carb spacer

[fryedaddy]

 i have a 1 inch carb spacer on my 428 right now.bbm heads,rpm intake,msd pro billit,..245 comp hyd cam,850dp,speed pro 10.7 pistons,arp.my question is should i have a noticeable amount more low end torque without the spacer?

[blykins]

Just try it and see.  I'm always amazed at how different engines don't follow the curve.   One engine might want extra plenum volume, another may lose 20 hp with a carb spacer. 

[fryedaddy]

Just try it and see.  I'm always amazed at how different engines don't follow the curve.   One engine might want extra plenum volume, another may lose 20 hp with a carb spacer.

i forgot to say its a open spacer.i guess your right Brent,i'll try it without the spacer and see what it does.its hard to tell on the street compared to a dyno or the track unless its a real noticeable difference.i may try a 4 hole spacer too,i need to get one with a vac line port on it anyway.it being a dual plane intake,it might like a 4 hole.i seen some results in Jays book on the spacers but i did not see anything on the rpm intake with spacers

[blykins]

I've never seen an engine yet with a Performer RPM not like a 1" Super Sucker. 

Also, depending on the camshaft size and how much plenum volume you need, I've seen a gain of 10 hp going from a 2" Super Sucker down to a 1". 

[Falcon67]

I have had generally good luck with 4 hole spacers on dual plane intakes.  I've picked up - on a 302 - going from a 1" to a 2" 4 hole.  As noted, your mileage may vary.  Also, it's not much of an issue to get a decent Moroso 1" spacer from Summit or Jegs, then just drill a 3/8" hole in the center of the rear until it breaches the rear bores.  Glue a piece of 3/8" steel brake tube in the hole, instant PCV port.

[fryedaddy]

i may try one of those super suckers,a little pricey,but boy their purdy

[Falcon67]

If I could find a china shop to repop those things, I'd make a killing.  Ain't paying $140 for a spacer LOL.  Yes they work, but looks to me like you could DIY just as well with some epoxy and a bastard file.

[jayb]

Those Super Suckers don't always work.  We added one on Royce's recent MEL that I dynoed, and the engine lost 25 HP with that thing.  See this post:

http://fepower.net/simplemachinesforum/index.php?topic=4736.0

[blykins]

If I could find a china shop to repop those things, I'd make a killing.  Ain't paying $140 for a spacer LOL.  Yes they work, but looks to me like you could DIY just as well with some epoxy and a bastard file.

You will find that even the "extremely close replicas" won't even work as good.....one of my buddies did a back-to-back between a Wilson and a Super Sucker and there was a difference (albeit small) in horsepower.   Between me and a local buddy, we go through them by the dozens.  If you want to try one, I'll sell you one for about half that price. 

Jay, can't say I've used one on a MEL, but I've been hard-pressed to find an engine that didn't at least pick up a few ponies with one.  Never had an engine take a nose dive in power when trying one. 

[jayb]

Yes, that was a surprise to us also.  But the test repeated; the power loss was real.

[fryedaddy]

SUPERSUCKER

[fryedaddy]

If I could find a china shop to repop those things, I'd make a killing.  Ain't paying $140 for a spacer LOL. 

  Between me and a local buddy, we go through them by the dozens.  If you want to try one, I'll sell you one for about half that price. 

can you send me info on one of these spacers

[Joe-JDC]

I have hand ported the four hole spacers into a super sucker type, and made more horsepower then the store bought ones.  I have never seen a 2"super sucker lose power on a 4V intake.  Joe-JDC

[plovett]

The cloverleaf style spacer always seems to get left out.  Mine works good.

[fryedaddy]

i took my 1 inch wood laminated open spacer off today.me and my son went for a ride.we both agreed that it felt more responsive on take off.thats the only spacer i have so i guess i will buy a 4 hole of some kind,supersucker,etc

[plovett]

You might try a cloverleaf spacer.......   

[fryedaddy]

You might try a cloverleaf spacer.......   

what is a cloverleaf and who sells them

[plovett]

It's just a 4 hole spacer with the center cut out and radiused.  A person could make one out of a 4 hole pretty easily.

It's in-between a 4 hole spacer and an open spacer in terms of function. 

I'm a fan and I've tried all sorts of spacers, though I haven't done scientific testing.

I don't even remember where I bought the one I have, but here's a link to one.

https://www.summitracing.com/parts/drt-62100002/overview/

paulie

[fryedaddy]

thank you Paulie

[plovett]

thank you Paulie

de nada, enchilada!

Another note.  The type of spacer you use can affect your optimum carburetor jetting.  In general, an open spacer presents less signal (or suction) to you carb.  So, in general, to optimize an open spacer the carb jetting should be slightly bigger, maybe 2-4 sizes?

A 4 hole spacer tends to increase signal to the carb.  So less jetting is usually required for optimum performance.

The "in-between" spacers like the super suckers (tapered) and clover leafs are generally "in between" in terms of optimal jetting. 

Just something to think about before deciding if a particular spacer is best for your combination.  You might try a jet change or two before making up your mind. 

JMO,

paulie

[Heo]

Talking about carb spacers. What spacer do you think
390 +.060 ,10-1comp, ported C4G heads, shorty
castiron headers, streetmaster intake,750 VS comp cams
282S

[chris401]

Talking about carb spacers. What spacer do you think
390 +.060 ,10-1comp, ported C4G heads, shorty
castiron headers, streetmaster intake,750 VS comp cams
282S

My 4800 lb F250 had a .060 over 390, Street Master, 3310-4 best liked 2 1/4" total 4 hole spacers with that cam. I changed to a  smaller carb and dual plane intake before I had it dialed in well. The lighter F100 the engine was originally for got away with my home made clover leaf with another 3/4" 4 hole on top of it. I do not know how good of a combination it was. Best to have it on a dyno or a few time slips to get it dialed in.

[fryedaddy]

would it require a change with the air fuel idle screws going from a open spacer to a 4 hole spacer

[chris401]

would it require a change with the air fuel idle screws going from a open spacer to a 4 hole spacer

In that case yes. The carburetor was bran new. Spent the whole weekend running it and checking plugs and making changes. Had the help of a few car magazines, no internet then. Having wideband O2 sensors will cut the time and work to probably 1/3 or less.

[Joe-JDC]

Spacer type and height are all dependent on what intake and engine size you are dealing with.  A dual plane intake will not always respond the same to open vs four hole spacers or super sucker type intake, especially if the intake has a notch for the butterflies, or has been cut down.  I have helped test dozens of combinations on the dyno, and found that engine size changes the characteristics of how they work.  I have tried the super suckers up-side-down, in many configurations to try to find the absolute best combination, and again, the results changed with cubic inch and compression.   It comes down to actually trying several on your vehicle and picking the one that you feel works best.  Sometimes the best torque and horsepower will be found with three inches of spacers, two inches of spacer, or even no spacer.  The EMC this year for Traditional Muscle Big Block and Small Block can not use a spacer.    Joe-JDC

[chris401]

Spacer type and height are all dependent on what intake and engine size you are dealing with.  A dual plane intake will not always respond the same to open vs four hole spacers or super sucker type intake, especially if the intake has a notch for the butterflies, or has been cut down.  I have helped test dozens of combinations on the dyno, and found that engine size changes the characteristics of how they work.  I have tried the super suckers up-side-down, in many configurations to try to find the absolute best combination, and again, the results changed with cubic inch and compression.   It comes down to actually trying several on your vehicle and picking the one that you feel works best.  Sometimes the best torque and horsepower will be found with three inches of spacers, two inches of spacer, or even no spacer.  The EMC this year for Traditional Muscle Big Block and Small Block can not use a spacer.    Joe-JDC

My first Street Master was not modified and always had more middle range grunt on my small 3.5" and 3.78" stroke engines than the other two I had. Was the Edelbrock update aimed at the larger cube engines or was it just a coincidence?

[fryedaddy]

if your vac was low with a open spacer should it improve with a 4 hole compared to the open one.i bought a 1 inch 4 hole,1 inch clover leaf today,and i already have a 1 inch open spacer.when i get up in the morning i think i will see what works best.i might even put them all on at the same time!

[Joe-JDC]

If you were to look at all the intake manifolds as cast, you would see a trend with runner size and cfm.  I have flowed nearly every FE intake as cast, and ported nearly all of them except the Cross Ram types.  The difference between a stock Streetmaster and RPM is significant in flow potential because the RPM runners are cast with a larger cross section.  A Streetmaster has a couple of runners that only flow in the 250 cfm range, and averages ~270 cfm.  The RPM averages 305-307 cfm on the ones I have flowed as cast.  The Victor 427 averages over 340 cfm as cast, with those tiny angled ports.  A HR single 4V averages ~365 cfm as cast.  Anyway, the Streetmaster can be ported to flow ~360 cfm and make well over 600hp on a stroker engine.  Joe-JDC