brokebolt

The Z roof is a turtle shell and very difficult to get nice and straight (that is to say properly shape), it also lacks a good strong support structure. With that said any good quality body work done in that area will be difficult. Yes, you can mud it and do the same type of repair that was done before and it will look OK for a daily driver and that is fine. I have done those repairs before, why sink $5000.00 into body work on a car you want to value at no more than 6k or 7k, but that is my opinion. Body work is like fine wine, the more you spend the smoother the finish, just in a different bottle (again that was a joke so no need to bash on the wine sentence). It rivals engine work in theory in some reguards, the more you spend (in both time and materials), the nicer it is. Anytime you see that type of rust, formed under the filler layer (or paint bubbles) you have to ask yourself if more maybe present. Has a worm hole formed and run all the way down the back to the rear hatch, or over to the side by the 1/4 window? Dose another spot exist that I can't see yet. Any body work will always pose a risk of potential rust unless done professionally by professionals. doohopark makes a good point about cutting the area out until you confirm that a good clean repair can be made. Knowledge of proper technic and experience play a role here. I strongly suggest you seek out a good book for reference or a body guy in your area or Z club for advice. Hands on is worth more than anything else in my opinion, especially for items like this. If you do the body work yourself in your garage and you are willing to risk the unknown (I assume your are a fist time body guy?), I say have at it msthaiii. I am one that would support your decision, but the flip side of the coin is the gamble of future repairs. But this small repair maybe good experience to see if you would like to tackle more repairs on your car, or another car later. I say all this as both advice on bodywork and warning of the work that is needed and knowledge of tools and technics. I can't stand to see what would be a nice car cruising the yard with primer spots and unfinished body work. I say get on it and finish it, I want to see that thing put back together and looking nice (even it isn't show car nice!). Best of luck on the project, and keep us posted on the progress.

Bond-O...that was a joke. Bonding filler, not fusing = Bond-O. We used to skim the entire car and than sand it smooth. It left a lot of small thin areas where the metal had small imperfections. We did use high build primer when needed, high quality needed more work than others. We produced quality work, show quality and it cost $$$. And yes you can slather it on; up to 4 inches (stripped a rear quarter once..). Sloppy sheet metal workmanship uses more filler/primer. That's just the way I roll.

Why yes it is large cable. I use 25 feet of 2/0 on my personal 300 amp DC tig welder. Works fine. For a battery relocation kit the largest I have seen is only a 2/0 so my suggestion for an 4/0 isn't that far off, remember as copper corrodes it looses conductivity and voltage drop becomes apparent and a real problem. If your moving your battery to the rear and possibly using a disconnect switch than 10 feet should just about cover the distance, so if someone is tracing your steps they can ask the local welding shop dealer for 10 feet and they should be covered. That's the length I bought/used, and routed the cable under the car. Yes, for most battery cables 3-6 feet your going to find precut and terminated ends at #4 to 1 or so. But if your relocating your battery I would strongly suggest you use a larger size for those reasons stated above. But your coin do what you like. I also solder the ends of the terminations to prevent corrosion and wick it up the copper into the insolation, then tape off the contact point and dip them in some tool handle dip.

I agree with 78280z, if you can break of the bondo than you have bad adhesion, in this case looks like rust compromised the repair (and a poor one I might add). Now you need to strip, prep, clean, bondo, primer, paint, and color sand. Obviously that is an over simplified order of events, but the concept is the same. The blue color is the bondo layer and the color layer is very thin on top of that bondo layer. The bondo should never be more than the width of your fingernail (in my opinion) if it is any thicker than your are masking the problem with the metal underneath. Also if you can flick it off than the bondo doesn't have a good adhesion and needs to be stripped off and reapplied. Bondo is a mechanical adhesion not a fusion process, hence the name "Bond-O". Best of luck on the project.

I would go with a 4/0 or better (larger size). Here is a bit of information concerning wire size. It is scaled starting with the smallest size first and the last being the largest; 14 smallest in this example 12 10 8 6 4 3 2 1 0 00 usually written as 1/0 000 usually written as 2/0 0000 usually written as 3/0 250 300 etc. to 2000 largest in this example Welding cable is fine strand which is excellent for DC Voltage, like a battery connected to a starter or high amperage stereo system. So for a quick reference, 300 amps DC if you used 4/0 size copper fine stranded wire it should be fine for like a 10 foot run and that wire should be about 3/8 of an inch thick. Best of luck on the project.

Go here for a bit more on the topic: http://forums.hybridz.org/showthread.php?t=103511 http://forums.hybridz.org/showthread.php?t=79631 Nothing is in concrete but information is key in making the decision.

Ever Z I have crawled under has his hunk of metal in different configurations though. I agree that is a factory item, my 1973 had it even though the other site listed here said it was an upgrade in 1974. It made a great exhaust hanger when I was making custom pipe. Also great for a rub rail on lowered cars. I couldn't tell a clunk from a clump in my old heap, she is a bit of a rattle trap!

Piece of cake! Place the rubber seal on the windshield glass and make sure it is nicely seated in the bottom of the channel of the rubber all the way around the glass. Now go down to the hardware store and get a nice fat (3/8" or so), soft cotton (or other soft to the touch) rope and than grab a spray can of white grease. Spray the white grease in the channel of the rubber gasket for the window frame, lay the rope all the way around the rubber channel over the grease so that the ends are at the bottom of the glass. Spray a bit more over the top of the rope. Now place the glass on the cars window frame and gently pull the rope both right and left at the same time not getting ahead on either side. This may take a few tries to get it right but it should work. If it doesn't seem to be going in smoothly stop and restart. You don't want to bind the window too much or it will break. You may even want to add a little white grease to the window frame before the rubber is placed over it. The white grease will help lubricate and pull the rubber into place and the rope will pull the rubber back and allow the edge to overlap the window frame lip. I have done this may times on many different cars (I used to work in an auto body and paint shop). Now go drink a beer and rejoice in your success. Cheers!

Your welcome!

The water flows from the front carb (radiator side) to the rear carb though a passage pipe that should be between the two manfiold halfs. Sometimes these pipes have been removed. Basically each manifold half has a hole threaded for, if memory serves me correctly, a 1/4" NPT barb hose fitting. The water inlet on the front manifold is feed from the thermostat housing throught the front manifold body and exits into the passage pipe (if still pressent). The rear manifold is feed from the passage pipe throught the rear manifold body and exits the rear (transmission side). This coolant will be returned to the other side of the motor to a 'T' fitting that is feed from the heater core return and both feed into the water pump pick up which has a large radiator hose connection and a 3/8" NPT threaded hole, again it memory serves me correct. The heater core is feed from the passenger side of the cylinder head in the rear (just a bit of info).Your car may not have this set up exactly as described as it is 30+ years old and people like to remove stuff, but that was how it came from the factory. Both sets of inducitons you have should have water passages in the manifold. The 1973 version also had one that fed the balance tube and additional water passages on the carb bodies, if memory serves me correct. While I'm at it, they used a funny thermostat that when hot cut off the water feed to the manifold, remove that junk and toss it. It gives you nothing but problems as they never really did work well...at least mine didn't. The dealer no longer sells them and actually suggest that I do this years ago when I was looking to replace mine, smog reasons. If the fuel rail is in good shape, great!!! I would disconnected the fuel rail from the car and use some compressed air and blow thourgh it to remove any bugs that may have made a home. The non-smog balance tube may be hard to locate singlely but check out E-Bay and this sites 'for sale' posts for some good used junk. Also Zcar.com has a 'for sale' section. You may want to post a advertisement in the 'parts wanted' section. Best of luck on the project.

I'll answer each inturn. 1. Use either one. I have heard that the 1973 version has larger internals and flows better, honestly I have inspected them both and see no difference. I used the 1972 cuase smog wasn't an issue. If you want to keep it *cough* smog legal use the stocker than came on the car. The 1973 version will have, or at least at one time, had all the smog stuff mounted to the balance tube. 2A. I think your talking about the balance tube? It links the two manifold halfs together on the top and uses two bolts on each manifold. The 1972 will have no EGR port and the 1973 will have an EGR and it is ported for such. It also has water jackets for faster cold start warm ups. Unless your worried about smog you can use either balance tube. 2B. Use what ever fuel rail you like. I have seen no major advantage between the different fuel rails. But make sure you use a return line, all the stockers should have them but being 30+ years old good luck finding something that is in original factory condition, they are usually all rusty and such as they were covered with a insolation wrap to prevent vapor lockup and a host of other problems. 3. The heat sheild should bolt up fine. The only difference between the variations of the heat shield is that they are cut for a heat riser tube that is used on some of the 1972 air cleaner intakes. Those air cleaners usually had a winter/summer selector. The 1973 used an intigrated version but still used the heat riser tube from the exhaust manifold. DO USE the heat sheild (weather stock or aftermarket or home made) as it will greatly reduce carb heat saturation, especially in stop and go driving or long idleing. Never used, Ztherapy so I can't comment on them but lots of others here have and they seem to have a good reputation. If the carbs you got work than, no worries! Happy motoring.

"on most others...big bore TB on a round manifold flange..." I wasn't really talking about the round TB and intake manifold from the L-6 cylinder Datsun. I was more speaking towards the 240SX swap that is popular for EFI guys on an aftermarket manifold, although I seen a Weber TB once. As I stated the stock manifold is oval or "egg-shaped" as you called it. While we are on it, I seen a round log style intake manifold that looked like it was made from round stock welded together with equal length runners. Looks like that could be a performer. Seen one with a TB between cylinders 3 and 4. That too might perform.

Plastic if not designed for solvents do get brittle. I would definetly make sure that the plastic was safe. You should be able to find a oil filter assemble from Mc Master Carr that would better suit the need. Look for a hydrolic assemble and that would work the same...

I stripped a car once long ago with this type of TB. If memory serves me correctly the manifold is also shaped to match the "oval" TB shape vs. the round version found on the round bore TB that is on most others. I did some "light research" and again if I recall the gains is much less than a big bore TB on a round manifold flange...

Personally the bang for buck is just too high. As stated you can get new carb set up for about that, cheaper for used stuff which if unbroken and in good working order will operate the same as new stuff (the bodies don't wear out just the wear parts). Also the troulbe to convert maybe too much trouble when you look at the easy of bolting on a set up designed for the L-series head. Moreover the Mikuni web site list the pilot jet really small like max of 35. Unsure if that would do it or not.

Hey I noticed that nobody mentioned that motorcycle carbs have two types (or I just didn't see it). Like the SU carb their is a slide bore carb (as I heard a bike guy call them) and a open bore carb (again his terminology not mine). I would think the open bore carb would be the better of the two types as the slide bore would be using engine vaccum to open the venture. I would think the vacum would be different between the two engines simply becuase the RPM range is different and the fuel requirements would be different. But if you figured out the fuel curve on either set up it should work. The bore size, if larger than like 32mm should be fine; what does the SU meassure??? 38 or something. After all the magic of the carb is the bore size vs. the ventrue size...the rest is just fuel metering. With a smaller bore carb you may not gain any performance advantage over a twin SU set up or 40mm triple carb set up but that picture posted here sure looks like a nice set up. And if your a bike guy you may have everthing you need to tune them which in multi carb world is a HUGE advantage; six bores means six sets of everthing; huge expense their. Kiwi303 I say try it and if it works...great!!! Just post your results for others to follow and sponge off all your hard work!

Mine didn't backfire when it was rich but did puke out blue smoke...and lots of it. No backfire on deceleration and none of acceleration, from either out the intake or exhaust manifold. Also had a motor where the timing chain jump a link due to worn/broken chain tensioner. Same issue but raw fuel that would burn the eyes, like a top fuel drag car warming up in the pits, just not as bad. A backfire can be produced by for many reasons both out the intake and exhaust manifolds. You would really need to determine the condition when it exist and work from there. Yes bad ignition can also produce a backfire condition. But like he stated it isn't doing it now, so... My main tip was check the easy stuff to confirm it is where it should be. Guage should cost about 20 bucks and a great addition to any tool box. They smoke when they are lean and they smoke when they are rich.

I am willing to bet that the electric fuel pump is overpressuring the needle and seats in the fuel bowl thus over flowing the fuel bowls. This is why the problem is the same on both sets of inducitons. Do a search here on solutions to this problem, fuel pressure or carb inlet pressure. I have responded to several posts so I know they exist. During testing mode, get a good quality fuel pressure guage and test the pressure first to confrim the potential problem and I bet your pushing greater than the required 5 P.S.I. Be advised that even with such a low pressure that with old or used needle and seats you can over flow the fuel bowls.

Remove the vaccum hose to the brake booster and plug the hole (do the same to all other vaccum taps). Do not drive the car in this condition it is just for analyst purposes. Start the car and check for the same problem. If the problem continues than varify the ignition timing to the crank. If the timing is good check the crank mark to the actual top dead center of the motor. Remove the valve cover and check the cam marks to the crank mark, and the top dead center on cylinder number one. If these three marks do not line up than you may have spun a harmonic dampener (very common) or your timing chain tensioner or slack guide is damaged/broken (also very common). A Chilton or Hayes manual will illistrate the location of the cam timing mark as well as how to determine the number one cylinder top dead center. If this all checks out than check the valve lash and cylinder compression numbers. It is possible their some issues with this area as they are adjustable and do need adjusting over time.

My best guess is you will have to make one. I do not know of any aftermarket product that fits the bill. I would suggest using a very thin sheet metal so you can easily bend it with your hand and also use a prick punch to put holes where you need them; better than trying to drill it, and quicker too. Once you got a basic shape and bends than you can make a permenant heat shield with a thicker material and aluminium too. My Webers have a bolt stud on the front of the carb so it makes mouting them quicker and easier on the air inlet side of the carb. I would mount it in the rear as a main mounting point and use some kind of support on the strut tower side...somewhere. Best of luck.

I ran a 3.1L with bell top SU's for years with stock needles and nozzles. It can be done very successfully. I prefer my engine with triples however. I also used a 600 Holley 4 barrel on a Clifford manifold. The Holley carb was a bit much for that engine. If you ever decide to switch your induciton there are many options to consider...EFI is also a good choice. I am not a big fan of the DGV but it is also out their. You didn't say what type of rods your using...stock L-24 or some aftermarket H-beam rod? Don't really understand the hood venting comment. If it is heat build up your commenting on, I would suggest a stock heat sheild on the induciton. I ran without one and it seems to keep the carbs cooler with one. I would highly suggest running one to prevent fuel bowl/carb. heating. My underhood temps were never bad but I did have to run a 280 Z radiator as the stock 240 Z unit was too small on hot days (90+) and in stop and go traffic too. I also used a 180 high flow thermostat. The 280 Z radiator was a direct drop in unit in my 1973 240 Z. Many a write up on aftermarket radiators here and other sites. Happy motoring.

My bell top SU's did the same thing, mainly on the rear carb. The fuel bowl would actually go dry (long story). I agree with what has been said, try one more thing to confirm your suspicions. Use a inferred tempature gun and get a reading off each carb top and then the bottom just after you stop then after the problem starts and just after it dies. Record these numbers so you know what the optimal temp is for your car. Now you can base line any mods and confirm that the mods are working. A good heat sheild is always a good idea. Buy a starter thermal blanket and bolt it to the bottom of the heat sheild for added protection. You'll have to cut off the velcro flap. Looks like hell but if done right nobody will see it without a mirror.

Square bore pattern on the Bob Sharp/Arizona Z car version. Clifford Research uses an adapter plate that mounts the square bore pattern to the manifold. The Clifford Research manifold has a large square hole without any carb mounting surface. If you use the Clifford Research manifold you can drill holes in the nitrous plate and mount it directly to the manifold...that's what I did. Makes it real low profile under the hood. I would gather that you "may" be able to drill a square bore to spread bore adapter plate (search Summit Racing SUM-G1401) to mount a spread bore carb, haven't looked at it close enough.

Tony D., Thanks for the info and the link. Great stuff. TimZ, Good call on the TB runner 'cut and paste' job that Monzter did. Monzter, Never too many pics. Great way to document your project...how many hours spend on machining/welding of the TB runners...or do you not want to add them up? On the plunum idea, I look toward the Pro Drag race guys for inspiration. By simply adding a half donut shape over the port that may produce a smoother transition into the throat of the TB, or I would think. Extruda body (advertised on this site) has a video on his my space page that demonstrates the effect and the half donut shape very well. It really is odd that something so simple in shape would generate that much more flow...but really I guess it is no more than a TWM air horn without the inlet tube. Post more pics as you finish more items in the project. This is definately a project I would like to closely follow. Might make a good multi-step article for Nissan Sport Z mag...

Sence you mention it, the plenum being at 90 degrees from the inlet to the individual runners, would that cause some blow over (not sure if that is a technical term)? But the question is as the air flows into the plenum would you have negative things happen to the air as it flows over the first, second, thrid intake runners and so on as it travels to the sixth runner. The original SU air cleaner put little side skirts on each side of the intake horns, I am assuming to prevent this...maybe it was just to hold the air cleaner in place? So with that said would their be any logical reason to experiemnt with an air horn that was round on the trailing edge and square on the leading edge? Just building off the ideas TimZ shared. The intake shown looks too long to me to be a Cannon and the intakes are curved, were as the Cannon I have is straight. Origiannly it looked to me that a stocker was cut up and the runners were re-organized as 1-4-5-2-3-6...than some fancy welding to make the standard side draft mounting surface either by cutting off the flanges on a stock Cannon (or other brand) or having some mounting surfaces fabed up as blanks like the headers were and welding them on. It is an interesting quiry. Either way it looks cool and original.