250 NA hp on a stock block

[t0pk0w]

Is 250 na hp on a stock block 325 reliable i know it can be done but how long will it last?????

[jrhaile]

okay I'm lost... what is NA... Nitrous Oxide?

[AutoFan]

no, NA is naturally aspirated and what do you plan to do to get that power?

[Deloriant]

NA = Naturally Aspirated (No Super or Turbocharger)
FI = Forced Induction (Super or Turbocharger)

How do you plan on getting 250hp out of a 2.5 liter 6 cylinder block?

[wulley1]

seems like it would be possible if you stroked it, ported and polised the sh*t out of intake/exhaust ports on the head, and switched to larger valves and a 3 degree valve job. Bumbed the compression up to 12.9ish, and got some custom cams made.

Expensive work though, not common to find shops who will do that to a BMW. If it was a V8, there wouldn't be a problem getting that all done.

[BlantonG13]

How many BMW V8s do you know actually come with under 250hp (newer models of course, e34, e39)? used

[Kevin325i]

He means old school V8 from the american muscle era, mmm 350 cubic inches...

[bitcore]

Nitros Axide... heh.

[bigred318]

if you can get all that done i will give you mad props! good luck on that!

David

[007ben]

I be it could be done. but it will get tricky once you start getting near the goal.

gonna take a lotta tuning. but we are already pushin nearly 200 and a chip alone and take up above that.

Cams, intake, headers and such meantioned by wuelly said.

and are we talkin bhp or hp at the wheels?

[wulley1]

it would certainly be a very achievable goal. Honestly, I think once you finished all of the engine work I listed above, you would be a little over 300hp. But, you probably would have spent $8K. For that price, go low boost FI.

[t0pk0w]

no forced induction not on a bmw its just not right :P the 250rwhp is just a number i thought would be good for an na i6 some where around there would be nice and i would plan on doing all but the E.H. my self but i just dont want to throw a rod....

high lift cams
extrude hone
valve job (3 angle)
full exhaust
intake
chip
fule system

one of those every time i save up a grand do something type projects.....

[frank de jonge]

It can be done.

[robbins6103]

[QUOTE]are we talkin bhp or hp at the wheels?

stock 328's come with 193 at the flywheel...who knows how much it is at the wheels. About 15% less.

[Mr White G]

100bhp/litre is a pretty good number!

You might be able to get close to 250bhp. The thing is that the first 30 - 40bhp is easy..... the more you want then the more difficult it gets.

Thought about doing a transplant?

The reliability will be questionable. To avoid problems with the engine you can change the gasket and leads for thicker, stronger ones which will help but we're talking a lot of cash for small reward here.

Drop the cash on a V8 engine from a 540i! That would be sweet.