madkaw Posted September 24, 2020 Share Posted September 24, 2020 (edited) Just thought I would start another thread . This was supposed to be a L28/54 MN47 , but it ended up with a Rebello prepared N42 /MN47. The N42 was sent to Rebello and he prepped it for JE 89mm pistons . LD crankshaft offset ground with Eagle rods to get me 3.2 The MN47 head was ported by me - no flow bench , just seat of the pants cutting. Ports were only opened up to 35mm . Manely 44/35 swirl valves with bronze guides . The head is at 39cc . The cam is a 535 lift Bonk cam . It’s advertise 535 , but I could only get that with 0 lash , so it’s more like 520 lift . Engine management is a Megasquirt 3X with 270cc 14mm injectors running on a stock N42 intake with a 240sx 65mm TB . Exhaust is a MSA 6-2 header with dual exhaust to the back . BHJ damper , Kameari oil pump and chain tensioner . GM alternator 90 amps D-585 ignition coils with MSD wires . 4 row radiator with single electric fan cam sensor from 4.0 Jeep modified by me . flywheel 12lb steel that doubles for my CAS . Currently rev limiter is set at 7500 . Power drops off before then with current cam and induction .His build wouldn’t have happened except for the knowledge base on this site . Thanks for all that contributed their knowledge . Dyno session is schedule a month out . Currently using butt dyno and GPS speedo to do 0-60 times . It will also do quarter mile . Best time is 4.77 to 60 with some tire spin . Timing is 37 degrees max with a 13.0 set for WOT AFR. 7DE94C66-077D-4635-A801-2A09769EC638.MOV 8B4867CC-29D6-428F-A1D7-5F72482973E3.MP4 Edited September 24, 2020 by madkaw Quote Link to comment Share on other sites More sharing options...
rossman Posted September 24, 2020 Share Posted September 24, 2020 It sounds really good! Looking forward to some dyno numbers. Quote Link to comment Share on other sites More sharing options...
Derek Posted September 24, 2020 Share Posted September 24, 2020 I'm doing exactly the same bottom end and after hearing that now I really need to move it along. Sounds great. You know a KN20 head would solve that pesky power drop off problem:) Quote Link to comment Share on other sites More sharing options...
madkaw Posted September 24, 2020 Author Share Posted September 24, 2020 57 minutes ago, Derek said: I'm doing exactly the same bottom end and after hearing that now I really need to move it along. Sounds great. You know a KN20 head would solve that pesky power drop off problem:) Believe me - I drool about it a lot . A better inductions system would still help in the meantime Quote Link to comment Share on other sites More sharing options...
Derek Posted September 24, 2020 Share Posted September 24, 2020 If it's any consolation I'm envious of the 3.2. Things keep getting in the way. Although the crank is done so that is a pretty big part of it. Quote Link to comment Share on other sites More sharing options...
DuffyMahoney Posted September 24, 2020 Share Posted September 24, 2020 6 hours ago, Derek said: If it's any consolation I'm envious of the 3.2. Things keep getting in the way. Although the crank is done so that is a pretty big part of it. I chickened out and went 88.5 pistons. So I will be 3.1something Quote Link to comment Share on other sites More sharing options...
Derek Posted September 25, 2020 Share Posted September 25, 2020 11 hours ago, DuffyMahoney said: I chickened out and went 88.5 pistons. So I will be 3.1something I'm leaning that direction as well. I have a block that will work at 89 but it's on the edge. I already have enough to worry about:) Quote Link to comment Share on other sites More sharing options...
madkaw Posted September 25, 2020 Author Share Posted September 25, 2020 I left the decision with Dave Rebello. I know he can offset bore to get the most out of the block. I also went with a N42 block after reading it had the highest nickel content and a better chance of being bored higher. Maybe because of the structure of the block . He must have felt pretty confident because I told him that there is a possibility of running as a turbo with a different head . I do not know what wall thickness I ended up with . Quote Link to comment Share on other sites More sharing options...
DuffyMahoney Posted September 29, 2020 Share Posted September 29, 2020 On 9/25/2020 at 4:48 AM, madkaw said: I left the decision with Dave Rebello. I know he can offset bore to get the most out of the block. I also went with a N42 block after reading it had the highest nickel content and a better chance of being bored higher. Maybe because of the structure of the block . He must have felt pretty confident because I told him that there is a possibility of running as a turbo with a different head . I do not know what wall thickness I ended up with . We went through 5 N42 blocks before we found one that sonic tested and the machine shop said could take the 88.5 bore. Quote Link to comment Share on other sites More sharing options...
madkaw Posted September 30, 2020 Author Share Posted September 30, 2020 16 hours ago, DuffyMahoney said: We went through 5 N42 blocks before we found one that sonic tested and the machine shop said could take the 88.5 bore. I guess it also depends on what the builder decides is the safe minimum wall thickness too! Maybe Dave pushes the envelope or is basing it on his experience . I told him I would be pressurizing , but it would be lower psi , higher CR build if anything . Maybe I just got lucky Quote Link to comment Share on other sites More sharing options...
madkaw Posted October 1, 2020 Author Share Posted October 1, 2020 Well it’s harder to get an appointment with a dyno than my doctor . I’m booked out to November . Business is good enough that most shops don’t want to give up there dyno to walk ins , they have so much in house projects . It’s all corvettes and Mustangs , etc.. I did upgrade my injectors to 42 lbs and re-tuned with success. Did another 4.77 split , so happy . Might play with valve timing a little to get more top end, but I think I’m at the end with the N42 intake . My buddy is converting a diesel intake for me to run EFi . I’ll go from 31mm runners to 35mm and looonger runners . It will be interesting . Quote Link to comment Share on other sites More sharing options...
Howsurcargo Posted November 1, 2020 Share Posted November 1, 2020 On 9/30/2020 at 10:07 PM, madkaw said: My buddy is converting a diesel intake for me to run EFi . I’ll go from 31mm runners to 35mm and looonger runners . It will be interesting . I am doing my own turbo build and was thinking about using the early EFI intake manifold flange with maybe 2" worth of the original intake runners as the base for fabricating a bigger runner manifold. I cut off the rest of the manifold. Do you have another one of those diesel manifolds or can you post a picture please? Quote Link to comment Share on other sites More sharing options...
madkaw Posted November 1, 2020 Author Share Posted November 1, 2020 The one to the right Quote Link to comment Share on other sites More sharing options...
madkaw Posted November 3, 2020 Author Share Posted November 3, 2020 Did a dyno run today . 226 HP and 226 torque . pretty happy considering I’m running a stock N42 intake . Quote Link to comment Share on other sites More sharing options...
madkaw Posted November 12, 2020 Author Share Posted November 12, 2020 Quote Link to comment Share on other sites More sharing options...
DuffyMahoney Posted November 13, 2020 Share Posted November 13, 2020 Nicely done. Those are great numbers. Quote Link to comment Share on other sites More sharing options...
AydinZ71 Posted December 16, 2020 Share Posted December 16, 2020 On 11/11/2020 at 6:32 PM, madkaw said: look at that torque drop off! You got room to run! If you can improve the head flowrate, You can bump up your HP quite a bit, even if you didn’t add a single peak ft-lb of torque. Quote Link to comment Share on other sites More sharing options...
madkaw Posted December 16, 2020 Author Share Posted December 16, 2020 13 hours ago, AydinZ71 said: look at that torque drop off! You got room to run! If you can improve the head flowrate, You can bump up your HP quite a bit, even if you didn’t add a single peak ft-lb of torque. I contend that it’s more intake manifold then head . Stock plenum Quote Link to comment Share on other sites More sharing options...
AydinZ71 Posted December 17, 2020 Share Posted December 17, 2020 8 hours ago, madkaw said: I contend that it’s more intake manifold then head . Stock plenum Could be for sure! It is flow-limited based on the linear(ish) torque drop-off. If you are confident the intake manifold is the largest factor, Protunerz out of Ottawa makes a custom intake manifold with larger TB. I purchased as a bundle with turbo exhaust manifold and downpipe. Looking forward to seeing the build quality when he is finished sometime in Feb. Let me know if you want me to make some measurements when I receive mine. Quote Link to comment Share on other sites More sharing options...
madkaw Posted December 18, 2020 Author Share Posted December 18, 2020 22 hours ago, AydinZ71 said: Could be for sure! It is flow-limited based on the linear(ish) torque drop-off. If you are confident the intake manifold is the largest factor, Protunerz out of Ottawa makes a custom intake manifold with larger TB. I purchased as a bundle with turbo exhaust manifold and downpipe. Looking forward to seeing the build quality when he is finished sometime in Feb. Let me know if you want me to make some measurements when I receive mine. Got one in the works now with tapered runners . Stock manifold has 31mm runners . New will be 44-37mm Quote Link to comment Share on other sites More sharing options...
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