Thread: carb spacers

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Just a question about carb spacers... I have a 77 1/2 ton with a 350ci/300 hp and a mild cam, it is a crate engine. Was wondering what a carb spacer would do for me. I have a rochester q-jet with a edelbrock 2101 performer intake. My question is this.... Would it really performer like they say? what size should I get? I have heard you can make your own. Will it help the carb run cooler? i am looking for some more performance. Thanks for all the help and advise!

Depends on what you do with it, a dual plane intake would give low end so a spacer may raise your power band.

joe's correct, especially if you use an open spacer as opposed to a 4-hole. You can indeed make your own, using a gasket as a template. Make it from a nice piece of 1"thick wood. Use a holesaw to cut the 4 holes. Make sure the wood is flat and parallel when you're finished making it. Many times, the air/fuel mixture will make the turn from the carb throttle bores into the manifold runners easier with a spacer without crashing into the bottom of the manifold and creating turbulence.

The wood will insulate the fuel in the bowl from manifold heat.

I tig'd one out of aluminum for my ford 351c.... like ya say, use a gasket as a template and away ya go...

Mine is around 2" high, but i want as much mid range torque as poss,and with the combination of my 509*/509* cam and the predator carb is sweet...

the predator was really crappy without the spacer, wasnt getting much
fuel vapor, more like i was turnin a frickin tap on.....riser has given the turb's i needed and is a good low cost tuning mod..

Hey Tech.. what gains do ya get running inlet risers and spacers together??

evil, I'm not sure what you mean by inlet risers, but as for spacers, like you said, they're a great tuning aid.

It all depends on what you want from your motor and where you want the "sweet spot" of torque peak or horsepower peak to be. When advising on spacers and manifold volume (180 versus 360 manifolds), if the motor is for a fairly heavy street-driven car with a stock converter or slightly higher stall converter, I'll always recommend a 180 manifold and 4-hole spacer to build max torque at a lower, street-useable rpm. In my opinion, it's a matter of creating a strong negative pressure in the manifold to increase velocity and maintaining a homogenous mixture, minimizing fuel separation.

With any manifold manufacturer and Edelbrock in particular, you can read the characteristics of the different manifold designs on their website.
http://www.edelbrock.com/automotive_...lds_main.shtml

In spite of this information, there are neophyte engine builders who will want to use a Victor manifold on their warmed-over street motor. Or they'll choose a RPM variant of a 180 manifold. I guess they think that the higher rpm manifold will magically turn their cam-limited motor into a fire-breather.

Back to spacers. Again, in my opinion, if you are building a mild street motor with a 180 manifold, use a 4-hole spacer and experiment with spacer height. Using an open spacer will turn your 180 manifold into a 360 (open plenum) manifold and move the sweet spot higher in the rpm range, away from streetability. Now, of course, if you are looking for a street motor that makes power higher up, by all means use a Torquer or Victor intake and stack open spacers on it 'til hell won't have 'em. But you had better back the 360 manifold and spacers up with the proper cam and that means the proper valvetrain and the proper converter and the proper rear gear.

99% of the first time engine builders out there will be better off with a reasonable compression ratio, mild cam to match the compression ratio, 180 manifold, 4-hole spacer and mildly modified stall in the converter. Like I've said from day one, everybody starts from the wrong end of the car. The first thing you need if you're wanting to build a fast car is a stiff rear gear, then a looser converter, THEN go-faster goodies in the motor.

We've all seen dyno tests by magazines where they mount open spacers on a 180 manifold and it's true that they'll make a little more horsepower and torque, but take a close look and you'll see that it's at a higher rpm level, away from where you want your street motor to pull hard.

COMBINATION of parts is the key to any build, figuring out exactly what you want the car to do and choosing the proper parts to get there.

i meant The aftermarket Intake heat risers risers when used with carb spacers.. see pic below........
wondered what would happen if you ran both together...

on another note..
The 351c has a hipo street/strip cam,
full lightened n balanced assembly(crank ,rods,pistons,Flywheel etc)
port match,light polish on heads, 3angle seats,big valves
aluminum hipo manifold 360, with 2" spacer n Predator >996cfm)
and is mated to rebuilt FMX(stock Convertor) which in turn goes to a 50's narrowed Olds Rocket 88 Rear(cant remember Ratio)

the current cam choice and spacer have raised my torque range to around where it needed to be, between 2500 n 5500-6500rpm..
i was losing traction with too much bottom end torque, so figured moving the torque range with the cam n spacer would help get the power down once it the thing was moving....
and it seems to have worked jus fine...
was that the right way to do it??

oops forgot how to post pics

Well, they say the proof of the pudding is in the taste and it seems to have worked for you. That's all that's important.

Originally posted by techinspector1
Well, they say the proof of the pudding is in the taste and it seems to have worked for you. That's all that's important.

Does that mean i did it correctly??? as there were a few of the local cool kid scenesters..oops i mean 'more experienced' car guys who said i was barking up the wrong tree.. i jus sat and thought about it and it seemed like the right plan of action...
well havent had any problems as to yet.. *fingers crossed*

Well what I really need is some good torque around 2500 to 4500, so I guess its going to have to be a 4 holer huh? I am thinking that I will make my own and give it a try. There nothing better then to make it yourself and it work good!!! I will start this weekend and let ya know thanks for all the input it is nice to have that around here !!!!

Since you have a pickup, you'll have room underhood to stack spacers. Make two 1-inch 4-holers and two 1-inch open spacers. Use one 4-hole first and see how that works, then two 4-holers. Then one open and then two. Be careful about sealing 'em up so you don't have a vacuum leak and report back with your findings. All of us would be very interested in the results of your testing and which one (or two) gave the best results that you're looking for.

what kinda wood should I make them from? and do I need a gasket for the manifold and the carb or just one for the spacer to the manifold?

My intake looks just like a dual plane, except that divider in the center has a square opening at the top.

What is the deal with this type, why did they make it a dual plane if they were gonna open that divider?
will a spacer help me here?
I've been having a little trouble with cold starts. My engine won't just start up and keep running, it takes constant attention on the throttle until it's warm. I thought when I swapped out my 255 @ .050 cam for a 225 @ .050 I would prevent this.

Originally posted by 77chevy
what kinda wood should I make them from? and do I need a gasket for the manifold and the carb or just one for the spacer to the manifold?

Nothing special. Just go to your local building supply and pick up a short piece of nice, flat 6" wide x 1" thick pine or other wood that is knot-free. Brush or spray on a clear urethane sealer when you're finished making 'em so they won't get discolored from fuel and so you can seal up the porosity of the wood inside and out. Make sure the sealer you use is gasoline-proof. Some sort of epoxy might be a better choice. The clear will also give you some good "eyeball" to amaze the geeks at the drive-in. Use a gasket between the manifold and the spacer and a gasket between the spacer and carb, using a thin film of gasoline-proof RTV sealer available at any auto parts store to make sure you prevent vacuum leaks. If stacking two spacers, you'll need to use three gaskets. This is gonna be a neat low-buck project. I wish I was there to see you do it.

You can sell the spacers you don't use to other guys who've seen yours and recoup the cost of making the spacers. I can see this turning into a nice little side business. Make up some flyers and hand 'em out.

just order a phenolic.... they work really well I have one on my Q-jet rpm with a Q-jet and it does help a bunch and it only cost me 20.00