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6K views 11 replies 6 participants last post by  TorqueInc 
#1 ·
so i was looking through a jegs catollog and i come across some thing i hadn't noticed before...carb spacers. does anyone know if these things are as bennificial as they advertise? and if so what kind(cnc aluminum, plastic,..wood?)? has anyone used these? i have a 68 472 w/ stock everything which spacer wood be best? :hmm:
 
#2 ·
I've researched carb spacers plenty. While I haven't got one yet I'll give some input. Of your options, I'dsay the phenolic plastic is the best choice. It doesn't absorb much if any heat so the incoming charge stays a bit cooler and denser. Secondly I've noticed EVERY manifold intake spacer for an EFI (like a 5.0 mustang) is plastic. I've heard the spacer will cause the powerband to kick in a little higher in the RPM's, the taller the spacer the higher. 1/2" to 1" should be fine enough for a stock engine. I'm also assuming that your manifold has very little to no rise at all, like mine. The spacer will allow the fuel/air to mix better before entering the manifold resulting in more power and probably slightly better fuel economy.

That's about all I know on that topic.
 
#5 ·
Would this also make a big difference on a efi 500 intake and if how close to a edelbrock. I have made one big plenum like a 4 barrel intake smoothed the edges and added a 1" 2 hole spacer. I have also a open 1" spacer i might use to raise the throttlebody even more as i have to use a aircleaner spacer to clear the fuelrail if i dont use it. I have a megasquirt computer so changes are no problem.
 
#6 ·
Your Call Bro! When you increase plenum volume..(what a spacer does), you decrease the signal from swept volume. May help if ya got eight healthy and sealed cylinders. No Ram effect happens without a big draw..LOL or SUCK!

Volume slows the action. 500 inches oughta manhandle a manifold, so ya prob OK!
 
#7 ·
from past experience, lower rpm (under 4500) likes a 4 hole carb space at most 1.5"
whereas upper rpm (4500+) likes an open spacer up to 3". I've found a couple hp gain with a spacer. it will make a small but noticeable difference in power.

man, these little cartoon things are neat.
:fan:
 
#9 ·
If you are using a q-jet and you should a 1/2 inch spacer with the intake mods will run right with an edelbrock in any type of street driving.
At the track on a 500 the edelbrock will show a distinct advantage.
And as far as what spacers are suposed to do ,im telling you what dyno/track testing shows works
use an open spacer
 
#11 ·
going to put the carb spacer on tomrrow. its a 1" 4 whole phalonic plastic spacer from summit. i'm not going to to mess with my stock intake cause i will be getting an intake from cad company some time soon. are there any tips i should know about taking the q-jet off and what not cause i've never done it before? whould i have to make any adjustments to the carb to optimize the effectivness of the spacers? or is it as simple as un-bolting the carb popping the spacer in with the gaskets and bolting the thing back on?
 
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