Carburetor Spacers

Thinking about positioning my RS34's rearward with 3/8" (10mm+/-) spacers inserted between the head and manifolds. This would correct the spacing relationship with the air box, so the air boots could be fitted properly to it, and provide a little extra working room in front of the carbs.
Anyone venture to suggest whether the effect on my engine performance would be positive or adverse?

Here's an example of a similar spacer for use on a racing motor, but for an obviously different end purpose:
aperaceparts.com/resources/nos/manifolds.jpg

This spacing product proposes positives for an automotive application: :blink:
www.enginebuildermag.com/2014/05/trans-dapt-carburetor-spacers/

I received this response from technical support at hedman.com for the concept applied to a motorcycle engine:
"Unfortunately, that is not a market we are looking to get into at this time. I do know there are performance gains to be seen in the spacers and sometimes some really good gains. I would like to wish you luck in your endeavor."


Why does curiosity always bring me to the same place? :S

It will add a little down low and take away a little up top.
And I mean very little with just 3/8". You probably will not tell the difference.


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Nebr_Rex wrote: It will add a little down low and take away a little up top.
And I mean very little with just 3/8". You probably will not tell the difference.


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3/8" thickness does seem pretty narrow to encourage much of an effect, even with rifled bores to enhance swirl motion of the gaseous air mixture. :huh:

Should I use sealant between the spacers and the head? I think the manifold side will be fine without it. :whistle:

How about a gasket?

Nessism wrote: How about a gasket?

Do you have a recommendation what to use, and where to get it?

I used threebond 1184 on the intake manifolds on my H2 750 , worked very well, nothing else sealed them except that , got that tip from an old triple guy.
Also it's not hard to cut gaskets there's all kinds of material available diffent types and thicknesses.

Felpro Fiber-Rubber gasket material type would work well. www.amazon.com/Fel-Pro-3187-Gasket-Mater...keywords=felpro+3187

RS34's on a standard 1100 shaft bike with an airbox...this is April fools 4 months early right?


When it comes to extracting every last bit of horsepower from an engine, heat is always the enemy



wow, maybe I should have smoked tons more weed too when i was a student doing engineering thermodynamics.

You are looking for a plenum chamber effect 'pulse tuning' with tuned intake lengths, trial and error dyno tuning work for minimal gains in your case. Sorry to be controversial, as usual.

As long as they don't leak, they should work fine.
Steve

When it comes to extracting every last bit of horsepower from an engine, heat is always the enemy

ironically, heat being ' such an enemy ' that euro spec kawasaki zephyrs , GT shaft series and IIRC GPZ900 had electric heaters in the carb bowls to prevent carb icing in cold weather (due to latent heat of evaporation)



Gotta go, there is some chicken wings on ebay, I read somewhere it makes your bike faster. :laugh:

It would be interesting to be able to dyno all the little things we all do and see what happens.
The big gains are easy to tell. But in certain situations like this one it may be just a touch better (or worse) throttle response.
Or just easier to jet if the air flow is improved due to the air box, carbs like still air. or not, less pick up signal the further away,
Interesting anyway you slice it.
Can I ask why space the carbs and not lengthen the air box rubbers, longer intake before the carbs can help also?

The spacers look great by the way!