ATI Harmonic Crank Balancer - Want to safely rev your S52 to 8k?

[Smitherines]

Please tell us WHAT OTHER POTENTIAL BENEFITS ARE THERE BESIDES POWER NUMBERS? Stretching a gear out an additional 200rpm sure, but an additional 800-1000rpm is foolish when you could upshift back into the torque band.

S50b32's make peak power at their permissable constant speed aka soft redline (~275whp@7400rpm). BMW set the max permissable rpm to 7600 when it starts shutting everything down. And this is a motor that was built to rev...

S52's have inferior airflow angles/patterns compared to the Euro (Chime in here Alex Lipowich, Mike Akard, Chuck Stickley, Mike Mccoy, Dave Jasper?) and yet we see 260-270 @7000 out of cammed motors. Search the misshift threads - they start bending valves during brief visits to 7600+... how long do you think sustained trips there would last? Food for thought: The redline on an S62 is set to 7000 and that is a far more advanced motor that uses the same hydraulic lifters.

But I digress; here's some "proof" of FLOW for you.





You seriously think an S52 can keep up?

jworms- BFC as my witness, I'll give you $50 towards one of these dampers if you post a video revving your car to 8000rpm on the dyno. No strings attached.

Judging by your specs and pictures here jvit, someone needs to get flowbench numbers of a STOCK CLEAN (IE, no carbon build up, oil/crud deposits, etc) S52 head, then PROCEED to port match the exhaust ports on the head and exhaust manifold/headers, and see what the flowbench numbers report at that point. Small things make the biggest of differences without having to redesign a motor. Look how much room there is for improvement on the S52 head alone? Theres TONS of room for port matching.

The head on the S52 sucks no doubt, we should have gotten the S50B32, but we didn't because BMW was hesitant to do such a thing because they were concerned with the additional costs, hence raising the purchase price of the E36 M3.

One of the biggest issues facing the BMW crowd is the price of parts and availability. I had a DSM before this, and you could pick heads up for 200 bucks, and there were tons of them. People were porting their heads and exhaust manifolds, and O2 sensor housing at home on their living room table, true story. 99.9% of people here do not want to Guinea pig their S5x head for the sake of knowledge. What needs to be done is people collecting TRASHED S5x heads, ones where there are cracks in the combustion camber, or on the head, and use those, since at that point they're useless, and can contribute something to science, much like how the bodies of drunks who get in accidents should be used.

After finding the optimal port size, shape, and other tidbits of the exhaust ports, then attention could them be turned to the intake ports, and then the cams. You'd be surprised how much power could be unlocked in the most simple of things.

Leave 8K RPM redlines on a motor that wasn't designed for it for another day after the we, the "BMW scene" has exploited all the information and through trial and error figured out the stock motor.

If you want to go fast, go FI, that's my plan. If I want to rev the piss out of my motor, I'll get an E46 M3 or a Z4 ///M variant.

EDIT: 2d port area for S52 is 1.6275"^2. 2d port area for S50B32 is 3.85"^2. That's means that the S52 head is 42.27% of the 2D area that the S50B32 is. That's CRAZY! The S52 head needs work!

2nd EDIT: It APPEARS that the S52 exhaust ports can be ported .25" out in either direction. That would make for the LxW measurements to be 2.05" x 1.55". The total 2D area of just that would achieve a nice opened port of 3.1775"^2. That's a big increase. That would make it 83.18% of the total 2D area of the S50B32 port. Notice that the S52 ports are oval, and the S50B32 exhaust ports are rectangular with rounded edges. Porting the US S52 head out in the same fashion should get you REAL close to the S50B32 port sizes. Now you'd have to shape the exhaust manifold/headers accordingly.


BTW: EDIT 3: M52 and S52 heads are the same. We could use trashed head from both cars.

[jworms]

ugh, you failed to acknowledge what has already been said in this thread so many times in your post.

i'll keep my responses brief; i'm not doing the legwork for you on this one.

Please tell us WHAT OTHER POTENTIAL BENEFITS ARE THERE BESIDES POWER NUMBERS? Stretching a gear out an additional 200rpm sure, but an additional 800-1000rpm is foolish when you could upshift back into the torque band.

8000RPM would be great with additional work to the motor, but how about safely revving to 7400RPM on an off-the-shelf modded car (mentioned multiple times in this thread)?
no matter how naive you pretend to be, there are other, non-power related benefits to revving these engines higher safely.

S50b32's make peak power at their permissable constant speed aka soft redline (~275whp@7400rpm). BMW set the max permissable rpm to 7600 when it starts shutting everything down. And this is a motor that was built to rev...

a brief search for dyno charts of S50B32 engines shows they are more than capable of making power up to and beyond 8000RPM with not much work. as said numerous times in this thread, we're not talking about throwing this on a stock S52 and saying it will make power.

S52's have inferior airflow angles/patterns compared to the Euro (Chime in here Alex Lipowich, Mike Akard, Chuck Stickley, Mike Mccoy, Dave Jasper?) and yet we see 260-270 @7000 out of cammed motors. Search the misshift threads - they start bending valves during brief visits to 7600+... how long do you think sustained trips there would last? Food for thought: The redline on an S62 is set to 7000 and that is a far more advanced motor that uses the same hydraulic lifters.

in this thread it has already been proven that the hydraulic lifters can rev that high though the springs might need to be replaced to sustain anything beyond 7500RPM. again, all documented in this thread. search buddy.

But I digress; here's some "proof" of FLOW for you.





You seriously think an S52 can keep up?

what exactly does this prove? ...nothing.

another worthless post filled with straw man arguments just like you've been doing throughout this entire thread.

jworms- BFC as my witness, I'll give you $50 towards one of these dampers if you post a video revving your car to 8000rpm on the dyno. No strings attached.

it may happen one day. it might not even be me. only time will tell.

[Smitherines]

ugh, you failed to acknowledge what has already been said in this thread so many times in your post.

i'll keep my responses brief; i'm not doing the legwork for you on this one.


8000RPM would be great with additional work to the motor, but how about safely revving to 7400RPM on an off-the-shelf modded car (mentioned multiple times in this thread)?
no matter how naive you pretend to be, there are other, non-power related benefits to revving these engines higher safely.


a brief search for dyno charts of S50B32 engines shows they are more than capable of making power up to and beyond 8000RPM with not much work. as said numerous times in this thread, we're not talking about throwing this on a stock S52 and saying it will make power.


in this thread it has already been proven that the hydraulic lifters can rev that high though the springs might need to be replaced to sustain anything beyond 7500RPM. again, all documented in this thread. search buddy.


what exactly does this prove? ...nothing.

another worthless post filled with straw man arguments just like you've been doing throughout this entire thread.


it may happen one day. it might not even be me. only time will tell.

jworms, with all due respect, those pictures said a lot. It shows you exactly why the S50B32 has the capability to use the extra 1000ish RPM that it has over the S52. His plight is that there is no point in revving the motor past it's 7000RPM redline if there's nothing to gain. Reference my post above.

The fact that the S52 exhaust ports are 52% smaller than the S50B32 ports is a HUGE issue. The S52 has 75% of the power that the S50B32 has. Theres a lot more to it than redline.

[jworms]

jworms, with all due respect, those pictures said a lot. It shows you exactly why the S50B32 has the capability to use the extra 1000ish RPM that it has over the S52. His plight is that there is no point in revving the motor past it's 7000RPM redline if there's nothing to gain. Reference my post above.

The fact that the S52 exhaust ports are 52% smaller than the S50B32 ports is a HUGE issue. The S52 has 75% of the power that the S50B32 has. Theres a lot more to it than redline.

of course it means something, but not to the topic at hand. like i mentioned, the S50B32 engine has been known to make power all the way to 8000RPM and beyond with supporting mods. if the S50B32 engine can do that who is to say that the S52 couldn't at least benefit from a 7500RPM redline? see my point?

you simply cannot compare the stock rev limitations of the S50B32 to the S52 and expect to get anything of relevance. if for no other reason, because the S50B32 engine has so much more to offer and its stock power curve does not show its max potential with higher revs. if anything, you would need to look at where the S50B32 tops out at and try to string together some proportional comparison with the S52 based on that...but that's really reaching.

it comes down to the fact that they are two completely separate engines. comparing them like jvit is trying to do without any relevant numbers on flow vs RPM power output is not going to bring any conclusive evidence to this discussion.

yes, the flow of the engine is definitely relevant, but it's a shot in the dark without proper math to show the max capabilities based on those figures.

[jvit27]

2nd EDIT: It APPEARS that the S52 exhaust ports can be ported .25" out in either direction. That would make for the LxW measurements to be 2.05" x 1.55". The total 2D area of just that would achieve a nice opened port of 3.1775"^2. That's a big increase. That would make it 83.18% of the total 2D area of the S50B32 port. Notice that the S52 ports are oval, and the S50B32 exhaust ports are rectangular with rounded edges. Porting the US S52 head out in the same fashion should get you REAL close to the S50B32 port sizes. Now you'd have to shape the exhaust manifold/headers accordingly.

That doesn't account for the different port angles on the intake side though. The flow patterns of an S52 are nowhere near as good as the S50b32(which is quite inferior to the S54!) but you are right, they would certainly help.

ugh, you failed to acknowledge what has already been said in this thread so many times in your post.

No, you just don't like what I have to say because it doesn't supplement YOUR agenda. I've addressed everything that has been brought up without calling you a hopeless troll yet. That includes real world experience and the names of respected guys you can go ask yourself, who will probably echo what i've said in the 12(!!!) posts i've contributed to this thread.

8000RPM would be great with additional work to the motor, but how about safely revving to 7400RPM on an off-the-shelf modded car (mentioned multiple times in this thread)?
no matter how naive you pretend to be, there are other, non-power related benefits to revving these engines higher safely.

I've asked you multiple times to name these benefits but you just sound like Matthew Lesko or Dean Graziosi who will share the secret if you buy their books. What are they? Let's hear why it's good to rev your motor that high if it's not making power Jonathan...

a brief search for dyno charts of S50B32 engines shows they are more than capable of making power up to and beyond 8000RPM with not much work. as said numerous times in this thread, we're not talking about throwing this on a stock S52 and saying it will make power.

Proof you didn't make that up on the spot? S50b32's can make about 300whp with some breather mods. Anything beyond that is past the law of diminishing returns. Revving them past is 8000 is futile. I've seen them run to 8800 with no gain. And yes, I would know. I had a GrpN S50b32 built by Stickley himself and have spent many hours speaking with him and Alex Lipowich. S50b32's are very efficient in stock form. BMW didn't leave a whole lot on the table when Munich tried to build a better 6cyl than Stuttgart.

FYI most S54 race motors are only revved to 8200-8400, with the exception of Grand Am spec stuff going to 9000 ($40k motors).

in this thread it has already been proven that the hydraulic lifters can rev that high though the springs might need to be replaced to sustain anything beyond 7500RPM. again, all documented in this thread. search buddy.

LOL where? I read it twice. Just one guy saying it can be done, and another saying maybe. Search yourself.

what exactly does this prove? ...nothing.

another worthless post filled with straw man arguments just like you've been doing throughout this entire thread.


it may happen one day. it might not even be me. only time will tell.

Actually the pictures just go to show that you're within 15whp of an S50b32 at 7000 with half the flow. Revving to 7600 is not going to close that gap and provide 20whp like you claim (see post 75).

The only thing worthless is this thread. You refuse anything but the truth and you've dismissed everything I said. You won't even take free money to prove your fallacy so I tell you what Worms, i'll give you the only answer you're willing to hear... Sure you can rev an S52 to 8000rpm, make 300whp, and it'll last for 150k miles.

Please give Santa and the Easter Bunny my regards.

[Inicent Child]

Personal experience: my buddy's s50 revved to 8k more than ones with stock internals in-front of my face.

Can it be done reliably? Yes.

Is there a point? It was making flat power past 7k and even less getting closer to 8k. The gear that followed did feel pretty good since it was back in peak power-band but still I would say its pointless. The car was faster when shifted at 7.2k than it was shifted at 8k.

That is where this whole fread fails. Want max out of your s52? get evosport cams and about every other bolt on possible and you will be flirting with 300whp with a rev limit of 7.2-4k rpms. That is your peak, anything more will pull you downhill, revving to 8k especially will not help you. Driver mod to help you utilize that sort of power-band at that point would be a better idea.

[bay707]

That is where this whole fread fails.

The whole bread sails?

[V8EATR]

Ive never heard of the bottom end not able to handle 8k rpm on an s52, has anyone else?

[jworms]

I've asked you multiple times to name these benefits but you just sound like Matthew Lesko or Dean Graziosi who will share the secret if you buy their books. What are they? Let's hear why it's good to rev your motor that high if it's not making power Jonathan...

one example, given multiple times in this thread, is to keep the gear longer so one doesn't have to waste time in shifting. this would be especially nice in tracks (straight line or curvy) where having that last bit of gear would be beneficial. why do you think car manufacturers typically set their factory redline after power has already started dropping? cmon man, this is simple stuff here.

that one response was to humor you. talk about feeding the troll.

look up all the responses in this thread on the topic (hell, look outside the BMW community even) and you'll find more answers to your question.

Proof you didn't make that up on the spot? S50b32's can make about 300whp with some breather mods. Anything beyond that is past the law of diminishing returns. Revving them past is 8000 is futile. I've seen them run to 8800 with no gain. And yes, I would know. I had a GrpN S50b32 built by Stickley himself and have spent many hours speaking with him and Alex Lipowich. S50b32's are very efficient in stock form. BMW didn't leave a whole lot on the table when Munich tried to build a better 6cyl than Stuttgart.

FYI most S54 race motors are only revved to 8200-8400, with the exception of Grand Am spec stuff going to 9000 ($40k motors).

and what of the S50B30? are the ports on those engines just as big as the S50B32? take a look at this:

here is an S50B32 that has original computer reflashed with custom tune, also has custom exhaust (still with cats) and CAI, still makes power right up top
multiply KW by 1.34 to get hp ( then add 12% for dynojet number, but not important for this exercise)




and my S50B30 before carbon airbox and alpha n (will have to go back again soon and see what I am making now) car had chip, alloy flywheel, custom exhaust and CAI, max power at 7800rpm

according to your logic the s50b30 head, with its smaller intake/exhaust ports, shouldn't be able to do that. bigger ports means more RPM in your world, right? now do you see why you can't just say the size of the ports dictates power@RPM max? there's a lot more to it than that and i have a feeling you don't have the qualifications to get the flow details to prove anything you're trying to say. prove me wrong.

LOL where? I read it twice. Just one guy saying it can be done, and another saying maybe. Search yourself.

yes, one guy proves it can be done...because he did it. end of story. there is no refuting this. paypal that guy $50 if you want to offer a similar challenge to him as you did me.

Actually the pictures just go to show that you're within 15whp of an S50b32 at 7000 with half the flow. Revving to 7600 is not going to close that gap and provide 20whp like you claim (see post 75).

The only thing worthless is this thread. You refuse anything but the truth and you've dismissed everything I said. You won't even take free money to prove your fallacy so I tell you what Worms, i'll give you the only answer you're willing to hear... Sure you can rev an S52 to 8000rpm, make 300whp, and it'll last for 150k miles.

Please give Santa and the Easter Bunny my regards.

revving to 7600RPM alone may not provide 20rwhp initially, but show me where you provided evidence that additional tuning wouldn't be able to take advantage of the new rev range. oh right, you haven't and most likely can't.

Personal experience: my buddy's s50 revved to 8k more than ones with stock internals in-front of my face.

Can it be done reliably? Yes.

Is there a point? It was making flat power past 7k and even less getting closer to 8k. The gear that followed did feel pretty good since it was back in peak power-band but still I would say its pointless. The car was faster when shifted at 7.2k than it was shifted at 8k.

That is where this whole fread fails. Want max out of your s52? get evosport cams and about every other bolt on possible and you will be flirting with 300whp with a rev limit of 7.2-4k rpms. That is your peak, anything more will pull you downhill, revving to 8k especially will not help you. Driver mod to help you utilize that sort of power-band at that point would be a better idea.

definitely interested in your buddy's setup. that might shut a lot of the nay-sayers up (wishful thinking).

i have no doubt that, without 8000RPM specific mods, the car will be faster shifting at ~7200RPM. these cars weren't meant to make power that high and to do so would require quite a bit of work if it's possible at all.

[pbonsalb]

If you want to dump some money into the S52 head, try Bavarian Solutions. Always best to use a shop that has done some rather than to be the tester for the first time. Each successive port job is usually an improvement over the last one. I am sure the S52 can be improved significantly with bigger valves and a full port job. I don't know, but I tend to doubt that a $3000 fully worked S52 head will equal a stock Euro head. Maybe if fitted with radical cams versus stock cams in the Euro head. Would be interesting. I wanted torque, so I went with boost and only light porting on the head plus a multi angle valve job.

[336motorsports]

I dont have a whole lot to add, and I dont wanna get too mixed up in this but Im all about trying to max out an s52, I have 10k grand into mine and with the sunbelts and just about every bolt on money can buy. Im pretty close to being maxed out. I damn well better be in the 265-275 rwhp range or Ill be an unhappy camper. I dont want an s50b32 for obvious reasons. (parts and availability being a few)

As far as the topic at hand, (keeping an open mind about it) if we were to run these engine's to speeds of say 7800-8000k RPM, I would think that would be the start of possible modification paths.

Maybe some WILD cams can be designed to make power that high, maybe dbilas intakes will help (doubt out), as said, costume tunes and so on and so on.

I mean, I will admit, its pretty far fetched, but I just wanna keep an open mind about it.

I also wanna see the 2 of you guys continue to discuss this like adults and keep this fairly civil. You both provide alot to the community.

[jworms]

I dont have a whole lot to add, and I dont wanna get too mixed up in this but Im all about trying to max out an s52, I have 10k grand into mine and with the sunbelts and just about every bolt on money can buy. Im pretty close to being maxed out. I damn well better be in the 265-275 rwhp range or Ill be an unhappy camper. I dont want an s50b32 for obvious reasons. (parts and availability being a few)

As far as the topic at hand, (keeping an open mind about it) if we were to run these engine's to speeds of say 7800-8000k RPM, I would think that would be the start of possible modification paths.

Maybe some WILD cams can be designed to make power that high, maybe dbilas intakes will help (doubt out), as said, costume tunes and so on and so on.

I mean, I will admit, its pretty far fetched, but I just wanna keep an open mind about it.

I also wanna see the 2 of you guys continue to discuss this like adults and keep this fairly civil. You both provide alot to the community.

yes!

i think that a lot of people coming into this thread only look at what is currently out there for these engines. they are not considering that this could open up a slew of new aftermarket solutions designed with the new rev range in mind.

[jvit27]

one example, given multiple times in this thread, is to keep the gear longer so one doesn't have to waste time in shifting. this would be especially nice in tracks (straight line or curvy) where having that last bit of gear would be beneficial. why do you think car manufacturers typically set their factory redline after power has already started dropping? cmon man, this is simple stuff here.

As a racer myself, I'm far more familiar with gearing than you think.

And I already addressed this point in post #199, but you conveniently ignored it: "Stretching a gear out an additional 200rpm sure, but an additional 800-1000rpm is foolish when you could upshift back into the torque band."

according to your logic the s50b30 head, with its smaller intake/exhaust ports, shouldn't be able to do that. bigger ports means more RPM in your world, right? now do you see why you can't just say the size of the ports dictates power@RPM max? there's a lot more to it than that and i have a feeling you don't have the qualifications to get the flow details to prove anything you're trying to say. prove me wrong.

Here you go. A modified S50b30 (GT!) being revved to 8800 still gets walked by a standard 7600rpm S50b32
[ame]http://www.youtube.com/watch?v=-p1TfAl3gnQ[/ame]

revving to 7600RPM alone may not provide 20rwhp initially, but show me where you provided evidence that additional tuning wouldn't be able to take advantage of the new rev range. oh right, you haven't and most likely can't.

No tuner can program more air flow. An engine is still an air pump and it's power comes from the design of the head. cmon man, this is simple stuff here.

You yourself are a big proponent for the M50 manifold and have said many times, it shifts the powerband to the right. It's no different with these mods; You may be able to find a way to rev an S52 higher but you're still neglecting how anemic it will feel under 5000rpm. Fortunately, BMW answered these questions and did the legwork for us. Instead of reinventing the wheel, just setup a tv and couch at 8000rpm and hang out with an S54 all day.

You cannot realistically expect a 20 year old design for an entry level motor to be able to do everything by modern standards.

[jworms]

As a racer myself, I'm far more familiar with gearing than you think.

And I already addressed this point in post #199, but you conveniently ignored it: "Stretching a gear out an additional 200rpm sure, but an additional 800-1000rpm is foolish when you could upshift back into the torque band."

you're loosening your grip
i know you know this stuff. that's why it seems silly for me to constantly repeat it and it's precisely why i get the troll mentality from you. anyway, back on topic...

so, you agree that an additional 200RPM would be beneficial. maybe something like the 7400RPM sunbelt originally set their cams to run to, but found that the crank harmonics didn't allow it to? ...something where this harmonics balancer could come in handy

i mentioned in this thread before that this would be a stepping stone process. i think 7400/7500RPM would be a logical first step (a mere 200-300RPM increase over current limitations) and based on the findings there we could venture further. if the head becomes a limiting factor after the first stepping stone then at least we can walk away with the ability to rev to 7500RPM without worrying about the block rattling apart.

Here you go. A modified S50b30 (GT!) being revved to 8800 still gets walked by a standard 7600rpm S50b32
http://www.youtube.com/watch?v=-p1TfAl3gnQ

that video shows nothing. it doesn't prove that the S52 cannot make power at a higher RPM and definitely doesn't prove that the benefits are still there for revving an S52 higher. i have little interest in improving the S50B3X platform. start another thread on that if you want to explore that. cool video though

No tuner can program more air flow. An engine is still an air pump and it's power comes from the design of the head. cmon man, this is simple stuff here.

You yourself are a big proponent for the M50 manifold and have said many times, it shifts the powerband to the right. It's no different with these mods; You may be able to find a way to rev an S52 higher but you're still neglecting how anemic it will feel under 5000rpm. Fortunately, BMW answered these questions and did the legwork for us. Instead of reinventing the wheel, just setup a tv and couch at 8000rpm and hang out with an S54 all day.

You cannot realistically expect a 20 year old design for an entry level motor to be able to do everything by modern standards.

well, i think that puts another nail in the coffin.

you use the m50 intake manifold as an example, saying it moves the torque curve to the right. then you go on to say that "You may be able to find a way to rev an S52 higher but you're still neglecting how anemic it will feel under 5000rpm." which means you aren't ruling out the fact that revving higher could produce more "m50 intake manifold like mods" that would merely move the torque curve to the right more.

will there most likely be a "torque loss" down low? yep, most likely...but will there also be a potentially huge gain in higher RPM HP similar to what our beloved m50 intake manifold does? yep, you betcha.

[SG_M3]

jworms, so why haven't you done this? You champion it so much, put your idea into action. Lets see you run a motor to 8k, repeatedly, without issue. If you can't, then I would suggest going with the knowledge you have been presented with, until you can prove otherwise.

[jworms]

jworms, so why haven't you done this? You champion it so much, put your idea into action. Lets see you run a motor to 8k, repeatedly, without issue. If you can't, then I would suggest going with the knowledge you have been presented with, until you can prove otherwise.

i would love to. unfortunately, i don't have the time/resources to do it now, but that shouldn't detract anything from this thread. the point of this thread was merely to provide information to the community on an issue that has plagued these motors for some time now.

[jvit27]

so, you agree that an additional 200RPM would be beneficial. maybe something like the 7400RPM sunbelt originally set their cams to run to, but found that the crank harmonics didn't allow it to? ...something where this harmonics balancer could come in handy

i mentioned in this thread before that this would be a stepping stone process. i think 7400/7500RPM would be a logical first step (a mere 200-300RPM increase over current limitations) and based on the findings there we could venture further. if the head becomes a limiting factor after the first stepping stone then at least we can walk away with the ability to rev to 7500RPM without worrying about the block rattling apart.

Nah. I was referring to the additional RPM's tuners bump up from the stock 6800/6500 redline. 7000-7200 is plenty, and that was actually pretty high for it's time.

This 'process' is blinding you. There's no point in spending years and thousands of dollars to create the engine you want because BMW already built it. It has part numbers. It exists. And you'll spend 10x as much as what you could drop one in for.

that video shows nothing. it doesn't prove that the S52 cannot make power at a higher RPM and definitely doesn't prove that the benefits are still there for revving an S52 higher. i have little interest in improving the S50B3X platform. start another thread on that if you want to explore that. cool video though

It DOES prove a modded S52 cannot make power if the S50b30 cannot. It's pretty safe to compare the two motors since they have very similar output.

You're watching it get beat by 275whp.

well, i think that puts another nail in the coffin.

you use the m50 intake manifold as an example, saying it moves the torque curve to the right. then you go on to say that "You may be able to find a way to rev an S52 higher but you're still neglecting how anemic it will feel under 5000rpm." which means you aren't ruling out the fact that revving higher could produce more "m50 intake manifold like mods" that would merely move the torque curve to the right more.

will there most likely be a "torque loss" down low? yep, most likely...but will there also be a potentially huge gain in higher RPM HP similar to what our beloved m50 intake manifold does? yep, you betcha.

There's no huge gain left to be had dude. All you're doing is giving up driveability... talk to any club racer (like the one who just posted) and they'll tell you the best S52's only made 300whp with 40hr lifespans. An S54 with a tune and headers makes that AND has a super flat torque curve.

[pbonsalb]

I think it is a good point that the higher rpm shifts the torque curve higher up. You simply cannot have your cake and eat it too, in that if you get another 1000 rpm out of the S52, it comes at the cost of bottom end power. Look at the S54 -- nice up top, weak down low. Same goes for the S65 V8 in the newer M3, though it has 4.0L displacement instead of 3.2L and the resulting extra torque helps offset some of the extra pork weighing down the car. Both need aggressive gearing to make them accelerate nicely.

Maybe the S52 is really a pretty good daily driver motor with more mild mods and 7200 rpm. I think so. The Sunbelts put a hole in the torque curve down low, right where you daily drive. The Eurotuner project M3 with Sunbelts plugged part of the hole with shorty headers that still added a few hp up top (though not as much as long tubes that would have left the hole down low). I am a daily driver kind of person, not a drag racer, but like to have some power when I want it, so my needs may differ. I'd take a centrifugal or turbo (have done both on an S52) before a Euro or S54 swap. To me that is closer to having my cake and eating it too.

[jworms]

Nah. I was referring to the additional RPM's tuners bump up from the stock 6800/6500 redline. 7000-7200 is plenty, and that was actually pretty high for it's time.

This 'process' is blinding you. There's no point in spending years and thousands of dollars to create the engine you want because BMW already built it. It has part numbers. It exists. And you'll spend 10x as much as what you could drop one in for.

you're too stuck on the numbers and comparing engines that have no place being compared. for the last time, nobody in here is interested in swapping an S54 into their car. assume that somebody reading this thread is hell bent on expanding on the S52 platform.

also, provide your source on why it would be 10x as much as an S54 swap. if you actually have something concrete to back that up then share the information/data points you have. i'll save you the trouble: you don't, or this thread could have ended a while ago with your experience in spinning an S52 higher with this damper, etc and what process you went through to get there.

It DOES prove a modded S52 cannot make power if the S50b30 cannot. It's pretty safe to compare the two motors since they have very similar output.

You're watching it get beat by 275whp.

how exactly does an S50b30 engine spinning to 8800RPM (obviously without being tuned for it) getting beat by a stock S50B32 engine have ANY relevance to what an S52 can do?

i already posted a graph of an S50B30 revving to 8000RPM and making power all the way up there. using your logic, i might as well say that because this S50b30 example could make power at 8000RPM this "somehow" proves that the S52 can make power all the way up to 7500RPM. see how that makes ZERO sense?

you're going to need to further explain how that is all somehow connected to an S52 revving to 7500RPM (i'm sticking to 7500RPM for now because you are keen on saying that won't benefit the S52 either and that's easier to disprove for now).

There's no huge gain left to be had dude. All you're doing is giving up driveability... talk to any club racer (like the one who just posted) and they'll tell you the best S52's only made 300whp with 40hr lifespans. An S54 with a tune and headers makes that AND has a super flat torque curve.

so what about the S54? that logic is no good here. the people interested in this thread are not interested "why not swap XX engine in instead?". please give it a rest.

I think it is a good point that the higher rpm shifts the torque curve higher up. You simply cannot have your cake and eat it too, in that if you get another 1000 rpm out of the S52, it comes at the cost of bottom end power. Look at the S54 -- nice up top, weak down low. Same goes for the S65 V8 in the newer M3, though it has 4.0L displacement instead of 3.2L and the resulting extra torque helps offset some of the extra pork weighing down the car. Both need aggressive gearing to make them accelerate nicely.

Maybe the S52 is really a pretty good daily driver motor with more mild mods and 7200 rpm. I think so. The Sunbelts put a hole in the torque curve down low, right where you daily drive. The Eurotuner project M3 with Sunbelts plugged part of the hole with shorty headers that still added a few hp up top (though not as much as long tubes that would have left the hole down low). I am a daily driver kind of person, not a drag racer, but like to have some power when I want it, so my needs may differ. I'd take a centrifugal or turbo (have done both on an S52) before a Euro or S54 swap. To me that is closer to having my cake and eating it too.

i hear ya. this thread's ideas aren't going to work for everyone's wants/needs. but at least there's more information here for those who want that performance path.

[Smitherines]

Upon further research, the S54 has a bore x stroke travel of 87mm x 91mm, 4mm out of being a square engine. The S52 is 86.4 x 89.6, which makes it 3.2mm out from being a square engine.

The question at this point, is what prevents the rotating assembly from spinning that high? Even a more conservative 7500rpm should be what the sights are set upon. Is it the crankshaft material? The counterbalances? Is the crank too heavy? Is it perfectly balanced? Is it a lubrication system insufficiency? Is it the harmonics balancer? Bearing material? How about a forged rods and piston setup balanced with the crank? Would that make it better?

How about using M52s for research rather than more expensive S52s? Make some groundbreaking discoveries with that before someone goes dicing and slicing into a S52 for "research purposes". Throw the ATI dampener on an guinea pig M52 and see what happens. If it can handle it, then move on to the next question.

The test subject should have a high flow oil pump, new OEM rod and main bearings, fresh rings and a perfectly honed cylinder wall, and a perfectly balanced rotating assembly along with that ATI product. Run that, 7000rpm for a set amount of time, slowly increase it to 7500rpm, and hold there for a bit, then shut down. Pull the engine apart, check the bearings and cylinder walls, then gather info and go from there.

Until something like this happens, there will be no progress made with this ideology that this ATI dampener will be able to take the M52/S52 to a safe raised rev limit. Merely throwing words and ideas back and forth at each other isn't going to prove or make any progress with anything. You'll need a sponsor for such research unless one of you has deep pockets. It would be safe to say that Turner, bimmerworld, sunbelt, etc do not have any interest on pushing an S52 beyond it's limits anymore, it's an old design with a decreasing number of enthusiasts. Their minds and resources are focused on the S54 and the new M3.

The next question is if the S52 could be revved to 7500, how long will it last there.

[jworms]

Upon further research, the S54 has a bore x stroke travel of 87mm x 91mm, 4mm out of being a square engine. The S52 is 86.4 x 89.6, which makes it 3.2mm out from being a square engine.

The question at this point, is what prevents the rotating assembly from spinning that high? Even a more conservative 7500rpm should be what the sights are set upon. Is it the crankshaft material? The counterbalances? Is the crank too heavy? Is it perfectly balanced? Is it a lubrication system insufficiency? Is it the harmonics balancer? Bearing material? How about a forged rods and piston setup balanced with the crank? Would that make it better?

How about using M52s for research rather than more expensive S52s? Make some groundbreaking discoveries with that before someone goes dicing and slicing into a S52 for "research purposes". Throw the ATI dampener on an guinea pig M52 and see what happens. If it can handle it, then move on to the next question.

The test subject should have a high flow oil pump, new OEM rod and main bearings, fresh rings and a perfectly honed cylinder wall, and a perfectly balanced rotating assembly along with that ATI product. Run that, 7000rpm for a set amount of time, slowly increase it to 7500rpm, and hold there for a bit, then shut down. Pull the engine apart, check the bearings and cylinder walls, then gather info and go from there.

Until something like this happens, there will be no progress made with this ideology that this ATI dampener will be able to take the M52/S52 to a safe raised rev limit. Merely throwing words and ideas back and forth at each other isn't going to prove or make any progress with anything. You'll need a sponsor for such research unless one of you has deep pockets. It would be safe to say that Turner, bimmerworld, sunbelt, etc do not have any interest on pushing an S52 beyond it's limits anymore, it's an old design with a decreasing number of enthusiasts. Their minds and resources are focused on the S54 and the new M3.

The next question is if the S52 could be revved to 7500, how long will it last there.

GREAT post! a breathe of fresh air in this thread!

using an M52 wouldn't help in this because it has a different crank than the S52 ( list of engines with the same crank as S52: http://realoem.com/bmw/partxref.do?p...=on&showeur=on ). the whole reason i got the idea for this thread is from another build thread with a 330ci where the owner revved his motor to 8000RPM with the same crank design as the S52 that was previously known to be the show stopper for the E36 M3's revving ability.

the theory is that the harmonics of the crank rattle things apart when revved higher than 7200RPM over time.

totally agree that 7500RPM would be the first goal with this balancer. 7500RPM is also the point where we know the stock head can probably handle it ok without modification...making the entire cost of revving to 7500RPM an inexpensive ~$500 mod.

[sirius815]

@smitherines - perfect way to put it.

@jworms - If the M52 is going to be put through the abuse - and because it needs to be cleaned up before it's spun to 7500rpm, taking the s52 crankshaft from a different source *shouldn't* be much of a problem, since they are relatively abundant according to realoem. Not trying to argue one way or another.

Carry on...

[Serious]

Will someone please just blow up a motor so this thread will die and we can all go our seperate ways.

[Smitherines]

GREAT post! a breathe of fresh air in this thread!

using an M52 wouldn't help in this because it has a different crank than the S52 ( list of engines with the same crank as S52: http://realoem.com/bmw/partxref.do?p...=on&showeur=on ). the whole reason i got the idea for this thread is from another build thread with a 330ci where the owner revved his motor to 8000RPM with the same crank design as the S52 that was previously known to be the show stopper for the E36 M3's revving ability.

the theory is that the harmonics of the crank rattle things apart when revved higher than 7200RPM over time.

totally agree that 7500RPM would be the first goal with this balancer. 7500RPM is also the point where we know the stock head can probably handle it ok without modification...making the entire cost of revving to 7500RPM an inexpensive ~$500 mod.

jworms, perhaps you're missing my point. Remember, this whole thing rides on someone having an abundance of cash to perform such tests, especially on an S52 where good running engines are going for 3-4k. M52s could be had for <1000 bucks, so if someone would use those to at least bring some news to the table, some great findings, some inspiring ideas to at least break the ground on a cheaper engine, things could progress from there, and it would make testing the S52 have a purpose without wasting money. You'd at least spark some big things in the M52 world if you were able to make some interesting discoveries.

The E46 330s use the same crank, but with a smaller bore to keep their displacement at 3 litres. So it makes a lot more sense that they can rev higher, without as many negative effects if any at all.

@smitherines - perfect way to put it.

@jworms - If the M52 is going to be put through the abuse - and because it needs to be cleaned up before it's spun to 7500rpm, taking the s52 crankshaft from a different source *shouldn't* be much of a problem, since they are relatively abundant according to realoem. Not trying to argue one way or another.

I think the main point is trying to spin a BMW past it's intended maximum RPM safely with this ATI product. If it can be done with an M52, there should be some success to an extent with an S52, maybe not as high as a spinner, but an improvement none the less.

Will someone please just blow up a motor so this thread will die and we can all go our seperate ways.

Judging by your garage, you shouldn't be in this forum anyways, and I'm sure theres tons of other threads, especially in the M3 section, M Coupe section, as well as the regular E36 section that you could be trolling. Out of all the threads on this forum, this is probably one of the more productive ones. Thank you. Nice car by the way, I really like those. That's what I'd like to pick up next.

[SG_M3]

jworms keeps referring to this magic M54. As far as I've seen, its one guy who's total running time was less than a couple of hours. No one really proved its safe for the m54 to go to 8,000 rpm, IMO. This motor also has a built oil pump, a known weakness in the M54.

Most Grand Am teams that were running M54's, not allowed to change the balancer, kept them to 6500. The z4 team I worked with did this.

FWIW, here is my M52 that is currently in my race car. Rev limit is set to 7400 rpm

Sunbelt sport cams
KK header
3" exhaust
BW intake
BW intake boot
3.5 hfm
Epic chip



You can see the curves flatten up top, what benefit is there to turning this motor to 7400 rpm?