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M5 engine block swap...is it possible and what are the projected gains?

2K views 14 replies 6 participants last post by  hh3uunp 
#1 ·
#3 · (Edited)
Your heads should bolt to it and you will make more power than you have now not m5 levels but you should see a power boost. The m had bigger displacement and higher'compression.

After looking at dyno graphs for the s62 though I suspect most of the difference in power is coming from the heads, the heads allow it to rev a few thousand rpms higher and thus net higher peak HP.

I suspect the reason BMW went to larger displacement and higher compression was to compensate for the loss in low rpm torque from the more aggressive cams and the individual throttles.

Your Max power output is most limited by how much your head can flow.

All that said should you do it I would be very warry about buying a block off eBay. Chances are that block spun some bearings or snapped a con rod and is a junk block they are trying to ditch on someone.

Also the shipping on something like that should be high like 300.00 because it will have to go truck freight and you'll pay more automatically if it has to go somewhere without a loading dock or with fork lifts.
 
#4 ·
And then when it arrives if it checks out you may run into minor fitment issues and you'll have to spend about another 1000 to put it all back together.

3-500 in parts 100. In machine shop time for the heads, the rest would be from labor cost and miscellaneous part costs
 
#5 ·
So that sounds like a whole bunch of time and money that I'd rather spend on a supercharger. I'm basically just trying to figure out what my best options are for engine tuning. One major issue that I need to sort out is throttle lag. When I'm cruising along at say 60 in 4 gear and I punch down on the accelerator the throttle response is not ideal. What can I do to fix this? I've heard of sprint booster, but don't entirely trust that it will make any difference.
 
#6 ·
Your engine has a real cable attached to the accel pedal. You need to sort out the intake tract: idle control valve, vacuum leaks, poorly adjusted throttle cable. Any pending codes? Fuel pressure level? Age of O2 sensors, cats?

I get bodacious acceleration at that speed and gear. It's my fave technique for accelerating onto the freeway. In no time, I'm doing 80.
 
#8 ·
Thanks for the ideas! My acceleration leaves something to be desired right now, but I'll have a look at all those components for any signs of failure. I need a code reader desperately too. I'm studying in Germany at the moment and have the car covered, so I hope to sort it out this summer when I return. I do the same thing when getting on the freeway. Drop it into 4th and punch it! :thumbup:
 
#7 · (Edited)
Os your car manual or auto.

If its auto the lag is caused by the torque converter, nothing u can do for that you maybe able to source an after market one with a higher stall speed but I doubt it

If its manual get a lightweight flywheel

Do you have a drive by wire throttle setup or a accelerator cable. If its drive by wire your screwed. If its a cable tighten the cable.
 
#9 ·
I have a manual with a cable setup. I do want to upgrade my clutch, but i'm only doing that once the one I have in it starts slipping.
 
#14 ·
If the OP needs more power, these may help:
- CAI 101 should I do it or not (1) and which is better, stock or aftermarket cold air intake (1) (2) & a home-made CAI (1) & the general consensus on the effectiveness of an aftermarket CAI versus the stock BMW CAI (1) (2) (3) (4) (5) & how to reduce the risk of hydro lock (1) (2) & what about a K&N oiled air filter over the stock air filter (1) & a forced induction group buy (1) and adding nitrous oxide to your E39 (1) & links to suppliers to improve performance of your E39 (1)
 
#15 ·
I have some m5 heads if you're down. Get some pistons and do this
 
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