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Home made plenum spacer VT V6 what material would work best?

TI3VOM

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Hi there I want to make a plenum spacer for my car, as I have just cut out a MDF jig for making one out of some decent wood.

My first question is:
Would the MDF cutout do the job with gasket goo on the outside, and some type of sealant on the inside that would be resistant to petrol and high temperatures. If so what kind of stuff can I buy to coat the inside of the spacer with?

Second:
If not what would be a good type of material for one?

Cheers Glenn.
 
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TI3VOM

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I have found this on an american forum.

"Hi being from Australia I am not sure if the name's are the same or available to you but I made mine out of a scrap piece of laminated MDF (manufactured wood) then sealed the part exposed to fuel with a product called Bondcrete (for water proofing concrete) =fuel proof,flame proof ,easy to work with & best of all cheap as I had it laying around"

Does anyone have any other ideas as to what can be used?
 

Claudy

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i used bakerlite havent used the spacer yet but it looks pretty solid and heat proof. by the way was a pain to cut...went through 2 packets of jigsaw blades lol holesaw and die grinder works great for the holes but
 

Hektic

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Hi there I want to make a plenum spacer for my car, as I have just cut out a MDF jig for making one out of some decent wood.

My first question is:
Would the MDF cutout do the job with gasket goo on the outside, and some type of sealant on the inside that would be resistant to petrol and high temperatures. If so what kind of stuff can I buy to coat the inside of the spacer with?

Second:
If not what would be a good type of material for one?

Cheers Glenn.
what is the reason for puting a spacer between the plenum and the block?
 

Tsunamix

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Whatever material you use, it has to be able to stand the maximum engine temp, which is around 106 degrees c. The glue used in MDF dies at about 65-70 deg, which is well below the temp the thermostat even opens at.

On top of that, it needs to be absolutley non poropus or air will be pulled in through the material. MDF wont cut it. Most plastics wont.

Bakerlite will, depending on the grade. Most bakerlites are 'B' class whihc means they handle about 130 degrees C max. They are also usually totally non porous as they are resin filled. Fabric bakelite is so tough it will blunt saws. Glass bakerlites will blunt diamond saws. Additionally, Paper and Fabric bakelite dust is and irritant, and doesnt bio-degrade, so avoid inhaling dust and burnt fumes. (Epoxy Phenolic resins contain some serous nasties). I don't recommend home users machining this stuff.

Putting a spacer inbetween the top and bottom halves of the Intake manifold increases runner length, builds torque. It also reduces heat transfer from block toplenum, keeping your intake charge somewhat cooler. Putting a spacer at the top of the plenum increases plenum volume improving throttle response.

if you could put one between the block and the lower manifold you could seem some more gains, but that would push runners oput of alignment so it ain't gonna happen without a custom manifold with shorter runners anyway.
 
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Always very informative Tsunamix :spot on:

I brought lower and plenum spacers from Mace for my wagon and they worked well.
I'm going Maces 25mm lower & 10mm plenum for my N/A Ute.

:mods:
 

LSV MALOUF

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As bad as this may sound to everyone that knows everything or to the nfi's with google at hand mdf is a viable and capable insulator for use in manifolds as long as it is fitted well! with a compound not unlike a paper gasket when used with 3 bond grey or any decent rtv, one downfall is you won't get to reuse it if glued well ,I've put nearly 2 bar of boost through mine and they hold it no problem not to mention it's going to blow out in a bad nitrous backfire instead of the whole intake! for convenience and durability I'm using a mace 25mm runner spacer and mdf plenum spacer for safety, i regularly pressure and vacuum check my whole system from intake to exhaust as well as regular valve and ring leakdown tests and so far mdf hasn't failed having said that I wouldn't use it on a nice car or customer's car.
 

LSV MALOUF

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Yes definitely 2 bobs a decade late but with it being a regular question asked to me by many dore owners a different opinion available can't hurt
 
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