Phenolic Intake Spacers - Redux

[apex944]

OK i did a search here and did not find anythig but if there are threads about his please point me to them.

Yes it's the age old question... Do phenolic (or any insulating) intake manifold spacers really work? Do they actually cool the intake change and make power?

I vote 'No'. But after searching the net I find so many convicing arguments that they do work that I'm curious. Do any of you Automotive Engineers have any real data to end this ?

I cant see the intake charge being affected after the engine is up to operatng temps. Sure the manifold might be cooler at start up or after shutdown but the column of fast moving air inside the runners??

 

[patprimmer]

Do they work. Yes

Do they cool the intake charge. Hardy. Probably not to a measurable degree at anything like full throttle, and part throttle does not matter.

Do they help stop vapour lock or boiling fuel in the carby. Certainly.

Regards

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[reidh]

Like Pat said, the main advantage to phenolic spacers are the extra margin they give for vapor lock.

Reidh

 

[Majik]

I know it sounds goofy but check out hondata's spacer setup. there are several studies they did showing like 50+ degree drops in intake manifold temp. Dyno tested gains (not that I belive the dyno is accurate enough to measure them) but alas. It's accepted as "tested true" in the honda-tech community. Now granted this is more for turbo cars. On a NA Small block I doubt you'd see much of anything HP wise.

 

[apex944]

The column of air moving through the manifold is al lI'm concerned about. Manifold surface temps at idle or after shut down are of no interest.

The research I've done suggests that spacers do nothing to the IAT from TB to back of valve.

The boundry layer is a nice insulator.