed.

Passenger axle you need, driverside you can reuse yours.

Fuel lines are going to be a consideration. They don't adapt well from L36 to L67 in any of the ways I've tried. They always look like they are kinking and about to break. Being thin wall plastic..it's a bad thing.

I apologize i thought i put the year i have a 99 grand prix gt and the motor and tranny is from a riviera so i removerd the uneccessary brackets and such . wouyold it be esier to just by a new harness or just use mine and add the connections. id feel more comfortable just using a new harness as im not to good when it comes into wiring into things into cars. inless someone will can explain in more detail how to route the new wiring into the system. I have a riviera wiring harneess so i couold probly just cut out the bypass valve and wire it up into my harness correct? what pine would i need to cinnect this to in the pcm or is it easier to just wire into something else? Thanks again for all your help its greatly appreciated that someone will take time to write good replys liek you

99 GPGT, and what year Riv?

The map connector is literally taking and running it from it's original location to next to the EGR. The connector itself is different. ZZP has a plug and play harness piece to convert it. I'd literally teach you to solder over the phone. It's three wires and the color remains the same.

The BCS is a matter of adding one pin into the right place on the PCM connector. Literally it's a remove a piece of plastic or hold it out of the way and push a piece in, then hook the other wire up to one of the pink circuits like fuel injector which is right next to the BCS.

It's tough for me to express how easy these can be. Having the Riv harness, you have all the parts you'd need and could even practice before working on your harness.

Being a Riv motor. Swap the rear exhaust manifold if you aren't going headers. The outlet is in a different position.
Since you are using the transmission/starter etc.. you are good there.
Take a look at the transmission line connections at the transmission itself. Depending on the year of Riv, they may or may not match up to yours. Fairly easy to fix if they don't. IIRC it was a 98 Regal that had click style fittings at the radiator and screw in at the transmission. Newer would most likely be click on both ends. I'm just unsure of the actual date they switched over.

The alt bracket might be different, again depends on the year of the Riv. At most, swap over your alt and alt bracket.

ICM coil pack bracket: you will want to swap over to the GP bracket and tensioner. It fits better in the bay and has the dogbone mount on it. The Riv doesn't have a dogbone.

Add the driverside dogbone mount onto the engine. You have to pull the coolant temp sensor to bolt this up.

Remove the bracket from in front of the water pump that holds the motor in the Riv engine bay. When looking at the motor straight on to the water pump, there is a bolt that needs to go in where the upper right bolt of that bracket. The bolt plugs the LIM valley.
off to get pic.

Here is it. It's tough to see the bolt I'm talking about. It's the rusty looking blob under the orange rtv sitcking out of the LIM. Left side of the picture vs the the bolt I'm measuring. It's a round headed torx bolt. You can use any bolt that plugs the hole.


Riv will have a stud in there like this picture.


That should cover the differences.

Awsome man . the riverawas a 99 and i am going to be doing headers instead of the stocks . I should prolly put the fron and back minfold on berfore i put the motor and tranny in throught the botttom. is there any clearance issues with this? i was thinking of just dropping the sub fram out the bottom of the car with the motor and trans still on it and hoist the car over the motor and trans and pull it out from under it and then just repeat for the install i have a cherry picker and i have a ceiling hoist at my shop so it should be preety easy. with multiple jacks under the subframe so i can roll it arond a lil better. i cant view the pictures right now because of work having a stupid filter but im off break now so once i get home ill view the pictures and let you know if i have any questions . Thanks bill

Easiest way to do what you are about to do is jack the car up enough to get your hoist under it. From there, do everything from the top. There's an engine swap and trans swap write up in the how to, but it sounds like you likely have that covered.

Here's how I'd do it and have done it before.

I'd pull the axles
unhook the electrical off the motor/trans
unhook the coolant hoses
Unhook throttle/cruise cables
undo the nuts on teh motor and trans mounts
Remove the two nuts holding the master cylinder to teh booster and swivel it out of the way onto the strut area (no need to unhook it, just the two nuts) This is for more clearance and takes no time.
Unhook the prop rods from hood and prop the hood a little further back
Lift both up and out.

Now roll your carcass out and pressure wash the engine bay/subframe.
Roll back in and lay your rear header piece into the tunnel
Lower the motor/trans about halfway or 2/3 of the way into place and put the header onto the rear head while you have a ton of wiggle room.
Sometimes I also bolt up the ps and ac at this time as well (because you unbolted them from teh brackets and left them laying in the bay w/o draining or disconnecting them from their hoses.
Lower it in the rest of the way and you are 90% of the way there.
I'd finish up the top of the headers at this point following the rest of my headers the easy way thread

^ Awesome, awesome info. Sadly, my swap was a bit more involved, but it's not that bad. I took everything out through the top as well.

A post like yours Rook, reminds me... I've done it too many times lol

thank you bill is it ok for me to pm you if i come up with any more questions along the way?

Sent you a pm.