myles Posted October 29, 2020 Share Posted October 29, 2020 Hi, I'm wondering how I can build my L28 from a 1975 280z to get to 9,000 rpm. I want to do this because I want to use the Jenvey Individual throttle body kit which says that it is most optimal at 9,000. Quote Link to comment Share on other sites More sharing options...
Derek Posted October 29, 2020 Share Posted October 29, 2020 What it takes to get there is not going to answered here most likely because it is a list that is long. The absolute best advice I would give you is to contact Datsunspirit. Pay the price they quote and you will get what you want. It will be expensive. Plus they work directly with Jenvey. This is going to sound harsh but it is reality. If you are asking here then you probably don't have the skill set ( I don't) to actually leverage the different opinions that may be presented and actually build this type of motor. Getting to 9K reliably is a really heavy lift in my opinion. Getting to 7000 is easy. That that extra 2000 is where the real talent comes in. I'm going to rephrase your question for you: Question for those that have motors that go to 9000 RPM's. What did it cost:) Quote Link to comment Share on other sites More sharing options...
jonbill Posted October 29, 2020 Share Posted October 29, 2020 my £8k motor doesn't go to 9k. 8.7k turned out to be the limit. I reckon titanium valves and retainers would get it there. Quote Link to comment Share on other sites More sharing options...
Neverdone Posted October 29, 2020 Share Posted October 29, 2020 The easiest way to get to 9k is to take the L28 out, and replace it with a Honda F20C or Mazda 13B Rotary engine. The next easiest way is to throw 10's of thousands of dollars at an L28. There might be a 3rd way but I'm not aware of it. Quote Link to comment Share on other sites More sharing options...
myles Posted October 29, 2020 Author Share Posted October 29, 2020 43 minutes ago, jonbill said: my £8k motor doesn't go to 9k. 8.7k turned out to be the limit. I reckon titanium valves and retainers would get it there. What else is in your motor? Rods, pistons, cam, crank etc: Quote Link to comment Share on other sites More sharing options...
jonbill Posted October 29, 2020 Share Posted October 29, 2020 (edited) 14 minutes ago, myles said: What else is in your motor? Rods, pistons, cam, crank etc: its an f54 bored to 88.5, standard l28 crank balanced with the flywheel and clutch, maxpeedingrods l28 rods, Kameari forged pistons. welded p90 head, standard valves, 0.585"/308° cam, Kameari twin idler tensioner, kameari crank damper, zstory exhaust, fajs ITBs, Speeduino EFI. thats probably about it. Edited October 29, 2020 by jonbill Quote Link to comment Share on other sites More sharing options...
myles Posted October 29, 2020 Author Share Posted October 29, 2020 (edited) 3 minutes ago, jonbill said: its an f54 bored to 88.5, standard l28 crank balanced with the flywheel and clutch, maxpeedingrods l28 rods, Kameari forged pistons. welded p90 head, standard valves, 0.585"/308° cam, Kameari twin idler tensioner, kameari crank damper, zstory exhaust, fajs ITBs, Speeduino EFI. thats probably about it. thank you, also have you had it dyno'd? I would love to know the power it's making. Edited October 29, 2020 by myles Quote Link to comment Share on other sites More sharing options...
jonbill Posted October 29, 2020 Share Posted October 29, 2020 12 minutes ago, myles said: thank you, also have you had it dyno'd? I would love to know the power it's making. well I found that 8700 was just too much as it was getting dialed in on the dyno, so we didn't get a run recorded. the machine was saying more than 300bhp somewhere after 8000 as I was watching before it ended abruptly. Quote Link to comment Share on other sites More sharing options...
myles Posted October 29, 2020 Author Share Posted October 29, 2020 1 hour ago, jonbill said: its an f54 bored to 88.5, standard l28 crank balanced with the flywheel and clutch, maxpeedingrods l28 rods, Kameari forged pistons. welded p90 head, standard valves, 0.585"/308° cam, Kameari twin idler tensioner, kameari crank damper, zstory exhaust, fajs ITBs, Speeduino EFI. thats probably about it. One more question sorry. Do you think the p90 head is necessary? Quote Link to comment Share on other sites More sharing options...
NewZed Posted October 29, 2020 Share Posted October 29, 2020 7 hours ago, myles said: I want to do this because I want to use the Jenvey Individual throttle body kit which says that it is most optimal at 9,000. This is a bad reason to try to get to 9,000 RPM. Not logical. Buy a kit that is most optimal at 5,500 RPM. Quote Link to comment Share on other sites More sharing options...
myles Posted October 29, 2020 Author Share Posted October 29, 2020 12 minutes ago, NewZed said: This is a bad reason to try to get to 9,000 RPM. Not logical. Buy a kit that is most optimal at 5,500 RPM. Well really the reason why I wanted the Jenvey throttle kit was because it is optimal at 9k rpm. I wanted my engine to be able to be there anyway. Quote Link to comment Share on other sites More sharing options...
madkaw Posted October 29, 2020 Share Posted October 29, 2020 So it’s optimal at 9k - so that doesn’t mean you build an engine around them. I’m quite sure they are very efficient below that . What ID are they? Start shopping for a billet crank at 3500$ plus and then throw in another 10k on the engine build and you might get there Quote Link to comment Share on other sites More sharing options...
jonbill Posted October 30, 2020 Share Posted October 30, 2020 10 hours ago, myles said: One more question sorry. Do you think the p90 head is necessary? I don't think the p90 is critical to being able to rev that high, but its a good starting point if you want to make power up there. There's lots of info on here about the qualities of the p90in terms of air flow and Squish. Quote Link to comment Share on other sites More sharing options...
Howsurcargo Posted November 1, 2020 Share Posted November 1, 2020 Fwiw Rebello is placing an order for Crower billet cranks. I ordered an 85 mm stroke crank for $3000. Your ITBs would sound sweet even at 7500 rpm plus that would be a lot more attainable and possibly even more streetable and fun. Quote Link to comment Share on other sites More sharing options...
DuffyMahoney Posted November 2, 2020 Share Posted November 2, 2020 9k is a lot of RPMs. 7000 sounds wild in a straight six. I have all the fancy valve train parts and I plan to never go above 7500. Quote Link to comment Share on other sites More sharing options...
Zetsaz Posted November 3, 2020 Share Posted November 3, 2020 You should consider your use for the car as well. 9k rpm sounds ludicrus on an L series, but if you're in a mostly street car you'll rarely get opportunities to get even close to that unless you're on freeway on ramps. My L28 is a pretty much stock block but with improved accessories and MS3x with sequential fuel and spark. It drives great even though the acceleration isn't like modern cars, but I rarely get chances to go past even 5.5k where the power starts to fall off in the stock motor. Quote Link to comment Share on other sites More sharing options...
jonbill Posted November 3, 2020 Share Posted November 3, 2020 9k rpm sounds epic on an L engine. Quote Link to comment Share on other sites More sharing options...
Tony D Posted November 19, 2020 Share Posted November 19, 2020 Sadly, before the Koreans hijacked my YouTube Channel, I had videos of us making runs at El Mirage where we shifted at 9,500, and 9,300 depending on the gearing or tire height. No titanium Retainers or Spring Caps, and we ran that engine to over 12,500 doing valvetrain stability tests without any issues whatsoever. An L24 will do it easier than an L28 or larger simply because you are limited on flow through the ports on the non-crossflow head (about 240-250cfm max) and that will cap your power peak realistically in the 8,700 rpm range. Been there, done that, got the videos to prove it. Got the land speed record plaques and jacket as well... Quote Link to comment Share on other sites More sharing options...
AydinZ71 Posted November 19, 2020 Share Posted November 19, 2020 35 minutes ago, Tony D said: Sadly, before the Koreans hijacked my YouTube Channel, I had videos of us making runs at El Mirage where we shifted at 9,500, and 9,300 depending on the gearing or tire height. No titanium Retainers or Spring Caps, and we ran that engine to over 12,500 doing valvetrain stability tests without any issues whatsoever. An L24 will do it easier than an L28 or larger simply because you are limited on flow through the ports on the non-crossflow head (about 240-250cfm max) and that will cap your power peak realistically in the 8,700 rpm range. Been there, done that, got the videos to prove it. Got the land speed record plaques and jacket as well... I might be wrong, but I also recall the shorter stroke on a stock L24 contributes to better reliability at higher rpm’s? Typical high-rpm engines run larger bore and shorter stroke for that reason. Less rotational inertia? once you start modifying crank, rods, bearings, Bolts, etc. then the L24-L28 trade off probably diminishes. Quote Link to comment Share on other sites More sharing options...
primaz Posted November 20, 2020 Share Posted November 20, 2020 (edited) On 10/29/2020 at 11:43 AM, Derek said: What it takes to get there is not going to answered here most likely because it is a list that is long. The absolute best advice I would give you is to contact Datsunspirit. Pay the price they quote and you will get what you want. It will be expensive. Plus they work directly with Jenvey. This is going to sound harsh but it is reality. If you are asking here then you probably don't have the skill set ( I don't) to actually leverage the different opinions that may be presented and actually build this type of motor. Getting to 9K reliably is a really heavy lift in my opinion. Getting to 7000 is easy. That that extra 2000 is where the real talent comes in. I'm going to rephrase your question for you: Question for those that have motors that go to 9000 RPM's. What did it cost:) I agree 100%, Datsun Spirit in my opinion if the best Datsun L series engine builder and I would recommend them over Rebello. Eji take so much pride in his work from his more mild affordable engines to his more expensive 9000+ RPM engines. There is no cheap way out but remember a quality blueprinted engine from Eji will be reliable and well worth the investment. There is skill in a quality engine builder so I recommend to just go with a proven builder like Eji. If you want an engine at that level expect to pay $17K or more for his stage 5 engine but if you look at any modern performance car like a BMW, Porsche, etc. you can expect to pay the same for a new factory engine so for a Datsun L series you can get a incredible powerful, reliable engine that will last longer than those new modern engines and have low maintenance as L series engines are so easy to service compared to any modern sport car engine. If that price is out of your budget then get his Stage 4 for around $12K and that is a great engine that will rev to 8000 comfortably and put down 300 HP at the rear wheels. Even his stage 3 will rev nicely and put down 240 HP at the rear wheels for only around $6,800 and is a great setup for your ITB's if your budget will not allow for a Stage 4 or 5. Edited November 20, 2020 by primaz Quote Link to comment Share on other sites More sharing options...
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