Derek Posted July 20, 2021 Author Share Posted July 20, 2021 Just had a long talk with Rob. He has some valid points but mostly they are just so busy that it kind of has been pushed aside from a social media standpoint. He was hesitant to post numbers because he knows he can get more out of it with a better tune. The owner of the car loves the head and has zero complaints about it. The problem is Rebello is just so busy all the time that they take forever on a regular build. Add the complexity of the KN20 and waiting a year for a motor is a real buzz kill. Other avenues are being explored to speed it up and at the request of Rebello I'm now selling the heads with guides and seats installed. This has been a major time vampire for them and has caused a ton of delays. I built a custom head oven and purchased a nitrogen dewar. Made custom installation drifts for the guides and seats. I've done 2 heads so far and it has gone really well. I'm big on the science and realistically, heat soaking a new head and nitrogen chilling the seats and guides is the way to go. If you are using brute force then you are broaching. I think it's especially critical on a new casting. Now for the good news. Rob is putting the car back on the dyno for a new tune and they will be doing a complete writeup including pictures of the install and will be posting them soon. We can put away the pitchforks now:) 1 Quote Link to comment Share on other sites More sharing options...
DuffyMahoney Posted July 23, 2021 Share Posted July 23, 2021 On 7/20/2021 at 2:19 PM, Derek said: Just had a long talk with Rob. He has some valid points but mostly they are just so busy that it kind of has been pushed aside from a social media standpoint. He was hesitant to post numbers because he knows he can get more out of it with a better tune. The owner of the car loves the head and has zero complaints about it. The problem is Rebello is just so busy all the time that they take forever on a regular build. Add the complexity of the KN20 and waiting a year for a motor is a real buzz kill. Other avenues are being explored to speed it up and at the request of Rebello I'm now selling the heads with guides and seats installed. This has been a major time vampire for them and has caused a ton of delays. I built a custom head oven and purchased a nitrogen dewar. Made custom installation drifts for the guides and seats. I've done 2 heads so far and it has gone really well. I'm big on the science and realistically, heat soaking a new head and nitrogen chilling the seats and guides is the way to go. If you are using brute force then you are broaching. I think it's especially critical on a new casting. Now for the good news. Rob is putting the car back on the dyno for a new tune and they will be doing a complete writeup including pictures of the install and will be posting them soon. We can put away the pitchforks now:) Well that is good news! Quote Link to comment Share on other sites More sharing options...
Tony D Posted July 24, 2021 Share Posted July 24, 2021 (edited) On 4/4/2019 at 3:29 AM, Gollum said: I think 600hp on pump gas at around 16-18psi wouldn't be unreasonable. Going beyond that you'd better have done some serious prep to keep bores round and such. For repetition and completeness sake, that is possible on the current non-crossflow head. Add about 400HP to that estimate for this head... if you can keep the bottom from moving around. Edited July 24, 2021 by Tony D Quote Link to comment Share on other sites More sharing options...
Tony D Posted July 24, 2021 Share Posted July 24, 2021 On 6/8/2021 at 6:49 AM, Derek said: Is there a class it could even run in at all? If so how much horse power would it need to put out to be competitive? I'm not into road racing so I have no clue. I can think of one or two... and it's right in the running horsepower-wise both N/A and potentially turbocharged. Quote Link to comment Share on other sites More sharing options...
rturbo 930 Posted July 31, 2021 Share Posted July 31, 2021 (edited) https://www.instagram.com/p/CR-vb6TrSjL/ https://www.zcarblog.com/2021/07/30/performance/datsunworks-twin-cam-power-for-your-l-series-engine.html Quote TWIN CAM power for your L-Series! Z Car Garage is excited to collaborate with @datsunworks and develop their brilliant KN20 dual-overhead cam (DOHC) cylinder head designed for the Nissan inline-6 L-Series engine.This is a custom 6-cylinder head derived from Honda's venerable K-series 4-cylinder engine. The KN20 offers superior head flow rates combined with modern valvetrain components to effectively transform your L-series single-overhead cam into a high-revving, dual-overhead cam engine. The power potential is impressive.We have installed the KN20 into our long-time client Gary's Datsun 240Z, affectionately named the "Behemoth". A few details: Rebello 3.2L Engine, Jenvey ITB EFI, @haltechecu Elite 750, CD009a six-speed transmission, R180 4.11 @osgiken LSD and out ZCG Big-Brakes (@stoptech)Still in the tuning phase so Gary's car is on a comfortable (conservative) setting. With the Datsunworks head it made 350hp/248tq at the wheels on 91 octane.Even in a testing stage, it is absolutely thrilling to drive. The sound it makes is a sonorous tone only the K-series derived KN20 head provides...with a gnarly exhaust note to match. It’s a sensory overload and revs seem to climb endlessly. 350hp/248ft lb at the wheels. Pretty damned impressive. Edited July 31, 2021 by rturbo 930 Quote Link to comment Share on other sites More sharing options...
Derek Posted July 31, 2021 Author Share Posted July 31, 2021 I own one and the videos even got my blood pumping. That car is really amazing. Hopefully after this round of heads I'll be able to finally finish my 3.1 ish build. I will say that the sound is pretty much the same with mine. It's really great that now there are some real HP numbers on the head. It's an expensive head for sure but getting 350HP at the wheel out of a regular ported head wouldn't be cheap. The best part is that is the SEMA car that HAD the OSG head. Had..... Bwahaha Quote Link to comment Share on other sites More sharing options...
Ben280 Posted July 31, 2021 Share Posted July 31, 2021 I'm right at the crossroads of what do I do with my L series for time attack/road race use. Swapping for a V8 has appeal, but I just saw the post on Z car garage, and, well. Time to investigate! This is really an incredible project Derek. Quote Link to comment Share on other sites More sharing options...
Derek Posted August 1, 2021 Author Share Posted August 1, 2021 Thanks Ben I'm glad some numbers on a 3.2L (3.18) are finally out. 100hp per liter is pretty decent from what I hear. Rob feels like there is still some more to be had via tuning but it's a street car so there is always a balance to strike. I'm just glad that for Zcar Garage it's now an itch they need to scratch. Quote Link to comment Share on other sites More sharing options...
Ben280 Posted August 1, 2021 Share Posted August 1, 2021 3 hours ago, Derek said: 100hp per liter is pretty decent from what I hear. Rob feels like there is still some more to be had via tuning... ZCG's numbers show it's certainly no slouch, although I wonder if with some compression and ethanol this would support 400whp+..... Quote Link to comment Share on other sites More sharing options...
DuffyMahoney Posted August 3, 2021 Share Posted August 3, 2021 On 7/31/2021 at 8:23 PM, Ben280 said: ZCG's numbers show it's certainly no slouch, although I wonder if with some compression and ethanol this would support 400whp+..... I see they say it's tuned not for all out HP but for drivability. Also it's a 3.2L. Which means still over 100hp per liter. Pretty darn epic. I want to know what size throttles? I think Derek needs to try injectors at the head next. I have a feeling throttle response would be better and street use will be slightly better. I have read a few articles on the subject. Closer to head for throttle response, all out hp/ high rpm furthest from the head as possible. Quote Link to comment Share on other sites More sharing options...
Derek Posted August 3, 2021 Author Share Posted August 3, 2021 43 minutes ago, DuffyMahoney said: I think Derek needs to try injectors at the head next I think Derek's injectors are at the head I purposely have left that stuff up to others since A: I know very little about making power and B I know even less than that I do know how to make a casting though so that's more important in my mind. 46 minutes ago, DuffyMahoney said: Which means still over 100hp per liter. Pretty darn epic. I did a search on production vehicles that make over 100 HP per liter NA and it's a pretty impressive list. Rob sent me a link to an article that came out. https://www.thedrive.com/news/41805/nissan-240z-roars-with-honda-style-dohc-head Links to and mentions this build thread which was nice. Quote Link to comment Share on other sites More sharing options...
DuffyMahoney Posted August 3, 2021 Share Posted August 3, 2021 5 minutes ago, Derek said: I think Derek's injectors are at the head I purposely have left that stuff up to others since A: I know very little about making power and B I know even less than that I do know how to make a casting though so that's more important in my mind. I did a search on production vehicles that make over 100 HP per liter NA and it's a pretty impressive list. Rob sent me a link to an article that came out. https://www.thedrive.com/news/41805/nissan-240z-roars-with-honda-style-dohc-head Links to and mentions this build thread which was nice. You know far more then me. But aren't you casting the intakes? That article is very cool, Rob sent it to me this am. Quote Link to comment Share on other sites More sharing options...
Derek Posted August 3, 2021 Author Share Posted August 3, 2021 1 hour ago, DuffyMahoney said: But aren't you casting the intakes? I am but as soon as I put bungs there I guarantee you someone will want them somewhere else. Also the majority of the builds are running Jenvey stuff and for the most part they come with bungs. And last but not least the casting works for both tilts depending on how I machine it. The bungs would over complicate that. Quote Link to comment Share on other sites More sharing options...
DuffyMahoney Posted August 3, 2021 Share Posted August 3, 2021 59 minutes ago, Derek said: I am but as soon as I put bungs there I guarantee you someone will want them somewhere else. Also the majority of the builds are running Jenvey stuff and for the most part they come with bungs. And last but not least the casting works for both tilts depending on how I machine it. The bungs would over complicate that. Darn! Quote Link to comment Share on other sites More sharing options...
Zetsaz Posted August 5, 2021 Share Posted August 5, 2021 (edited) @Derek out of curiousity, is one of your buyers MZR Roadsports in the UK? Was looking more at their 50th anniversary build since they recently did the full reveal of the first one they built. Went to their site and noticed their "Evolution" package comes with a DOHC head. Is that yours? I know the OS Giken head is an option for those high dollar builds, but I can't imagine them going with it when there's a better cost option around. Edited August 6, 2021 by Zetsaz Typos Quote Link to comment Share on other sites More sharing options...
Derek Posted August 5, 2021 Author Share Posted August 5, 2021 50 minutes ago, Zetsaz said: is one of your buyers MZR Roadsports in the UK? Nope. I saw that awhile ago and assumed that they were either developing their own head or had made a deal with OSG to buy complete motors. It also say's Nissan 3400 straight 6. Neither the OSG nor mine is a Nissan product so I'm not sure what is going on. I suppose they could be doing some sort of RB thing. Can you get an RB out to 3.4? I don't think the head will flow enough to feed it though in a NA application. Quote Link to comment Share on other sites More sharing options...
rossman Posted August 5, 2021 Share Posted August 5, 2021 19 minutes ago, Derek said: Can you get an RB out to 3.4? I didn't know either so after a bit of Googling I got a hit to a company selling a 3.4L RB30 stroker kit. Quote Link to comment Share on other sites More sharing options...
Derek Posted August 5, 2021 Author Share Posted August 5, 2021 Ok well we know it will go to 3.4. Still a lot of questions though. Also the lack of actual pictures of the MRZ 3.4 DOHC makes me wonder. I will say that knowing MRZ's price points even if they offered a head like mine it would be pricey. Quote Link to comment Share on other sites More sharing options...
Zetsaz Posted August 6, 2021 Share Posted August 6, 2021 7 hours ago, Derek said: Ok well we know it will go to 3.4. Still a lot of questions though. Also the lack of actual pictures of the MRZ 3.4 DOHC makes me wonder. I will say that knowing MRZ's price points even if they offered a head like mine it would be pricey. Yeah, the RB can go to 3.4 but MZR seems pretty keen on keeping NA for the purist perspective on past builds. I follow Peter McDonnell and he's also pointed out that it's probably easier to build a high HP L Series than an RB. Considering his builds, I wouldn't doubt it. There's always the chance they're sticking with the L series and using diesel blocks like Rebello has done. Was just curious! Quote Link to comment Share on other sites More sharing options...
rturbo 930 Posted August 26, 2021 Share Posted August 26, 2021 There's an article about the KN20 head on Road and Track, nice to see this thing get some recognition. https://www.roadandtrack.com/car-culture/a37360407/datsunworks-kn20-head-brings-dohc-to-the-240z/ 1 Quote Link to comment Share on other sites More sharing options...
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