BMW's B series Engines Pistons & Rods Explained

[@samuelpacheco37]

Finally found someone that have answers for the b48e engine. Thank you Sir.

[@samuelpacheco37]

Love this type of videos. Thank you sir i have a jcw countryman 2023 can wait to tune it.

[@godfatheratlsu]

Great discussion on all the different B48 internals throughout BMW's iterations. It's exactly what I was looking for, a whole hour very well spent watching you go at it. Much appreciated! On topic of B48's, one very worthwhile curiosity I get very fogged up about is the differences in B48E vs B48's, the B48TU's turbocharger setup. You mentioned that the heads on the gen 1's are more of a bottleneck, I get that as I've a gen 1 head laid out in my garage, but I don't have a gen 2 head to compare against. But I do realize the runners and the valve angles to be questionable at different locales. A port job will definitely raise the bar and get some improvements. But what about the turbocharger differences? I know much of the turbochargers they used between the B48's and the B48E's, and by comparing the part numbers, most peripheral parts do share the same part numbers, but both the turbocharger itself and the downpipe are different; I'm speaking so on behalf of the Mini Cooper S's against the JCW Countryman's. I'm guessing 302HP from the E versus 228HP on the gen 1's 2's can't just be a tune and internal parts being different. I remember you mentioned there's that boost difference between 25 psi and 17 psi, so I'd reckon turbo diameters to also seek a slight difference, too? Hope you can also put out a thorough episode to elaborate on those. Bunch guys in the States can greatly benefit from your valuable finding and input. Again, much appreciate all your effort and content. Keep up with the great stuff. Love it!

[@NavardiTuned]

thanks for your reply! I actually already have you covered here on this, all the info you are asking for is in the wiki -> bmwenginewiki.com Yes the B48E turbo is in-fact a totally different turbo to the B48TU and B48, B48 -> TD04 Based B48TU -> Garret Based B48E -> Garret Based (different again to the TU turbo) The Mini/UK11 Cylinder heads do differ in port angle compared to the BMW Longitudinal setups which can have some impacts on power / TQ due to things like swirl effect for example The Mini/UK11 Intake Manifolds are also a valid contributor to power / TQ ability of those engines over the BMW Longitudinal equivalents.

[@godfatheratlsu]

@@NavardiTuned Yeah, I found the vid and watched it all the way. It does seem like the B48E turbo is the golden ticket in terms of OEM options, which is what I really like. Once again, love the work you're doing and will absolutely be on the watch out for your contents about these B48 mods. I did a N55 build with CP pistons and Manley rods, didn't get to a turbo that I like, yet; but it's running on MHD stage 2 on 91 OCT and made about 360whp which is pretty good already. I will have to watch more of your vids to gather my ideal part combination for the car. I have the 2022 X2 Sdrive 28i which is a whole step below the X2 M235i, and I think at the end of the day, I would like to bring my car to right below 400whp and call it. Based on your detailed assessment on the TU pistons and rest of the internals, I think 400whp is quite safe. I'm thinking to do this with the B48E turbo and 58TU HPFP, DP, FTP brachials, and really don't know if there's an OTS tune for this. My local tuner I hear is recently closing and shutting their shop down. So that's going to be a big bummer and time spent to find another tuner. By the way, do you know if I can send my ECU to Femto to bench unlock? I'm thinking of acquiring another ECU and clone it for the unlock to put the tune on, strictly for safety and future troubleshooting use.

[@Robwra320]

Amazing video harry , thankyou for your support for community

[@corradopsi]

Very informative, thank you

[@chippyjohn1]

Thanks for the video mate, was hoping on more B57 data but nice anyway. Id like to see what the cylinder pressure is on the B57 as they now have a built in pressure transducer.

[@NavardiTuned]

Unfortunately Diesels are not my forte, I have seen the turbo setup on some BMWs are they're nutty and stupidly hard to work on lol being so compact and crammed together

[@chippyjohn1]

@@NavardiTuned What? You think 3 or 4 turbos is excessive, that's strange. I was a BMW tech for many years here in Aus, big fan of the M54 and M57, but the newer 6's are becoming very complicated. The M57 is a common swap, excellent engine even for boats. Either the N57 or B57 is used in the OXE diesel outboard. I would like to use one for an experimental aircraft but the timing, oil pump and valve train have become very complex. They would require a lot of modification. B57 components are weaker compared to M57 but it outputs more power. Where in Aus are you?

[@NavardiTuned]

@@chippyjohn1 Not strange compound setups are nothing new to diesels just, seeing the OE setup is wild due to how compact they are that was the point I was making. Syd based usually attend some of the meets etc around Syd

[@chippyjohn1]

@NavardiTuned I'm very familiar with compound, have designed and implemented it on an engine. I think the 4 turbos used on a BMW engine are more about not being able to fit just two turbos. As you mentioned, there is not much room. Last time I drove my E30 to Sydney from Melbourne, Sydney was full of potholes. Best of luck with the projects.

[@leoorsag4746]

Great Video mate, thank you very much for all the Data you share :-)

[@indyrock8148]

Good video thanks.

[@christopherparham-l8t]

After reading these comments who has the safest best ots and customer tune for gen 1 b48s j have a 2018 f30 330i b48

[@NavardiTuned]

OTS I would be pointing to MGFlasher tbh

[@ashleywressell4664]

How do you find out if you have B48 gen1 or gen2?

[@NavardiTuned]

All BMW G series engines are a Gen 2 (except pre LCI G30 BMWs) All BMW F44 and F40 cars are Gen 2 U11/12 X1/X2 are Gen 2 some X2 F series are Gen 2 (M35ix for example) Minis released in 2019 onwards are typically Gen 2 the same is said for the BMWs except for the F22/F20 cars as they were still Gen 1 until late 2020 Basically the engine model number on the engine block or valve cover can also tell you Any BMW B48 that has T1 T2 or TU in the model is a gen 2 I.E B48A20T1 B48A20TU or the new B48A20T2 - B46 follows the same naming scheme without that its a gen 1

[@kd2833]

what power can the supra with b48 take ?

[@bartoszcholewa7100]

hi on my 20i x3 2019 piston cracked. i think injector fault. i will buy new injectros... but what pistons would u recomend to build engine. i want to go around 300HP nothing more but i want to bulit it and run with no more piston problems..

[@NavardiTuned]

well these engines are extremely reliable so that is a 1/1000 unfortunate event Going OEM would be fine going forged is super overkill especially for the power you want a 2019 X3 is a Gen 2 B4x engine which uses some of the most reliable OEM pistons todate Maintain OE CR of 10.2:1

[@bartoszcholewa7100]

@@NavardiTuned can I switch them if length gudgeon pin is 51 to 55? 30i is only 55 version

[@kd2833]

​@@NavardiTuned what can the b48 take with 10.2 same engine as the supra i wanne buy. I want like 340 whp

[@NavardiTuned]

@@kd2833 already well documented can do 500 on stock internals with the right turbo etc

[@NavardiTuned]

@@bartoszcholewa7100 always match the pin to the piston and rod

[@gabrielplesea9731]

Do you know the datta for B48 gen 1 piston ring gap for stock pistons?

[@NavardiTuned]

@@gabrielplesea9731 i could measure the used one but brand new out of the box I don't I believe its in newtis though

[@mihaialexns]

Thank you so much Navardi for your efford explaining this. So basically at 13:34 is the difference between 184hp and 224hp B48 ? Left high compression / right lower compression? If so, that back reinforcement from the high compression piston looks better then the right one. I am curious about the difference between those.

[@NavardiTuned]

My comparison between the 11 CR and 10 CR was more in the context of the changes in the mini cooper Gen 1 early pistons with issues. As I mentioned the valve relief area's don't change in depth with different compression its usually just the dome design or height that does When it comes to 11 CR vs 10 CR What separates whats possible power wise is when do you become knock limited on a given fuel at a given engine compression? The 11 CRs increase the quench in the engine as such everything works alittle harder which means you have a reliance to use high octane fuels like ethanol on big turbo setups to get more power out of them as opposed to a lower compression piston

[@NavardiTuned]

Also at that point in the video that you tagged left is the 10.2 CR piston and right is the 2014 Mini 11 CR piston

[@Reaper_f30]

So the early mini cooper pistons, are these the same ones in the 320i 2016 to 2018? I myself have a 320i 2018 (post August build, 68 plate) 320i m sport shadow

[@NavardiTuned]

@@Reaper_f30 early Mini Cooper pistons were replaced with a revised model that revised model was also used in the BMW release of the B48 (both 20i and 30i variants)

[@Reaper_f30]

@@NavardiTuned thats great to hear, so is my 20i m sport shadow 2018 plate variant piston while being a higher compression than say any of the 2016 to 2018 330i made of the same revised material? meaning 20i being weaker comes from the compression effect on the piston, not the pistons material itself??

[@zero696]

would you then say that 350Nm for the high compression b48 is safe? generally speaking

[@NavardiTuned]

The limitations on the 11 CR pistons is purely due to knock threshold - which is why you become knock limited faster on gasoline than alcohol based fuels on the 11 CR over 10 CR The Mini 11 CR & 10 CR had the defect whereas the BMW ones did not

[@zero696]

@@NavardiTuned so the BMWs won't suffer from LSPI if ~400Nm is not exceeded? That is what ultimately kills the engine. My plan is to tune an F30 320i MSport with 350Nm (fuel quality from Spain).

[@NavardiTuned]

​@@zero696 No the concept of LSPI and max tq has been misunderstood. LSPI is likely to occur when you have high load at low speed and you are approaching the knock threshold for your given fuel The LSPI zone is typically 1500-3000 RPM Then depending on the fuel, engine compression, engine load/tuning will determine if you get into a LSPI condition Its not set at a fixed tq value B48s have plenty of great examples into the 500-800nm range just depends on the tune, fuel etc as to if LSPI will happen

[@zero696]

@@NavardiTuned my understanding is that LSPI is determined by combustion chamber geometry and compression ratio (and, obviously, the fuel resistance to knock). But you're saying that LSPI depends on the tune, and that is where I get lost. You can enrich the mixture to keep the knock threshold away, but LSPI is not knock, its preignition, and preignition can (and will) happen randomly, destroying the engine in one single event. The only workaround that I see is getting more boost (which won't be easy as the rpm are very low) and reducing the spark efficiency. That might reduce the peak temperature of the combustion and keep LSPI slightly away, but the boost will pull the knock threshold up. I'm very hesitant about tuning my car as you can observe :) thanks for your time.

[@NavardiTuned]

​@@zero696 No Not what I am saying at all, its not just tune dependent, engine configuration, fuel, tune etc all play a part in how, if, when the conditions are right for LSPI What I was trying to illustrate with regards to the knock threshold of a fuel is that a fuel is more likely to pre - ignite when you are close to a knock threshold as you're basically achieving close to the maximum of what the fuel will be happy with in the context of the engines operation at a given load and engine rpm. Yes enriching a mix can assist in cooling the chamber and reduce the chance for hot spots to form to pre ignite the fuel, or contribute to knock or super knock but also at the cost of reducing engine efficiency. At low speeds there is only so rich you want to go to avoid an over fuelling situation and lead to something like a hydrolock condition. Given heat is the usual culprit for pre ignition, reducing your ignition timing and adding some level of enrichment does assist in reducing the chances - there are also certain oil additives that limit the chance of LSPI All in all given majority of this can be easily mitigated by the tune and ensuring you aren't loading the engine up at high load even if the customer was to slam the throttle to 100% The LSPI argument for B48s is so over hyped/blown out of proportion, Alot of the cars that had a problem were typically the 11 CR ones and because tunes had requested Ludacris loads in the 1500-2500 rpm zone given the factory turbos can spool to full boost by 2K RPM and most were running a gasoline mix the conditions were almost always right to cause LSPI or super knock in those regions and it was a pretty quick way to destroy the pistons usually by failure of the compression ringland Which regards to your comment around LSPI occurring "randomly" its only going to occur when the conditions in the chamber are right just like if the car was to knock or super knock - usually super knock is the immediate follow-up to LSPI The knock sensors do have calibration in place to try and listen out for LSPI and automatically react to those conditions by way of adjusting the tune on the fly within a certain range of adjustments (like reducing ign timing for example) Whilst combustion chamber design plays into it, just about anything todo with the engine will, at the end of it, anything that's involved in the process of combustion can and will play a part in the outcome of a controlled or uncontrolled combustion event