08-20-04, 03:11 PM
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:
08-21-04, 08:39 PM
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.
09-12-04, 11:18 AM
thanx man i've decided to go with summit racing's "spiral bore phelonic spacer" i'll let ya know how it works out:banana:
09-13-04, 03:37 AM
If you want it to work like its supposed to
take off the intake and either cut or machine the middle of the intake so you have exposed the whole plenum.
makes a BIG difference
you should only use a 1/2 inch spacer
Ive done probably a dozen of them
09-14-04, 10:44 AM
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.
09-14-04, 04:17 PM
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!
09-15-04, 05:46 AM
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.
09-15-04, 12:50 PM
I dont mind moving the power curve a bit to use a mt10 or mt15 cam in the future. The engine is in a 67 firebird so bottom end is not a big problem.
09-16-04, 12:46 AM
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
09-16-04, 03:28 AM
Im not going to use the quadrajet anymore im conerting to megasquirt. No mather that i do it wont open the secondaries. It just keeps full vacuum.
09-26-04, 11:40 PM
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?
10-09-04, 08:03 PM
Within the useable operating range of that engine a modified stock intake will work better,