I know that the Euro spec s50/52 Engines have the potential to rev up to 8000 rpm no problem... but my question is why cant our US spec s50/52 Engines rev so high... And if its possible for our engines to do so...What would I need to do to get my engine to that RPM Range????
Not within reasonable budget. The bottom end simply cannot take it. But with enough money you could get it to that point I suppose. It would be much cheaper to buy a euro motor and build it to a moderately safe 8k RPM (although much more than 7600 is pushing it on a stock euro bottom end, and much more than 7400 is going to fry a US motor with a stock bottom end.
You want 8000 RPM? Buy a Honda.
My GS-R revs to 8,100. But I prefer to have some torque and a redline about 1K lower.
EDIT: ok, ok...or an S54
-Nick
What do you mean by bottom end... Block,Pistons,crank,Con Rods,????
everything below the head, like in the bottom of the engine
"Every BMW Begins Life As A Meticulously Engineered Blur"
chip, software, & cam shafts.
G/L
Well Ive got Cams, Pistons, Conrods, Im working on getting a Euro Spec S50B30 Crank ..... The Euro Cranks are forged compared to our cast iron cranks...
The thing im worried about is my rod bearings... Even if I do get the euro crank Im still worried about spinning my rod bearings...
and as far as software... do you mean tuning or am I gonna need to get a custom TUNED chip or comp???
titanium retainers, high rev springs, and a chip, but dont expect to rev to 8k for more than 5 minutes!
E31 M73 Forever
I got the whole motor worked all im missing is the crank but do I really need the crank???
to hit 8k in any of the US spec e36 engines your talking a complete change of every part that moves in the entire engine
the engine wasn't designed to rev that high, and it wont unless you change the entire top end with the best, lightest, strongest, perfectly balanced/matched pieces money can buy, same thing definitely goes for the bottom end, even more than the top end really
you'll also need aggressive cams, a new intake manifold and intake, software to open the rev limit up and tune for those revs, as well as some head work so that the engine will flow at that high of rev's and make everything actually worthwhile
...or you can swap basically any other engine in for less money and have more power...
LS1
S54
S50B32
should be a fun project though
"Every BMW Begins Life As A Meticulously Engineered Blur"
Ok heres a list of what Ive done to my motor:
Shrick 264/256 Cams
Ti-Retainers
Ferrea Dual Valve Springs
Ferrea 1mm Oversized Valves
New Lash Adjusters
Port & Polished Head
Dinan Oversized Throttle Body
Euro 3.5" HFM
Turner Custom Conforti Chip
24lb Injectors
Wiseco Forged Pistons
Arrow Forged Con Rods
My Chip now rev limits at 7000 rpm...
no point, no matter what you do, it wont make much power at 8k. NOT worth the hassle in a US spec head, it just doest flow enough.
BUT
if u dont want to do it:
solid lifters (a must)
re-balanced crank
higher rate valve springs, preferably double spring.
lighter pistons would help DRAMATICLY!!! the S52 goes through INSANE piston speeds at anything over 7k and puts A LOT of strain on all moving parts.
M50 manifold, or better yet, shrick honed intake.
3.5" CAI and MAF, with ASC delete.
chip with custom tune.
some nice oil (10w-40 should suffice i would think)
a LTW flywheel, the steel one from UUC is the best bet, wont warp, and get it balanced to 10k rpm.
Sunbelt cams or evosport, or custom.
/\
the engine would hold together at 8k, but it WILL NOT! make much power at 8k. peak power will be at 7k-7.3k, and start to die off A LOT. Not to mention that is a high strung engine, and wont last more than a few minutes at those rpms. Engine life will be read in Hrs, not miles.
"Be who you are and say what you feel because those who mind don't matter and those who matter don't mind."
-Dr. Seuss
DIY BMW Tools. Charlie For President
nice, must be fast. mine limits at 7200
'95 Avus Blue M3|Dinan tune|Cosmos V1 CAI|Recaro|3.23 lsd|Magnaflow| -SOLD
'95 Cosmos M3 |Cosmos Racing V1 3.5" CAI|Samco rep TB boot|740i HFM|Turner Tune|UUC Pulleys|CF Hood|Depo 6000k|Depo french fogs|Depo Tails|Black Wide Kidney Grill|AA exhaust|Zimmerman Drilled rotors|Sparco|B&M SSK|Koni S&S|BMP Bushings|Wahlbro 255|Stewart Thermostat| 240whp -SOLD
'09 135i 6mt |BMS JB4 g5iso| MHD BMS Flash| BMS DCI| BMS Chargepipe | BMS Inlets| RB PCV| N54 Perf 3" DP| Wagner FMIC| Ryan Racing DV Valves| Fuel it Stage 2| e60| 480whp
"Be who you are and say what you feel because those who mind don't matter and those who matter don't mind."
-Dr. Seuss
DIY BMW Tools. Charlie For President
Thanx for the Info...
I appriciate all thefeed back...
Im currently Doing a rebuild... wish me luck!
"Be who you are and say what you feel because those who mind don't matter and those who matter don't mind."
-Dr. Seuss
DIY BMW Tools. Charlie For President
My Motor decided loose compression on me!!!
So now Im at the point where Ive diagnosed it and Its either Valves are bent, or my rings are history!!! Thats what happens when you race... but I didnt brake it while I was racing lol Oh well gonna fix and and Im gonna keep racing... lol
If you have a stock head then 7200 rpm is the highest reasonable rev limit for actually making power. It would take some port work to get enough flow and a non stock intake manifold to actually make power up to 8k. Functionally I think the engines are fine if in good condition to rev to as high as 7400ish with no issues with the right cam.
euro crank is designed for longer rods to reduce piston speeds, the big ends are wider than M50 rods as well, the euro block is taller to accommodate the change in geometry, mine revs happily to 8000, max hp is at 7800, stock internals including cams with 3 litre euro with carbon plenum and alpha n tune
cheers, Alan
1/4 mile-12.92 @ 108.64mph-NA 3.0L m3 daily driver
The main issue that the S52 can't rev past 7400 is the lifters. Hydraulic lifters are maintenance free but have performance limitations. Going to solid lifters will allow for a higher RPM limit. Stiffer valve springs will also be required. Keep in mind that the stock S54 RPM limit is 7800.
If you're rebuilding the engine, you should bump up the compression (to around 11.5-12:1) with high compression pistons, rods you can keep if you're on a budget but balance the crankshaft and rotating assembly and change the main bearings as well as the connecting rod bearings.
For the top end, a serious porting and polishing endevour is required to have the head flow properly. Evosport has a nice set of cams that would be a good match to a high revving, high compression s52 motor (290/290) - http://www.evosport.com/product/prod...NG.CAM.M52.201
It is important that you talk to a professional engine builder and discuss your project and goals. They will be able to offer you more solid advice then people on a message board...
Good luck!
T.
Last edited by JazzM; 11-05-2008 at 07:33 AM.
T.
Who really cares what rpm it revs to, wouldn't it matter more how much torque & hp you can make ?
Revving the crap out of it just shortens it's lifetime, while making more power at lower rpm's is not quite as punishing on bearings etc.
Sounds like you are pretty new at all this and are about to learn an expensive lesson.
Best of luck with it.
Why not just go ahead and build your own F1 motor? They rev to 19,500 rpm & you don't even need valve springs..
Last edited by The Letter M; 11-05-2008 at 08:14 AM.
1999 Estoril Blue ///M3 with common mods to the car, and driver training mods to the driver. It's a safe, intelligent, and fun combination. Member of our local BMW Club Driver Training Team.
Bookmarks