what should I do to rev a m50 to 10k

[Sagaris]

"WHY DO YOU NEED 10,000 RPM TO DO THE SPEED LIMIT?"

[xikyle]

my fzr600 redlined at 11,000. i wish you the best of luck, i think your best bet is to give the idea up and look at why you would ask a question like that.

[Justin B]

why? no, really. why?

here's a data point for you - BMW says for every 100 rpm past 8500, engine wear *doubles*. Tell me how long an M50 would last at 10k.. and then think about how much it would cost to make it last more than 4 seconds.

where do people get these ideas? it's almost as if you don't know anything about engines. ;)

Sounds about right...

geez, way to stomp on someone dreams. How about a little encouragement for the guy! You all have to admit It'd be pretty cool if he did it........for at least a min or 2 before it smashed throught the side of the block

Not an e30 tech groupie circle jerk.

[moatilliatta]

1. Just r3v it to 10k
2. Just rebuild what broke
3.?????
4. Profit!

[DTM190]

Streetable practical 10k M50 hey.
I think you should just double the number on your tach.
12k super M50




or start with an ETA, that would work better

[Roysneon]

What is the fucking point of an RPM based goal? Why not a power or time goal? You probably could design an engine to rev high as fuck but still won't make any power. What's so cool about that?

[MattM]

What is the fucking point of an RPM based goal? Why not a power or time goal? You probably could design an engine to rev high as fuck but still won't make any power. What's so cool about that?

if a rotating mass could be designed that would handle the 10k RPM, then the head could be worked to better take it and make it usefull, but by that time you could have just bought a brand new M3... so whats the point

[Justin B]

It sounds sooo good! it's just fascination with a number probably. My car has a stock m52 obd1, and its droningly annoying at anything above 3k anyway. Fast as stink too, but only 6800 rpm or something? Build for power goals, the rest will be primarily dictated by how its already been done, and it isnt 10krpm

[The Humjet]

Just get a bike

[The Volta]

Please ask yourself these question first.

Why?
What am I wanting to accomplish from this?

Then post them here.

[ogbimmer]

Please ask yourself these question first.

Why?
What am I wanting to accomplish from this?

Then post them here.

I would like To accomplish a car with alittle less toque so I just don't burn up the tires but with a higher redline number for more horse power. The head has already been ported and polished and has a 5 angle valve job. Instead of straight critism it would be nice if someone just gave advice. Yes 10k is just a number that I though all you r3v member would get a kick of And just have to say something, but I do want it to r3v higher because I know I can keep flowing and make power atleast alittle higher up in the rpms.

[nando]

my advice is you don't have a clue and probably should just have an engine built by somebody who does. ;)

"I would like To accomplish a car with alittle less toque so I just don't burn up the tires"

seriously?

try for a 7k redline. despite what people might think, M50s really aren't great revvers.

[FredK]

Bottom end limitations:

the bottom end likes to come apart when run significantly higher than the stock rev limit.

the timing CHAIN spinning to 10k.

if nothing else, you're looking at fun harmonics. And don't forget to dry sump it because there is no way that he stock oil pump will take it.

here's a data point for you - BMW says for every 100 rpm past 8500, engine wear *doubles*. Tell me how long an M50 would last at 10k.. and then think about how much it would cost to make it last more than 4 seconds.

Top end limitations

it's not going to be streetable, either. you can't just rev it to the moon, the head has to actually be able to flow at those speeds or it won't make any more power. all that top end flow = lost velocity at the low end.

I'm not sure there are many M5x engines that do fine past 7400 RPM or so. The oil pump likes to blow up, and there are nasty harmonics everywhere.

I think that if you were to get a custom vibration damper, lighten the rotating assembly, improve rod ratio, switch to a solid lifter valvetrain, that you could improve the chances your engine will stay together.

I believe Rebello Racing in CA has spun an S50 to around 8K with a lot of development work.

It would be cheaper to install an S54, though.

[Wanganstyle]

Can go 8,888rpm stock with this one for short bursts if desired.

The s54 cylinder head copies ducati's famous desimonic in a form for the bucketless springs. Small rocker arm like a Honda vtech actuallates the camshaft; this saves weight and allows extreme stability on top end.

Head makes the power, throttles can injest more air also, cams and valvetrain is setup for top end.
No port nessacary; stock cams are incredibly aggressive. Crazy duration, crazy lift.

This motor is one attitude below 6,000 where the dual vanos is making torque happen via retardation of the Oem lumpy cams

From 6,000-8,000+ it is a complete different animal screaming and howling till you shift.

Velocity on top end acceleration is extreme with insane engine rpm's

You'll blow up an e36 euro motor faster at top end compared to s54 also; it's designed stouter; newer; smarter; better.

Last of the high rpm NA power 6cyl's

[LJ851]

The s54 cylinder head copies ducati's famous desimonic in a form for the bucketless springs.

Thats a bit of a reach, there. Yes Ducati opens the valve with a cam on a rocker over the valve, but lots of motorcycles are done that way, also F1 cars, etc. Desmodromic valve actuation is unique because of the way the valve is closed, not opened .

Most likely the main problem of revving to 10k is the crank. Inline 6 cranks in an engine of decent capacity (stroke) just don't want to stay in one piece. The only ones that will spin that high (or higher) are pretty small engines.