Phenolic Spacers ?

[Crafty]

So who has tried them ? Did they work ?

I've seen results from the states to suggest it does work, but is this due to the higher ambient temperature over there ? would they have much less effect here in the UK ?

What about injector positioning ? How much would this change the way the fuel atomises ?

[Paul-RS]

I know Simon Elman has them on his S3 here in the UK.

Question is... what the hell are they?

[Crafty]

It appears to be an idea from the states.

Phenolic is a heat & pressure resistant plastic.

the spcaer is made of this stuff and is 1/4" thick. The idea is you put it in between the head and inlet manifold, in doing so you insulate the manifold from the head, this means the manifold stays cooler and doesn't radiate so much heat to the air being inducted into the engine.. cooler air = denser air = more ign advance = more power.

[jeffw]

I looked on the web after you mentioned this and....

The same amount of heat is still generated from the engine but it is no longer conducted through the inlet manifold...This extra heat has to go somewhere so I would guess that the inlet manifold would still heat up due to radiated heat instead. I'd be interested to see a temperature reading before and after using these spacers/gaskets.

[Crafty]

Jeff,

see here

the ign advance increases look good, although I presume this graph isn't showing advance from TDC as 12degrees isnt much, I would expect this to be 25+ at 3000rpm...

You are correct in that the heat will still be generated, but radiated heat from metal to air to metal will be far less effective than metal to metal, thus the intake temps will be lower.. I saw a quote on ( I think audiworld ) saying that it was possible to put ones hand on the intake manifold directly after a dyno run because it just hadn't got that hot...

[toasty]

A friend has done what appears to be the same as this on his Ford Probe 24v. Not sure if they were phenolic spacers but they were spacers none the less, designed to keep the manifold cooler.

He reckons it's quicker now, but he may just be trying to justify the cost and effort of fitting them. Certainly he doesn't have any before/after dyno plots.

Cheers