Guest 240_Skyline Posted July 6, 2007 Share Posted July 6, 2007 Hi to all of you out there. This is my first post and I have read through most of the postings and I must say that they are very informative. Most of the questions that other members ask is more so project specific and so I have a set of questions myself. Here we go!!! I'm in the middle of a RB25 swap in my '73 240z and i'm now running into some bumps. I read multiple forums on the fact that the rb25 transmission will require to make more room in the transmission tunnel. Now the part that gets me mixed up is that some forums say that the previous year models will need the tunnel enlarged but the '73 year in specific does not. (To beat it up or not to beat it up is the first question). Next I'm being told by my mechanic that the original drive shaft of the 240z will work with the RB25 transmission. I asked Mckinney Motor Sport if that is indeed correct and I was told that I will need a custom drive shaft due to yoke mating and length. (To buy a new one or to use the original) Any advice on this? Thanks Quote Link to comment Share on other sites More sharing options...
Bob_H Posted July 6, 2007 Share Posted July 6, 2007 I read multiple forums on the fact that the rb25 transmission will require to make more room in the transmission tunnel. Now the part that gets me mixed up is that some forums say that the previous year models will need the tunnel enlarged but the '73 year in specific does not. Most of your questions are answered here, but not exactly in the direct way you are asking, so I'll bite. First, welcome to HybridZ - its not like nico forums or freshalloy,(or even zcar.com, etc..). You'll find some of the best Z car RB swap info on the net here. First, not true about the tranny. I have a 72 and a 73 and have test fit the motor in both cars - there is no appreciable, if any, difference in the transmission tunnels besides the tranny mount configuration, (bolt from beneath on the 72 and earlier, bolt front to rear on the 73 and later). You will have to make a custom tranny mount of some kind. I have the later model RB25 RWD trans - which is physically larger than the earlier models. Yes, its a tight fit, but no beating required. you will have to removed the trans mount "ears" in the trans tunnel. If you have a pre 73 with the bolts that go straight up, it will fit w/o cutting. 73 and later required some cutting of the "ears" and new mounts fabricated, but no beating of the tunnel, etc.. Next I'm being told by my mechanic that the original drive shaft of the 240z will work with the RB25 transmission. I asked Mckinney Motor Sport if that is indeed correct and I was told that I will need a custom drive shaft due to yoke mating and length. (To buy a new one or to use the original) The Original driveshaft will not work with the RB25 transmission - the input yoke is different. Depending on what you received, the "front" portion of the rear driveshaft on the GT-R can be made to work - depending on where your engine mounts are, that you have the R200 flange, etc... Its a big iff - I happen to have one that will work - but each GT-R model is slightly different, and my driveshaft was actually from a Stagea 260 RS - basically a station wagon version of the GT-R with R33 parts. The rest of the info for driveshafts is contained in posts in this forum. My recommendation is to have a custom driveshaft made - it will run around $200 at a decent driveshaft shop and will fit perfectly assuming you measured correctly. Here is a thread on driveshafts: http://forums.hybridz.org/showthread.php?t=105297&highlight=rb25+transmission+driveshaft Good luck - again, you'll find 90% of your answers in previous threads. I suggest when you post questions that you post a link to threads you did find, but that didn't quite match what you were looking for - it helps us from pointing you in the wrong direction. -Bob (72 Datsun with RB26 swap ongoing). Quote Link to comment Share on other sites More sharing options...
Guest 240_Skyline Posted July 6, 2007 Share Posted July 6, 2007 Bob, Thanks for the info. I got the engine and trany mounts from Mckinney and so that's one less thing to worry about. I will then go and have a shaft made. You have been very informative and thanks for the welcome. I do plan on using this forum for the " real deal info" not a buch of crap I read on other forums. To be quite honest I need to further familiarize myself with finding threads and posts to info I seek. Thanks again Bob. I will be posting pics of the work in progress! Rob Quote Link to comment Share on other sites More sharing options...
ZXRockie Posted July 6, 2007 Share Posted July 6, 2007 Bob, Thanks for the info. I got the engine and trany mounts from Mckinney and so that's one less thing to worry about. I will then go and have a shaft made. You have been very informative and thanks for the welcome. I do plan on using this forum for the " real deal info" not a buch of crap I read on other forums. To be quite honest I need to further familiarize myself with finding threads and posts to info I seek. Thanks again Bob. I will be posting pics of the work in progress! Rob Bro, you should wait on the mount. CRS has the whole kit for around 300 bucks shipped to your house. good luck in you swap and all the info you need is here. read a lot before taking a step. Quote Link to comment Share on other sites More sharing options...
alexideways Posted July 7, 2007 Share Posted July 7, 2007 IIRC, I read somewhere (probably here on HZ) that if you use the stock 200ZR engine mounts, the 200ZR shaft will just slip right in. Run a search for that as I'm not 100% positive on that, it might also be the front portion of the Skyline shaft but, I'm pretty sure there is one that's bolt in with the 200ZR mounts. I'm also in the process of shoehorning an RB25DET in my 73. Good luck & welcome to HZ, you've found the best place for your endeavor. Quote Link to comment Share on other sites More sharing options...
Guest DevilZwannabe Posted July 10, 2007 Share Posted July 10, 2007 I can't find a link for the CRS mounts, $732 shipped is a rip! you'd think you would get some pipes with that! Thanks Quote Link to comment Share on other sites More sharing options...
Z U L8R Posted July 10, 2007 Share Posted July 10, 2007 on the fuel tanks for the non 280z's....the return hose is pinhole size since the factory motors are/were carb'd. when doing a friend's 240z we capped the original return bung and ran the return hose from the fpr/rail to one of the "vent" bungs on top of the fuel tank. any reason whatsoever 240_skyline would have a problem doing the same? my friend hasn't had a problem with that. i mention this because, a lot of people swear you have to get a 280 fuel tank, and this was a viable/easy overcame hurdle. Quote Link to comment Share on other sites More sharing options...
ZDrifter Posted July 10, 2007 Share Posted July 10, 2007 The 200zr mounts do bolt the RB25DET in but it sits high and forward in the engine bay. You wont be able to close the hood all the way. I made my own mounts, motor and tranny for about $40 bucks. I placed my engine as low and far back as possible. Hopes this helps you out, and also get a walbro 255 fuel pump, high flow rate and I got mine on ebay brand new for $120. Quote Link to comment Share on other sites More sharing options...
synthtk Posted July 17, 2007 Share Posted July 17, 2007 I have an early 71 with an R34 RB25DET trans in it, I did not have to modify the transmission tunnel except for cutting off and then moving the stock transmission mounts back. I am using the driveshaft for the R34 RB25DET trans and it fits perfect, I just had the rear flange changed to fit my R200. I am using Rick Wong/Infinity Machining motor mounts and the Supra Mk3 isolators for the main engine/trans placement. Quote Link to comment Share on other sites More sharing options...
NismoZ Posted July 18, 2007 Share Posted July 18, 2007 Link to CRS http://www.rodshop.com.au Quote Link to comment Share on other sites More sharing options...
alexideways Posted August 7, 2007 Share Posted August 7, 2007 I can attest that the 200zr mounts WILL let you close the hood but, as stated by Zdrifter, it places the engine a little too high & forward for "IDEAL" weight distribution but, for a street car, it's not that bad as it makes the car less prone to over-steer. Quote Link to comment Share on other sites More sharing options...
stony Posted August 7, 2007 Share Posted August 7, 2007 I can attest that the 200zr mounts WILL let you close the hood but, as stated by Zdrifter, it places the engine a little too high & forward for "IDEAL" weight distribution but, for a street car, it's not that bad as it makes the car less prone to over-steer. Have you weighed out the car. My 200zr mounts with the rb26 slightly heavier then the rb25 put my car at a 51 front 49 rear. This could easily be tuned out with suspension changes. You can move the engine back maybe an inch ( for more ideal position) and the mounts put the oil pan right at the bottom of the crossmember. so lowering the engine more will make the oil pan the lowest thing in that part of the car. Not sure if that is a good idea. My 2 cents Quote Link to comment Share on other sites More sharing options...
ZDrifter Posted August 11, 2007 Share Posted August 11, 2007 As far as a street car goes I wouldn't be so strict on it especially since it will bring the oil pan low like Stony said. But if you get that engine in there as close to the middle center of the car then you have will the best setup for tuning your wight distribution, more of the vehicles weight brought to the center of the car= better handling... This is my 280's weight on the scales with the mounts I made... Without me in the car. LF: 644lbs. RF: 753lbs. LR: 700lbs. RR: 672lbs. Total: 2,770lbs. Me in the car. LF: 695lbs. RF: 750lbs. LR:759lbs. RR: 672lbs. Total: 2,907lbs. Quote Link to comment Share on other sites More sharing options...
DJACEY Posted August 11, 2007 Share Posted August 11, 2007 Sorry to barge in but has anyone got photos of how they fabricated and fixed the mounts for a RB25DET gearbox in a 260Z ? Thanks guys. Quote Link to comment Share on other sites More sharing options...
ZDrifter Posted August 11, 2007 Share Posted August 11, 2007 This is in my '78 280z. I'm pretty sure it will be the same... This is where it sits... Quote Link to comment Share on other sites More sharing options...
DJACEY Posted August 12, 2007 Share Posted August 12, 2007 Thanks for the photo's. You couldn't get the stick lined up more central than that ! Quote Link to comment Share on other sites More sharing options...
turbo_fb Posted August 19, 2007 Share Posted August 19, 2007 Link to CRShttp://www.rodshop.com.au CRS har engine mounts for : EM81 3 Litre Turbo RB30 To Datsun 260Z Aren't the rb30 block similar to the rb25 or 26? Quote Link to comment Share on other sites More sharing options...
alexideways Posted August 25, 2007 Share Posted August 25, 2007 CRS har engine mounts for :EM81 3 Litre Turbo RB30 To Datsun 260Z Aren't the rb30 block similar to the rb25 or 26? Yes they are and yes they will work but, with the cost of the mounts + the cost of shipping, you'd be better off looking at mounts that are built and sold by HZ members... Or build your own. Quote Link to comment Share on other sites More sharing options...
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