rturbo 930 Posted October 4, 2021 Share #25 Posted October 4, 2021 8 hours ago, AK260 said: The procedure is to fire up and let it idle for 20-30 mins, then baby it along at constant revs for 200-300 miles. While I am hardly an expert on the topic, I know enough to know that's exactly what you don't do when breaking in a motor. I'd be questioning the credibility of the engine builder if he told me that, and would likely ignore his instructions. 1 Link to comment Share on other sites More sharing options...
Diseazd Posted October 15, 2021 Share #26 Posted October 15, 2021 On 10/4/2021 at 7:39 AM, Patcon said: Im ok with the babying part to some degree, but I agree on accelerating and decelerating to set the rings. The idle part wouldn't be my choice. What kind of warranty is he offering? Motors are motors. His shouldn't need a special procedure compared to someone elses. @Diseazd What is yours or Eijis preffered break in method? Patcon......I initially fire up a new engine and bring it up to 2000 to 2500 rpm for 15 to 20 minutes. After that initial run, check timing and look for leaks and then I try to get it on the road (usually hoodless). I’m with you in that I run her up to about 3000 to 4000 rpm and let off (drag her down) over and over a dozen or so times. This back-pressure is supposed to force the rings out snug against the cylinder walls. I try to put 50 miles on her, check for any leaks and then gradually take her up more and more aggressive. After 100 miles, you can pretty much play games with her. All IMO......Guy 2 1 Link to comment Share on other sites More sharing options...
Diseazd Posted October 15, 2021 Share #27 Posted October 15, 2021 Just another point to consider.........I would definitely go with the SU’s to break in a new engine. One of the worst things that you can do with a break-in is to wash out the rings with too much gas. A scored cylinder is the result and will ruin an engine. 3 1 Link to comment Share on other sites More sharing options...
AK260 Posted October 15, 2021 Author Share #28 Posted October 15, 2021 (edited) 56 minutes ago, Diseazd said: Just another point to consider.........I would definitely go with the SU’s to break in a new engine. One of the worst things that you can do with a break-in is to wash out the rings with too much gas. A scored cylinder is the result and will ruin an engine. Agreed chap! My buddy did go with his SUs and we got them tuned right pretty quickly. It produced excellent power below the 4k rev limiter ceiling on the first drive, so he's going to use them for the first 1000 miles and send the car with the triples to the RR once the run-in period is completed. With the AFR sensor / gauge installed, we should be able to find a needle in my collection that is rich enough to fuel it sufficiently further up the rev range. On that note, to prove that the SUs can deliver enough fuel for over 230bhp to 6.6Krpm, I dropped in super rich KV needles into mine and the carbs can hit high 10s on the AFR at 6K rpm on a third gear pull - clearly over-rich, but point made! With that argument out of the way, there is only the question of flow, which his OERs will clearly address in good time. The beauty of going this way is that he will now have a direct comparison for SUs v DCOE (for the sake of scientific research 😛 and my personal curiosity). This way he will not wonder if he should have just kept the SUs, he will know through real-world driving experiences, where the SUs work best and where the DCOEs bring the engine to life even more. I'm personally a die-hard SU man for a road car, but with this nearly 3.0 engine being something quite special, even I have to concede that it needs the extra flow and sound track of the triples. But equally, I want to see what they do to the engine's current scintillating pull between 2-4Krpm - where we spend a lot of time in 2nd /3rd around the UK's fun twisty country roads - and it's still not "on cam" at that point!!! Can't wait to see what it will do between 4-7K. I've seen too many dyno charts of triples showing a rise in torque at 2/2.5k only to drop off quite noticeably until 4K where they come to life and produce great power / fuel atomisation. I'm hoping with some proper tuning and choke sizing, he can have the best of all worlds. Either way, that engine needs triples or Efi to give its full potential. Edited October 15, 2021 by AK260 1 Link to comment Share on other sites More sharing options...
Diseazd Posted October 15, 2021 Share #29 Posted October 15, 2021 (edited) @AK260I wouldn’t worry too much about running your motor with SU’s. I run both of my 3.1 stroker motors with SM needle SU’s with no problem through the range. Eiji and I race each other in the quarter mile once or twice a year. Earlier this year my SU powered 3.1 won by .25 seconds vs his triple sidedrafts. He ran a heavier 280Zx…….we race again on November 6th……….bragging rights till Spring of 22…LOL Edited October 15, 2021 by Diseazd 1 Link to comment Share on other sites More sharing options...
madkaw Posted October 15, 2021 Share #30 Posted October 15, 2021 5 minutes ago, Diseazd said: @AK260I wouldn’t worry too much about running your motor with SU’s. I run both of my 3.1 stroker motors with SM needle SU’s with no problem through the range. Eiji and I race each other in the quarter mile once or twice a year. Earlier this year my SU powered 3.1 won by .25 seconds vs his triple sidedrafts. He ran a heavier 280Zx…….we race again on November 6th……….bragging rights till Spring of 22…LOL What kind of times in the 1/4? Link to comment Share on other sites More sharing options...
Diseazd Posted October 15, 2021 Share #31 Posted October 15, 2021 High 14s @madkaw….…trying to get low 14’s……we’ll see in November. Link to comment Share on other sites More sharing options...
siteunseen Posted October 16, 2021 Share #32 Posted October 16, 2021 (edited) 1 hour ago, Diseazd said: High 14s @madkaw….…trying to get low 14’s……we’ll see in November. But it looks good! Question for the Guy. Which is quicker, one of the Zs or the NSX? Edited October 16, 2021 by siteunseen Link to comment Share on other sites More sharing options...
Diseazd Posted October 16, 2021 Share #33 Posted October 16, 2021 The NSX…….haven’t raced it, but it’s supposed to turn high 12’s out of the box. 2 Link to comment Share on other sites More sharing options...
madkaw Posted October 16, 2021 Share #34 Posted October 16, 2021 I’d like to get to the track on a official timer . My GPS speedo says 13.10 ! 2 Link to comment Share on other sites More sharing options...
siteunseen Posted October 16, 2021 Share #35 Posted October 16, 2021 1 hour ago, Diseazd said: The NSX…….haven’t raced it, but it’s supposed to turn high 12’s out of the box. I had a GSXR 750 Suzuki that I got 10.49 on a print out receipt from a local track. That's my best but on a motorcycle with the front tire barely off the ground. Scary fun! 1 Link to comment Share on other sites More sharing options...
AK260 Posted October 16, 2021 Author Share #36 Posted October 16, 2021 I had a GSXR 750 Suzuki that I got 10.49 on a print out receipt from a local track. That's my best but on a motorcycle with the front tire barely off the ground. Scary fun!I’ve been on the back of a GSX-R600 and MY GOD that thing could accelerate. Cant imagine what it must have felt like in yours full throttle aiming for the horizon! 1 Link to comment Share on other sites More sharing options...
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