Mikelly Posted January 11, 2001 Share Posted January 11, 2001 Screw the fact that it is NISSAN, The fact that the 'Yota motors eat Headgaskets is enough for me not to want to do one, unless you plan to Oring it. Of course, my view there is that ANY Forced induction motor should have the block or head Oringed anyway, That is just good and cheap insurance! As for the L series motor being the "Cheaper" solution, I'd have to lean towards Morgan's thinking here (Did I say that?) and say that they are cheaper to setup with a turbo and run with "Safe" boost and relatively smaller expense compared to most of the other options... However, The fact that it is NISSAN shouldn't be a factor... H-Y-B-R-I-D.... Mike ------------------ http://hometown.aol.com/dat74z/myhomepage/auto.html "I will not be a spectator in the sport of life!" mjk Quote Link to comment Share on other sites More sharing options...
jeromio Posted January 11, 2001 Share Posted January 11, 2001 Boy is that ever a wierd comment. "Fancy head"? So in your estimation then, the LT5 from the Corvette ZR1 is equivalent to the 350 from the 60s. Same block, just some fancy heads thrown on there. That's just silly. Engine technology is heavily tied up in the head(s) - valve gear, combustion chamber shape, flow characteristics, etc, etc. With few exceptions, a block is a block. Not much new there that is being implemented ni the main stream. The Datsun L head is old technology. As has been stated before on this thread, the 7M and the RB are pretty close to each other in having a modern head design. The main difference is that you can't go to a salvage yard (in the US) and pick up an RB. Now, the issue with the head gaskets, that I find interesting. I haven't uncovered any other info on this beyond replacing the gasket with a premium HKS unit, upgrading the head bolts and being very careful to torque the head bolts. Does the block have to be O-ringed? What aspect of the Toyota design makes it more suscptible to failure? Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted January 11, 2001 Share Posted January 11, 2001 hah! Mike agrees with me! I knew he would see the light eventually I don't want 500 horsepower. My car only weighs 2200 pounds(maybe less now!) Add in slightly heavier brakes and a turbo and it'll probably be 2300ish. I don't care the least bit about drag racing, and 350-400hp will be plenty for my car for a good while. Using an l28t is cheap, less work fitting the drivetrain in the car, and is turbocharged. After having this weber-ized garbage I've vowed to never again own a car that wasn't turbocharged and injected. It's also a nissan engine, which I prefer if possible. It'll do 400ish hp without much trouble, and more power is only a fancy head and cam away. It's easy to work on and has the cool straight 6 sound. So it's plenty adequate for me, and I bet it'll end up with more power than most v8 Zs put out. As for the toyota engines, seach for "head gasket 7m trouble" on your favorite search engine and you should find plenty of info. ------------------ Morgan http://z31.com/~morgan/s30 http://carfiche.com Quote Link to comment Share on other sites More sharing options...
Owen Posted January 11, 2001 Share Posted January 11, 2001 I was thinking about the Supra engine too, I hear it's almost bulletproof. What changed my mind was how much tuning parts cost for it, at least with my V8, I can go to PepBoys and pick up something in the "performance" section! And as for is it better than the RB26, it's close. You can't compare track times, etc b/c the GTRs are AWD and the chassis is just so much better than the Supras on the track. My opinion is, unless you can get the AWD Skyline junk to fit on your Z, there's no huge difference between the JZ engine or the RB engine. You still have to worry about how to keep the rear tires from spinning into bald rubber donuts! What I wanna know is, are there any diffs from the Supras that will fit on our Zs??? Owen ------------------ http://www.homestead.com/s30z/index.html Quote Link to comment Share on other sites More sharing options...
Oltmann Posted January 12, 2001 Share Posted January 12, 2001 quote: Originally posted by jeromio: Boy is that ever a wierd comment. No, wierd is saying that an engine has got to be way better simply because it is high-tech. In this case high-tech brings alot of problems along with the benefits. I think the problems come from Toyota improperly applying a "fancy" new head to an old block. Maybe this is simplistic and maybe I'm just wrong. I don't think I'm wrong in thinking the 7M is inappropriate for a swap. Oltmann btw, sorry if I haven't contributed much to this thread. Quote Link to comment Share on other sites More sharing options...
jeromio Posted January 13, 2001 Share Posted January 13, 2001 Granted, high-tech doesn't always mean better. But more valves and better flow is hard to argue with. As far as Morgan's comment regarding "Machining mods" I have found nothing. Certainly I can verify that these engines have a deserved reputation for choking on head gaskets.. What I have found is that, depending on wear, they may need to have the gasket surface (primarily of the head, rarely of the block) machined to eliminate wear marks due to the gasket. There is then the issue off attaining a suitable finish (post machine-work) that is compatible with the steel (HKS) head gasket. IOWs, if the head is not worn, then the stock gasket can (and should be) replaced with a steel gasket and the head bolts torked to 70lbs (as opposed to the recommended factory 52lbs). There seems to be agreement that a properly (70lb) torked, steel gasket motor is very robust. Certainly when dealing with a Junkyard motor, it is questionable. Most yards offer a 30day guarantee and this would seem sufficient to remove the head and verify whether it needs machining or not. I can find no details on how the J motor solves this gasket problem, but apparently it does. Also, no one seems to address the problem of attaining the proper "post milling" finish that would be compatible with the steel gasket. even though many sites seem to mention motors which have had their heads milled. Makes one appreciate all the more the wealth of info availabkle for the Z - low-tech engine and all... Still, I am intrigued. My plan up 'til now has been to (eventually) get a junkyard datsun L28t to swap in. At this point, I am widening my search to include a suitable Supra motor. Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted January 15, 2001 Share Posted January 15, 2001 If you're looking at a non-l2x engine, then it's not a bolt-in swap. That being the case, why don't you look for a better drivetrain weight-wise that still makes the power? Like, a vg30t perhaps? Dirt cheap, dead reliable, and plenty of power. You'll spend the money you save on initial cost on modifications though, so it'll probably even out in the long run. But you'll be left with a short v6(the lightest iron block v6 ever made as a matter of fact!) that is lighter than either straight-6 and also puts it's weight significantly farther rearwards. ------------------ Morgan http://z31.com/~morgan/s30 http://carfiche.com Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted January 15, 2001 Share Posted January 15, 2001 the 7mgte is a great engine after you get the head milled flat and use a hks mhg and arp bolts on the head its dead reliable the head gasket is caused by a toyota's head gasket not the engine itself Quote Link to comment Share on other sites More sharing options...
jeromio Posted January 15, 2001 Share Posted January 15, 2001 There are definately alot of the vg in the yards. But, as you discovered, the turbo plumbing in the 240 with this engine is not straight forward. Plus, the trade-off for the front heavyness of the inline engine is that there ends up being more room to work on it. Those are pretty much my 2 main goals - easy to work on, and inexpensive. The datsun L28t definately fits both of those requirements, and that's what I was originally shooting for. That may, in fact, end up being what I install. But it does look like this whole head gasket fiasco has its upside - the yards and classifieds appear to be full of 7M-GTE cars. Quote Link to comment Share on other sites More sharing options...
jeromio Posted February 1, 2001 Share Posted February 1, 2001 I've got a line on a pair of Mark3 supras. Apparently one was a project and the other is the parts car. The guy wants $1500 for both. One has had the engine rebuilt with the head milled and the HKS gasket (and a port and polish and valve job apparently). The other is missing front sheetmetal and has a blown HG. So, my devious mind is thinking: get these (perhaps for a skonch less than asking price), drop the good motor and trans in my Z, then, if I have the energy left over, put the other engine together and put it in the good car to sell cheap, $1000 maybe, as a driver. Misc. parts for the swap (driveshaft, mounts, hoses, etc) probably cost about $350. But, at this point this is all simply devious conjecture. I've also found 2 280ZXTs for $500 each. But they're much farther away (6 hours in opposite directions vs 2 hours for the Supras). And they're both Autos, so I'd still have to find a 5speed. The ZXs do have the rear axles and calipers that I could use though. And it would be an easier swap. But, they'll need rebuilds - about $400 by my calc. Hrm. I likely won't do anything. But it's fun to ponder such possibilities. Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted February 1, 2001 Share Posted February 1, 2001 BS. You're being lied to or not told the whole story. You can't get 2 mk4 suras for $1500, esp. with one of them running. If those prices are real, you'dve never heard of the car because it would be sold before it was ever put up for sale. PS. Point me in the right direction and I will buy 2 mk4 turbos, 1 running, for $1500 sight unseen. ------------------ Morgan http://z31.com/~morgan/s30 http://carfiche.com [This message has been edited by Morgan (edited February 01, 2001).] Quote Link to comment Share on other sites More sharing options...
Sean 83ZXT Posted February 1, 2001 Share Posted February 1, 2001 I thought he said mk3 supras? Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted February 1, 2001 Share Posted February 1, 2001 Oh. So he did. I'm illiterate, nothing to see here, move on people. No wonder one of them is blown up presently and the other has been repaired from blowing up. ------------------ Morgan http://z31.com/~morgan/s30 http://carfiche.com Quote Link to comment Share on other sites More sharing options...
Guest Speaker Posted March 6, 2001 Share Posted March 6, 2001 anyone got a site with info on modding the 7M-GTE? besides the head gasket problems... can the bottom-end of the motor handle lots of power like its 2JZ-GTE relative? i'm looking for a motor to go in a 280Z that would give lots of top-end... does the L28T have the top-end? i think the 6k rpm redline kinda holds it back... Quote Link to comment Share on other sites More sharing options...
randy 77zt Posted May 4, 2001 Share Posted May 4, 2001 when i win the lottery i want a 20bt mazda 3 rotor turbo in my z.these engines are around but not cheap 3 to 4 grand.i found a place that makes a bell housing for a t5 or t56 trans.i like the mad swarm of bees sound.these things make 300 or 400 hp with out turbo and rev to 9000 rpm. Quote Link to comment Share on other sites More sharing options...
Scottie-GNZ Posted May 4, 2001 Share Posted May 4, 2001 RacerX, not sure I agree with your comment regarding the head on a SupraTT to make serious HP. Of course you did not define serious HP so I have no idea what that target is. I can tell you from personal experience that 400RWHP in a 1st-gen Z-car is serious. Now, note 2 things in that comment. I said RWHP and I said serious, not serious HP. 400RWHP in a 1st-gen Z-car is serious HP enough to run 11.0 1/4-mile at the track. On the street you can translate that to 0-120mph on less than 11-secs so the potential top-speed is insane because I can tell you that the Z is pulling HARD at that speed. That begs of some serious braking and suspension. The whole point of that diatribe is that if you plan on more than 400RWHP, your main concern should not be on the cost of the headwork to support that HP but the chassis/suspension/brakes needed to make the car safe. The SupraTT requires no internal work to support 400+RWHP and if you were planning on much more, you would have to open up the engine (or any engine for that matter). Someone else made an excellent point about the RBs. When you buy one used, you have no idea of the condition and of course the same applies to the SupraTT. However, if something goes wrong or you need to make upgrades, that is where the SupraTT has an advantage, IMO. Quote Link to comment Share on other sites More sharing options...
Supra510 Posted May 4, 2001 Share Posted May 4, 2001 Re: the 7M gte engine.For info go to the Sogi (Supra Owners Group Int'l) or Sonic web pages and check out the tech pages. The reason for headgasket failure seems to be related to the fact that the factory torque specs for the headbolts were not high enough. Because the bolts were not torqued tight enough they would loosen--Read these sites and there are instances of going to pull off the head and finding the bolts hand tight. These sites are full of info and the author of many is Reg Reimer who finished 4th in Car and Drivers One Lap the latest Supra. He has a very good article on swapping the 7m into the previous gen Supra. Basically when buying a used motor a safe bet would be to pull the head and install an HKS metal headgasket. I put this engine into my 71 510 wagon and before installing I pulled the head and put in the HKS gasket. I smoothed the head and block surfaces with emery cloth prior and installed the gasket with copper seal gasket dressing. I ran 16psi at Thunderhill park last summer and have had no problems as of yet. Check out racetep.com to see what they think of this engine--Also Toysport has a very informative website. I had my used engine shipped from K. Watanabe 450.00 + 150 for shipping. I sold the factory turbo for 150.00 and purchased the HKS gasket for about the same. Tough to beat price wise and you can use the W-58 transmision which came in the N/A Supra's from 86-92 and was used in the SC300. The Turbo Supra's trans is harder to find and has a very expensive and weird clutch system. It is not needed. This engine has 24 valves, oil squirters piston cooling and is very strong. Hard to beat for the price and availability Quote Link to comment Share on other sites More sharing options...
TonyZXT Posted May 8, 2001 Share Posted May 8, 2001 Hey all, I just wanted to dispell a couple of misnomers. First of all the supra engines do have a problem with blowing alot of headgaskets, but there's a good reason for that. The supra engine is one of the few engines that need nothing done to the internals, meaning turn up the boost way higher without ever having the heads off than they would dare to on most other engines. The weak link is the head gasket, not because of poor design, but because of the false sense of security supra owners have about their engines. Now that I've defended the Supra engine I'll play devil's advocate and say that it can't compete with the RB engine!!!!!!!! A couple of years ago Top Secret, a tuning company in japan set about building two of the most radical street cars ever built. One was a Toyota Supra and the other an R33 GTR skyline, both had almost 1100HP. They decided that they would rather stroke an RB26 and swap it into the Supra than use the Supra powerplant, because the RB is superior! Thats as fact, and there are magazine articles out there to prove it. Besides in the Japanese touring series the Skyline dominates everything!! GO NISSAN!!! Laterz, TonyZXT Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted May 9, 2001 Share Posted May 9, 2001 The RB isnt better then the 2JZ, THAT IS A FACT. Only 86-92 MKIII 7M-GTE Turbo Supras have head gasket problems. The reason is because they werent torqued down to the right specs.0 Vinny Ten ran his Supra at 907 RWHP with stock internals at a couple of races because his RACE motor was being built. Also, the 2JZGTE is bulletproof and does not have ANY head problems. Also, skylines dont dominate the JTC, SURPAS DO, and they ALWAYS qualify ahead of Skylines. I hate when people say stupid things like XXXXXX dominates JGTC when they have never even watched a JGTC race. Also, that RB26 in a supra was just an experiment, right know they are running a 3S-GTE that Supra. It did 199MPH in 4th and ran out of straight away. Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted May 10, 2001 Share Posted May 10, 2001 Hey guys. First post. Cool board. I have a '94 Twin turbo 6-speed Supra. Power upgrades are 3 inch downpipe into 3.75 inch exhaust pipe, manual boost controller, after market air filter, and Boost Cut Controller (allows to boost beyond preset factory limits). Stock boost on a TT Supra is about 11psi. The mods described above are BPU (basic performance upgrades) and with those installed Supra guys usually boost around 17-19 max psi on the street. They sometimes will go higher though. The fuel system (6 550cc injectors) and ignition system (individual coil packs) can support 500 rwhp. It has been done. Tranny can handle the power too, of course an upgraded clutch is needed when making BPU power and up. I ran a 12.7 1/4 mile at 115mph my first try at BPU power. That was on stock 255/40/ZR17 tires. A good driver could do low 12s to high 11s. Just wanted to give you guys some info on just how easy it is to make power from the Supra motor (2JZ-GTE) . Now if you have the money there is always aftermarket turbo systems/fuels systems too. Hope I helped with my long post! Quote Link to comment Share on other sites More sharing options...
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