Custom, Performance Carb Intake Manifolds ( 2bbl / 4bbl )

[A20A1]

Yup thats what I like about their carbs they offer venturi sleeves, possibly even different boosters but I didn't see that.

[2oodoor]

I couldnt get the info link to open up but I think i wet my pants
that is one mean mixer

[crucial]

What kind of secondary type sould i get. Vacuum, air valve, mechanicall etc.

Was looking at this one.
http://store.summitracing.com/partde...5&autoview=sku

[2oodoor]

What kind of secondary type sould i get. Vacuum, air valve, mechanicall etc.

what kind of carb,what engine mods, etc... ?

[lostforawhile]

Hey, I used to have that Rochester book back when I was driving an '86 Cutlass. It had a computer controlled version of the Q-jet. The primary mixture needles were connected to a solenoid that would open and close depending on what the oxygen sensor thought the mixture needed to be. It was quite a piece of engineering. I remember rebuilding it once. There were so many little pieces and parts it was amazing.
Eventually I got rid of the car and started driving an import ('89 Nissan, fantastic car). So I sold the book figuring that I would never see another carb again. What was I thinking?

I'll admit it would be cool as hell to see a Q-jet on a 4-cyl.

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the rochester rebuild book? i have it around here somewhere.

[A20A1]

Well I bought another 4bbl
this time it's an old holley 4bbl for $10

I doubt this will be any easier to work with than the quadrajet but it gives me some options.


http://cgi.ebay.com/ebaymotors/ws/eB...ayphotohosting

looks like crap but I think it can be rebuilt.
and it's a steal for $10 but I still need to pay for it... I'm missing funds today so I hope I can pay for it tomorrow after I deposit my check and wont get bothered by the seller.

[A20A1]

450cfm

LIST# 4548-S
MODEL# 4160 or 4160 HP (unsure on this)

Holley 4bbl

Vacuum secondary

I think it's perfect.

I'll try and get pics of it on the manifold later.


from the mounting base for the stock carb to the top of the carb with no air cleaner on it is about 6.5" - 7.0" tall
Air cleaners themselves are usually 2" - 3" tall

the air cleaner does mount about 2" down from the highest point so even at 3" it will only sit 1" above the carb.



I'm looking at either getting a Renew kit or Trick kit to rebuild the carb

TRICK KIT: HLY-37-933
RENEW KIT: HLY-37-119

also a quick fuel adjustable secondary diaphragm
http://store.summitracing.com/partde...3&N=700+400990

[A20A1]

So far I've figured out it's side hung float... unfortunately I don't think there is an application for the billet aluminum throttle baseplate. I looked at all the list #'s for the proform and quick fuel and neither lists My number but do list other numbers for the rest of the 4160 models

anyone know why this is? or if I can use a billet throttle plate even if it doesn't say it will work with my list but works with my model?

[2oodoor]

could be a date of production thing?

I recommend a power valve guard for that thing though, the first time it spits back there goes the new valve.

Good to see the project back

[A20A1]

yeah thats what the billet aluminum throttle base plate was for, it has the power valve protection built in and will probably seal and open/close smoother then the one I have now.

[A20A1]

The Q-JET


The HOLLEY 4160





I got a cell phone and I'm learning how to use one... damn this things are difficult especially trying to type text, it keeps trying to spell words for me.


the q-jet really suits the manifold, not really because it's throttle plates are too large for the adapter plate beneath them, but because it looks more at home on the manifold.

[A20A1]

alrighty I'm getting used to the new tapping set I just bought. I want my threads to be metric so I got a metric set damn thing keeps slipping. I need to find some pliers or something to help me tighten the chuck/

[2oodoor]

I agree the q-jet does look good on that thing, but the holley will probably be more tune-able in detail.
Proform has a billet Thr plate but it is pricey
I saw one somewhere recenty that was like a governer plate (billet) for bracket cars to keep from opening the throttle too much EDIT nilch on that, it was Dendenbear Products, DED TS6, throttle stop plate.. wierd looking critter.
I usually use the small vise grips and concentrate on keeping it streight up on the work. The chucks are a PITA for small stuff.

[TWOLOUDNPROUD]

There Go's the gas mileage

[A20A1]

There Go's the gas mileage

True, but it'll depend more on how I treat the gas pedal. I don't need to use all 4 barrels all the time.

[2oodoor]

Any thoughts on the holley 2300 series 2 bbl, using a percy's metering block?
Those are available in 500 and 350 cfm versions.
A new set up like that can be had for less money than a 38/38.

[2oodoor]

I am working on this custom manifold and I have come to a point that I am not sure I should take out the entire plenum divider. It seems to hold some structural support for the carb flange. Any recommendations?
Cygnus-x1 did you remove the whole thing, I dont want to remove the carb on the one I got from you.
I am going to be welding a plate on top of the flange so I am not too worried about how much I cut out of the opening, not too much more than it is now in this picture. I am still trimming off tabs I will not need, and there is still the middle part. I really want to loose some of that but without disturbing structural integrity. It would be easier to acces the middle lower intake nuts if I had just a little more room there. I am going to use the three vaccuum taps on the top and close off all of them in the back, just keeping the coolant holes in the back.
[IMG][/IMG]

[cygnus x-1]

I removed that divider entirely. There should be plenty of material left for structural integrity.





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[A20A1]

don't forget to weld that small coolant hole shut. I'm glad you're welding on the flange, it will solve a lot of problems.

Weber users should weld too. Considering how many adapter plates there are, it just increases the chance for a vacuum leak.



I don't think it's structural, it probably just needed to extend deep enough into the runner to be worth the while of having a divider there.

[2ndGenGuy]

While we're showing off our manifolds:



The 1g had a huge, oval-shaped port for the bigger barrel. Took a long time to port that beyotch out... I don't even know how Cygnus got in there with the dremel and cut the whole divider out... I got as much as my dremel would allow... I do notice a nice puddle of fuel in the plenum under the primary when I pull the carb off though. I'm guessing it's not got enough velocity by the time it gets down there or something and it sticks. Prolly should have gotten rid of the whole thing, or divided the whole thing off.

If you could build the divider wall up and match it to the bottom of the carb, do you suppose you'd get some better results? Even with a DGS?

[2oodoor]

That looks good 2ndGenGuy, that is how I did my first one for the DFEV 2 years ago. I just took a notch out of the wall and opened it up some and port matched the plates.
Cygnus used a roto-zip, like a dremels big brother. lol

You mention a puddle, that is something that I have been wondering about. Everytime I park my DX the one with the A20 and "temporarily" using Cygnus's manifold and 38/38... I get a strong gas smell, no obvious leaks anywhere. I wonder if it is puddling a little there. Also it spins real fast with out cranking up after it sits from a half hour to 9 hours, like it is flooded. Overnight it doesnt seem to do it.

[cygnus x-1]

While we're showing off our manifolds:

The 1g had a huge, oval-shaped port for the bigger barrel. Took a long time to port that beyotch out... I don't even know how Cygnus got in there with the dremel and cut the whole divider out... I got as much as my dremel would allow...

I used a Rotozip with a flex attachment, so it's easier to get into tight spaces. I was always annoyed with the low power and cheapish construction of the newer Dremel tools so I decided to try the Rotozip. Oddly enough it uses the same flex attachment as the regular Dremels, just with a larger clamp to fit the Rotozip. It's a little more expensive but well worth it I think.
But even then, it was still a pain in the ass and took forever.

I do notice a nice puddle of fuel in the plenum under the primary when I pull the carb off though. I'm guessing it's not got enough velocity by the time it gets down there or something and it sticks. Prolly should have gotten rid of the whole thing, or divided the whole thing off.

If you could build the divider wall up and match it to the bottom of the carb, do you suppose you'd get some better results? Even with a DGS?

Oooh, now that's interesting. Because of the fairly large volume under there I could definitely see it being a place for fuel to puddle, especially at low RPMs. That's the downside to big plenums. I bet this is caused by the extra thickness of the adapter plates and how the primary can now feed into the secondary passage. With a 32/36 you might be better off to actually extend the divider almost up to the base of the carb to keep the passages more separated. With a 38/38 you can't really do that because the passages are just shaped wrong. What I would really like to see with a 38/38 is a manifold modified to fit the carb without the extra plates. I'm thinking that would generate some more turbulence in the plenum to reduce puddling. And it would eliminate the potential for vacuum leaks with the plates. AND, if you're doing this on a Prelude it might actually lower the carb enough to be able to close the hood without having to cut a hole or bash a big lump into it. AAARRRGGGHHH! Why didn't I think of that at the time!


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[2oodoor]

How about for the 38 as well, making a plenum "booster".. ie welding a half diamond shaped piece of aluminum plate in the bottom. A cross shaped, cone to discourage puddling and give more surface without being restrictive.

[cygnus x-1]

How about for the 38 as well, making a plenum "booster".. ie welding a half diamond shaped piece of aluminum plate in the bottom. A cross shaped, cone to discourage puddling and give more surface without being restrictive.

Yeah, I was thinking of that too. Could work.

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