TheNeedForZ

Woohoo! Man you restore with a vengeance! Keep up the good work.

JEG'S? Where? Can't find it on their site...

The S30 Z cars relate so well to a Nickelback song that goes : "...Something's gotta go wrong cuz I'm feelin' way too damn good..." Well, keep us posted.

Acetone is CH3COCH3, it's in the ketone class, not really a nitro compound or aromatic. .......O .......|| H3C-C-CH3 Other than to make more profit, I BELIEVE there's one more reason why acetone is not added to our fuel. Acetone is used as one of the solvents in the manufacturing of propellants(nitrocellulose.) Since acetone is not a petrolleum distillate(not produced from crude oil), it must be manufactured. Thus acetone is relatively expensive to obtain and easily spent. During WWI, The British ran out of acetone and England could not produce cordite which is the smokeless propellant they used. They had to borrow acetone (300,000 tons?)from other source, I forget which country. That's why I think acetone are "reserved."

You can find it in "how to build horsepower vol.2" p83, bottom right corner : "The bottom line here is that careful work on the primary side alone can net in excess of 30 cfm and the good news is that all this comes with an increase in booster signal." plus some photos on p84. The Q-jet needs some mod because it has a lot of unwanted stuff in the primaries, like the "support wing". Your Holley should not need any mod but will still benefit from a thinned down butterfly shaft.

and I thought those dohc v8 heads are trick! Their company don't give out the running numbers of an actual engine though. Would be nice to compare a typical OHV , dohc, and rotary valve engine side by side.

Usually the 2ndaries are disabled by the choke mechanism before engine is hot enough. I Don't know about Carter, but on my Q-jet the 2ndary throttle plates are locked until choke heats up. You can read any internet link to know roughly how a carburetor works in general. But you have to read a book written about one particular carb to really understand that one particular type of carb. The car looks nice and clean, it even has the headlight covers.

Thanks to all replies. True, I was only modifying the booster clusters and butterfly shaft. The main venturies are untouched. I even went so far as removing the "wings" that connect boosters to the wall. So the metal is zinc....I heard the original finish is "zinc dichromate". Well, dichromate solutions can cause cancer so I'll just paint it. Tony78_280Z, I wouldn't dare to modify my carb if it weren't recommended by David Vizard. He said modding the primaries like so not only increases cfm but also increases booster signal. Here's what I think : Increased cfm can be had in two ways--- 1. Increase size of passage---all else being equal, this reduces air speed, therefore could hurt the low end. This happens when too big a carb is used. 2. Remove protrusion in the passage---all else being equal, this increases air speed which improves booster signal. Here you have some cfm increase as well as booster signal increase. It's a win-win situation. You are prolly right, it is likely something will need to be changed after that kind of mod. "Changes one thing changes everything", especially in a carb where everything is hanging on a balance.

awd92gsx, I am assuming that you don't already know these : You might want to check the power piston system. If the manifold backpressure was enough to squirt fuel/air back out, there's a chance that the power piston can be popped out and remain stuck. Then what you get is a constant enrichment because the primary metering needles are raised at all time. Also, to really tune the idle mixture, not only do you need to tune the idle mixture screw, you also need to tune the throttle stop screw. Throttle stop screw adjusts the throttle blade position on the transition slot. opening the throttle a bit enrich the mixture(less air pass thru the slot), this also speeds up idle a bit; Closing the throttle a bit leans the mixture(more air to pass thru the slot), this slow down the idle a bit. An old carb usually have worn butterfly shaft bores that create vacuum leak : air enters the manifold thru the bore gaps. This is a main cause of rough idle. When you have a worn butterfly shaft bore, you either have to find a tighter throttle body or have a specialty shop install bushings on the old throttle body. Where exactly of the carb was the fuel shooting from when you had the problem? Hope this helps, keep us posted

I too just started to know about SBC since I bought a V8 240Z few months ago. I strongly recommend David Vizard's(aka "Vizard the Wizard") books : How to build horsepower vol.1---must read, especially beginners How to build horsepower vol.2---this book focuses on intake and carburetion How to build max performance Chevy small blocks on a budget---has more to do with actual engine building than general power production knowledge These great books are well written and easy to read. Vizard is a very precise kind of guy. He's very knowledgeable and very experienced. You can't point out anything wrong in his books.

Thanks for posting, it's a beautiful car!

I spotted an local ad about a wrecked diesel maxima : 1982 DATSUN MAXIMA Diesel 5 speed wrecking, runs good. Cloth interior, motor suspension everything $10 up Does this car have the right crank for building a stroker? Thanks

Hi, I've done some modification on the primary side of my spare Q-jet(mainly streamlining the air path and modifying venturies). Now a lot of bare metal are exposed, which I assume to be aluminium? The carb originally has a yellow-green finish for protection, I wonder if I can get the carb refinished myself by buying the right chemicals? Any idea how to refinish the carb? Thanks

lol

What can be done to the torque converter? Do they lose fluid or efficiency over time?

What is the "underhood info" you are referring to? Is it a sticker or ??

Thanks for the link! IMO these info should be carved and kept on stone tablets.

I was gonna say Dremel + miniature circular saw or like said above, wire saw. But since you tony helped solve the carb problem on my 240Z, I'll lend you my laser

Looky here : http://tak.jumbotak.com/video/budweiser.wmv

Hi, all First let me start off with a question : When I try to start my car eqipped with a Q-Jet, do I have to pump the gas pedal once to reset the fast-idle cam? Now here's the update : I brought a stick of crazy glue with me to troubleshoot the 240Z. I was hoping to use a tiny bit of glue to temporarily glue the 2ndary lockout lever to a stem so it woudn't lock the 2ndary, but the carb is full of gunk just from the looks of it so I didn't even bother to try the glue. Then I proceeded to start the car. I had problem starting the car at first, so I messed around a bit. Then I tried to hold the throttle open slightly as I turn ignition and the engine fired up. Since the 2ndary lock is not disabled, I had to somehow test the 2ndary manually. With the engine running, I opened the air valves and used a screwdriver to push open the secondary throttle gently. I pushed the 2ndary throttle open, heard the engine sped up a bit, which is expected. When I stopped doing the test I hear the engine gradually speeding up faster and faster !!! Freaked out, I dashed back into the car and shut off the engine immediatly. I didn't know what's going on. I went back to checked the 2ndary system to see what the heck just happened. Turns out the air valves are stuck open when I opened it with my hand. Since the air vlaves are stuck open and the 2ndary throttle are slightly open too, there was a steady supply of airflow to keep the 2ndary throttles open a bit. That explained the gradual speeding up of the engine. With the engine off I checked the air valves again. Indeed, if I open it fully with my hand, the air valves will stuck at full open position. The entire carb has just too much gunk. The air valve tension is also too tight to my liking; I doubt it will ever opens as is. Once the air valves are closed the engine acted normal again. Obviously the 2ndary system will work nicely once the throttles are unlocked. I took the car for a bit of test drive in the alley with the 2ndary system still locked. Somehow the car feels very different than last time(last time I used a crooked air filter. This time I used K&N Xtreme so perhaps air metering is correct) I'd say the car is much faster than my VW Jetta even though it is only running on primaries. This time I had A TON OF FUN in five short minutes because I KNOW the car can easily be better if I unleash the power hidden inside the 2ndary system. After the test drive I let the engine cool and spent 10 minutes looking at the car from different angles. It is such a sweet looking car with such awesome power! With a silly grin on my face I covered the car up with waterproof tarp and went back into the house. Conclusion : -The carb on my 240Z desperately needs a thorough cleaning. Fortunately, I just finished a practice cleaning of my spare Q-jet -Electric choke will be installed. -Air valve spring tension needs to be lightened. ....I still have that silly grin on my face. To think retrospectively, I almost gave up after having trouble starting the car this afternoon. I am glad I kept on trying.

I like it too, sent to friends.

paparaska, It looks nicer indeed. I esepecially like the second photo of the three.

If you can find a way to produce these heads, you are going to be rich!

The man that sets record for fastest piloted flight in earth's atmosphere...drives a 240Z. Someone fill in the details? (Heard this from one of the SportZ Magazine)

I've always wondered how would the 240Z~280Z look like if the shiny window trims are painted or replaced(ie not shiny) BTW Are those stainless steel or plated? Is there any photo of mods like that?