Ceramic coating intake manifold

[Lambolica]

I think that your initial idea is valid. If you stop the heat transfer to the manifold from the head, the head will run hotter. A mate of mine has a 2 layer coating inside of the mainifold runners (1st layer is Ceramic coating, 2nd layer is a coating to reduce fuel drop out) Whilst the second layer may not apply until after there is fuel in the mix he is seeing reduced intake temps but marginally higher head temps. (V8 Chev + Blower) He also has a thermal layer between the head and the intake that lowers the heat transfer.

He also has also has the exposed area of the manifold coated in a heat dispersant.

Add to that some way of channeling air flow across the top of the manifold runners to assist the dispersion of heat and a heat shield over the turbo to drop the engine bay air temp. I'm not up on the MR2 engine bay flow but it appears to draw air from under the car, through the engine bay and out the vents in the lid??? can you provide additional deflectors to ram more air in? I realise that this won't solve the heat soak issue that you are pointing the finger at, but your engine bay must get hot as hell in traffic.

[MWP]

phenolic spacer plate and a re-think of air flow in the engine bay would be the way to transfer of heat from head to manifold.

Remember that most factory throttle-bodies and/or inlet manifolds are heated by coolant too.
If you live in a warm climate, the coolant lines can be blocked.

Dont block them in a cooler climate though, it may cause your throttle butterflies to freeze up (you dont need sub-0 temps for this to happen either).

[nick.parker]

You need to keep the intake manifold interior course, if the ceramic was smooth you with get the fuel disasociating from the air.

Aren't the fuel injectors (not cold start) at the port entry on the head? So no fuel would be in danger of dis-associating from the air since it doesn't contain any fuel yet?

[thechuckster]

true, but there's a fair amount of fuel-air mixture up in the pipe as the injectors squirt multiple times per engine cycle so that cloud does go up into the runner.

[nick.parker]

The 3SGTE has sequential injection, that means one injection per cylinder, per cycle, but I guess you could be right about the 'cloud' thing - I don't know what the injection timing is set to.

[thechuckster]

injectors usually fire at the valave before it opens

i know the 3SGE eus have 4 injector drivers but i figured they'd be like the 1Js that actually fire the injectors in pairs - otherise they need complex phasing maps to accomodate different firing times for varying amounts of rpms and map.

7mge/7mgte/4agze/4age all batch fire (usually 2 shots per 720 degrees)

[nick.parker]

Yep.
I'm not that familiar with how Toyota do it on the 3S, but in general Injection timing for a port injected engine is as simple or as complex as you want to make it. Fixed injection timing on an average EFI engine will work fine. Vary the timing so the injection always completes at the end of intake stroke..still works fine.

Injection timing is only varied in a complex manner because is affects emmisions a bit and power slightly too. Power can be enhanced _slightly_ by injecting such that the fuel enters the chamber without being spray on the back of the valve (charge cooling). Spraying onto the back of a closed valve helps emmisions (fuel vaporises/mixes well with air)

Cheers, Nick.

[thechuckster]

right you are... the 3SGx does sequential injection.

page 15 for injector timing <http://www.autoshop101.com/forms/h22.pdf>

[Camryman]

So my theory is to get the inside of the intake manifold coated with a thermal barrier coating and then potentially also coat the outside with a thermal dispersant. My concern with this plan is I really don't want to go pumping pieces of ceramic coating through my engine and turbo if it comes off the manifold.

Has anyone seen this done before or would like to add their idea's?

Hey Josh,

Did you end up coating the inside of the manifold? Is that the same kind of high temp coat they use on pistons?

I'm toying with the idea of insulated pheonlic intake gasket myself but Mos' words keep haunting me " heat doesn't dissappear, it has to go somewhere, it going into the head."

Maybe another option is to upgrade the radiator at the same time plus increased airflow to the whole engine bay?

[Joshstix]

I've stuck with the stock manifold and done no development of the old 3S for some time unfortunately.

[allencr]

Keeping the intake charge as cool as possible means the entire system, air & fuel, from the front & tank, all the way into the intake valve/s, so to me the ceramic stuff seems like it isn't much bang for the buck, but everything counts.

[ICS]

I did see a 3sgte going together that had had the intake & exhaust manifolds coated but they didnt stop, they seem to have done the chambers & ports to try and maximise the delivery speed & heat factor. Maybe a water to air intercooler would have helped a little more with this car. Not to sure how it went because holiday was over to soon.

[Camryman]

Another option to look at if you are going to put in the insulated intake gasket is to install an davies craig electric water pump if you are worried about the extra heat to the head. Might also see if you can fit an oil cooler as well.