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Discussion Starter · #1 ·
I have a '71 240Z with an L28 block, flat pistons, E31 head w/280 valves, mild porting, moderate cam, Cranes hi-6 ignition and Weber DGV carbs. I've heard so many stories (pro & con). Can anyone help to sway me one way or the other. Would I get that much more power with triples, keeping in mind that I drive Autocross and need reliably broad power range.
The car runs great, but I want MORE!!!!!!!

Impatiently waiting.
 

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> I have a '71 240Z with an L28 block, flat
> pistons, E31 head w/280 valves, mild
> porting, moderate cam, Cranes hi-6 ignition
> and Weber DGV carbs. I've heard so many
> stories (pro & con). Can anyone help to
> sway me one way or the other. Would I get
> that much more power with triples, keeping
> in mind that I drive Autocross and need
> reliably broad power range.
> The car runs great, but I want MORE!!!!!!!

> Impatiently waiting.

Brian,
I would dump the Weber DGV's first. A well tuned dual SU setup will be much better than the DGV's. Look at the manifold, and the 90, then 45, then 45 degree turn again it has to make. It does not promote good airflow. I would say for your setup, that unless you have a fair amount of money to spend on someone tuning and jetting the triples just right, stick with the Dual SU's. They are an excellent setup, that are very easy to tune. I really think that is your best avenue. Unless you are into serious race, and/or have a bigger motor,(3.1, etc...), you will see a minor increase from the triples, maybe a decrease if they are not jetted and or tuned right. If you want another form of triples that are very easy to tune, look into the triple SU setup. A company in phoenix (Performace Z I think), actually Dave the owner, makes a really good setup. I think the cost is comparable to a new triple setup, ie 1100 or so. With a color tune and a good airflow meter,(not a Uni-sync), you can maximize your performance in short order.
-Bob Hanvey
 

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Bob's right dump the DGV's and get some SU'

I ran the DGV's on my first 72 240 thinking they would make more power than my stock setup.Man was I wrong,not only did they make the car SLOWER the mechaical secondaries would cause an annoying cough whenever I floored it below 3500 rpm.The constant velocity SU's make excellent low end torque and good HP.My old 2.8 engine would run a [email protected] with the stock SU's with only the throttle shafts cut down for improved airflow and richer fuel needles.I think if you have the money go with the tripe SU setup. I have had many friends who have run triple webbers and had nothing but problems and could never outrun me with my stock SU's. Later, norm
 

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Bob's right dump the DGV's and get some SU'

I ran the DGV's on my first 72 240 thinking they would make more power than my stock setup.Man was I wrong,not only did they make the car SLOWER the mechaical secondaries would cause an annoying cough whenever I floored it below 3500 rpm.The constant velocity SU's make excellent low end torque and good HP.My old 2.8 engine would run a [email protected] with the stock SU's with only the throttle shafts cut down for improved airflow and richer fuel needles.I think if you have the money go with the tripe SU setup. I have had many friends who have run triple webbers and had nothing but problems and could never outrun me with my stock SU's. Later, norm
 

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> Brian,
> I would dump the Weber DGV's first. A well
> tuned dual SU setup will be much better than
> the DGV's. Look at the manifold, and the 90,
> then 45, then 45 degree turn again it has to
> make. It does not promote good airflow. I
> would say for your setup, that unless you
> have a fair amount of money to spend on
> someone tuning and jetting the triples just
> right, stick with the Dual SU's. They are an
> excellent setup, that are very easy to tune.
> I really think that is your best avenue.
> Unless you are into serious race, and/or
> have a bigger motor,(3.1, etc...), you will
> see a minor increase from the triples, maybe
> a decrease if they are not jetted and or
> tuned right. If you want another form of
> triples that are very easy to tune, look
> into the triple SU setup. A company in
> phoenix (Performace Z I think), actually
> Dave the owner, makes a really good setup. I
> think the cost is comparable to a new triple
> setup, ie 1100 or so. With a color tune and
> a good airflow meter,(not a Uni-sync), you
> can maximize your performance in short
> order.
> -Bob Hanvey
conversion to triples w/o a one peice manifold will result in no manifold vacuum for the power brakes. Vacuum pumps are available, but are something more to go wrong.
 

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Discussion Starter · #6 ·
> conversion to triples w/o a one peice
> manifold will result in no manifold vacuum
> for the power brakes. Vacuum pumps are
> available, but are something more to go
> wrong.
I want to thank all of you who replied to my question. The wierd part about this is that I know two people with 240's w/triple Webers who say they run great and never have to touch them. All the pros and cons seem to make sense (which acually makes NO sense) but I am grateful for you all taking the time to respond.
 

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> I have a '71 240Z with an L28 block, flat
> pistons, E31 head w/280 valves, mild
> porting, moderate cam, Cranes hi-6 ignition
> and Weber DGV carbs. I've heard so many
> stories (pro & con). Can anyone help to
> sway me one way or the other. Would I get
> that much more power with triples, keeping
> in mind that I drive Autocross and need
> reliably broad power range.
> The car runs great, but I want MORE!!!!!!!

> Impatiently waiting.

I have had a set of triple SK carbs on my punched out 280 motor for several (9)years and I would have a difficult time liking anything else. I have an E-88 head on a hawged out motor with TMW manifold. I did a couple of things to make it run a lot better, one was to install tees in each manifold runners so that It would equalize things a bit. This made a huge difference. If I remember right, Canon makes a trip manifold that is already connected between the runners. I didn't have any trouble with the brakes, however I did build a setup to install 79 discs on the rear of my 74. That's another story. I must agree with the others, finding a supplier of jets and figuring out the numbers can be a headache. The best advice I can offer is to pick up the SK book on Weber carb and read it from cover to cover. (It may be by HP books, can't remember) The horsepower from these carbs is remarkable. Mark Walker.
 

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I disagree with most all of this.

> I have a '71 240Z with an L28 block, flat
> pistons, E31 head w/280 valves, mild
> porting, moderate cam, Cranes hi-6 ignition
> and Weber DGV carbs. I've heard so many
> stories (pro & con). Can anyone help to
> sway me one way or the other. Would I get
> that much more power with triples, keeping
> in mind that I drive Autocross and need
> reliably broad power range.
> The car runs great, but I want MORE!!!!!!!

> Impatiently waiting.

If you do go back to SU's let us know, I need a good laugh, sorry but after reading some of the posts all I can say is there is a need of carburator learning and setup that is in need here. You should get a min. of 35hp increase if you go to tripples, I recomend getting a manometer for syncing them, unlike others around here I can set up a tripple set in less than 15min and don't have much of any trouble with them at all but I know the right tools help a lot. If you get the tripples go to your local motorcycle shop and pick up the Manometer tool, it's what they use to sync the cycles and they work just as good on cars also. I recomend getting the Mallory distributor that Victoria British sells for the Z's, it works super with these carbs and even the DGV's (which I replaced SU's with and get MUCH better perfomance with. And get a book on weber carbs also, it's a must, if you understand their jetting system and how to make the most use out of it you'll find you have one tuneable carb. that can be set for any RPM range. Must be I know carbs and what cam/exaust size to use with them, only been doing it over 20 years and I'll be dammed if a SU would ever beat a weber, ask the jag. racing team about it sometime.
And never use that worthless 4bbl setup or your in for lots of trouble, maybe even a good car fire. The manifolds arn't made well at all.
I also recomend finishing the job that wasn't done with the DGV's adaptors, they are very rought inside and a bit of smoothing out will help a ton with these. And make sure you have all the water jackets hooked up, I've seen a few folks that did a lazy job in this area and it really hurts this setup a lot. Also get ahold of TWM (I think that who but it's been awhile), they have some real nice ram air adaptors for the DGV's that at least get cool air into them.
 

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Discussion Starter · #9 ·
Re: I disagree with most all of this.

Ah, alas, B.W., Ive been waiting to here what you had to say. The day I posted the question was my first time ever at zcar.com and had seen some of your advice to others with problems. Regarding my DGV's, I'd aready done the polishing of the runners on the inside of the manifolds. The car runs great, and I've not experienced that lag between the primary and secondary opening on acceleration, that someone else spoke of.

Well, the reason I asked the question was because there was an add for triples that was quite reasonable. to make a long story short, I bought them (sorry to the SU fans). Hopefully I will be able to find you when I have all the questions. I've already purchased the Weber... book so I on my way.
 

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Re: I disagree with most all of this.

> Ah, alas, B.W., Ive been waiting to here
> what you had to say. The day I posted the
> question was my first time ever at
> zcar.com and had seen some of
> your advice to others with problems.
> Regarding my DGV's, I'd aready done the
> polishing of the runners on the inside of
> the manifolds. The car runs great, and I've
> not experienced that lag between the primary
> and secondary opening on acceleration, that
> someone else spoke of.

> Well, the reason I asked the question was
> because there was an add for triples that
> was quite reasonable. to make a long story
> short, I bought them (sorry to the SU fans).
> Hopefully I will be able to find you when I
> have all the questions. I've already
> purchased the Weber... book so I
> on my way.

Glad to hear you got them, you'll really love them, I prefer the Mikuni's to the webers as far as the Mikuni's are easier to work with and I like the diaphram accel. pump to the gear type the webers use but either are great carbs. I really REALLY stress getting a syncing tool Called a Manometer, if you have ever been around the biger motorcycles with 3 to 4 carbs it's the tool they use to sync them and this tool can be bought from just about any Motorcycle shop for around 65.00 to 75.00 and with the tripples it's worth every penny of it. A friend of mine used to have one for his cycle but I forgot about it and was using a unisync gauge to sync the Mikuni's and was getting pretty fed up with it as it's really a pain to sync with. I talked to the Mikuni folks who reminded me of the Manometer and I went and bought one and wham-O, I am syncing the Mikuni's in less than 15min and this is with the aircleaners on which affects flow so you get a overall better sync job done using this over the unisync plus the ease it makes of the job. You'll never be intiminated of working on the tripples again. I highly recomend getting the Mallory distributor offered by Victoria British for 199.00. It's a strictly mechanical advance with a great curve (the tripples don't really give enough vacume to work a vacume advance properly so it's not recomended) plus the new Mallory they are offering has a adjustable advance so you can really tune it in to your setup which is really a plus. What kind of air cleaner are you using? are you using airhorns with the carbs? If you want the best in airhorns check out TWM, they have some that make the standard bell shaped ones obsolete (Price is a bit high, around 60.00 per horn so there's another 240 or so added but wow, they are worth it).... I am using a very expensive air cleaner, around 270.00 but it's great because it flows from all directions and some aircleaners don't give enough distance to the tops of the airhorns, you need a min. of 2.5 of clearance for proper airflow so it's good to get a aircleaner that will flow from the top as well as the sides so I got the ITG filter setup from Motorsport, it's the best filter for these carbs but very expensive as I mentioned before. Any other question feel free to e-mail me.
 
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