kimdrummel Posted October 28, 2014 Share Posted October 28, 2014 Just as the title says. How much power can i produce from my turbo L31 stroker with L24 rods and Ross pistons before i need to start worrying about a rod giving in? I am looking to produce somewhere in the 400HP region with a lot of mid range torque. Thinking about installing H-beam or X-Beam rods instead, but only if it requires me to do so. Quote Link to comment Share on other sites More sharing options...
NewZed Posted October 28, 2014 Share Posted October 28, 2014 I thought the issue with rods was RPM, not power output. Inertia at the top of the stroke. So it would depend on how fast you intend to spin the crankshaft, mainly. Quote Link to comment Share on other sites More sharing options...
Xnke Posted October 28, 2014 Share Posted October 28, 2014 The stock rods have been run in racing service, prepped and checked, at 1000hp+ and 9500rpm+. The rod bolts, however, will need attention. At the 400hp level, the stock rods, checked for flaws, will be just fine when installed with good rod bolts. Quote Link to comment Share on other sites More sharing options...
SleeperZ Posted October 28, 2014 Share Posted October 28, 2014 Pretty sure stock rods in the L series are reliable at 400hp. Close inspection, balancing and de-stressing are good insurance however. Quote Link to comment Share on other sites More sharing options...
Tony D Posted October 29, 2014 Share Posted October 29, 2014 (edited) 100 per hole. After that, you're on borrowed time, I don't know who was making 1000+ at 9500+ on them, but it wasn't the boys at Electramotive, Edited October 29, 2014 by Tony D Quote Link to comment Share on other sites More sharing options...
Xnke Posted October 29, 2014 Share Posted October 29, 2014 (edited) Don Devendorf, prior to switching to the sports option rods. The stock rods didn't last long enough between races, and took too much time to prep. Tony...I said 1000+HP and 9500+RPM...I didn't mean to imply that they did both at the same time. I see now how that could have been construed; I do not know of anyone pushing both of those numbers at the same time. I have seen prepped stock rods spin 12,500RPM in an L18, for limited use, but that's about the fastest I've seen them turned. That particular engine now has sintered titanium alloy rods installed...some ridiculous exotic that I don't even want to think about the cost of. Edited October 29, 2014 by Xnke Quote Link to comment Share on other sites More sharing options...
NewZed Posted October 29, 2014 Share Posted October 29, 2014 There's a lot of good stuff about rods in the Honsowetz "How to Modify.." book. Stock, sports-option, race-prep, oiling holes, rod bolts, etc. Quote Link to comment Share on other sites More sharing options...
kimdrummel Posted October 29, 2014 Author Share Posted October 29, 2014 Wow, never thought the L24 rods would be that tough. I'm not planning on revving it so much as i am more after low down and mid-range torque. So rev limiter at 6500 RPM or somewhere around there.The rods are balanced and i also think they have ARP bolts. Not sure about that though since it was a while since i checked the bottom end. The engine was first built around 2005 or something by Z-Gad here at the Forum. And as far as i know it has always been running with the L24 rods and turbo. First with a P90 head and now it has an N42 head. Calculated the AFR to be around 8.5.But anyhow, it sound as if i should be able to run about 400 HP and lots of torque pretty safely then when listening to you guys. Gonna check the bolts though. And maybe mount some new piston rings. Also, gonna check out that book you mentioned NewZed. Thanks a bunch! Quote Link to comment Share on other sites More sharing options...
Xnke Posted October 29, 2014 Share Posted October 29, 2014 When I say rod bolts...I mean throw the old rod bolts out and replace them with aftermarket units. The stock rod bolts are the only major weak point I can think of in the stock L28 bottom end...and they are CHEAP! Quote Link to comment Share on other sites More sharing options...
Tony D Posted November 1, 2014 Share Posted November 1, 2014 (edited) "So rev limiter at 6500"--that is your personal choice. That conclusion did not get get extracted from the above statements. I have L20B rids that equal Xnke's experience in terms of RPMs in an L6. Horsepower N/A and RPM capability are completely different discussions. For a low revving, boosted engine only making 400HP, the track record for the stock unprepped rods is clear: ARP Bolts & Run It. I can't think of the last time I disassembled the rods on any L-Series and used stock bolts. Had to be back in the 80's when I couldn't get the 396 Chevy Bolts easily in Japan. Since ARP started making them for the L-Series, I haven't ever bought a stock new rod bolt! Development on the turbo Z in the early 80's resulted in the dropping of the Nissan Rod on anything approaching or over 600HP. The car tested in Road and Track did not have stock Nissan Rods, Prepped Nissan Rods but they did have a Nissan Part Number and were available to anybody from any Nissan Dealership in the world, so they were technically in the eyes of the sanctioning body "Stock Nissan Rods"---were they in ANY engine from Japan, in ANY production car for sale on ANY lot in the world? Not on your life! Today you would refer to them as "aftermarket" rods...Carrillo, Metchart, Cosworth, etc... Not "prepped Nissan-Produced Rods" by a longshot! By the rule, though, they were "Nissan Production Rods", there is a BIG difference in the terminology. This is actually in the FH book in part... Edited November 1, 2014 by Tony D Quote Link to comment Share on other sites More sharing options...
Xnke Posted November 1, 2014 Share Posted November 1, 2014 Might look into FJ24 rods before you relagate them to non-stock....technically they were stock too, and are the basis of some mighty fine "stock" rods... At 600hp, the rods can start to show cracking across the beam near the small end. it isn't immediate, but there isn't much time at that level before rod failure occurs. Quote Link to comment Share on other sites More sharing options...
Tony D Posted November 2, 2014 Share Posted November 2, 2014 (edited) Era is late, if I'm not mistaken the FJ24 for the 240RS was well after production of the L-Series had ceased. I went to look at the new for 87 or 88 FJ-Powered 240RS at Naha Prince when it came out. The DR30 Skyline had the FJ20, and I think was (?) 81 maybe 82... But that's not an FJ24. Which, oddly, was carbureted. The turbo FJ20's were stick running 250+ BMEP as I recall, with the N/A FJ24 right near that at around 200. The early FJ20s were well below that for use in the Gazelle and Sylvia. It was the DR30 Skyline where the Turbo FJ made the most power. Those rods were...800gm? 740 or 840 sticks in my mind... Beefy-heavy, They were not Nissan-Produced Rods in the Nissan L28 making 1,000 rods. They had a Nissan part number, but you couldn't by any car anywhere where those same rods were installed into an engine at the Nissan Engine Assembly Facility. Edited November 2, 2014 by Tony D Quote Link to comment Share on other sites More sharing options...
Xnke Posted November 2, 2014 Share Posted November 2, 2014 That's true...but they were sold through the Nissan dealerships as the "Sports Option" rods. I bought a partial set here in town about three months back...They still haven't found my sixth rod, so I may never have a complete set. I have a complete set of 6 12100-N7170, and an incomplete set of 5 12100-B2501 rods...The -B2501 PN is the FJ24 140mm rod, and was supposed to be sold as sets of 4 or 6, weight-matched and sold as a set. Both of these part numbers have bronze bushed small-ends at 23.5mm, and standard big ends, with cap-screws instead of rod bolts. You wouldn't know where I could get the 12113-H5820 rod bolts for the -N7170 rods, would you, Tony? Quote Link to comment Share on other sites More sharing options...
Tony D Posted November 3, 2014 Share Posted November 3, 2014 They were throwing those sets in the dumpster back in the mid-90's... Quote Link to comment Share on other sites More sharing options...
AZGhost623 Posted November 3, 2014 Share Posted November 3, 2014 Who's up for some dumpster diving? Quote Link to comment Share on other sites More sharing options...
Tony D Posted November 3, 2014 Share Posted November 3, 2014 Hoardalicious..... I'm sure a lot more got written off before "The move to Dogpatch" Quote Link to comment Share on other sites More sharing options...
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