3900 in RWD

[darncars]

Considering doing a 3900 swap into a 96 Firebird to replace a blown 3800. My main question is can the 3900 intake be turned around to have the throttle body at the right end for RWD or do I have a lot more fabbing to do on this swap. Thanks Dan

[ericjon262]

it's not impossible, but it's more work then doing a 34/3500 RWD. IIRC, the main problem lies with the timing cover and water outlets.

[Guest]

it's not impossible, but it's more work then doing a 34/3500 RWD. IIRC, the main problem lies with the timing cover and water outlets.

I don't know that it would be more work, he's swapping from a completely different engine family anyway.

In a case like this, unless there was some underlying reason that you wanted to go to a 60 degree V6, I would just find another 3800 that will fit the F-body, and drop it in, or as it actually is, lift it in. lol

[ericjon262]

I don't know that it would be more work, he's swapping from a completely different engine family anyway.

In a case like this, unless there was some underlying reason that you wanted to go to a 60 degree V6, I would just find another 3800 that will fit the F-body, and drop it in, or as it actually is, lift it in. lol

yeah, dropping another 3800 would be the easy button. if the OP is who I think he is, it's for more then just to get the car on the road, but I've been wrong before. the other big factor is how "intact" you want the 3900? VVT?

[darncars]

The VVT is what concerns me the most and yes another 3800 or even a 3800SC as I have done that would be easy but really why do the easy when the challenging is more fun plus you learn while you work. Thinking the 3900 would work decent power wise in the Firebird, be some thing different and have that nice 60 deg sound over the harsher 90 deg noise I mean sound. Plus going this route instead of the 3800SC route I have a car that runs on pump gas not the much more expensive high test.

[ericjon262]

here are my thoughts.

• Flywheel may cause hangups.
• bellhousing is the same, which would allow for easier mounting
• later 3800 F bodies are DBW, you may be able to easily get away with "stockish" programming.
• VVT will make the process harder, but I do think it's more then possible.

Are you actually planning to do this or just spitballing ideas? if you are, I would love to see the progress.

-Eric

[darncars]

Planning on doing this over the winter if it will fit ok and the intake can be turned around. Dan

[ericjon262]

cool, please keep us updated. is the car a auto or a manual? I don't see why a 3.4 flywheel wouldn't work.

old thread, but lot's of info, and some pictures.

http://60degreev6.com/forum/showthread.php/34223-3900-Info

[ericjon262]

LZ4 not LZ9, but you get the idea.



to me, it looks like the hard part would be getting the motor mounts situated with the accessories so far back.

[Guest]

I wouldn't call that a problem, could also move all of the pulleys forward if you really wanted to, using some RWD pulleys and spacers.

The engine mounts bolt to the side of the block, the only thing that would get in the way is if the FWD A/C compressor was retained in it's stock location, but at that pout, you're making the mounts anyway, so something can be fabricated to go around it.

I have a different plan for my RWd conversion of a my 3500, more like how the GM mounted some of their engine years ago.

[ericjon262]

I've made mounts around the A/c compressor in that location, and it's a bit of a pain, not impossible, but def a pain. the water pump isn't easily moved though, because it's part of the timing cover, yeah, I guess you could make some kind of spacer, but I'd expect that to cause wear issue on the pump bearings.

http://s296.photobucket.com/user/mrtohil/library/LZ9?sort=2&page=1

[NateD4]

The oil pan is part of the mount on an LZ engine. There is a nice mount on the left of the engine. On some versions they mount an engine mount to the heads and valve covers. I see nothing wrong with that as the majority of reaction torque is transmitted via the bell housing.