Quin

www.supramania.com has more information and more knowledgeable people than any place listed yet. 7Ms are undersquare (83x91), 2Js are square(86x86). Both have a displacement of just shy of 3l, both have extremely tough factory internals. 2JZ heads flow a lot better, both stock and otherwise. In fact, a fully ported and +1mm oversize valve (biggest you can get) 7M head is still out flowed by a stock 2JZ head after 5500RPMs (might be 6500 RPMs, can't recall for sure). 7Ms come with under torqued head gaskets from the factory, and the oiling system leaves much to be desired. That said, 7Ms aren't bad motors at all. Factory internals have been proven to hold over 700rwhp. They're also a LOT cheaper than a 2JZGTE, and very easy to find. An alternative to the expensive 2JZGTE is the 2JZGE-T, basically an NA-T setup. A thicker headgasket (at least 1.3MM, most use a 2MM) is used, and that's basically it. The factory motors have also been taken over 700rwhp (once the compression was lowered, of course). 2JZGE heads don't flow as much as the GTE heads, but they are still very good.

I was also planning on putting this stuff on the bottom! Stealing my ideas are you?!

An early 260Z is a 240Z, so if it worked for you he should be good to go.

Wow, didn't even notice that! More fail

Main concern circled in yellow, that's nearly twice as long as several others. I provided an easy solution, simply copy the other grouping and use two of that style for the manifold. Btw, that's not the equivalent of a downpipe in any way shape or form, that's for the wastegate. Down pipes come off of the back of the turbos;-) Also, I disagree with your statement jgkurz, most turbo manifolds I've seen (Toyota motors, still I6s) have nearly equal length runners.

Fuel pump died on the 81.

Any updates on this?

Had a buddy do that to his Supra (gutted the interior from the front seats back) and was considering it if the interior in the Z I get it is gross. I planned to put carpet over mine, are you planning on leaving it as is?

I'm not shooting for crazy high numbers, looking for between 350 and 400rw with the spray, definitely not sustained. Mainly DD purposes with occasional track/street/strip racing. Maybe it's just because I'm used to the Supra world (meaning mainly 3500lb cars, but also extremely easy power), but that is pretty much normal for me. Hoping to make around 250rw NA (don't mind a high RPM powerband, so an aggressive cam is OK in my book). How thick are the cylinder walls from the factory? I've seen a couple guys running a 3.2l motor, but I thought using the L28D crank only netted you around a 3l with the stock bore of 86mm (could be off on my numbers, I'll definitely be double checking everything before I start spending money on it). By my estimation that means you need a 90mm bore to hit 3.168l, close enough to .2. I used the calculator here - http://www.ozdat.com/ozdatonline/enginedesign/ for my numbers. Btw, after doing some more calculations (okay, so I let that calculator do them for me ) it looks like 7500 RPMs would pretty much be the end of safe powerband, due to very high tensile loads on the rods. I've always heard 3550ft/min was the cutoff for gaurunteed safe and reliable motors, with 4000ft/min being the end of the reasonably-risky zone, and anything after that resulting in very short life. 7500 RPMs yields 1245m/min, which is right around 4000ft/min. Thoughts on this as well?

If it were me, I'd pick up a Walbro 255lph pump (assuming the Z pumps are in tank and not in line, I'm not sure). Should be about $100, not too bad for a pump that can support over 500hp! It'd be a real dog without the turbo with the lowered compression, but you should be able to do it. I don't think it'd be that much if any harder to just use the ECU and stuff from the 81. Btw, inline sixes are naturally balanced, so you shouldn't have to worry about it. Not to mention that it's the same motor! I've read on here that all L6 drivetrain parts work with all the L6s (the older ones at least, dunno about the RBs).

I would say no, due to seriously unequal runner length. If you were planning on replicating it, copy the back half where they're all a lot shorter and use that. It still wouldn't really be ideal but it'll be a lot better than that.

How thin is too thin on these blocks? Is there a particular block you can bore a little farther? I plan on boring out to 89MM (3.2 stroker motor, NA, 100-200 shot possible), would I run into any problems with a specific block vs another? I don't mean to thread jack, seems to be kind of in line with the OPs posts.

Carb'd swaps rock. I'm used to people doing 1/2J swaps into their MkIII Supras, and the wiring takes twice as long as everything else lol

A buddy of mine in Australia had a twin turbo 3.4l Toyota Hemi in his 240Z, he used a carb set up, worked pretty well for him... Twenty years ago. I'd go with a MegaSquirt system, seem pretty easy to use and quite effective. EFI isn't really that bad, honestly. Coming from EFI and trying to learn carbs is a lot harder than learning EFI was! =/

That's a sweet project, can't wait to see that done! Cute kid, too

130 in my old Celica with the front end about to pop off the ground, 140 in my Supra (solid as a rock, felt just like 50MPH), and a friend's Mustang GT (was okay, not great, maybe a little shakey but still perfectly managable), me driving. Welllll over 160 in my uncle's Cobra. We maxed out his speedo and kept going for another ten seconds or so, car was still pulling HARD. Had trouble lifting my head from the seat... That was the ride that got me into cars. When my Supra ran, 100-120 was a daily thing. Still do it pretty often in a buddy's Z28 (you REALLY feel the speed in that car, in the Supra it was nothing).

I have troubles with that sometimes myself. I really want to do the stroker (and some spray... 100-175 shot, somewhere in there) so I have enough power to beat basically anything, whoop ass on a road or auto X course and still have a decent daily. Hopefully my torso is longer than yours then, I gotta put my arm on that window ledge lol

I posted that, then decided to go find the post I read about it in so you wouldn't have to go hunting all over the internet for it. I'd think of it more as a don't plan on sustaining this RPM kind of thing, I'm sure short bursts into the middle area would be okay (apparently Toyota did, too). Wow, that bar under the steering column would make that car a no go for me. Definitely molest my legs trying to drive that (6 2")

Funny you should mention that, an acquaintance of mine just called and said a friend of his (car collector) has a RHD one that's starting to rust away that he would nearly give away! The other car was a 2+2 anyway, fail

How hard would it be to convert a SBC Z back to an L series motor? I found a local one for sale (literally, only one but it's got a SBC in it. I don't dislike small blocks but I have other plans for this car. Would anyone here be interested in trading the swap parts for their (good condition, obviously) stock parts?

ARP stuff will probably hold more than the rod, lol That's a general formula, it should give you a general idea on what you should be okay revving up to. Seeing as this isn't a production car or a race engine, you should be okay with the general idea. The ranges posted aren't just for 7Ms, they're the recommended safety range for all normal motors. Btw, If you actually join the site, there are a few guys on there (light blue screen names) called Subject Matter Experts. Any of them would be happy to help you out with a question in their particular field, and I know at least the turbo, oil, electrical and internal guys can help with more than just their field. Any reason you're building the BMW to be a track car instead of the Z? Even if you left full interior in it, that's not really that much weight in this car, not a whole lot there. It's probably safe to say the Z car also has easier to find and cheaper upgrades for it than an old 2k2 BMW, too.

If your cam is good until 7500, I'd try and rev to 7500 (not during the initial break in I described above, of course). There is a formula to determine how much force your pistons exert on your rods and hardware at a certain RPM. You need to do some math, and then find out how much your hardware can safely hold, and decide how unsafe you want to be. I can't even hazard a guess at how high it'd be, sorry. No experience with an L28, and especially not with this hybrid stroker dealio (at least, not yet ). I'm attaching a post from Supramania made by Supracentral, the site admin, about stroker motors. It's about 7MGTEs (stock MkIII Supra Turbo motor) but the math and principles apply here as well. Another thing to keep in mind, a 7M (very much like a 2JZ) is a motor you can just keep adding air and fuel into and it'll keep making power. The stock components are very strong (there is a guy in Utah by the name of Sean (goes by Xman on Supramania) that is making over 700rwhp on stock Toyota internals), and it still has a large aftermarket support as well (not sure if that's true about an L series or not, haven't done any research, just throwing it out there). Also, stroking a 7M doesn't do a whole lot in terms of increasing power, and I know that's not the case with an L series motor.

I'm quite sure the method will be fine for a six cylinder! Many friends have used it in their Supras with great results. It's more about new ring technology then it is displacement or anything else, for that matter. gjc5000, you hit the nail on the head. Warm the engine up to operating temp by driving around gently, then start doing controlled loading of the engine. Just like he said, but we usually go 2k-5k, engine brake back to 2k, next gear, 2k-5k, engine brake, next gear, so on up through fourth. If you have a four speed, should probably only do that in 1-3 lol Even just in fourth, in most cars you end up going over 100MPH. After that's done, drive it how you would normally drive it. If you get on it a lot, get on it a lot, if you don't, don't. It doesn't really make a difference, the majoritry of sealing takes place in the first 20mi or so the engine is run. Hmmm... ASL for the sister? I kid, I kid.

Also of note, another 7M + R154 guy is interested in moving down to a 3.54 from a 3.7. If you have a good bit of power coming from that 2J, you should be fine. Learn something new everyday! My bad :embarrassed:

A forum member here running a 7M and R154 is running a 3.73 gear in an R200 diff. That data you posted looks correct, it is of note that MkIIIs also came with 3.91s. It was a pre89-post89 difference, but I cannot recall which is which.