lbhsbZ Posted December 31, 2006 Share Posted December 31, 2006 This is my first post here, I've done a lot of reading in the past couple eeks though. Today I brought home my new Z. its a 73 that had the sb chevy swap done back in 84, and it hasn't been run since 86. I'm yanked the thermostat housing tonight and the coolant passage was full of a nice gel-like substance. The motor is coming out tomorrow for at least a good hot tank, and probably a full rebuild. It came with a Muncie 4 spd (not sure which one yet), bolt in roll bar (up for sale) and some old school corbeu seats. The original builder also made it into a wide body, its got some really nice looking flares, but they're mostly bondo I think. I paid $3500 for it. I have a couple of questions, and yes, I searched. This is replacing my VW GTI as my road race car, and I'm concerned about weight distribution. As it sits, the distrubutor (mallory dual point) is about 4 inches away from the firewall. The motor mounts use a "C" shaped piece of 3/16s and what appears to be the original datsun rubber mounts with an adaptor to bolt onto the chevy motor. Is this an off the shelf kit or some kind of homebrew setup? I'm a fabricator, so I plan on making new mounts anyway to put the motor where I want it, I was just curious. Second, regarding the rear diff. I read the FAQ that stated that the general weekpoints in these diffs were the spiders, and that for road racing applications, the factory LSDs are kinda weak as well. Has anyone ever road raced with a welded diff? I've done it in a FWD car and it wasn't much fun, but I haven't driven a RWD car on the track a long time, so I'm not sure what road to go down here. You guys have a great site, I hope to contribute something useful to it someday.....oh, and I just donated to the site too. EDIT: just got the heads off, its a 327 Here's some pics. Click on the thumbnails. Quote Link to comment Share on other sites More sharing options...
240zV8 Posted December 31, 2006 Share Posted December 31, 2006 The scarab position is what you have installed with ur v8. The JTR and newer mounts put the engine right against the firewall for better wieght transfer. I can get you the diagrams/schematics for the JTR mounts that set it back against the firewall if u want, so it's easy to fabricate. The rear diff should be changed to a r200 if u plan on adding any power with a v8 (280z, and 280zx have them in there manual trans cars, and the 75, 76 280z auto has the r200 as well) There's good step by step instructions here somehwere, just do a quick search if u want that part. Quote Link to comment Share on other sites More sharing options...
Savage42 Posted December 31, 2006 Share Posted December 31, 2006 While having the motor all the way against the firewall may be good for better weight transfer for drag racing, it's not necessarily ideal for road racing. You need to have weight on the front tires and not have all the weight farther back if you want to maximize handling. My buddy has a 400 SBC in his car and is one of the fastest autocross and track cars around and it sits close to where your's sits. So, you'd have to spend a lot of time getting the car dialed in handling-wise before a few inches in motor placement will make a difference. I'd spend that time, effort, energy & money getting everything else good to go. Just my experience, as I'm an autocross, hillclimb, road racer, not a "straight-liner" like many on here. Different strokes and it's all good. As a side note, my buddy listed above, originally planned to go drag racing, since he had lightning rods in the car for shifting his automatic, etc. Once he came to an autocross & track day and saw he could get so much more "seat time" than doing his 11-12 second stuff, he was hooked. It's always cool seeing a V8 Z as a front runner and often "Top Time of Day" winner at the autocrosses. Our club usually pulls 150-175 cars per event, too. Can't wait to get back out there myself! http://album.hybridz.org/showgallery.php?cat=552 Congrats on the new purchase!! Give 'em hell. BTW, got any pics? Quote Link to comment Share on other sites More sharing options...
lbhsbZ Posted December 31, 2006 Author Share Posted December 31, 2006 OK, next question. I know there are a million post here about it, but I couldn't find any diffinitive answers. On the drivers side, I have a header tube that is about 1/2 away from the radius rod mount, when I move the engine back, it will hit. Is the only alternative, when setting the engine farther back, to use block hugger shorties or S10 shorties. I know I can make my own longtubes, but I'd really rather not. I imagine the only way to know for sure it to order 20 sets of different headers and see what works, but thats not really doable either. Quote Link to comment Share on other sites More sharing options...
buZy Posted December 31, 2006 Share Posted December 31, 2006 I use MSA mounts with hooker long tube headers. It all works out good...and clears. Great ground clearnace too. MSD small cap dist is about an inch or so from firewall. You have to ditch the oem hood latch same as JTR. If you want to use the oem latch style a bracket replacement from MSA works out fine or just run hood pins if your racing anyways. Here are some pics in my hybridz gallery if interestsed. This to me is the best set up for a V8z but to each there own. http://album.hybridz.org/showgallery.php?cat=500&page=3&ppuser=10889 http://www.thezstore.com/page/TZS/CTGY/PRC01 http://www.holley.com/2147HKR.asp http://www.holley.com/data/Products/Technical/2147HKR.pdf Quote Link to comment Share on other sites More sharing options...
240zV8 Posted January 1, 2007 Share Posted January 1, 2007 If you want to move the engine back, there will be alot of little things that will have to be dealt with. like the header/manifold issue for clearence, hood latch, driveshaft shortening, new trans mount etc....So you might just think about driving it how it's setup and if you don't like the wieght on the steering or somthing, then go and move it back a couple inch's. But I say get the engine running great and see how you like it, because you can always change the other things if you don't like how it handles. Since you have to get the engine running anyway, just handle that first, bolt it in and see how it drives. Quote Link to comment Share on other sites More sharing options...
lbhsbZ Posted January 1, 2007 Author Share Posted January 1, 2007 I think thats the plan....for the time being anyway. The deeper I get into this car, the more hack the conversion looks. All the wiring will have to come out and I'll build a new harness for it....nice and clean. I found 4 ballast resistors throughout the engine bay...and 3 coils. 2 ballast resistors were hooked up and one coil. I'm going to simplify things a bit....its a race car anyway and doesn't need half the stuff thats in it. I pulled the pan and the bottom end looks decent, just needs a hot tank and I'll hone it and do the rings and bearings. Its got 202 camel hump heads that have some very nice port work done, which I'll clean up and use for now but probably replace with aluminum down the road for weight savings. Its got an M21 gearbox, which I hope will hold up. I'm going for 450-500 hp with the motor, and as long as I don't abuse it, the trans should be fine. I found a R200 diff and halfshafts locally for a couple hundred bucks, so I'll probably pick that up next week. I've got lots of reading to do here...and lots of work to! Looks like I'll be busy for the next couple of weeks. Quote Link to comment Share on other sites More sharing options...
jbk240z Posted January 1, 2007 Share Posted January 1, 2007 I had a .040 over 327, very nicely ported camel hump heads like yours. It had a comp cams 292H hydraulic cam, Torker II intake, 750 Holley. All of this was in my '80 Olds Cutlass, TH350 trans, 3000 stall. When I had some 2.90 something gears, that motor had one heck of a topend. Then came 4.56 gears and the car hauled pretty good for being 3,5000 pounds or so. Your 327 should do VERY nicely in the Z with the 4-speed. Good luck. Quote Link to comment Share on other sites More sharing options...
iaconsultants Posted January 1, 2007 Share Posted January 1, 2007 Just to let you know it appears that the flares are Bob Sharp built especially if the entire front fenders are fiberglass. Looks like a very nice find. Quote Link to comment Share on other sites More sharing options...
Pop N Wood Posted January 1, 2007 Share Posted January 1, 2007 Looks like a steal for that price. I can save you some reading on the headers. There is no one size fits all solution for long tube headers and the JTR position. If you want long tubes, either keep it in the Scarab position like it is now, or switch to the MSA set up. If you go JTR you are looking at shorties or customizing your own long tubes. Like mentioned above, you will essentially be doing a new, from the ground up swap to shift to the JTR position. For example, JTR will mean switching from a mechanical to electric fuel pump. Then there is the driveshaft, exhaust, shift linkage, maybe clutch linkage, radiator fan.... Either way you should consider moving the fuel and brake lines away from the headers. If you get a chance, I would be interested to see what the shift linkage looks like on that 4 speed. The driving factor in the JTR kit was to get the shifter to come out of the stock hole. You should invest $40 and get the JTR manual. All of the info is probably spread about this site in one post or the other, but it will help you immensely in planning what you want to do with this car to read the JTR book. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted January 1, 2007 Share Posted January 1, 2007 Savage42's comments are a bit counterintuitive. Usually road racers move the engine BACK to reduce polar moment of inertia. GT2 Z cars move the L engine back for example. I've never ever heard of a road racer moving the engine forward to get more weight on the front wheels. That said, if the guy with the Scarab mounting position can go fast at an autox, he must be doing something right. I wonder what the same car would do with the engine in the JTR position... As far as the diff goes, there is one clutch LSD that came in a 87-89 300ZX turbo that is particularly weak. They used a big spacer inside instead of adding 2 more clutches to the clutch stack. This is a cheesy money saving thing to do, and we've seen several people strip the clutch tabs off of the one remaining clutch and then the LSD doesn't work anymore. However, the Power Brute LSD has a full stack and they should be MUCH more durable. They are well worth the price of ~$500 through http://www.reiderracing.com or http://www.differentials.com. If you want to spend more you can get an even better unit from KAAZ or Cusco. Quote Link to comment Share on other sites More sharing options...
Kbhead Posted January 1, 2007 Share Posted January 1, 2007 I like how the hood and side vents were done! Just have to loose the back bumper and put on a euro 240z bumper. Car has lots of potential, well done! Quote Link to comment Share on other sites More sharing options...
lbhsbZ Posted January 1, 2007 Author Share Posted January 1, 2007 About the diff.....I couldn't find anything nissan specific on either of those websites, I'll try calling them on monday. But should I find an LSD to put in the original R180 or should I swap the whole rear end out to a ??? and get a diff for that? Quote Link to comment Share on other sites More sharing options...
240zV8 Posted January 1, 2007 Share Posted January 1, 2007 About the diff.....I couldn't find anything nissan specific on either of those websites, I'll try calling them on monday. But should I find an LSD to put in the original R180 or should I swap the whole rear end out to a ??? and get a diff for that? do a search for any of the following: r230 r200 vlsd lsd you should have all the info you need. Quote Link to comment Share on other sites More sharing options...
240zV8 Posted January 1, 2007 Share Posted January 1, 2007 this is a great thread in the faq section http://forums.hybridz.org/showthread.php?t=116207&highlight=r230 Quote Link to comment Share on other sites More sharing options...
Savage42 Posted January 1, 2007 Share Posted January 1, 2007 Savage42's comments are a bit counterintuitive. Usually road racers move the engine BACK to reduce polar moment of inertia. GT2 Z cars move the L engine back for example. I've never ever heard of a road racer moving the engine forward to get more weight on the front wheels. That said, if the guy with the Scarab mounting position can go fast at an autox, he must be doing something right. I wonder what the same car would do with the engine in the JTR position... I hear what you are saying. We all know that the L motor hangs farther past the front crossmember than the V8, so it makes sense with that long, straight motor. When it comes to weight transfer, handling, etc, it's a bit different with a V8 than the L6. My buddy actually tried different locations of the motor and this setup proved to be the best to help handling. Heck, they say V8 Zs aren't supposed to work for autocross & road racing, but he constantly proves them wrong! He found that he needed more weight distributed on the front and not have more weight in the back. I guess it goes back to the whole "more of what I see and less of what I hear" concept. Remember, the car was originally built as a drag car and then modified to being a damn fast street, autocross & track car. Weird how things work out sometimes! Quote Link to comment Share on other sites More sharing options...
JMortensen Posted January 1, 2007 Share Posted January 1, 2007 It's impossible for me to say for sure from here why his car reacts that way, but in theory the car with the V8 mounted further back should be the better turning car. I suspect the issue with this guy's car was one of setup, but again, impossible to say for sure. Look at just about any modern front engine/rear driver sports car and you'll see the same thing... S2000, Vette, etc. Engine is stuffed way in the back of the it's compartment in an attempt to get the PMOI to a minimum. They certainly don't do that to make them easy to work on... Quote Link to comment Share on other sites More sharing options...
lbhsbZ Posted January 1, 2007 Author Share Posted January 1, 2007 I cleaned the parts up a bit and started measuring things. The guy I bought it from told me that the engine was rebuilt 500 miles before the car was parked...and assured me that all that was needed was an oil change and the motor would be ready to go. The cylinders are already bored .060 over, and theres about another .020 of wear, so the block is toast. All the main and rod bearings were down to the copper, and the rear main seal was in backwards. The crank has already been ground to the minimum, and its nicely grooved up, so into the scrap pile with that. I haven't taken apart the heads yet, but I'll assume that they're probably junk too. This throws a wrench into things a little bit, now I've got to find another engine. Quote Link to comment Share on other sites More sharing options...
wheelman Posted January 1, 2007 Share Posted January 1, 2007 Sorry to hear about the engine being junk. I wanted to make a comment about the idea of welding the rear diff. A young guy who is a member of the local Auto-X club drives a 240SX with a welded rear diff (he set it up for drifting) and he has problems keeping the rearend behind him. The car has an SR20DET so it's got power similar to a V8 Z which makes it a resonable example. Wheelman Quote Link to comment Share on other sites More sharing options...
Savage42 Posted January 2, 2007 Share Posted January 2, 2007 It's impossible for me to say for sure from here why his car reacts that way, but in theory the car with the V8 mounted further back should be the better turning car. I suspect the issue with this guy's car was one of setup, but again, impossible to say for sure. Look at just about any modern front engine/rear driver sports car and you'll see the same thing... S2000, Vette, etc. Engine is stuffed way in the back of the it's compartment in an attempt to get the PMOI to a minimum. They certainly don't do that to make them easy to work on... They sure don't make new cars easy to work on, that's for sure! As for engine position, there is also a point where there can be too much weight on the rear and getting some up front to get a more even weight distribution is also a key. Of course, we are dealing with a car with nearly 40 year old technology, so it's apples & oranges, sometimes! Quote Link to comment Share on other sites More sharing options...
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