Spaced out: divided or open

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fnaramore

fnaramore

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Hey guys! So I'm revisiting a topic I know I read up on about a year ago, and just felt like "hey, haven't hit my head against the wall recently" lol So bought a four hole 1/2" spacer awhile back, liked it but took it off to replace with too much filter. Now I'm figuring to put another spacer on and by what iv been reading, looking like a 1/2" divided will give the most gains. Any differing views out there? I can't recall, but I faintly remember someone saying too much open space on a duel plane will hurt you over all.

P.s. I know that carb spacers can be very engine/setup dependent, just like to gather from other people's experience

Thanks!
 
fnaramore said:
Hey guys! So I'm revisiting a topic I know I read up on about a year ago, and just felt like "hey, haven't hit my head against the wall recently" lol So bought a four hole 1/2" spacer awhile back, liked it but took it off to replace with too much filter. Now I'm figuring to put another spacer on and by what iv been reading, looking like a 1/2" divided will give the most gains. Any differing views out there? I can't recall, but I faintly remember someone saying too much open space on a duel plane will hurt you over all.

P.s. I know that carb spacers can be very engine/setup dependent, just like to gather from other people's experience

Thanks!
Click to expand...

open space increases plenum size. big engines need big plenums, smaller -not so much.
 
The consensus I really came across is that in general

Four hole can-
Aid in evening out fuel to cylinders at partial throttle
Increase low to mid range torque
But can also cause air/fuel separation due to causing it to have to take a sharper turn into the runner

Open can-
Increase mid and high rpm hp
Give the air/fuel a straighter shot into the runners
But can also weaken the vacuum signal pulling air through the carb

Divided can-
Increase power mostly centered around midrange
Increase tunnel effect but since it's divided has less chance of weakening the signal

So pros and cons added, it just seems divided might just give a bit more. But am I missing something?
 
I'll add to the confusion....On my current 410 stroker I run a 1" 4 hole tappered spacer on top of a 1/2" wood open spacer...all on a Victor intake. It works well for my application.

My previous 360 motor liked 1/2" open wood spacer with a 1/2" nitrous plate above it....all that sitting on a RPM Air-Gap intake. Again, it worked well for my specific application.
 
flyfish said:
I'll add to the confusion....On my current 410 stroker I run a 1" 4 hole tappered spacer on top of a 1/2" wood open spacer
Click to expand...

See I would love to have a tapered, just not willing to spend the 100 or so for it and would prefer a phenolic one lol the biggest factor really is space though and I really just have a little over 1/2" to work with. At this point it really just is open vs divided. I think without an open below it, a four hole just isn't conducive.
 
Thinking about it, might also just take my four hole and then round off the edges some.
 
On my stuff, I will NEVER, EVER run a std style 4 hole spacer. Did I mention NEVER!

Only spacer with 4 holes I run are tapered. Everything else gets an open spacer.
 
fnaramore said:
So bought a four hole 1/2" spacer awhile back, liked it but took it off to replace with too much filter. Now I'm figuring to put another spacer on and by what iv been reading, looking like a 1/2" divided will give the most gains. Any differing views out there? I can't recall, but I faintly remember someone saying too much open space on a duel plane will hurt you over all.

P.s. I know that carb spacers can be very engine/setup dependent, just like to gather from other people's experience

Thanks!
Click to expand...

I have had dyno proven results on 2 engines with what I would call none of the above. I ran the 1" on a dual plane intake.

http://www.highvelocityheads.com/ss.htm
 
Looks like tapered. Again, sadly I don't have space for a 1" spacer. Why I was considering taking a dremel to a 4 hole. Anyone know if that would ruin the fuel restistent properties of the phenolic though?
 
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