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Carb Spacers

3K views 21 replies 13 participants last post by  igotachevyor2 
#1 ·
I was told that carb spacers make bottem end torque is this true? And if so would it be worth spend money on one and bolting it on?


Thanks

Ed
 
#3 ·
If you're using a dual-plane (180 degree) manifold, then a 4-hole spacer may help the fuel/air mixture make the turn into the manifold runners a little better, rather than smashing into the floor of the manifold as it exits the carb bores and creating turbulence. You may see this improvement on the dyno, but I doubt that you'll feel it in the seat of your pants. You will however, add volume to the manifold with a 4-hole spacer, or any spacer for that matter. Generally speaking, the more volume in the manifold, the more power the motor will make up higher and the less it will make down low.

With a 180 manifold and an open spacer, you will effectively change your manifold from a 180 to a 360 degree design and kill off bottom end torque because now, each and every cylinder "sees" the entire manifold volume rather than just half of it like with a segregated 4-hole spacer, so low-rpm cylinder filling will suffer along with low-rpm torque. It's a trade-off. You'll make more power on the high end (assuming you have enough cam to make power up high), less on the low end.

My best advice: Leave it alone and save your money for something more important, like a set of gears or converter.
 
#5 ·
BIGSKY said:
I installed a Moroso "plastic" 4 hole spacer on my SBC because I was getting heat sink into my Edelbrock. I don't know if it makes more torque because I changed exhaust at the same time, but it did solve the heat sink problem.
Good point BIGSKY. The most efficient spacer I've seen to prevent heat transferred to the carb is one made from wood and sealed with "bar finish" epoxy.
 
#16 ·
400smb_s10 said:
Well I would have to say 10 hp is 10 hp and it will bring me closer to the allmighty 200 hp from a stock 350 lol

This is on a 475 hp 406. Actually I gained 10 hp with the tapered style 4 hole spacer over a standard 4 hole spacer. If memory serves me correct I made somthing like 20 hp over no spacer. You wont see that much gain on a 200 hp 350 though.
 
#19 ·
HVH who makes the Super Sucker knows exactly which of their spacers will work the best. You have to up your carb jet size as you will lean it out due to more air flow. I had to rejet 3-4 sizes on mine but now can keep up with big blocks with my 362 as long as they keep stock valve angles on theirs.
 
#20 ·
Who knows, maybe a spacer will improve performance. It doesn't cost that much to try one or even a couple of different ones.

Personally though, I would not be swayed by magazine articles that show power increases at the top range of rpm's, unless that's where the motor is going to spend most of its time. I suspect you can make more "area under curve" horsepower on the way up to max and the car would be faster without one. You can't race a dyno. Just my opinion.
 
#22 ·
you want be disapointed. the best i have done was a helical air raid spacer on a 4.0 jeep with a k&n cold air kit . it was a huge difference in the seat. i have ran several on sbc i think the single hole made the best improvement. also the wood is the better heat insulator. :D
 
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