opinions on the motor setup

[525iT_Feen]

ok, i know im only 15 and the cars not mine yet, but just like everyone else, im here to learn.

So, heres my question:

My knoledge of BMW engine setups is not extensive, but im allways trying to learn. I wanted to know what people though about buying an S50 block and putting my m50 head on it. Then buying the kit that Turner sells, that gives you Shrick cams, a chip, and a few other things that i dont remember.

IF the M50 head were to fit on the s50 block would it make sense.

Or would it make more sense to find a E34 M5 motor and dump that in there.

Please don't be to harsh on me, like i already states, im speaking in theory, and am asking for opinions.

Thanks.
:) :):)

[525iT_Feen]

:help

[5mall5nail5]

Well as far as I know, the S50 bottem end is the difference between the M50 and S50. The heads, as I recall, are the same. What makes more sense though, is finding a S50 bottomend with some miles on it, have your head worked, and keep your M50 intake manifold since (and the S50 may be the same as M50 intake manifold) it is much more freeflowing than the S52. We did an M50 intake manifold on an S52 '99 M3 and the torque curves was dramatic

[Brandon J]

Well, the US S50 is a built M50tu. The changes are in the valve springs, cams, crank, pistons, connecting rods, flywheel, and chip. Everything else is the same including the head, block (besides being bored), TB, intake manifold, fuel injectors, vanos, etc. The bigger question is to find a S50 block that doesn't have any damage. Usually the biggest problem that occurs with the S50 is from driver error; they are usually over revved. That means that the valves will make metal to metal contact with the pistons. So, the pistons gets scored or damaged and sometimes the cylinder walls are affected too. The alves stem can be damaged in the process as well and would need to be machined out and new ones inserted. Both engines suffer not-so-strong valve tappets that were changed to harder units in the S52. Even if you are going to be doing the work yourself, it is probably best/cheaper to buy a used short block(head and block w/o ancillaries) 3.0L or 3.2L and use the M50tu stuff for an OBDI conversion. If you do find a stand alone block that is in good condition for cheap, well it will bolt right on. Then you will need the cams, valve springs, chip.

Now if you are talking about the M50 only, not the M50tu, then that is a different story. I would not recommend the S50 block. The m50 head uses dual valve springs which is good for durability, but you will need new cams. Then, the valve stems are thicker, so the overall flow into and out of the head is not as good. You will need a custom chip for this set-up as no one makes an already made chip for this kind of set-up. Even if you do find a chip maker that might have a file for the set-up, you will probably need to pay custom chip prices. Again, even if you do all the work yourself, the price could catch-up to be over a used M3 engine.

[5mall5nail5]

Brandon, is it reasonable to put a S38 in? How much did it cost you when all was said and done?

[Brandon J]

If you are going to consider an S38 swap, you will need everything. You need to find a donor car. There is no other way to do it. When you change the engine in a 525i, everything is pretty much the same. The S50 engines are the same externally with the M50tu. That is what makes that swap easier. You don't have to find parts to just fit the engine and tranny. Of course an S38 swap already gives over 300hp and 270lb/ft of torque. So after droppin the engine in, there is almost no modding that takes place. With say a S52 swap, you would need to get cams, the euro HFM, etc. Still not a bad route. Just some things to consider overall with both engines. Then there is the "finding" factor. How to find a good used donor car, or even just then engine alone. It is much much more difficult to find S38 engines compared to S52 engines.

I was very lucky to find my S38 stuff for the price of what a used M3 engine and tranny would cost.