Has anyone tried fitting heat shield in between their plenum runners and the rear head to reduce the heatsoak into the runners?

I had the runners off the other day to give them a good throttle body clean and they were ****ing hot. It was amazing how much gunk was in there when there did not seem to be much in the PCV return line.

The gunk won't hurt anything, it will also build up again in a few 100km.

The plenum well heat up regardless of the manner it is connected to the head. The bolts will transfer heat just as quickly as the gasket faces anyway.

That sort of mod is along the same line of credibility as a hi-clone.

Didn't somebody do a before and after of installing those thermal gaskets and measured a reduction in intake temperatures?

Surface area of the 7 bolts is less than 7 cm^2
Surface area of the gasket is (at a guess) 60 cm^2
Surface area of the runners over the head (at a guess) is 300 cm^2

I was not talking about conduction through the bolts or the gasket (looks pretty minor to me, Higher temperature but not much surface area to conduct through.)
I was talking about radiation/convection from the head up to the runners.

TC. Looks like you are referring to Barry's gasket mod.

I think VHT (http://72.10.43.141/high_temp.htm) Flame Proof Coating can help a little, it has a blend of ceramic and silicone chips which may reduce the temperature of your intake manifold.

My thinking would be that conduction would be the main transfer of heat into the inlet manifold. No doubt convection and radiation play some part as well. You can only try right?

Get the tin snips out and make a solar sheild. Then take some measurements and tell us how you went.

But to answer the original question, no, I don't think anyone has made a solar/heat shield to shield the inlet manifold.

I had the RPW thermal insulator blocks fitted and they reduced the plennum temperature by 50 degrees (they were 100 before fitting). I measured the temp with a non contact thermometer. The plennum will stay cooler than the rest of the engine while you are moving but will increase in temp if you stop due to no airflow and heat soak from the engine bay ambient temp.


Has anyone tried fitting heat shield in between their plenum runners and the rear head to reduce the heatsoak into the runners?

I had the runners off the other day to give them a good throttle body clean and they were ****ing hot. It was amazing how much gunk was in there when there did not seem to be much in the PCV return line.

Whatcha gotta do, see, is ya gotta disconnect the plenum from the gaskets, see. Then when ya next go to touch the plenum, schee, the whole thing is icy. nhuck nhuck nhuck.

its a nice idea, but in reality it will gain you maybe 0.1hp

you could get a better power to weight ratio increase by just washing and vacuuming the car, and taking out the maccas rubbish.

I think VHT (http://72.10.43.141/high_temp.htm) Flame Proof Coating can help a little, it has a blend of ceramic and silicone chips which may reduce the temperature of your intake manifold.

I actually emailed VHT about using this paint on these intake manifolds to reduce heat uptake - they replied that they recommend it for just such a purpose. So yeah - got it happening on mine soon.

It actually doesn't gain you any extra power at all, it prevents power loss by limiting the amount plennum temperatures rise due to heat soak.

For every 2.7 degrees rise in intake air temp, you will lose 1% of power (10% for every 27 degrees). Insulator blocks help keep intake air temps from rising.



its a nice idea, but in reality it will gain you maybe 0.1hp

you could get a better power to weight ratio increase by just washing and vacuuming the car, and taking out the maccas rubbish.

It actually doesn't gain you any extra power at all, it prevents power loss by limiting the amount plennum temperatures rise due to heat soak.

For every 2.7 degrees rise in intake air temp, you will lose 1% of power (10% for every 27 degrees). Insulator blocks help keep intake air temps from rising.

It is not a linear increase/decrease, so that is flawed.

You will never get the air entering a combustion chamber cooler than probably 60 degrees anyway, so 0.001 degree isn't going to do much at all is it.

Your clutching at straws trying to gain power from no where.

you could install a C02 fogger directly underneath the plenium, that would cool it down quickly but only fiesable for drag racing as you'd empty the bottle rather quickly

The gunk won't hurt anything, it will also build up again in a few 100km.

The plenum well heat up regardless of the manner it is connected to the head. The bolts will transfer heat just as quickly as the gasket faces anyway.

That sort of mod is along the same line of credibility as a hi-clone.

I disagree. After I got Barry's plenum gasket (among other things), the plenum feels very noticeably cooler to touch with my hand, it still gets hot quickly, but that temperature seems to peak much lower.

I know this isn't scientific, but if the difference is so obvious I can feel it easily with my hand, then I can see it making a difference, even if only a tiny bit. And to be blunt I was a bit skeptical at first (as I am of any cheap/new mod, especially the "miracle" ones), but thats my 2cents.

Well, let me explain it in a way that you may understand. Intake air enters a plennum that's 100 degrees; the air gets hot. Air enters a plennum that's 50 degrees; it doesn't get quite as hot. I'm sure most people can work the rest out.


.





It is not a linear increase/decrease, so that is flawed.

You will never get the air entering a combustion chamber cooler than probably 60 degrees anyway, so 0.001 degree isn't going to do much at all is it.

Your clutching at straws trying to gain power from no where.

And everyone knows the theory of cooler air is denser. So that being said, if the plenum is cooler you will have more air in there... More air = more power... Even if the air does heat up as it enters the cylinder, at least you know there is more volume of air waiting to get in...

How much does the air heat up from the manifold is the question? Im guessing not a great deal but would be worth investigation of actual air temps b4 and after any treatment to try reduce temps. Would be hard to get a probe into the airflow to test tho.

I disagree. After I got Barry's plenum gasket (among other things), the plenum feels very noticeably cooler to touch with my hand, it still gets hot quickly, but that temperature seems to peak much lower.

I know this isn't scientific, but if the difference is so obvious I can feel it easily with my hand, then I can see it making a difference, even if only a tiny bit. And to be blunt I was a bit skeptical at first (as I am of any cheap/new mod, especially the "miracle" ones), but thats my 2cents.

Hi Chisolm
Good perceptions there - spot on!
Anyone who has an original gasket, when placed on top of the new, cooler one can see the differences

It is made from aramid fibre, etc designed to insulate from heat - whereas the original is a kind of plastic material that actually allows heat to conduct from lower to upper manifold, and from TB to plenum in the case of the TB gasket!

It also does not seal between runners, and you can often see oil deposits there, even on low mileage vehicles!

You will notice that the contoured sides have been taken out to max dimensions, and there are two un-necessary holes, one on each side of centre that have been filled

All seemingly 'small' things, but collectively make a real difference...

The other main reason for the lower temps is having the correct A/F ratio

It is well known that lean mixtures create high combustion temps - the heat is transferred by conduction to the coolant which flows close to the combustion chambers (creating a 'hot' engine) and then on to the radiator

In the case of cars like the Magna, which uses vortex (or turbulence) type of air-flow detection, adding hi-flow air filters or hi-flow exhaust systems causes the MAF to miss-read the fuelling requirements and can easily run "lean"

This lean-out condition is often felt as a loss of torque in the lower rev ranges 1500 - 2500 RPM
This results in lean air-fuel ratios and usually a 'flat spot you can feel'

You can help this problem by fitting extra ECU management, or by fitting the Fuel Rail Mount kit
This makes the car's own ECU see the fuel as enriched, and often gives better throttle response too

In your case Chisolm, you also have the grounding kit which gives accurate sensor readings for fuelling and timing, and that further improves torque when climbing hills

Cheers, Barry

In your case Chisolm, you also have the grounding kit which gives accurate sensor readings for fuelling and timing, and that further improves torque when climbing hills

Cheers, Barry

Agreed.

I got Barry's grounding, fuel rail and gasket kits installed by the man himself all at once, and the difference in low-rpm response was staggering, much more than what I was expecting. I find myself hanging onto taller gears more often in day-to-day driving, as it feels much less laboured in the lazy part of the rev range. Perhaps this is particularly noticeable with manuals, due to the direct drive, as opposed to converter slip at low rpms.

Barry's kits also seem to add a tad bit of power up top too, judging by the seat of my pants (the difference is small, but I thought I could feel it after installation). Actually initially it felt like I had lost power up top, as by comparison the 1500-2500rpmg range felt beefier. But booting the boot in from 3,000 rpm + seemed to suggest a tad more power up top, which is always welcome.

With hindsight I wish I got dyno graphs before and after the kits, even if just for my own curiousity. I'm pretty sure it would have shown a fuller torque curve, extending to produce few more kw up top.

With hindsight I wish I got dyno graphs before and after the kits, even if just for my own curiousity. I'm pretty sure it would have shown a fuller torque curve, extending to produce few more kw up top.

I think a stopwatch would be good enough.

Any mod that gives a noticeable decrease in accelleration time by watch, is worthwhile.

I think a stopwatch would be good enough.

Any mod that gives a noticeable decrease in accelleration time by watch, is worthwhile.

There's way too much variation in using a stopwatch to be able to attain reliable times. Also I doubt mods like these on their own would translate into a measurable increase, maybe something like a 0.1-0.2 second improvement for the 1/4. But then the difference is so small, once you factor in other variables you can't really measure it accurately anyway, even at the drags with proper timing.

The main aim of these kits are to improve low-rpm response/torque, not peak power. So the only real way to measure the improvement is via a dyno graph, where you can see measure the difference over the entire revrange.