Who Makes the 4 bbl intakes that work on L-6s

[teamz]

I put a lighter secondary spring in. I had to play with that a little to get the right one. I used the stock jetting and it worked fine. This was on an otherwise stock L24 with 6x1 header. I am now working on a built L28 so I am sure I will need to change jetting for that.

[Guest rick458]

If I Jet-Hot coat the Exhaust Manifold, and Intake Manifold how much heat would that knock out from the hood?

 

Or should I just build a heat shield to ride between the carb and manifold.

 

Or is percolation not an issuewith this setup?

[Guest rick458]

What did you do with all the water lines, and evap stuff?

as well as all the extra fuel tank lines ?

nothing returns to the tank with this setup does it?

[SuperDan]

What did you do with all the water lines

Tossed the "T" that goes to the old intake with a straight heater connector. Now it goes from the heater core to the water pump.

On the thermostat housing I found that there was a plug in the old intake manifold that was just the right size so, a little teflon tape and bam I plugged it.

 

and evap stuff?

Drilled a small hole under the air cleaner and plugged it in there with a plastic nipple. (do not use any ports on the carb )

 

as well as all the extra fuel tank lines ?

nothing returns to the tank with this setup does it?

I kept the original fuel rail and just capped the forward outlet that went to the front SU carb and used the rear one for the new carb, works great! I am not sure but I think you need to do it this way or still keep some kind of return to the tank else you may have vapor lock problems.... not sure maybe someone else can comment. Like I said works great!.

 

I will be doing a little write up on this with pics and part numbers as soon as I can in case someone else needs more info. So far I am very happy with the results. Going to play with it some more this weekend and change the secondary spring out like teamz said, I have noticed a small flat spot when I smash the pedel and the secondaries kick in.... only seems to happen once in a while, might even be something else.

[Guest rick458]

excellent info Dan

hopefully, I can be rockin soon:-D

 

Where did you get your gaskets

local BAP GEON or Nissan, Online, where?

[SuperDan]

Where did you get your gaskets

local BAP GEON or Nissan, Online, where?

I lucked out, there was a brand new intake gasket in the back of the car when I bought it.

 

Also, I threw out my ghetto style throttle return spring setup and ordered part#

SUM-G1327 from summit racing. Should be here tommorow, hopefully.

 

Dan

[Guest rick458]

I pulled the Intakes, Carbs, Balance tubes, and exhaust Manifold off last night.

I was supprised how easily (comparatively) they were to take off.

[lazycyril]

the Arizona z car 4 b intake does not quite work with the motorsport 3into2 exhuastheaders due to tube routing conflits.

It can be made to work if you want to dimple an exhuast tube a little to clear an intake runner.

Also gasket match the intake and exhust flanges to make shure they will

clear each other on the head.

 

Matter of fact I reccammend avoiding the motorsport 3/2 exhuast headers

alltogether and just getting the headers from arizona zcar.

Spent far to much time wrestling with the 3 into 2 setup getting the lower half

onto the upper half. The pipes were warped and had to be heated with a torch

and wrestled with for awhile. Amused the muffler shop people for awhile.

 

Also thanks for the tip on the vaccum line needing to goto the manifold and not the carb port. Lil tip not found on thier website.

[SuperDan]

Anyone need a new Holley 390 carb? has like 2 hours on it.

 

Decided to go with a Carter AFB style since I know how to tune those.

[Guest rick458]

I need one but it will be a month before I can afford it

[Guest rick458]

Dan; After I PM'd you I clicked on your home web page

Guess where it took me:hail:

[Guest rick458]

I know they Make really good stuff, but what is their shipping time (IE Order to recieve time)

[Toysport]

Anyone need a new Holley 390 carb? has like 2 hours on it.

 

Decided to go with a Carter AFB style since I know how to tune those.

 

You never touched it? Where did you buy it from? I need one for my AZ IM/ Thanks Dan!3

[4everDATSUN]

why would you want a 4-barrel carb on a datsun? i want to kick the guy who designed that manifold square in his nuts. stick with SU's or webers, or somthing of that sort.

[SuperDan]

why would you want a 4-barrel carb on a datsun? i want to kick the guy who designed that manifold square in his nuts. stick with SU's or webers, or somthing of that sort.

 

Easy tiger!

[Guest rick458]

Dan I got the 390 Holley happy, and all the plumbing hooked up correctly, and the best I can put it is WOW!!!.

She starts everytime, Pulls hard, runs smooth, doesn't backfire through the carbs (I still flinch a little when switching off the ignition), and that Growl talk about your mechanical music.

Now that I have the motor sorted out, I can find and fix the rubbing noise from the back of the car.

But I have moved it farther along in the last 2 months than the previous 2 years

[SuperDan]

Finally had a chance to take pic of my setup.

 

56k WARNING!

http://album.hybridz.org/uploads/7794/IMG_0168.JPG

[Tony D]

9000rpms? Hardly! When you dyno test it, the 390 will start loosing power compared to triples as early as 4500rpms!

 

As the rpms go up, so does the disparity. When we were doing initial developmental work on our Bonneville Car, we briefly had a Clifford manifold on it, and kept going to progressively larger four barrels, ultimately using a Predator that we horked off a 500CID Cadillac engine that was used for bracket racing!

 

That got us our first world record at ElMirage in 1999, but the power just was not there on the top end. We swapped to 45DCOE webers, and pickd up 17HP at 6500 if memory serves correctly. Made a peak of 250+ at 7500rpms.

 

When we went from DCOE's to a Tec2 and 45mm TWM throttle bodies, there was almost a 40hp difference between the Webers adn the TWM stuff! (ultimately 315+hp at 8250rpm)

 

For anyone making statements about kicking people in the nuts for hanging a four barrel on a Nissan Six, learn a bit of history: The Nissan L is derived from a Mercedes Licenced product. Mercedes used a four barrel VERY successfully on their passenger cars with their SOHC 2.8L inline six.

 

Were the meatheads designing manifolds for the Nissan to look a bit closer at the Mercedes design they could learn a bit. In either case, for ultimate power, if you can stand to give up the ultimate power (I know another person who had a 3.1 Stroker, and the difference between HKS ITB's with an SDS and the four barrel was 30HP, 224-vs-255hp at 6250rpms) the four barrel will work fine for a streeter, Just don't dissillusion yourself into believeing it's a "hot ultimate setup" like many of the salesmen make it out to be.

 

i would be interested in seeing dyno numbers from the Arizona Manifold. Lately there has been quite a buzz about that manifold, and claims made, but nobody is posting dyno figures, or comparing apples to apples...

[ozconnection]

Tony, you mention the Mercedes 4 barrel manifold as a design done well. I have done some internet searching and discovered that the SOHC 2.8 inline six that was in the W114 had dual two barrel Zenith 35/40 INAT carbs. I also found mention of the Zenith 4A1 4 barrel carburetor(from an M110), so obviously there was a 4 barrel manifold but I cannot find a picture of it that shows it to good advantage.

 

Do you have any photos/schematics/ web sites that can show me what they look like?

 

So, without having seen one yet, why are they better than what's been designed for the L series sixes?

 

Your comments about the Clifford 6=8 manifold is what I also found on the dyno. It has this ability because of the 'single plane' nature of its design, a large open plenum under the carb which unfortunately drops gas velocity and drops some fuel out of suspension along the way. As a redeeming point, it does have a large water heated floor to re-introduce fuel back into the airstream. Cold or hot, the engine first needed a good stab on the throttle to get the thing to start though! Power was good with an annular discharge list 9002 600 vac, but throttle response was better with a vac 650 reverse idle spreadbore Holley with just as much top end as the 600! A four hole spacer under the carb helped with the transition into the plenum but it wasn't until I built an aluminium divider for the Clifford that response returned. I'd changed the single plane Clifford into a dual plane!

 

I bought an Arizona manifold for that reason, a dual plane manifold straight from the shop! A much smaller plenum helped heaps with throttle response but the top end was very limited compared to the Clifford (all else being the same). Reversion was a big issue with the Arizona and I had to have a list 4548 Holley custom calibrated to account for this phenomenon. But I would have to say that the Arizona is a great low speed torque booster if set up correctly. For the STREET, it's a good choice. (BTW, the greater curve on the dyno graph uses the Arizona manifold with a list 1848 465 Holley, headers and a 2.5 inch system. Compare it to the stock L28S and you can see the low speed torque increases for yourself).

 

Thanks for any light you can shed on the Mercedes manifold.

[Tony D]

I probably should have taken the time to pull that thing off just so I could say I had one!

It sat relatively close to the head, and the dual-plane setup was more akin to using the four barrel as two progressive two-barrels very close together each half of the carb supplying three cylinders. Probably something engineered off the dual-two-barrel setup. Less parts, less complexity. The runnners were somewhat longish, and snaked about a bit---largely I suspect because of the packaging requirements of the engine bay. Sorry I can't remember more...I took some time to look at it, but the yard was closing, and it was a 'Huh, lookit that!' kind of moment. When I went back, the engine was gone. I've seen others show up from time to time, usually sans the carb---which showed me the runner parsing and balance slots cut between primary and secondary barrels and planes in the manifold side.

I got called "B.S." for my comments on what we saw on our Bonneville Car Testing, I'm glad to see someone else had similar results or at least took the time to quantify them! I'm not digging out all those old dyno sheets...if I could even find them now! LOL