[brokee90]

Hey all. Got a 06 bmw 325xi currently and have been considering trying to trade it out for a different car or might drive the car til the engine blows/can afford a swap.
So what I'm wondering is how much "fun" is it going to be to swap in a atlas/vortec 4200 considering I'll have to do a piggyback set up. Engine & trans combos or cheap around me and I'll be going for a manual as my 325 is already a stick.
I know that doing the work myself would put the swap price just slightly higher than a 3 stage intake swap and the atlas would be a better engine to build up if i wanted more power.
Would following the lse9x swap guide be a good reference? Is there anything that I'm overlooking that I need to take a closer look? Is there a better/cheaper swap for similar power?

[desertman123]

Cheaper than a 3 stage intake manifold swap? With brand new valves that's still under $1000

Have you ever swapped a motor?

[brokee90]

my n52 has 220k miles on it and you can tell its starting to wear. Itll drink more oil than my subaru did between oil changes (about 1.5-2qts every 5k miles, subaru was 1qt every 5k miles).

The median price im seeing for a complete manifold swap is in the 1500 to 2k range with the tune included. If the motor was 150k miles id consider the manifold swap. I just dont want to put the money into it and end up having to buy an engine not too long after.

A decent 4200 is 4-500 in a junkyard, abt same price for a manual trans thatll bolt to it. dimensions for the 2 motors are similar as well
I haven't swapped an engine before but its fairly straight forward (aside from wiring. I hate doing electrical work) and fabbing up motor mounts and tranny mounts would be simple enough.

All of this is probably a year to 2 out yet, just trying to be as well prepared as i can be. Ideally id have everything on hand and the swap would take a weekend.

[desertman123]

As long as you're handy with metalworking tools - welder, grinders, saws, etc. - you'll be fine. Definitely not trivial though. Not a chance it'll take a weekend.

For the 3 stage intake manifold, you can do wayyy better than 1.5-2k. Used manifolds from junkyards can be had between $50-300. I got mine for $80 with valves in it still, had to replace them a few years down the line at $300/pop. For the tune grab a Bimmergeeks K+DCAN cable and flash the free Bimmerlabs tune. It's not a performance tune but it will enable the newly installed DISAs and be good for the stock 330i power.

That said, N52s are starting to see 200k+ regularly. No idea how your motor is looking, but someone on this board has 400k+ with the only complaint being oil consumption. The motor is not particularly in demand, so a running one has been around $800-2000 depending on who's selling, fully dressed, includes trans, etc.

The motor will be like $500 but the cost will creep way higher than that. See below

If you're keeping the stock transmission, you'll need an adapter plate machined, clutch and flywheel setup, etc. If you're swapping the transmission, you'll need to have a driveshaft made, relocate the shifter, crossframe, etc.

How will the electronics talk? I'm certainly no expert at this subject, but I know the EWS, DME, CAS and keys are all linked so you'll need to keep them quiet/happy so the car will cooperate (send fuel [EKP module] and keep the electronics on). Need to see what the LS swap guys do here.

Will need to look at merging the Atlas and E90 wiring harness, or make a custom one. Stock ECU(s) or standalones?

Cooling system? Power steering?

[hassmaschine]

no way you're doing an engine swap for anywhere near the cost of a 3-stage swap. Maybe for 10x that much but even then I doubt it, unless it's extremely janky and shoestring.

[Biginboca]

It’s always surprising to me posts like this where people say it’s cheap to do something that takes like 40 hours of time. 40 hours is a cost also! Spending $500 for a complete 3 stage swap that takes about 2 hours tops vs spending $2000 on junkyard parts and then 40+ hours fabricating parts and researching ECU diagrams and making wiring harnesses etc to me puts the swap cost at like $5000+ because I put a value on my time too.

Even working at Chic Fil A for $18.50/hr 40 hours is almost $800 lol. And as much as I like the food I am sure… ok hoping… you don’t work at Chic Fil A