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240zbabe

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It figures, my stepdaughter drives a sentra ! I could only have dreamed that she would buy a Z. I'm sure you two will will have a great time working on the car. Gook luck with your new car.

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Andrea, welcome to the site. You will love all the info you find here. I have to agree on the 4 bbl. conversion. I have a old buddy who I have worked on Z's with for awhile. He went with the 4 bbl conversion and it has never been "right". It originally came with a 650 cfm carb and it dumped way too much fuel into the cylinders. And he runs a mild cam!! He has since found a 500 cfm Holley that could help but as mentioned above, I am worried about some cylinders running lean. Stay with the carbs you have, they are the best. If you have to change check out the Weber DGV's, they work great also

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One other place you probably want to check for rust if you have surface rust to begin with is the area under the cowl inbetween the hood and the windshield. I thought my car was gonna be an easy bodywork project until I dove into this area.

Good Luck and Welcome to the Site!!!!!!!!!!!

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Welcome to the club!

The best thing I can do to give you a welcome gift is to say-don't do the conversion!

"my step dad wants me to do the conversion because they are easier to maintain"

That is ONLY because he knows about a 4 barrel, and doesn't know about the SUs.

If he sends ZTherapy the $20 for the tape, he will find out his problem with the learning curve is easily overcome, and the SUs will give both of you a car that is a great deal more fun to drive than a car with a four barrel conversion. Compare the manifolds, the SU manifolds have essentially equal length runners, the 4 barrel conversion does not-you are considering trading a superior and well designed induction system for a "roughed in" system.

The four barrel conversion will work, but anyone who has ever really dialed in the SUs, and then tried the four barrel setup has gone back to the SUs in short order-when they are properly tuned, they will easily out perform the best tuned conversion. I won't tell you how I know this, but I sold the manifold, and a 4 barrel three weeks after I installed it-spent nearly $600 to find out what I had was clearly superior to what I bought-I even took the car in and had it tuned by a four barrel GOD. The SUs ran better, the car was faster, and the slight extra maintenance was worth the benefit to the right foot, seat for the pants, and the stopwatch. That lesson cost me $322(the loss I took on selling the manifold&carb, plus the cost of having a professional carbureator tuner dial in the four barrel).

The SUs are also paid for-spring for the tape, the time to watch, the parts to rebuild as necessary, and enjoy knowing what you did was better for the car, and the smiles per inch of foot travel!

If you are deadset on converting to a four barrel-don't race anyone who has properly tuned SUs, you will see that spending the money and the time has also cost you performance. I am sure someone who has done the conversion would love to buy your SUs...

It is your car, your money, and your perogative to pay to learn this lesson yourself!

Will

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Hi Andrea,

Welcome to Z world! You won't regret having a classic Z car and you'll be proud of every hour of work you put into it. If you are interested in the Z therapy tape on SU carbs, I'll sell you mine. If you are sure about the 4 barrel conversion, it seems to me that I have seen a manifold or to sitting around Steve's shop (Z Therapy shop). I'd bet he'd love to sell you the manifold at a deal since he is a confirmed SU advocate.

I am very new to the Z world myself and I could be wrong, but my understanding of the problem with the 4 barrel is that the single carb doesn't provide consistant mixture to each cylinder. 2 cylinders will be too lean and 2 will be too rich. You will have to compromise to find the place where you get the best preformance. You may experience some knocking, pinging or ? The SUs are basically tuned since the 2 carbs supply 3 cylinders each rather than 6 for the one carb. If you convert, keep all of your old parts as you may want them later. The carbs, manifolds and linkages will bring you a few bucks now, but what a drag if you want them back.

But, as long as you are having fun, everything is good. Best of luck.

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You didn't waste your typing, you tried to help someone with a desire to install a bad implementation of a good idea! Saving maintenance is a good idea, doing it by replacing SUs with a 4 barrel is most definitely a bad implementation.

In 1976, an ASC certified Master Mechanaic and Nissan trained 240Z specialist told me: "Most of the time, aftermarket products are far better for lightening a wallet than speeding up a car. Usually a tuneup gives more results than the sayso of an ad."

This was his comment when I asked him about this very conversion-I bought it anyway-I have never doubted his direction since...

Will

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Hi Andrea,

You might check www.eastwood.com for sanding blocks and other body repair supplies. They have just about everything you need for doing body work. Another source for tools is www.harborfreight.com.

Harbor Freight mostly sells tools made in China. But hey, Harbor Freight, along with Walmart, has done more to bring China into the 21st century than Chairman Mao ever did... I have been pleased with most of the tools I've bought there, such as hvlp paint guns, strut spring compressors and other various tools.

Like your step-dad, I am more familiar with the older 4 barrel carbs. But like most everyone else here, I suggest keeping the SU's. They are actually much simpler to work on and have only a few adjustments, whereas most 4 barrels have many more adjustments to get them working good (I have an old Chevy to satisfy my 4 bbl cravings...).

Either way, I know you'll enjoy working on your Z. With a little time, effort & money you'll be rewarded with a great little sports car that is fun to drive!

Kenny P.

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G'Day Andrea,

Welcome from the Land Down Under.

Lady, ... PLEASE listen to what EVERYONE has been saying. Stay with the SU's. These blokes know what they're talking about. They've been there, done that and got the skinned knuckles and empty pockets to prove it.

Has your Step - Father read these posts ????? If not, ask him to. SU's are simple to work on. As a mechanic I make a damn good brick layer yet even I can work on 'em. (After being shown what to do by a fellow Zed owner).

If you check out the technical threads you'll find a wealth of information on Zeds.

As for car cancer, you might check out the area behind the headlights and the bottom of the doors. I'd also suggest removing the aluminium strips (with the word "Datsun" on them), from the bottom of the door jam and the side kick panels inside the car.

You now own one of the 10 most important cars in the history of motoring.

ENJOY.

Rick.

:devious: :devious:

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There was a suggested conversion to the Webber DGV carbs a bit earlier in this thread. This is not as bad as the 4bbl but still not as good as staying with a side-draft carb (i.e. the SUs or some tripple setup). These engines work best with side-draft carbs due to the location of the intake. As it was stated previously about the 4bbl, the air/fuel mixture travels down through the carb then must make a 90* turn to then travel into the head. This turn impeads the flow and results in a reduction in performance.

In all honesty, buy the video for $20 learn about the SUs; if yours are really jacked up then send them in to ZT as a core and get rebuild SUs from them. Then take the money you have saved and use it to fix things that really need attention like any rust in the car.

Down the road some day if you want a carb conversion you may want to consider a tripple setup like SK, Mikuni, or Webber; however you will not get the real benefit of this conversion without some other modifications such as a hotter cam.

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Welcome to the site from another female lover of Z cars. The guys here are the best and most friendly bunch of Z nutz on the planet. :classic:

Vicky

Ditto from another Z 'girl'. Rather than change the carbs, invest the money in a Factory Service manual specific for the year, and be as specific as possible when asking questions on this board (and trust me, you will have lots!).

When I got my Series I Z, these guys were able to diagnose a gunked-up gas tank (had it cleaned out), SU carbs in need of a re-boring, and some electrical problems. I love the fact that compared to my husband's upgraded '69 Camaro, my Z is easy to work on.

I also hope that you plan to learn about your car as you work along with your stepdad. (BTW, my first gut reaction to 'my stepdad wants...' was 'Get your own car!'...but then I calmed down) :cheeky: . Lots of people out there somehow think that the only way to get the 240Z to run is to gut the engine and change everything. While it can work for someone with the patience, knowledge and deep pockets to do upgrades, for the rest of us, the enthusiasm for this car also follows into the engine bay.

And show us pictures!

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