carb spacer for quadrajet

[chevyfreak]

Hi all.
im buzy making my own qjet spacers as the v8 shops around here only have square bore spacers and dont want to bring in for spreadbore. So im making my own. Im still waitng for my other sizes but the piece i had is 45mm thick (1.75"). This is for a very mild 350 sbc. Cast qjet intake but plenum cleaned up and changed to look like performer plenum entry.. Basically copied what david vizard did in his book on carb and manifolds.
Now the question. 4hole to extend the carb barrels or 2hole to increase the plenum area of each half of carb.
car mainly street driven but sees a race between friends as often as we can. So any input would be much appreciated.
thanks
chevyfreak.

[Tuner]

The only way to know is try the different possibilities but I vote two hole or one big open hole. It's OK to stagger jet a QJet if your need to for even plug color.

Be sure the secondary throttle blades do not open beyond directly below the baffle insert in the body. The angle is less than 90 degrees, about 85 degrees.

Some QJet stuff

QJet Secondary
http://racingfuelsystems.myfunforum.org ... ut498.html

QJet Idle Circuit
http://racingfuelsystems.myfunforum.org ... ut430.html

[strokersix]

Watch for screws dropping into your intake from under the carb! A 4 holer will prevent this. Only need the 4 holes next to the carb, you can open it up underneath.

[chevyfreak]

Have an 4hole spacer of 5/8 thickness but is layered phenolic and old it seeps fuel. And the 1/2" thick open spacer i have also seeping as well. So these i wanna make now is of plastic composite material. At least they wont seep. I was also thinking 2hole type but wondered on 4hole as well, reason for asking.
thanks tuner for those links. Went thru them quickly and will study them over weekend.
As for my best performing qjet thats giving me an uphill at this stage the idle circuit is basically perfect and i wouldnt change a thing . Just the issue with fuel being sucked out on secondaries before airvalve opens. But im in process of searcing everything i can find on a qjet.
And i always wanted to make the spacers and try but always something else to be done so never got to it, but i started with this one and ordered other thickness sizes as well.
thAnks
Chevyfreak.

[shiftbyear]

Here's one that looks pretty nice.

http://transdapt.carshopinc.com/product ... 27398/3213

[chevyfreak]

Just another question. Ive decided to go 2hole spacer, the sides of the holes must it be smooth or can i roughen them up? Just wondering if it might have an effect, ie aiding in fuel atomizing or something.
thanks
chevyfreak.

[chevyfreak]

Here's one that looks pretty nice.

http://transdapt.carshopinc.com/product ... 27398/3213

Yes it does look quite nice. But sadly for me to import that its like paying almost 4 times that in the US. With exchange rate and bank taking their share and shipping its really a bit costly for me. For that same amount of money spend on that spacer i can buy a aftermarket intake over here.
thanks for input anyway.
chevyfreak.

[chevyfreak]

Update. I finished the spacer and made it looks like 2 B's back to back. Put it on, adjusted for more idle so it would idle right, and increased pump shot, revs and idles good. But on the road it feels lazy, got to open blades more for cruising and huge lag at high rpm almost like its not enough carb, played with hangers and the needles i got and a bit on primaries as well. Still feels lazy.
Now i cant wait till teusday when i get my other pieces then i can some more bit thinner in thickness. Gonna do the 1" thick first and then see whats happening.
thanks to those that gave ideas and extra info.
many thanks
chevyfreak.

[dave brode]

on the road it feels lazy, got to open blades more for cruising and huge lag at high rpm almost like its not enough carb,

Did you go from a fully divided setup to the double D? I have found the same thing happen, as you are cutting the signal way down. I would look at the link that Tuner pasted on the idle circuit.

Dave

[chevyfreak]

Did you go from a fully divided setup to the double D? I have found the same thing happen, as you are cutting the signal way down. I would look at the link that Tuner pasted on the idle circuit.

Dave

I made this one as a 2hole spacer but instead of 2 oblongs i opted for the B shape. But its not sized to throttle blade sizes. Went a bit bigger but still matching intake. Just took a quick test and a bit of fiddling. But i still feel there is alot of more testing and fiddling to be done. Im just giving feedback as how its going and happening.
I went thru the mods on secondary system and very interesting. Only gonna go to the idle circuit shortly but as a guy i knew always said. We'll get there eventually.
Im also keen on building a spacer that tapers open from the size of blades to exact size of carb pad on manifold as mine has been opened a bit but thinking first a 4 hole and a 2hole maybe a open one as well. Only drawback is time, always buzy with alot of things, but hey its keeps us alive and livin.
thanks chevyfreak.

[pamotorman]

these are available at the auto parts and are 1/4" thick so you can stack them to what you want. they also come in all open center. you can mix and match to see what works the best