{"id":94046,"date":"2023-12-14T09:51:23","date_gmt":"2023-12-14T17:51:23","guid":{"rendered":"https:\/\/www.racingjunk.com\/news\/?p=94046"},"modified":"2023-12-14T09:52:37","modified_gmt":"2023-12-14T17:52:37","slug":"spaced-out-do-carburetor-spacers-really-work","status":"publish","type":"post","link":"https:\/\/www.racingjunk.com\/news\/spaced-out-do-carburetor-spacers-really-work\/","title":{"rendered":"Spaced Out: Do Carburetor Spacers Really Work?\u201d"},"content":{"rendered":"<p class=\"jetpack-slideshow-noscript robots-nocontent\">This slideshow requires JavaScript.<\/p><div id=\"gallery-94046-1-slideshow\" class=\"jetpack-slideshow-window jetpack-slideshow jetpack-slideshow-black\" data-trans=\"fade\" data-autostart=\"1\" data-gallery=\"[{&quot;src&quot;:&quot;https:\\\/\\\/www.racingjunk.com\\\/news\\\/wp-content\\\/uploads\\\/2023\\\/12\\\/1-min-e1702576126519.jpg&quot;,&quot;id&quot;:&quot;94047&quot;,&quot;title&quot;:&quot;Spaced Out: Do Carburetor Spacers Really Work?\\u201d&quot;,&quot;alt&quot;:&quot;Spaced Out: Do Carburetor Spacers Really Work?\\u201d&quot;,&quot;caption&quot;:&quot;Click Here to Begin Slideshow\\n\\nThe common consensus out there is that a carburetor spacer is a simple engine-tuning device, useable for only a select few applications, and they don\\u2019t produce much extra power either.\\u00a0 Short and simple, however that might not be completely true.\\u00a0 Certainly in many cases they can be used to change engine power characteristics. But they can also be used to find measurable horsepower (more on that later).\\u00a0 Here\\u2019s the bare basics of how a spacer functions:\\n\\nThe addition of a spacer effectively increases the distance between the carburetor and the floor of the intake manifold plenum.\\u00a0 In many cases, this straightens out the intake mixture flow pattern.\\u00a0 Because of this added distance, the carburetor signal is weakened.\\u00a0 And when the signal is weakened larger jets in the carburetor will be required.\\u00a0 Carburetor spacers designed with four separate holes tend to recapture the velocity of the mixture stream, which has been lost when an open carburetor spacer is installed.\\u00a0 In simple terms, more exit velocity in the mixture stream creates a stronger carburetor signal than that found with an open-spacer.\\u00a0 Generally speaking, the jet size will still have to be increased when a four-hole spacer is used, but not as much as with an open-spacer.\\n\\nHow much spacer should you use?\\u00a0 As a rule of thumb, single plane intake manifolds seem to respond best with larger spacers (in the order of 2-inches in height and larger).\\u00a0 On the other hand, most dual plane intake manifolds work best with open spacers with a height of between 5\\\/8-inch and 1-1\\\/2-inches.\\n\\nWhen it comes to materials for spacers, plywood is a pretty good choice. Thin layers of laminated wood, bonded together with resin, form a natural heat sink.\\u00a0 For example, a wooden spacer features top quality hardwood plywood with a sheet of phenolic resin-impregnated paper bonded to both sides. As expected, plywood spacers are easy to modify to suit a given manifold for optimum performance.\\u00a0 On the other hand, pure phenolic spacers are constructed from an advanced composite material (similar to plastic), which can reduce heat conductivity ten times greater than aluminum for a much denser air\\\/fuel charge.\\u00a0 Obviously, aluminum spacers are still widely available.\\u00a0 The advantage in aluminum is that it can be easily modified for a given application.\\u00a0 The disadvantage is that in some cases, an aluminum casting can be porous.\\u00a0 Because of this, several manufacturers now offer billet aluminum spacers CNC-machined from 6061-T6 material.\\u00a0\\n\\nDo they work? For the most part, the answer is yes.\\u00a0 Certain engine combinations respond more favorably than others, particularly to traditional spacers. But there\\u2019s a wrinkle in the world of carb spacers and airflow. It\\u2019s called a \\u201cSuper Sucker\\u201d and it\\u2019s manufactured by \\u201cHVH\\u201d (High Velocity Heads).\\u00a0\\u00a0 Like others, it\\u2019s made from an advanced composite material (you can also get them in aluminum).\\u00a0 And like others, most are 1-inch tall.\\u00a0 And yes, the top side (carburetor mount side) looks like any other four-hole spacer. But the bottom (intake manifold side) is far different than anything seen before (see the accompanying photos).\\n\\nOk. It\\u2019s different, but does it work?\\u00a0 A number of years ago, I tested one with remarkable results. My pal, the late John Heida volunteered to bolt one onto a small block Chevy he had strapped to his dyno. Both John and I weren\\u2019t expecting much.\\u00a0 In this case, we were wrong:\\n\\nThe engine we used for our test was mild 355 cubic inch small block Chevy complete with lightly ported small valve heads.\\u00a0 It was an efficient piece. Using a standard correction of 29.92 inches Hg., 60-degree F dry air, the tests were done in a conventional A-B-A format (for the sake of simplicity, the final back up test isn\\u2019t included \\u2013 it duplicated the first test almost exactly). When we ran the\\u00a0 baseline test, the horsepower peak was 432.4 at 6,300 RPM.\\u00a0 The engine torque peak of 402.8 foot-pounds occurred at 5,000 RPM. \\u00a0In truth, this is a pretty nice street engine with good manners.\\u00a0 For test number two, nothing was changed, except for the addition of a four-hole HVH \\u201cSuper Sucker\\u201d carb spacer:\\n\\nThe little Chevy saw a power peak of 447.3 HP at 6,400 RPM, coupled with a torque peak of 413.2 foot-pounds at 5,000 RPM.\\u00a0 Bottom line? The HVH Super Sucker added 14.9 HP and 10.4 foot-pounds of torque.\\u00a0 It\\u2019s actually a pretty serious power maker. In theory, the two-inch tall model should have produced even more power. Common consensus regarding minimal power gains with a spacer just went out the window.\\u00a0 What makes this thing tick?\\u00a0 We presented that same question to High Velocity Heads:\\u00a0\\n\\n\\u201cThese spacers work, obviously, by helping the fuel distribution.\\u00a0 If you look at the bottom of the spacer, you\\u2019ll see that the shape is different.\\u00a0 The reason is we wanted to improve the feeding of the outside runners on a single four-barrel manifold.\\u00a0 The design picks up the air speed and gives it a specific direction.\\u00a0 Finally, the plastic composite material insulates the carburetor.\\u201d\\n\\nHVH makes use of a Haas CNC mill to carve out their spacers from solid composite stock.\\u00a0 Included in their product mix are spacers for 4150 Holley carbs (1-inch, 2-inch, four hole and two hole), 4500 Holley carburetors (1-inch tall, 2-inch tall four-hole spacers), 4412 series Holley carburetors (1-inch tall open, 2-inch tall two hole). In case you\\u2019re wondering, these spacers aren\\u2019t inexpensive (they can cost $139 or more), but in our book, that\\u2019s still cheap power.\\n\\nFor more, check out the accompanying photos:\\n\\nClick Here to Begin Slideshow&quot;,&quot;itemprop&quot;:&quot;image&quot;},{&quot;src&quot;:&quot;https:\\\/\\\/www.racingjunk.com\\\/news\\\/wp-content\\\/uploads\\\/2023\\\/12\\\/2-min.jpg&quot;,&quot;id&quot;:&quot;94048&quot;,&quot;title&quot;:&quot;Spaced Out: Do Carburetor Spacers Really Work?\\u201d&quot;,&quot;alt&quot;:&quot;Spaced Out: Do Carburetor Spacers Really Work?\\u201d&quot;,&quot;caption&quot;:&quot;The folks from HVH offer a number of different spacer configurations, obviously for varied engine applications.  The four-hole setup on the left is for a Holley Dominator while the spacer on the right is a two-hole model engineered for a 4150 Holley carb mounted on a dual plane intake.&quot;,&quot;itemprop&quot;:&quot;image&quot;},{&quot;src&quot;:&quot;https:\\\/\\\/www.racingjunk.com\\\/news\\\/wp-content\\\/uploads\\\/2023\\\/12\\\/3-min.jpg&quot;,&quot;id&quot;:&quot;94049&quot;,&quot;title&quot;:&quot;Spaced Out: Do Carburetor Spacers Really Work?\\u201d&quot;,&quot;alt&quot;:&quot;Spaced Out: Do Carburetor Spacers Really Work?\\u201d&quot;,&quot;caption&quot;:&quot;On the topside, this HVH four-hole spacer appears almost identical to any other aftermarket model.  On the bottom side, though, it\\u2019s a different story:&quot;,&quot;itemprop&quot;:&quot;image&quot;},{&quot;src&quot;:&quot;https:\\\/\\\/www.racingjunk.com\\\/news\\\/wp-content\\\/uploads\\\/2023\\\/12\\\/4-min.jpg&quot;,&quot;id&quot;:&quot;94050&quot;,&quot;title&quot;:&quot;Spaced Out: Do Carburetor Spacers Really Work?\\u201d&quot;,&quot;alt&quot;:&quot;Spaced Out: Do Carburetor Spacers Really Work?\\u201d&quot;,&quot;caption&quot;:&quot;When flipped over, you can immediately pick out the differences.  As pointed out in the text, the idea is to pick up the air speed, to better feed the outside runners of the intake and to give the air speed direction.&quot;,&quot;itemprop&quot;:&quot;image&quot;},{&quot;src&quot;:&quot;https:\\\/\\\/www.racingjunk.com\\\/news\\\/wp-content\\\/uploads\\\/2023\\\/12\\\/5-min.jpg&quot;,&quot;id&quot;:&quot;94051&quot;,&quot;title&quot;:&quot;Spaced Out: Do Carburetor Spacers Really Work?\\u201d&quot;,&quot;alt&quot;:&quot;Spaced Out: Do Carburetor Spacers Really Work?\\u201d&quot;,&quot;caption&quot;:&quot;These spacers aren\\u2019t cast.  They\\u2019re CNC-machined plastic.  Note the intricate design.  Plastic is relatively easy to machine, but more important, it insulates the carburetor from the hot intake manifold.&quot;,&quot;itemprop&quot;:&quot;image&quot;}]\" itemscope itemtype=\"https:\/\/schema.org\/ImageGallery\"><\/div>\n","protected":false},"excerpt":{"rendered":"<div class=\"mh-excerpt\"><p>The common consensus out there is that a carburetor spacer is a simple engine-tuning device, useable for only a select few applications, \u00a0but do they work?<\/p>\n<\/div>","protected":false},"author":20,"featured_media":94047,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":true,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2}},"categories":[5028,5008,17,11,3470,4879],"tags":[10085,1076,281,41,461,321],"class_list":["post-94046","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-fuel-delivery","category-engine","category-guest-column","category-how-tos","category-news","category-slideshow","tag-carb-spacers","tag-carburetors","tag-how-to","tag-news","tag-tech-tips-2","tag-wayne-scraba"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"https:\/\/www.racingjunk.com\/news\/wp-content\/uploads\/2023\/12\/1-min-e1702576126519.jpg","jetpack_shortlink":"https:\/\/wp.me\/p42YSK-osS","jetpack_sharing_enabled":true,"amp_enabled":true,"_links":{"self":[{"href":"https:\/\/www.racingjunk.com\/news\/wp-json\/wp\/v2\/posts\/94046","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.racingjunk.com\/news\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.racingjunk.com\/news\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.racingjunk.com\/news\/wp-json\/wp\/v2\/users\/20"}],"replies":[{"embeddable":true,"href":"https:\/\/www.racingjunk.com\/news\/wp-json\/wp\/v2\/comments?post=94046"}],"version-history":[{"count":1,"href":"https:\/\/www.racingjunk.com\/news\/wp-json\/wp\/v2\/posts\/94046\/revisions"}],"predecessor-version":[{"id":94052,"href":"https:\/\/www.racingjunk.com\/news\/wp-json\/wp\/v2\/posts\/94046\/revisions\/94052"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.racingjunk.com\/news\/wp-json\/wp\/v2\/media\/94047"}],"wp:attachment":[{"href":"https:\/\/www.racingjunk.com\/news\/wp-json\/wp\/v2\/media?parent=94046"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.racingjunk.com\/news\/wp-json\/wp\/v2\/categories?post=94046"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.racingjunk.com\/news\/wp-json\/wp\/v2\/tags?post=94046"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}