Guest SS-Z31 Posted July 11, 2006 Share Posted July 11, 2006 Hi guys, I've been forced to sell the Z31 I had started but all is not lost. I'm doing a restoration of a 1976 BMW 2002 but the engine is shot and I'm not too thrilled with its stock performance (Yes, I've driven a running 2002 and 2002Tii and still wasn't impressed). I was thinking along the lines of a HybridBMW... Actually with an RB25 or 26 (if it'll fit dimensionally) - or an SR20 if the RB is too big. I still have the sump, pan, and crossmember from the 200ZR to use with the RB... hate for that to go to waste . I'm basically wondering if someone with an RB25 and someone with the 26 can measure the physical dimensions of the motor and trans. Height, width (with twin turbos if possible), length, etc. I realize all the structural reinforcing that needs to be added to handle the torque but thats not a problem... Also need to figure out what this will do to the weight balance of the car.... Quote Link to comment Share on other sites More sharing options...
Evan Purple240zt Posted July 12, 2006 Share Posted July 12, 2006 I can give you rough estimates, I just have to measure my car. However, I would think an SR20 may be a better candidate for that car. Did it come with a four or six? Evan Quote Link to comment Share on other sites More sharing options...
Guest SS-Z31 Posted July 12, 2006 Share Posted July 12, 2006 The car originally came with an inline 4, however there have been many conversions to the 325 6 cylinder motor without destroying the weight balance. Some even say it feels better (??). The 4 cyl is a great motor don't get me wrong but power options are somewhat lacking... typical carb upgrades, cams, header without porting and doing major engine work and even then you're only really looking at 140-160hp. I could do the "M2" conversion by putting the 1988-91 M3 4cyl in there but thats over $10k to do correctly. I'd really like to do turbo but I'm kinda weary of putting boost through an old motor like that without a complete rebuild ($$)... not to mention having to convert to fuel injection (also not cheap). I'm not restoring this to all factory original, nor will it be a daily driver. Just want something that'll be very fast and fun to drive. SR20 is still on top of my list of possibles but it'd be nice to see what I could actually fit in there. Suprisingly, there is a decent amount of extra space between the radiator and front of the stock motor, as well as between the firewall and rear of the motor. Evan - do you have the 25 or the 26 in your car? Does anyone have any rough estimates of what the RB25/26's weigh with trans? Quote Link to comment Share on other sites More sharing options...
Evan Purple240zt Posted July 14, 2006 Share Posted July 14, 2006 I have an rb25det, ill get you dimensions today. Weight is not terrible, and it did not upset the feel of my car at all IMO. I cannot find a weight though, and 750ish is a pretty good estimate from a buddy of mine. Evan Quote Link to comment Share on other sites More sharing options...
Guest SS-Z31 Posted July 14, 2006 Share Posted July 14, 2006 Sounds good - I really appreciate the help! I'd estimate the stock M10 in the BMW to be around 400-450 lbs with transmission. I think it's an iron block but didn't look too much at it. Depending on how I mount the new motor, the extra weight wouldn't be horrible for the power it produces... I'd imagine the RB26 to be similar in physical size to the 25 but the twins take up more space thats for sure. I'm trying to get a hold of a friend with an SR20'd 240sx to see if I can pull some measurements for that motor. I'll try to get some pics of my car taken and put up. I recently saw pictures of a 2002 with a 3.6L M5 motor in it... some rich German guy. it's a work in progress but that is insane for such a light car... http://www.speedworxs.de/newpage0.html Quote Link to comment Share on other sites More sharing options...
Evan Purple240zt Posted July 16, 2006 Share Posted July 16, 2006 Sweet I gotta learn german, thats one dirtyass motor! Ill try getting dimensions tomorrow, sorry for the wait but its like almost 100 and stupid humid out right now!! Evan Quote Link to comment Share on other sites More sharing options...
Careless Posted July 16, 2006 Share Posted July 16, 2006 im participating in hosting a drift event today and there are all kinds of engines today at the track. skylines, 240's, GTR's, 350z's. I'll get some specs Quote Link to comment Share on other sites More sharing options...
Guest SS-Z31 Posted July 17, 2006 Share Posted July 17, 2006 You guys are awesome! Thanks for the help! Evan - I'm not in a big hurry so no worries. I pulled the old motor out yesterday and started cleaning up the engine bay. There are some extra trays in the engine bay that I can cut out to free up some more room (while adding some tubular reinforcement to the front fascia, and a strut tower bar). I think I'll have enough space for an RB and definately an SR. The wiring is so crusty that I might have to make an entirely new harness. So much work... Quote Link to comment Share on other sites More sharing options...
Careless Posted July 18, 2006 Share Posted July 18, 2006 You guys are awesome! Thanks for the help! Evan - I'm not in a big hurry so no worries. I pulled the old motor out yesterday and started cleaning up the engine bay. There are some extra trays in the engine bay that I can cut out to free up some more room (while adding some tubular reinforcement to the front fascia' date=' and a strut tower bar). I think I'll have enough space for an RB and definately an SR. The wiring is so crusty that I might have to make an entirely new harness. So much work...[/quote'] im currently making a harness for a friend's corolla. i figure it's probably the best thing to do to get the most out of your electrical system, and to learn a lot along the way. Im building it for megasquirt, so it's not gonna be that hard, just a few changes... but the interior lighting/accessory harness is gonna be brand new aswell. i would NEVER touch that harness or try to make a new one. that one is rather tedious. especially for toyota's and their weird junction boxes that basically loop connections. there are kits on ebay called EZ-Wiring, they are comparable to Painless systems at half the price. available in all black with stamped labels on the wire insulation, or in colour coded sets. 8, 12, 18, 21 circuit combos. go with 18 atleast if you have all the options on your car, or intend to have them. as for the engine dimensions... i was a bit too busy taking pics yesterday, and totally forgot about the engine dimensions =( sorry, mang Quote Link to comment Share on other sites More sharing options...
Guest SS-Z31 Posted July 18, 2006 Share Posted July 18, 2006 im currently making a harness for a friend's corolla. i figure it's probably the best thing to do to get the most out of your electrical system' date=' and to learn a lot along the way. Im building it for megasquirt, so it's not gonna be that hard, just a few changes... but the interior lighting/accessory harness is gonna be brand new aswell. i would NEVER touch that harness or try to make a new one. that one is rather tedious. especially for toyota's and their weird junction boxes that basically loop connections. there are kits on ebay called EZ-Wiring, they are comparable to Painless systems at half the price. available in all black with stamped labels on the wire insulation, or in colour coded sets. 8, 12, 18, 21 circuit combos. go with 18 atleast if you have all the options on your car, or intend to have them. as for the engine dimensions... i was a bit too busy taking pics yesterday, and totally forgot about the engine dimensions =( sorry, mang [/quote'] Great info about the wiring sets. I was looking at the Painless but they are expensive and I am by no means a wiring tech so I didn't quite grasp the concept of the different circuit options. I was planning on getting an ass load of wire and connectors and go to town trying to duplicate the factory harness. I'm definatly going to give the wiring kits a second look. Not to get too far off topic but are there any benefits to running slightly larger gauge wire if I do end up making my own? I've never really looked into Megasquirt... was thinking along the lines of Haltech but its $1,400... ouch It's all good about the dimensions as I'm not in a huge hurry, I probably wouldn't have remembered at a show either... This might be good info for people who are trying to do RB swaps into other non-Z cars too. Quote Link to comment Share on other sites More sharing options...
Careless Posted July 19, 2006 Share Posted July 19, 2006 Great info about the wiring sets. I was looking at the Painless but they are expensive and I am by no means a wiring tech so I didn't quite grasp the concept of the different circuit options. I was planning on getting an ass load of wire and connectors and go to town trying to duplicate the factory harness. I'm definatly going to give the wiring kits a second look. Not to get too far off topic but are there any benefits to running slightly larger gauge wire if I do end up making my own? I've never really looked into Megasquirt... was thinking along the lines of Haltech but its $1' date='400... ouch It's all good about the dimensions as I'm not in a huge hurry, I probably wouldn't have remembered at a show either... This might be good info for people who are trying to do RB swaps into other non-Z cars too.[/quote'] if you make your own, i wouldnt change the guages of the wire, as they carry certain currents, and if you go thicker, you lose amperage across the line, if you go smaller, you run the risk of a wire fire thats why i think going with the ez-wire kit is the best bet. the whole "circuit" concept is in reference to how many options your car has. power mirrors would be one or two circuits, door locks and windows = another two or four. map light = another. basically wherever the neg and pos meet at a switch/device, it's a circuit. that's not exactly the best explination, but it's close to it. the ebay ez-wiring kits will tell you exactly what you can run and how many circuits you can have fun with. Quote Link to comment Share on other sites More sharing options...
Racinjitter Posted July 26, 2006 Share Posted July 26, 2006 As for the physical dimensions of the RB25DET it is 30.5" long about 28" tall and 26" wide. Quote Link to comment Share on other sites More sharing options...
Guest SS-Z31 Posted July 26, 2006 Share Posted July 26, 2006 As for the physical dimensions of the RB25DET it is 30.5" long about 28" tall and 26" wide. You're AWESOME! Now, is that with manifolds or just the bare block and head? I hate to ask this much of you but I will anyway... can you PLEASE get how far back the mounts are on the block? I'm going to construct a cardboard box the size of the engine and see how it fits in the bay... The location of the mounts will help me immensely so I know roughly where to place the engine. Does anyone know if the Z31 turbo 5-speed is about the same size as an Rb25 trans? I've still got one lying around from my old Z. If it is, I can use that to mock up the transmission to the car... although I'd still need an engine... Quote Link to comment Share on other sites More sharing options...
Racinjitter Posted July 27, 2006 Share Posted July 27, 2006 Not a problem. My RB is just sitting on the engine stand right now. That is with the factory intake plenum and the turbo with heat shields. The measurement from the front of the engine to the mounts is....14". That is the centerline of the engine mounts or to the top mount bolt(which is in the center). As for transmission size the RB tranny is the same length (within a half inch) and larger in diameter. Here is a pic of the auto from a Z31 vs. the RB tranny. The auto is the same length as the manual and very close in diameter. Sorry I couldnt line up the trannies, It is raining outside and do not want to pull out the cars to move stuff around. Maybe tomarrow I can get some better shots for you. Quote Link to comment Share on other sites More sharing options...
Guest SS-Z31 Posted July 27, 2006 Share Posted July 27, 2006 Not a problem. My RB is just sitting on the engine stand right now. That is with the factory intake plenum and the turbo with heat shields. The measurement from the front of the engine to the mounts is....14". That is the centerline of the engine mounts or to the top mount bolt(which is in the center). As for transmission size the RB tranny is the same length (within a half inch) and larger in diameter. Here is a pic of the auto from a Z31 vs. the RB tranny. The auto is the same length as the manual and very close in diameter. Sorry I couldnt line up the trannies' date=' It is raining outside and do not want to pull out the cars to move stuff around. Maybe tomarrow I can get some better shots for you.[/quote'] Exactly what I was looking for! Don't worry about lining up the transmissions... I just need to see if I'll have to make a shift linkage to get this to work or not. The stock 4-speed uses a linkage but I don't think it's nearly as long as the Z31 tranny. Diameter isn't a huge deal either since I'd have to bang out the tranny tunnel anyway to accomadate any sort of 5 speed. This weekend I'm going to finish cleaning all the extra crap out of the engine bay and I'm going to try to mock up a cardboard engine. I'll get some pics this weekend definately. This is why I love this forum. People always willing to help out. Quote Link to comment Share on other sites More sharing options...
Careless Posted July 28, 2006 Share Posted July 28, 2006 0h oh oh!! use those cardboard cylinders to make it a real RB! Quote Link to comment Share on other sites More sharing options...
Guest SS-Z31 Posted July 28, 2006 Share Posted July 28, 2006 0h oh oh!! use those cardboard cylinders to make it a real RB! Don't be hating Quote Link to comment Share on other sites More sharing options...
Careless Posted July 28, 2006 Share Posted July 28, 2006 Don't be hating im quite entertained by the idea, actually Quote Link to comment Share on other sites More sharing options...
Guest SS-Z31 Posted July 29, 2006 Share Posted July 29, 2006 Ok took some measurements tonight to get an idea of what was going on. No pics yet but this weekend definitely. RB25 is most likely going to be the choice. No way I'd be able to fit the twin turbos for the RB26 in there and putting an RB20 would almost feel like a waste of time. Looks like I'm going to have to move the firewall back 6" and possibly enlarge the transmission tunnel slightly... I don't think hitting it with a big hammer will solve the clearance issue. The motor will fit if I do the firewall or I can leave the firewall stock and not use a radiator On top of that, the transmission is about 12" longer than the stock 4-speed so I'm going to have to find/make some sort of reverse linkage in order to keep the shifter hole in the stock location and not have it at my hip. In doing that to my firewall I will lose the brake booster and will need to go with aftermarket pedal sets. Wilwood has a nice 2 pedal triple MC reverse mount that will put the master cylinders under my dash... away from heat and freeing up much needed space in the engine bay. I forgot I had an RB20 oil pan that might help me with some mock up... at least it'll give me an idea of how long and wide the bare block will be. If I need to ditch the stock manifolds so be it... Might also have to fabricate a new front crossmember but I'm not 100% sure on that one. The steering box is in a pretty iffy place so we'll see how that goes. It's funny - I'm actually pretty excited that I'm going to have to cut up the firewall... This is going to be by far the most labor intensive project I've done. I'll start a new post detailing my progress like some of the other guys have done... this thread doesn't really draw too much attention. Quote Link to comment Share on other sites More sharing options...
Racinjitter Posted July 30, 2006 Share Posted July 30, 2006 this might help you out... it is one of my other posts... well at least for some more engine measurements. http://forums.hybridz.org/showthread.php?p=667190#post667190 Quote Link to comment Share on other sites More sharing options...
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