lauko Posted September 12, 2016 Share Posted September 12, 2016 Hello fellow Z guys! It's my first post here so I hope no one minds being a technical question. I have been following some of the threads here for some time now and finally found a question with no answer. I have seen the combination L28 + L24 rods + 89mm KA24 pistons in a few threads (and on some other web forums), but everywhere it was just described as a possible option or as a "plan for doing a build". I want to hear some hands-on experience from someone who has already build it and drove it. And the most important question: would he build it again? The 3.0 that you get from that combination of parts sounds very nice to me (especially because there is no way to find a LD28 crank in Europe), what bothers me is only the cca 9.3:1 compression ratio that you get with the N42 head (probably the best option regarding CR). I am not sure if that is enough for a "performance" engine. Thanks, Peter Quote Link to comment Share on other sites More sharing options...
Villeman Posted September 12, 2016 Share Posted September 12, 2016 Well, I can point you to a diesel crank easily here in europe. Just write to Jelmerpatrol ..... its FAR more easy to get one in europe than in America. Just forget the "maxima crankshaft", it was used in Patrols, Laurels and other vehicles. Maybe this helps... Quote Link to comment Share on other sites More sharing options...
JelmerPatrol Posted September 12, 2016 Share Posted September 12, 2016 I have one for sale from a Laurel. The Patrol never got the LD28, only the SD33 and later the RD28. Quote Link to comment Share on other sites More sharing options...
Villeman Posted September 12, 2016 Share Posted September 12, 2016 oh, didn´t know that, wasn´t some guy claiming that he has lots of LD28 cranks from patrols in south africa? Anyways.....as I told, you can get those in Europe Quote Link to comment Share on other sites More sharing options...
lauko Posted September 12, 2016 Author Share Posted September 12, 2016 Oh, interesting. So maybe we will soon have another L28 / KA24 engine build thread, where the owner changed his mind? Anyway, I sent JelmerPatrol a message about the crank. I'm still curious about the KA24 combo, if anyone has some experience, please do share! Thanks, Peter Quote Link to comment Share on other sites More sharing options...
BluDestiny Posted September 12, 2016 Share Posted September 12, 2016 What your describing is just a bottom end. I've seen 3.1L strokers make less than an 2.8 with head work. You might very well get good and bad responses. As for the compression ratio, that can alwasy be modified with head work and chamber welding. Quote Link to comment Share on other sites More sharing options...
seattlejester Posted September 22, 2016 Share Posted September 22, 2016 (edited) ^Don't forget head gasket thickness. I was one of those who talked about it in the beginning of my build, but ended up just talking. I will have to look it up, but I think that combo can be run without the stroker crank for a slight displacement increase up to 3L. As stated it is just a bottom end spec, if the head doesn't flow or you don't supply it with enough fuel/air/exhaust out then it won't do much good. Looking at the numbers associated with good headwork a good triple carb setup and a good exhaust got me on my road to a swap. Edited September 22, 2016 by seattlejester Quote Link to comment Share on other sites More sharing options...
lauko Posted September 23, 2016 Author Share Posted September 23, 2016 Hi! Yes of course the head work is a crucial part of the build. But even with a good head work the 9.3 CR seems to me a bit too low to get some serious power. I imagine that also a good exhaust and intake / carbs can't help you much if the CR is not a bit higher than only 9.3. Am I mistaken...? Peter Quote Link to comment Share on other sites More sharing options...
Nismospek Posted September 23, 2016 Share Posted September 23, 2016 I was thinking of maybe going this route with my bottom end since there are so much risk with running the stroker crank. Would really like to find someone who has this done already so I can get more info on it. Quote Link to comment Share on other sites More sharing options...
seattlejester Posted September 26, 2016 Share Posted September 26, 2016 ^What risks? As long as the timing is in check and the fuel is adequate and the build is done appropriately there is no added risk. This also has a chain so there is more safety then a belt driven motor. If you don't use this combo and start going for a custom piston with a lower pin height for compression and have to machine in valve reliefs then you are looking at some risk. If CR is a concern you can get custom pistons, if you want to make power without changing the compression a turbo would be much cheaper. Quote Link to comment Share on other sites More sharing options...
OLDZZZ Posted October 28, 2016 Share Posted October 28, 2016 (edited) Finished a 3.1L build a few months back. LD28/VO7 crankshaft, late(9mm) L24 rods with ARP bolts, 89mm KA24 pistons with slight dish. L28 N42 block and N42 head, ARP head studs. Rebello hot street camshaft, Isky valve springs and retainers, OEM adjustable camshaft gear, lightweight steel flywheel, Performance Products SFI spec harmonic damper. OEM high volume oil pump, Mallory Unilite distributor and coil, triple Weber 45 DCOE carbs, Cannon intake manifold, ceramic coated Pacestetter header, etc. Block was clearanced for the LD28 crankshaft and bored using a torque plate, head received porting and smoothing work, intake manifold match ported, engine balanced to within 1 gram. .075" Cometic MLS head gasket used for approx. 9.6 to 1 compression ratio, custom carb heat shield, OEM fuel rail modified to add 3rd fuel outlet, valve cover and crankcase vented to catch tank with breather and drain, etc. 2 1/2" exhaust system, OEM Exedy/Daikin 240mm clutch set, 280ZX close ratio 5 speed, 300ZX Turbo R200 3.70 limited slip differential, etc. The engine had it's final tune with about 1,500 miles on it when initial timing was reset and the final set of advanced timing curve springs were installed in the distributor. The engine is in a 73 240Z and I tried to make the install look almost like it was stock except for the Weber carbs, but as soon as the engine is fired up you know it is definitely not stock. The engine revs to 6,500 RPM quickly and the car will make 90 MPH in 3rd gear like right now. A lot of fun to drive. The engine was not an inexpensive proposition but well worth it. Edited October 28, 2016 by OLDZZZ Quote Link to comment Share on other sites More sharing options...
seattlejester Posted October 29, 2016 Share Posted October 29, 2016 Rough estimate of cost? Would be interesting to put it in perspective to other options. Quote Link to comment Share on other sites More sharing options...
munters Posted October 29, 2016 Share Posted October 29, 2016 You can also buy a package from Rebello. He sells kits with cast or forged pistons. The price he gave for the kit blow was "arround 2k" in 2011 You can buy our stroker kit. It comes with a stroked L28 crank (81mm) forged J&E piston, billet long rods and engine bearings. We usually go about 1.5mm over bore which will give you a 2720cc engine. We have gone further on the over bore but you need to sonic test the cylinders. Quote Link to comment Share on other sites More sharing options...
lauko Posted November 2, 2016 Author Share Posted November 2, 2016 OLDZZZ you are very good at describing my dreams, ha! Both the engine compartment as the interior look fantastic! Do you have any data regarding power/torque? Quote Link to comment Share on other sites More sharing options...
jacky4566 Posted November 3, 2016 Share Posted November 3, 2016 lauko, getting back to your question. Nobody has done L28 + L24 rods + 89mm KA24? Seems like it would be a great turbo build 7.738 compression. Quote Link to comment Share on other sites More sharing options...
seattlejester Posted November 3, 2016 Share Posted November 3, 2016 I think you are mistaken. Should be around high 8.X to mid 9.x depending on if you go with flat pistons, the ones with valve reliefs, head gasket thickness, and head. Usually people run an E31 or a shaved P90, so pretty much in the 9.X category. Quote Link to comment Share on other sites More sharing options...
jacky4566 Posted November 3, 2016 Share Posted November 3, 2016 Oh. The Ozdat calculator has the KA24E pistons at 7.738 compression with a P90 head. Bore 89mm Pin height 34mm Dish 2.8cc Quote Link to comment Share on other sites More sharing options...
seattlejester Posted November 3, 2016 Share Posted November 3, 2016 (edited) Perhaps you forgot to factor in the L24 rods? 133mm vs 130mm http://atlanticz.ca/zclub/techtips/calcs/engine%20builder/index.html Edited November 3, 2016 by seattlejester Quote Link to comment Share on other sites More sharing options...
jacky4566 Posted November 3, 2016 Share Posted November 3, 2016 Nope. Head P90 Gasket Nissan Piston KA24E Rod L24 Crank L28 Compression ratio= 7.65:1 Total displacement= 2948.82 cc Quote Link to comment Share on other sites More sharing options...
seattlejester Posted November 3, 2016 Share Posted November 3, 2016 Ah you are using an unshaved P90 and a stock nissan head gasket. Based off of OP's desire for higher CR I would guess an NA build is in mind, so a shaved P90, or E31 would be preferable, even an N42 with a fel pro and flat KA24 pistons would net 9.2CR. Quote Link to comment Share on other sites More sharing options...
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