Shops making money off an upsell with no real benefit is what comes to mind
N54 head work
- Thread starter fmorelli
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Shops making money off an upsell with no real benefit is what comes to mind
Yeah, I'm not too sure on that either lol. I suppose it could fall under a "preventative mod" or "future maintenance" if you plan on installing cams eventually, but otherwise that seems silly to me.
@Rob09msport in regards to your most recent inquiry, I would say ported head and low lift cams will be more beneficial than the other options all day every day. IMO if you're looking at it from solely a peak HP perspective, the order would of "bang for buck" with a serious focus on cost would be:
1. ported head stock VT (assuming you have a drop-in head fully assembled and only are focusing on an increase in peak HP)
2. low lift cams/LL cams with upgraded springs
3. Ported head with LL cams
4. High lift cams with proper supporting mods (i.e. upgraded valvetrain both springs and valves, possibly having to replace pistons?)
5. Ported head w/ HL cams.
As I said before, I suspect due to the very nature of the cams and how the duration is actually higher on the LL cams than the HL while the lift difference is only .5mm, the LL cams will give you the most benefits across the range if you're looking for an "overall performance:cost" ratio. The LL cams dont require the head coming off at all, even with upgrading part of your valve train, but you'll still get the benefits of increased flow to your turbos across the power band and increasing your rev range by ~3-500 RPMs which can help a lot in many forms of racing. I would say that going the high lift cam route should be left for a fully built engine with ported head so you can rev out to 8K RPM and go crazy like @Hydra Performance due to needing to pull the head off either way and the costs associated with a fully new valvetrain and engine work.
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If the stock springs prevent valve float and you at keeping the stock rev limit I don't see why you would need to upgrade. That being said I am not an expert. I could think the reason most shops do it is because you are in there already and the cost to redo it would be prohibitive. How much more does the fully supertech springs add to the bottom line?
Can anyone confirm you can use the high lift with the stock pistons? I have read conflicting information. 1 place says you need custom pistons with reliefs for the valves, others say stock piston is fine.
Anyone know how the stock bottom end likes 8200rpm? It's only 1k more than stock so it's not that crazy to think you don't need a built motor to handle 8200rpms.
I would like to see a before and after dyno of a built head and cams and then adding an aftermarket intake manifold on to the head. Be interesting to see if the bang for your buck as the intake manifolds that actually work seem to go for roughly 2k.
Great thread, thanks for starting it @fmorelli as a new owner of a spare n54 head this is right up my alley.
If the stock springs prevent valve float and you at keeping the stock rev limit I don't see why you would need to upgrade. That being said I am not an expert. I could think the reason most shops do it is because you are in there already and the cost to redo it would be prohibitive. How much more does the fully supertech springs add to the bottom line?
Can anyone confirm you can use the high lift with the stock pistons? I have read conflicting information. 1 place says you need custom pistons with reliefs for the valves, others say stock piston is fine.
Anyone know how the stock bottom end likes 8200rpm? It's only 1k more than stock so it's not that crazy to think you don't need a built motor to handle 8200rpms.
I would like to see a before and after dyno of a built head and cams and then adding an aftermarket intake manifold on to the head. Be interesting to see if the bang for your buck as the intake manifolds that actually work seem to go for roughly 2k.
Great thread, thanks for starting it @fmorelli as a new owner of a spare n54 head this is right up my alley.
About $800
@Hydra Performance Omar can probably answer that, along with your question about bottom end RPM.
Filippo
I would imagine it has to do with valve float and higher cylinder pressures?
As far as only 1000rpm more...without doing any math, I would assume the piston speeds and therefore forces on the rotating assembly are noticeably higher when the revs are already pretty high.
As far as only 1000rpm more...without doing any math, I would assume the piston speeds and therefore forces on the rotating assembly are noticeably higher when the revs are already pretty high.
~13% increase from stock @ 7200rpm. I assume their is some headroom built in from BMW from the factory. I would be amazed if the stock head springs can't handle 7600rpm, for instance, and have zero valve float or other issues. That extra 1000rpms would be nice to have on hand.
Personally, I am surprised we have not seen more higher rev'ing N54s. But not many run stand alone so 8200 is the DME limit.
Like Fillipo said, upgraded beehive springs are "only" $800, Ferrea dual springs are ~$1000 if you can get them alone, and the full ferrea valvetrain (what you'd need for the HL cams) can be had for $2000 unless you opt for the titanium valves which I think are 100-200 more but "require regular inspections".
I believe the engine is hard-limited to 8K RPM max due to the DME, but I could be wrong. I just seem to remember Omar saying that's why hes revving to 8k instead of higher when his engine should be able to handle an extra couple hundred RPM as it stands.
Regarding the HL cams and pistons - I've heard 50/50 on if you need aftermarket pistons with valve reliefs, however everyone I've talked to who has them has aftermarket pistons anyway. The Motiv car runs the HL cams with stock-shaped pistons (and this is where I was told stock pistons would be okay), but an aftermarket forged version still so who knows if theres some slight difference still - they could be x MM shorter and thus allow just enough PTV clearance.
IMO at that point if you're dropping the money on a ported head (2k-4k depending on how and where plus core charge or not), HL cams at $1500, $2k+ worth of VT parts and you're going to be yanking the head off anyway (several hours of labor, which will be expensive and going that far in the engine isnt your typical N54 DIY-guy's specialty anyway), you might as well play it 100% safe and spend the extra thousand on aftermarket pistons, replace your head gasket and possibly convert to studs anyway. But that's just how I would do it if going that route, and like I've said before I'm pretty anal about getting everything done properly with the best parts for future-proofing and longevity's sake. That's why I wanted the LL version, especially since they would still be of good benefit to a fully built engine if something were to happen to the stock block and you decide to go all-in later. Like @fmorelli though, I wasnt planning on running everything at the ragged edge and was hoping to save some PSI and be rather "conservative" on the engine rather than go for a monster build.
I would assume there is some margin as well. I assume these springs are designed for "infinite life" as they probably don't expect the customer to ever have to replace them. However, I will say from direct experience recently at work with failed springs that spring design isn't an exact science so it's hard to say how much margin there really is. And if you ask the BMW engineer he won't give you an exact number either. The calculations to determine spring life gets you pretty close but there are assumptions that go along with it....frequency (engine speed), material, shot peening process, engine speed histogram, design factor of safety, etc. BMW would need to have tested the springs (installed in the head) to failure under different stresses (engine speeds) to develop an S-N curve in order to predict how long the springs will live....and that's still an estimate.
Increasing frequency (engine speed) too much and you start to get what's called spring surge which can quickly reduce spring life if the spring isn't designed for it.
Just some spring design knowledge in case anyone is interested
Yeah DME limit is like 8150 rpm or something, basically 8.2k. From everything I have read this is a firm hard limit and you have to get away from the stock DME, aka stand alone($$$), to rev higher. I believe the N54 is an under square design so we are never going to see 10k+. The extra 1000rpms would be nice on my single. 13% more rev range for each gear would be fun and I bet it sounds nice spinning that high.
A 'fully worked' n54 head and cams is going to be around 5k regardless of the vendor uninstalled I believe. Add an aftermarket intake manifold you are around 7k uninstalled. Sort of the thing to do when you have run out of other mods I guess as the bang for your buck is kind of shitty imo. I can buy an N54 car or a built motor for under 7k, to put that number into perspective.
A 'fully worked' n54 head and cams is going to be around 5k regardless of the vendor uninstalled I believe. Add an aftermarket intake manifold you are around 7k uninstalled. Sort of the thing to do when you have run out of other mods I guess as the bang for your buck is kind of shitty imo. I can buy an N54 car or a built motor for under 7k, to put that number into perspective.
The reason you see some peeps running upgraded valve springs on stock cams is because at higher boost (I'm sure these peeps have build engines too) it becomes easier for the valves to float/bounce at higher rpm. Still might as well spend a little more and get cams I say. I've said it before and I'll say it again, cams + head(work) on my specific setup were good for >20% more throughput, which is HUGE. I've said it before and I'll say it again, N53 > ported N54 and my results attest to this...
@Torgus,
HL cams are fine on a stock bottom end. That's what I'm running, and have been running for the past 9500km without issue. Xavier grenaded my 1M trans on Saturday while we were doing a filming shoot, but that's another story for another day...
@Torgus,
HL cams are fine on a stock bottom end. That's what I'm running, and have been running for the past 9500km without issue. Xavier grenaded my 1M trans on Saturday while we were doing a filming shoot, but that's another story for another day...
The reason you see some peeps running upgraded valve springs on stock cams is because at higher boost (I'm sure these peeps have build engines too) it becomes easier for the valves to float/bounce at higher rpm. Still might as well spend a little more and get cams I say. I've said it before and I'll say it again, cams + head(work) on my specific setup were good for >20% more throughput, which is HUGE. I've said it before and I'll say it again, N53 > ported N54 and my results attest to this...
@Torgus,
HL cams are fine on a stock bottom end. That's what I'm running, and have been running for the past 9500km without issue. Xavier grenaded my 1M trans on Saturday while we were doing a filming shoot, but that's another story for another day...
Were you at the stock rev limit with the high lifts?
If someone made a top mount single kit for the n53 head I would buy it. Probably not enough demand unfortunately. I would much prefer a fully worked and cammed n53 head for obvious reasons.
20% throughput is HUGE. It's just expensive but probably the best mods after a turbo upgrade assuming fueling is addressed.
8000rpm all day everyday @Torgus , and twice on Sundays
I thought I made this very clear in all the datalogs and onboard vids I've posted...
We return to the old adage, Speed costs money how fast do you want to go? In terms of whp/$$ its actually not bad at all compared to some other mods out there, I don't see much else giving you +20% at the same boost/octane...
I thought I made this very clear in all the datalogs and onboard vids I've posted...
We return to the old adage, Speed costs money how fast do you want to go? In terms of whp/$$ its actually not bad at all compared to some other mods out there, I don't see much else giving you +20% at the same boost/octane...
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Bingo. If you can put the power down, it's easy to see why this is a worthwhile mod. People are so quick to spend $4-5k on a ST setup and another 700 getting an M3 rep bumper and painting it, yet so few people seem to see the benefits that are staring them in the face. I guess it really does boil down to how serious someone is about wanting to go fast, but a 20% increase in HP is pretty crazy and not much else other than going from stock->tuned or stock turbo->upgraded turbo is even in the same realm. And once again, that's not including the increase in rev range or power curve that's gained, which is hugely beneficial for drag and road course racing.
Maybe VAC should start offering PayPal credit or some other online financing option
In the case of the N54, a relatively small displacement engine with overhead cams and poor exhaust ports, I would think the ported head would be a better bang for the buck, but the N54 head is junk.
I don't like rpms, and I think that since the lift isn't really increased very much, but duration is increased, your gains primary come from turning more rpms.
With a ported head, you get improved exhaust ports flow and reduced backpressure. That being said, the N54 head is so bad, exhaust port improvements are not that great. So in my opinion, I would go in this order:
Stock n53 head and stock cams
Stock n54 head and high lift cams
In any situation, I would want the high lift cams. I don't think the low lift cams over enough advantage. Fly cut those pistons!
All this is coming from someone that LOVES big cams in LS motors. I ran a 24x/25x in a stock head LS6.
I don't like rpms, and I think that since the lift isn't really increased very much, but duration is increased, your gains primary come from turning more rpms.
With a ported head, you get improved exhaust ports flow and reduced backpressure. That being said, the N54 head is so bad, exhaust port improvements are not that great. So in my opinion, I would go in this order:
Stock n53 head and stock cams
Stock n54 head and high lift cams
In any situation, I would want the high lift cams. I don't think the low lift cams over enough advantage. Fly cut those pistons!
All this is coming from someone that LOVES big cams in LS motors. I ran a 24x/25x in a stock head LS6.
Brian,
Even the "low-lifts" are pretty high lift as far as lift/diameter ratio goes, 11.5/10.5mm which is more than enough for 31/28mm valves - remember stock is 9.7/9.7. The high lifts are 12.0/11.5 with 4-deg LESS duration on the exhaust side. The high lifts are a perfect match with my N53 head, and once again you do NOT need to flycut pistons with the high-lifts. Don't recall the exact #s, but when I measured piston to valve clearance on mine it was generous - as long as your hub doesn't slip
I generally don't like RPM either (RPM = Ruins People's Motors) , but experience across other platforms has shown me time and time again that decent 500cc/cyl 4V engines with a mild turbo upgrade and a mild set of cams make excellent power up to 8000-8500rpm. FYI, the M3 CSL runs 268/264deg duration cams, just like the Schrick Hi-Lifts, with 12.0mm of lift, plus an 8000rpm redline with 9% bigger cylinders than ours.
Even the "low-lifts" are pretty high lift as far as lift/diameter ratio goes, 11.5/10.5mm which is more than enough for 31/28mm valves - remember stock is 9.7/9.7. The high lifts are 12.0/11.5 with 4-deg LESS duration on the exhaust side. The high lifts are a perfect match with my N53 head, and once again you do NOT need to flycut pistons with the high-lifts. Don't recall the exact #s, but when I measured piston to valve clearance on mine it was generous - as long as your hub doesn't slip
I generally don't like RPM either (RPM = Ruins People's Motors) , but experience across other platforms has shown me time and time again that decent 500cc/cyl 4V engines with a mild turbo upgrade and a mild set of cams make excellent power up to 8000-8500rpm. FYI, the M3 CSL runs 268/264deg duration cams, just like the Schrick Hi-Lifts, with 12.0mm of lift, plus an 8000rpm redline with 9% bigger cylinders than ours.
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OK let me clear up some more common misconceptions:
- You do NOT need (or indeed want) dual valve springs to handle a low 8k redline. Beehives > Dual Springs unless you want to rev well above 9k. Supertechs are all you need with the high-lift cams IMHO.
- The stock bottom end appears to handle regular trips to 8k without issue, assuming of course the use of fresh rod bearings. You WILL need a crank hub fix of one sort or another though, especially with the "hard" 2048-delete limiter option available as a flash option within MHD. It is worthwhile to note that on the S55, with its 7500rpm redline, BMW went with slightly LIGHTER pistons. (S55 rods are marginally heavier at 590 vs 581g/ea, whereas pistons are lighter at 450g vs 473g/ea. Effort made here to reduce reciprocating weight reduces friction and makes the engine better suited to high revs.
- You do NOT need (or indeed want) dual valve springs to handle a low 8k redline. Beehives > Dual Springs unless you want to rev well above 9k. Supertechs are all you need with the high-lift cams IMHO.
- The stock bottom end appears to handle regular trips to 8k without issue, assuming of course the use of fresh rod bearings. You WILL need a crank hub fix of one sort or another though, especially with the "hard" 2048-delete limiter option available as a flash option within MHD. It is worthwhile to note that on the S55, with its 7500rpm redline, BMW went with slightly LIGHTER pistons. (S55 rods are marginally heavier at 590 vs 581g/ea, whereas pistons are lighter at 450g vs 473g/ea. Effort made here to reduce reciprocating weight reduces friction and makes the engine better suited to high revs.
When I spoke with Ali he said they regularly spin stock valvetrain to 78-7900.
I've also been recommended a more conservative increased rev limit of 7500.
Either way rev limiter getting raised when I go dyno the car again lol
I'm thinking about trying 7500. 8k is tempting but I'll let someone else run that for a year or two before I turn it up.
Alex,
I believe Ali was referring to 7800-7900 on stock cams, not low lift Schricks. Not the same thing...
I believe Ali was referring to 7800-7900 on stock cams, not low lift Schricks. Not the same thing...
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