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4-barrel intake: THE FACTS

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As the owner of Arizonazcar.com and having sold over 800 of my 4-barrel intakes I would like to add my 2 cents on the subject.

First there is absolutely no way that the SU's give anywhere near the performance that my 4-barrel intake with the Holly 390 carb gives.... that's just a fact and I dont care who rebuilt the SU's or how they were tuned. The overall drivablity, ease of starting, horsepower and even gas

mileage are substantially improved. SECOND THE SO CALLED ISSUE OF MIXTURE DISTRIBUTION DOES NOT EXIST.

Hopefully many of you have seen Gary Meekins' WEST COAST NATIONALS

WINNER 260Z..... Gary is a master mechanic with 30 years Nissan experience and has rebuilt hundreds of SU's ...his opinion of my 4-barrel intake setup is that "it runs perfect and has no issues" as claimed. He also says that the engine has "radically improved performance" over the SU's . Everyone that claimes a mixture distribution problem always says "I heard that..." or "I read that..." . I find that people with no first hand experience are always the first ones to render an opinion. Why not take the opinion of someone who know's what they're talking about for a change.....Gary Meekins can be contacted at coyotegary@hotmail.com or at his Zcar restoration shop (Spanky's Auto Body) Tel. # 480-644-0060

Assuming you wont' take my word for it (I've only installed about a hundred of them personally)

Also I think you'll find that any of the customers who have actually installed it correctly have very high praise for it as is the case on this thread. I have seen some other manufacturers 4-barrel manifolds that had numerous design failures that would make the overall

performace substandard compared to mine.

Now I would like to discuss where problems arise:

Many customers choose to use junkyard carburetors..(without rebuilding)..if you build your car from junkyard parts (without proper rebuild or inspection) any money you saved on the purchase will be more than eaten up by the grief of trying to figure out what's wrong. VACUUM LEAKS.....I have seen more vacuum leaks on these cars than I can count........the typical backyard mechanic then jets the carb richer to make up for the lean miss, now the car runs over rich at cruise and fouls the plugs. IGNITION...I've seen every combination of burned points, wrong firing order, bad wires, worn distributor, cap, rotor , damaged coil etc. that you can think of........the 4-barrel will NEVER run correctly under those conditions. CAM TIMING......never seen a car run right with the cam timing way off. PCV....amazing how many people have NO understanding of PCV...the typical shade tree goof vents the valve cover to the base of the carb and puts a breather on the tube below the distributor.........THIS GIVES A WHOPPING VACUUM LEAK.....the car back fires and blows the power valve, now it runs SUPER RICH! What's the worst solution? of course they now lean the carb way out in a futile effort to make it run right but by now the plugs are fouled and the driveability is crap from the rejetting! FUEL PRESSURE: NO A FUEL INJECTION FUEL PUMP WILL NOT WORK! Carbs typically need 3-5 psi.....60 psi wont make it any faster it'll just crush the floats and spray fuel everywhere.

OVERALL MECHANICAL CONDITION : Customer comes over with a "correctly" installed 4-barrel.....runs horrible.....I do compression test, test shows 165 140 140 80 60 22.....sorry my manifold won't cure that problem, for that you'll have to get the magic engine restore pills from JC Whitney....that'll probably cure your rod knock and worn valve guides too!

Anyhow I hope this is of some use to anyone considering this option.

Please feel free to contact me on this or related subjects.

I'll be posting some thoughts on other fuel system options a little later.

 

Sincerely,

Dave Epstein

Owner

arizonazcar.com

2043 E. Quartz St.

Mesa AZ 85123

dave@arizonazcar.com

480-844-9677

 

http://www.arizonazcar.com/

 

4b1.jpg

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....if you build your car from junkyard parts it belongs in the junkyard......

 

 

Now that's a very strong statement....and very much incorrect......

 

Junkyard fodder?:

f98b3fd5.jpg

f9c316a2.jpg

 

I think not!

 

I believe that the vast majority of Hybrid Z'ers (if not all) use many items picked up at the junkyards, with overwhelming success!

 

 

I did appreciate reading another viewpoint on the 4-barrel conversion :2thumbs:

 

Tim

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omg Junkyard z's are only junk if you put junk in them.

 

i have many parts that are from junkyards and they have never let me down.

Some of us dont have the money to waste on just shiny parts versus same performance from a junkyard. Coming from a buisnessman i think that was a rash comment you better think about what you say this audience is your potential clients pal.

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I too use junkyard cores when necessary ..what I'm referreing to is that I've seen people use used carbs that look like they fished them out from the bottom of a lake and think thery're saving money because they got it for $20 bucks instead of paying $300 for a brand new Holly 390 and then expect

it to run right..........sorry I should have been more specific.

I was hoping we could have this thread be technical and not get into a pissing match.

A 12 second quarter mile time is not what this intake was designed for and misses the point entirely. The objective was to have very simple product that makes a significant improvement in performance over stock,

has beautiful driveability and and that anyone with decent mechanical skill

can install and maintain.

The Holly 390 seems to work super right out of the box with no rejetting,

I used to be A factory direct dealer for Mikuni and as such i kept about

$2000 worth of jets and small parts in stock for my customers..... The holly parts are available anywhere at pennies on the dollar campared to

Mikuni or Weber parts.

Hundreds of these intakes have gone to customers replacing fuel injection

.... I'm actually a big fan of the old L-jetronic and understand it very well.

However as the early 280Z's are now coming up on 30 years old it has become a significant liability for many owners......the cost of a new airflow meter (most of the junkyard one are worthless) six injectors, a pressure

regulator, dropping resistors, and replacement fuel pump may well exceed the value of some of these cars. Even if any or all of the above were replaced it doesn't begin to address the issues of the wiring harness

(corroded connectors and sensors etc). Again the 4-barrel offers a simple

and cost effective soltion to what otherwise might become a parts car.

With electric choke the Holly fires right up, requires no synchronization

,little if any maintainance and still maintains good gas mileage.

A 9 inch low profile aircleaner clears the stock hood but the underside of the one vent on the 77-78 needs to be clearanced slightly.

Here's a breakdown on cost:

4-barrel intake manifold $259

holly 390 CFM elect. choke around $300

cable linkage $25-$39

Chrome aircleaner $25-35

Low pressure fuel pump $29

Total cost should be around $650

All the other mechanical issues on the car should be addressed anyhow regardless of the type of induction system.

Tim your car looks sharp I only posted in the first place in answer to absurd and completely inacurate statments made by those with no first hand knowledge of a particular part that I've sold very sucessfully.

Sorry if I offend anyone.

Dave

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I would love to know more about them I truly would but if mine ever has a problem, well hell I can find a mechanic the knows Holley systems alot easier than I would an S.U. system..

 

THIS is the reason why people buy the 4 barrel carb setup. Nothing wrong with it, but this is exactly the reason IMO.

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Norm may be running 12's but have you seen his pics of the tranny? I have, that guy is hard on parts. Not bashing, but I'd like to drive my car home from the drag strip. I guess you gotta break a few eggs to make an omlette. Would be nice to see some dyno numbers same day of 4bbl and SU's on same engine. Dyno's don't lye.

Mike:D

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My point is really that Dave's proof is that one guy who has built a bunch of SU's prefers the 4 barrel and won a car show. That doesn't prove anything.

 

I totally agree with you brokebolt, as usual :wink: Dave, you've sold 800 manifolds? That's impressive. I would think that there is enough profit in those 800 manifold sales to buy a set of ZTherapy SU's and take your setup and a ZTherapy setup and do some dyno runs and have ACTUAL proof of what you're saying.

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In Norm's defense, we are talking about well over 1000 drag strip runs in his cars lifetime, and he's bound to break a few things regardless of how hard or nice he drives after 1000 runs.

 

I'd be very interested in seeing some dyno data too.

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I've got a Clifford research manifold and a stock set of 1970 bell top SU's, I used to have a Bob Sharp manifold but I sold it (what was I thinking). I'd be inclined to test my set ups on a Dyno for results BUT I have two 4bbls that are not 390 CFM Holley and only one is in good runable conditon. Junk yard carb as it were. If someone has a Bob Sharp manifold and 390 Holley out of the box it would make for a good comparison. Three inducitons, three dyno runs, all here in Sacramento Ca. 75 feet above sea level. That should set the record strieght. First I got to get my old heap off the jack stands.

 

We could even toss in some Dellorto vs. Weber vs. Mikuni comparisons on a TWM vs. Cannon vs. Mikuni manifolds.

 

Mike :D

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I would welcome that challenge and would provide a manifold and carb

in person if it can all be arranged. If anyone is in the phoenix area anytime soon and would like to do an independant review and go for a demo ride I would gladly welcome them.

Also you're still missing some of the main advantages of my 4Brl setup:

Throttle response/driveability

ease of maintanance/reliability

gas mileage

cleanliness of installation/appearance

 

Again 12 second 1/4 mile times aren't relevant to the discussion...I have personally driven several of my customers 800HP Skylines in Japan and that has no relation to this product either.

Dave

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Dave,

Unfortunately I have no plans to visit the Arizona area anytime soon, I just got back from Lake Havisu, nice body of water, liked the pasties on the girl in Havisu City. Would you be inclined to some other options? I have the other two set ups as stated but the Bob Sharp manifold I sold months ago (wish I had that back now!). Also are we discussing a stock L-24, L-26, or L-28, or a modified engine. If you want to go stock that I would have to assemble a stocker and that wouldn't be available until the end of summer or early winter. I'm not making a challange I'm just curious as to what the different inducitons actually look like on a Dyno. It would be best to use one car and only change the induction, I think everyone can agree to that. I can't recall anyone who has done this type of testing and if so would be nice if they would share the numbers with the rest of us.

 

A few questions Dave, you say "better throttle response and drivability", what are you angleing at here?

 

I'll address the other points as you stated cleanliness, I say personal perception, trippples are the cleanest. But the 4bbl doesn't take up that much space it is very compact. Ease of maintanence, yes parts are more readibly available at autoparts stores and such; ask your local parts guy for SU needles and nozzles or even needle valves. Gas milage, I can't comment on that but anything driven concervitily can be a fuel saver, also foot to floor=bad MPG numbers.

 

I think we are comparing apples to oranges here but the real issue would be performance. And performance is what most folks are interested in anyway...Dyno tyme.

Mike :D

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To be fair Dave you should also mention that Gary has also done many other mods to his engine.

He has also only had it installed for a matter of months.

I think your "challenge" is a good idea but it would have to be the same car comparing both intake options. This is the only way to do a true comparison.

Throttle response could be measured but "driveability" seems to be in the eye of the beholder.

Not trying to pick a side of the fence to stand on I'll be sticking with my fuel injection.

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The straightest path that the air has to follow the less flow loss will occur in the induction system. The check out all of the high performance cars before fuel injection and some after for their induction systems. All of the straight 4 and 6 had side draft carbs. There were also some V8s that used side draft Webers trying to keep the air flow in as straight a line as possible. Another thing on the 4 barrel manifold is the clearance between the hood and the top of the carb. I have down dual draft down Webers on my 260z and the air cleaner height is restricting flow. I would go to SU if I was not planning on an engine conversion. The less turbulence inside of the air cleaner the more air will flow into the engine. There are a lot of variables as to size of runners and how they are transitioned that will effect the air flow.

 

Remember that an engine is an air pump; the more air the more power.

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Good point 280ZONE about the motor however the 4-barrel was first installed on the bone stock L-24 and run for some weeks ...the only mods it had then were electronic ignition and a header.

The current motor is an L-28 block with N-42 head. The same ignition and exhaust have been on both motors. The L-28 has my .480" lift 280*

street cam but NO other internal mods or porting of any kind.

I do believe you to be impartial and since you're local why not conduct an interview with me and do a review on my products firsthand so you can post your opinion here as a service to the members. By the way why don't you post who you are and what your experience level with the Z car is for those that don't know.

Sincerely,

Dave

 

BY the way I have never suggested that anyone remove an perfectly running stock EFI system.

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SHO_Z The dual webbers sit to high to allow a decent aircleaner, This is one of the many advantages my 4-barrel intake has over it. A 9" aircleaner with 2" element clears the hood and allows plenty of airflow, Since you are in Arizona why not take a look in person so you can make a comment with first hand knowledge instead of speculating?

Dave

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Dave, I didn't mean to sound like I was stepping on your toes. I thought your comparison of both was an excellent idea. Dyno results would also go a long way to validate your products. I am not sure if I missed any previous discussions about this but some of the comments may have been about other 4 barrel intakes that have been around. From what I have seen your parts seem to be of high quality and reasonably priced.

 

My experience with the Z car would be an owner for several years, Z Enthusiast, Z rebuilder, recent newbie to the Hybrid world of the V8 swap.

I would never consider myself and expert nor would I present myself to be. My Z involvement is for pleasure, I enjoy the challenge of keeping my 30 year old cars running.

My mention of fuel injection was to indicate that I have very little expertise with carburated vehicles.

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I've been thinking all day about this. We Z guys should pressure not each other for facts but others with the resources to get things done. We should have an independent organization do a "Induction Challenge" and post the result for all to see. It would have to be someone impartial and knowledgable about Z cars and the different inducitons. We would need to use the same car and have a team organize it all. I'm no promotor just a Z guy looking for fact, what ever the facts are. Get "Sport Z" magizine to set up camp in Arizona (or someother location) and do some dyno pulls using a stock L-28 and the different inducitons. Sport Z can post the results over several issues keeping the sales up and getting the information out that we Z guys would like to see. It is Sport Z after all and we are discussing Z sport cars. I could see that many parties would like to see this, AZCar, Ztherapy, Sport Z, Clifford Research, Weber, Cannon, and TWM. All of who have a stake in the market for aftermarket Z enthusiests.

 

Dave, I see what your specific addressing about throttle response. I would not agree that the 4bbl is the only induciton with good pep on the throttle. Any hesitation, backfire, or other induciton related problem would need to be sorted out and would suggest a problem. The 4bbl may give the driver the perception of more power due to the different power bands of the induction, but the Dyno would varify beyond arguement. I'm not pro SU or 4bbl or trippple or even EFI but lets see some raw data on all of them, that is my only point. I agree tuning trippples for ANY purpose is a ball of wax. Cost goes up (everthing is in sixes, jets, etubes, etc.) and so does the skill level. Much more involved than a single downdraft or dual SU's.

Let's get Sport Z involved.

Mike :D

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The only reason I started this thread was in response to an absurd statement

posted that the 1st an last cylinder would run lean and that the 4-barrel can not be made to run properly. I NEVER sold these as a drag racing specific part. I'm sure that tripple webbers will make more power (at least they should) as will ANY turbocharged car with EFI, again you miss the point.

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Guest plainswolf

Wow this sure turned into an interesting thread! :)

 

But I must admit Dave does make a very valid point.. there are alot of guys out there just like me who have a Z and either just want to keep the thing up an running as well as possible, or want to see exactly what they can change on it to make it even better.

 

For less than 600.00 total(shipping included), I was able to get not just a rebuilt intake system, but a brand new one.

 

I compared the costs of a rebuilt S.U. system to Dave's Holley setup. But that was not my only reason.

It was the simplicity of his system (the engine compartment is SO much less cluttered up now)

the reliability of it(based on 2 years experience now),

combined with parts availability(I can get the parts quickly at almost any autoparts outlet in the country).

and it's potential for further power upgrades. (this intake can take alot more cam and head flow than stock).

And lastly, he's not kidding when he says driveability.(When it's a -20 degree winter morning this thing starts without fiddling with anything)

To be honest, I kinda though he was full of crap when he told me about the 'as good or better gas mileage' with this sytem, but I have to admit, he was quite correct.

 

But this is just my opinion based on my 2 years experience running this sytem. :-D

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Dave, I under stand you point and you reasons for the post. I have been preaching for years about the options available. As I've stated there is a stigma that follows the 4bbl. Most folks make claims about hood cleanances and such not ever running one or seen one upclose. I've run them all, I've tried to be impartial not bash or back up anyone or claim unless I can prove it. Like I've said before in other posts I've bought stuff from you in the past and have recommend you for parts to select personel. Go here and read the first sentence and then scoll down and read the last sentence.

 

http://www.cardomain.com/memberpage/496289/6

 

I think that eveyone who reads these recent threads about 4bbls will see that the most important thing here is information about the facts. I feel we have made some positive ground in the discussion about the 4bbl and perhaps posted some arguments both for and against the 4bbl. After all this site is dedicated to the HybridZ.

 

Plainswolf, what kind of MPG numbers have you experienced? Cold weather starts are a true testiment to any induction. I grew up in Idaho and anyone who has tried to start an engine (any engine; tractor, car truck, etc) at 30 below zero knows that those are the hardest conditons possible...especially for a street machine/daily driver. My Z has issues at 40 degrees above zero.

Mike...as Adam Corolla says, "Good times." :D

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