beandip

I was in Denver a month or so back visiting friends. While there I found a great Body/paint shop if someone out there is in need. EXOTIC BODIES there in Lafayette. 1265 rock Creek Circle 720 890 0952 . We rented a car next door to them. I was vary impressed with there work and just thought I would pass on the information . Gary

Depends on the compression ratio of your engine . What the higher octane fuel is, is that it will NOT ignite at a lower compression. So if you have increased the compression of your engine , then it may require the higher rated fuel. I witnessed a dyno test where a Z actually made more HP with lower octane gas. The lower compression was not burning all the fuel . The early Zs were high compression engines and suffer predetonation or ''pinging'' with low test gas. I am running 9.5 to 1 and usually use plus fuel . This is not really a high compression ratio , especially since I am running a moderate cam , which requires a higher compression . I haven't dyno tested my car with different fuel however , I am not having any predetonation . I could most likely run regular grade gas . Your timing also comes into the mix here as well , more advance BTDC will also require a higher grade fuel. You could vary likely make less power with 100 octane gas in your stock engine . Gary

The stock air cleaner has tuned air horns installed in them . You will loose performance with the aftermarket air filters . They do look cool and sound good.:surprised

Dog , this is a 4 month old thread.

You do have SUs and that is good. If you look on the driver's side below he #6 exhaust port you will see some numbers in the casting of the block. L-24 is a 240 L-26 is a 260 and L-28 a 280 . F-54 is from a 280 ZX . Without closer pictures I cannot tell more than that , it does look like a 280 type oil filler cap on the valve cover. Again it is hard to tell. The 260 is a emission tuned engine stock , but it had flat topped carbs that were not meant to be performance. The 260 engine is a 240 with a 280 stroked crank. That insulation that covers the fuel rail can be tossed and that will clean up the look of the engine. All the components on the present engine will fit a 280 and work well. The air cleaner looks like someone drilled a bunch of holes in a line along the top , I don't know what that was for. Does it have a 4 speed of 5 speed ? When you pull the engine it would be a good time to do the rust repair . The Battery area is a cramped space to work in . Is there rust through in this area or just surface rust?

I know of 2 that color in the Portland / Vancouver area , and that is just among my friends.

Welcome , this Z is a great find. You will be surprised at the options you have for engines since all the blocks are the same from '70 through '83 . THAT IS ON THE OUTSIDE . Personally I would look for a engine from a 280 ZX , that is from '79-'83 as it is the last evolution of development . If you can be selective you may find one that you just need to clean up detail and drop in . The carbs can be used and will provide good performance . We are hear to be of help , and there is a wealth of knowledge here , you just need to ask . Gary

J. C. Whitney has them for $13.00 a pair. Do change both. Gary

If you have the correct carbs and no vacuum leak , 3 1/2 turn should be way rich . When you reassemble the carbs. Use 20w oil in the dampeners , if you don't have any 20, 10w30 will work. I like the others here wonder if the carbs are both for Zs. measure the opening of the inlet of the carbs to see if they are the same size . It would be best to measure the flange side of the carb , but for now just check the inlet side. So these miss matched parts is how you bought the car , right ? You didnt do this, right ? To answer your question on the markings on the needles. They were simply printed with ink stamp. Most likely the markings are no longer there. If you have a set of 1'' micrometers you can compare the two needles , but it isn't' easy because of the taper. Needles are still available from Nissan . If I were you I would start looking for a set of carbs. Just ask there should be some extra sets someone here on the web site would part with . Gary

Yah a7dz . I agree. Gary

listen to what EZZZZZZZzzz said. you see , backfireing through the carbs can be from timing issues and lean mixture issues. Among other things . How many years have you been working on SUs and or Z engines ? None of us want to argue with you , we just offer knowledge and experience . Thats all . Gary

If you are going through all the work and trouble to strip and prep the Z , why in the world would you skimp on the paint ? Good paint is not that costly , if you want cheep , take the car to Maco or Schwab and be done with it . It will look pretty good and the paint will look every bit as good as what you are looking to buy. You wont need to go through all the work. I bought the best paint that PPG makes . Including all the sand paper and primer body filler, paint and clear, tape . Everything , it came to $700.00 . Now I know I could have done it much cheaper by not using 2 stage paint and I could have bought a lesser costly grade of paint but still good stuff. You get what you pay for with this stuff. If your car is in that bad of condition . There was a thread posted on this site about painting the car with a roller and brush then color sanding it smooth. Go to Home depot and go for it. Gary

Well , welcome to our group of Z drivers . Gary:rambo:

Are these 3 screw or 4 screw SUs ? On a 4 screw the mount for the nozzle can be adjusted for alignment . On the 3 screw the nozzle mount is fixed and there is no alignment adjustment. The adjustment or alignment is in the dome . So if the needles prove to be straight and still are sticking look to the alignment issue . Just be sure there is no grit on the vacuum pistons and or the cylinders they slide in. Some times when you spray cleaner it the throat of the carb , you will dislodge crud that will then bind the piston . DO NOT MIX the parts from on carb to the other they are fitted at the factory. Gary:rambo:

What do you mean fixed float ? there is no fixed float on a SU. As for a mixed set , it should be fine as long as the needles are the same and they are working properly . You said that you balanced the carbs with a air flow meter and adjusted the mixture now it has a 3K idle? Sounds like you need to go back and adjust things properly. This engine should idle at 700 RPM . What did you set the timing at ? Also the new Dist what is it , what kind of ignition are you using ? The parts you have circled can be removed as long as you don't have to stand a emissions inspection . One way to look for a vacuum leak is start the engine and take a spray can of carb cleaner and spray it around the intake manifold and suspected leak . If there is a leak the engine will change RPM when the spot of the leak is sprayed . DO NOT USE START FLUID FOR THIS. What is the casting # on the intake manifold ? Gary

BINGO . I installed a set of Urethane M B bushings with zero lube and have no squeak at all . Do look to the sway bar set especially where it connects to the body.

You need to determine top dead center . Remove the spark plugs and turn the engine over with a socket on the crank pulley. Either you or have someone else put there finger over he plug hole on # 1 cylinder . When the piston comes up on the compression stroke you will feel the air pressure build. Now if you look in through the plug hole with a flash light you will be able to see the piston rise . right when the piston stops , before it starts down . That is top dead center . It may take a few tries to get it. When you accomplish this then confirm by also looking for the timing mark on the pulley . Mark this with a pointer or paint a mark . This is a crude way but it will at least get you in the ball park. Why is the pointer missing ? Make a new one or replace it. Some times backfiring through the carbs is caused by too lean of mixture . That is if the timing is correct. The timing is the first thing to fix . If to far advanced major problems can be the result . If the engine pings under load , retard a few degrees , and do so until there is no ping . This will get you by for a short while , but do fix the missing pointer situation .

It is true that he 280 heads will yield lower compression , unless you mill the head. Do this when you change he heads and also do a valve grind . What is the condition and or how many miles on the L-24 your running now. If it original and in need of a rebuild . Consider installing a ZX engine , it's like a bored and stroked L-24 and stock it will liven up your '73 . I milled .030 off my P-79 head and that gives me 9.5 to 1 compression and have no trouble with fuel. If you are going to spend a bunch of money on a engine why not do it on a improved version of he L-6 . It runs great with SUs. Gary

Carol . I haven't forgotten. My friend went to a car show today and asked a bunch of the intranets where they had there work done . He said most had bought there cars the way they were. Go figure . However he said that several said to ask a certain person . As luck would have it , he had to work today but he has his name and is trying to contact him . So as soon as I hear I will pass on the info. Gary

Andrew , welcome to the club . You will find a great wealth of information here and members willing to help. Do use the search and you will find tons of good stuff there. All the best to you and yours , Gary

Carol , I am vary sorry for the loss you have had recently. And welcome to our group . We will help in any way we can. In looking for a shop to have work done and have it done right . Look for a Body Shop that does custom cars. I am sure there is one in your City. Most '' Body Shops '' today are really panel changers . To find real craftsmen in the body work business you need to find the ones that are building Hot Rods and doing custom cars . If you are not in a hurry go to a car show and ask around . Not a new car show but a hot rod show. You might ask your Insurance agent . Try a local Parts Store especially one that has speed products . I do know some one that lives in Pleasanton maybe he would know . I will give him a shout . All the best Gary:cheeky:

When you leave a fuel tank with little fuel in it over the winter. Every time the temp fluctuates up and down they sweat inside a little. The moisture collects at the bottom of the tank and can rust it. I am fairly sure on your year Z that there is a vary fine screen/sock attached to the supply inside the tank. If you are lucky this isn't blocked and it is just a filter . Check for a in line filter back by the tank . I would just replace it . Also any fuel filter up front as well. Any little piece of rust or crud if not caught by the filters WILL clog the injectors . It's best to keep the tank full , when over wintering a car. With hardly any air in the tank , it will not sweat, also use stabilizer in the fuel.

Mike B , looks like you dodged the bullet big time. It's amazing how well the metal ready and some scraping returns the metal rust free and ready for treatment. Good job! :rambo:

Thanks for this outline. I have seen this in the past but didn't copy it. Great info. thanks again . Gary:)