I assume N54 is an interference motor? So this is the case even with a lower compression turbo motor?
Filippo
Technical Hydra Performance 135 Leichtbau State of the Art Thread
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Filippo
Even the LS motors are interference engines. I'm sure smaller import/euro motors run tighter, but I think there can also be limitations in max lift just due to OHC design. In the Honda J series, the design of the cam followers limits maximum lift to a very small amount over stock.
Jesus. I should invent a search engine. Call it Google or something.
The effect from both is significantly greater than the effect from either in isolation. Low-lift schricks have 19% more intake lift and 7% more exhaust lift compared to stock, and the high-lifts have 29% and 19% more lift than stock, while maintaining the same duration as the low-lifts. Finally, a 268-deg duration isn't considered aggressive at all, and you can barely tell that the car is cammed when hearing or driving it
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Are you an ass...if you found a link please share. I’ve searched key words(N53b30, camshaft, lift) and I got nothing after viewing the first 30 google results.
Typically cams specs are not advertised by OEMs.
If you can share...the floor is yours.
The only info I found shows the N54 cams with 9.7mm lift for both intake and exhaust. The Schricks high lift are 12mm/11mm. Are those accurate numbers? That is a 24% increase in intake and 13% increase on the exhaust. 9.7mm seems to be BMWs 'default' lift on numerous inline 6s, but it could also be wrong from what I found.
However, even using the 29/19 increase you listed, that's a far cry from the 35+ that you get on most domestics. Granted, I'm neglecting the airflow of dual valves compared to a single one in an OHV.
I was curious, how far does the schrick cames extend redline? With cams being $1500 (springs/retainers needed for high lift?) and a ported cylinder head being $2000, it's a hard call with which to go if choosing one or the other. I think I'd still lean towards the cylinder head, as I'm not fond of RPM. Do you have a pricepoint in mind for the N53 cylinder head? The exhaust flow of 18x is a good bit more than even a ported N54 which would be very nice.
Gents,
Stock cams are 248/261 9.7/9.7
N53 cams, after measuring/eyeballing them, are probably 255/261 9.9/9.7 just like the N55
Schrick low lifts are nominally 268/268 11.5/10.5 (measured at 11.45/10.3)
Schrick high-lifts are nominally 268/264 12.0/11.0 (measured at 11.85/10.8)
Valve lift, in isolation, doesn't tell us the entire story, what we really should be looking at instead is lift/diameter ratio. Regular production engines usually fall in the 0.26-0.28 range on the intake side and 0.32-0.34 for exhausts, with max effort race engines (with highly developed heads/ports) typically coming in at 0.39I and 0.41E. With that said the stock N54 L/D ratio is pretty healthy, especially considering how poorly the stock head flows above 0.25 L/D. However, even a ported N54 head will still offer an abysmal exhaust side, as 2x 28mm valves merging into a 32mm ID port will always be a bottleneck to total engine throughput...
The question of how much cams extend redline depends on a lot of factors, such as headwork, turbo sizing, and boost level. But its probably safe to say that a 7500-8100rpm redline isn't too much to ask of a free-breathing setup with turbo capacity to spare. Give me just a couple more weeks and I will back all of this up with logs, dyno figures, and dragy runs. From what little I've seen so far (11 miles and 2.5 WOT pulls lol) I'm fairly confident its going to be EPIC!
Stock cams are 248/261 9.7/9.7
N53 cams, after measuring/eyeballing them, are probably 255/261 9.9/9.7 just like the N55
Schrick low lifts are nominally 268/268 11.5/10.5 (measured at 11.45/10.3)
Schrick high-lifts are nominally 268/264 12.0/11.0 (measured at 11.85/10.8)
Valve lift, in isolation, doesn't tell us the entire story, what we really should be looking at instead is lift/diameter ratio. Regular production engines usually fall in the 0.26-0.28 range on the intake side and 0.32-0.34 for exhausts, with max effort race engines (with highly developed heads/ports) typically coming in at 0.39I and 0.41E. With that said the stock N54 L/D ratio is pretty healthy, especially considering how poorly the stock head flows above 0.25 L/D. However, even a ported N54 head will still offer an abysmal exhaust side, as 2x 28mm valves merging into a 32mm ID port will always be a bottleneck to total engine throughput...
The question of how much cams extend redline depends on a lot of factors, such as headwork, turbo sizing, and boost level. But its probably safe to say that a 7500-8100rpm redline isn't too much to ask of a free-breathing setup with turbo capacity to spare. Give me just a couple more weeks and I will back all of this up with logs, dyno figures, and dragy runs. From what little I've seen so far (11 miles and 2.5 WOT pulls lol) I'm fairly confident its going to be EPIC!
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Assuming they could be had fairly cheap, N53 or N55 cams would offer a tad more intake lift and duration. With such a small difference I wonder if the difference would even be quantifiable.
Did you ever confirm if the high lift cams require pistons, as VACs website states?
@langsbr
N55 = valvetronic on the intake side so that's no good. I have a couple sets of N53 cams here, you can have them for cheap but I'm not sure they're worth the effort to install, unless you're changing out your valve seals and/or cam ledges and have to dig in there anyway.
I have the low-lift Schricks on my car, have not seen the high-lifts in person, but my gut feeling is it shouldn't make too much of a difference to P2V clearance. You can buy a +0.3mm thicker head gasket if you're really worried about it. I installed one on my car to lower compression a hair...
N55 = valvetronic on the intake side so that's no good. I have a couple sets of N53 cams here, you can have them for cheap but I'm not sure they're worth the effort to install, unless you're changing out your valve seals and/or cam ledges and have to dig in there anyway.
I have the low-lift Schricks on my car, have not seen the high-lifts in person, but my gut feeling is it shouldn't make too much of a difference to P2V clearance. You can buy a +0.3mm thicker head gasket if you're really worried about it. I installed one on my car to lower compression a hair...
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Per my discussions with Jake from Motiv, he was of the mind that you don't need special pistons, however he runs the JE forged pistons on his setup with the high lifts.
I wanted to retract/correct my previous statement to the contrary. I just spoke to someone with first-hand experience, and was told that high-lift Schricks + stock pistons = bent valves . Don't say I didn't warn you!
EDIT: I now have good reason to doubt the veracity of the above statement, will verify this first hand in due time and post my results accordingly
EDIT: I now have good reason to doubt the veracity of the above statement, will verify this first hand in due time and post my results accordingly
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so if install high lift schricks, what piston is OK?I wanted to retract/correct my previous statement to the contrary. I just spoke to someone with first-hand experience, and was told that high-lift Schricks + stock pistons = bent valves . Don't say I didn't warn you!
I wanted to retract/correct my previous statement to the contrary. I just spoke to someone with first-hand experience, and was told that high-lift Schricks + stock pistons = bent valves . Don't say I didn't warn you!
Yikes, thanks for the info!!! But at least we know the high-lift cams are a near max effort solution.
I think some adjustments to the VANOS tables may allow them to clear. it's not like we're worried about them at max lift when the piston is already heading on down the bore, it's just close to TDC where you may "run into" the piston with a valve
Possible, but not worth the worry IMO. Sometimes if the vanos solenoids are going bad or need to be cleaned, actual setpoint can lag behind request a good bit, which could still cause an issue even if your tables were set correctly.
Good point @jyamona , I will be flycutting the stock pistons to increase p2v clearance.
On a slightly different note, I just measured the high-lift schrick cams @ 11.85mm/10.80mm, assuming a rocker ratio of exactly 1.65 - extrapolated from stock cams and valve lift figures. Not such a huge difference compared to the low lifts (11.45/10.30). The plot thickens... Would probably be wise to measure piston to valve clearance @ TDC before touching the pistons, especially on the exhaust side since that is what is ultimately going to be the limiting factor as far as clearance goes.
On a slightly different note, I just measured the high-lift schrick cams @ 11.85mm/10.80mm, assuming a rocker ratio of exactly 1.65 - extrapolated from stock cams and valve lift figures. Not such a huge difference compared to the low lifts (11.45/10.30). The plot thickens... Would probably be wise to measure piston to valve clearance @ TDC before touching the pistons, especially on the exhaust side since that is what is ultimately going to be the limiting factor as far as clearance goes.
I would think most people who have high lift cams also have ported head with larger exhaust valves to get the most gains from cams to begin with and aftermarket pistons have deeper valve reliefs to ensure clearance for those valves.
