Gizzmo Thermal Gaskets?

[NUTCSE]

with my engine build almost done I came across these thermal gaskets and was interested in trying them out omy CA. Seems like there are some gains to be had. Has anyone used these or she'd any light on them would be much appreciated.

http://gizzmousa.com/thermal-gasket.html

[r34 gtr]

Oh sweet! I did not know anyone made these for the CA18. In my experience, they are pretty much the bomb. Even if you didn't see any decrease in temperatures with them, they are reusable and much easier to deal with than paper gaskets. They do work though. Maybe not that claimed 50 degrees, but they do work.

[float_6969]

I've had one for a few years now. I made a post about it, iirc. Anyway, I got the one that goes between the upper and lower plenum. I didn't see the point the the one that went between the head and lower due to the thermostat housing being integrated into it and heating it up anyway.

As far as performance, it's awesome! As soon as I put it on, I went and beat on the motor for about 20 min, then pulled over, popped the hood, and put my hand on the plenum of the intake manifold. It was hot, but I could have kept my hand there for as long as I wanted and not gotten burned. Before the gasket, there was no way you could do that.

[sjbsuperman1425]

Float,

Do you remember which part number that gasket was from Gizzmo? They have them listed kind of funny on their website..

[float_6969]

http://www.gizzmoelectronics.com/Produc ... issan.html
G6026 - Plenum to lower
G6016 - 8 port lower to head
G6017 - 4 port lower to head

[sjbsuperman1425]

and did you use any RTV or anything when installing or just put them on and tightened to spec? I'm going to be buying the upper and lower manifold gaskets in these I think. I will so take some before and after measurements with a temp gun to see the difference.

[Izento]

How hard would this be to install? I've never messed with my intake, so that's pretty foreign to me.

[mdb4879]

Getting the old gaskets off without gouging the mating surfaces will by far be the hardest part. At least in my experience with old motors that's the case.

IMO, I would use a thin coat of RTV to help them seal. You aren't suppose to use RTV on gaskets that come into contact with fuel because it eats the RTV and will eventually cause a leak. But that was a much greater problem on carbureted engines. With EFI the fuel is atomized well enough it doesn't usually cause a problem, especially on port injection since the fuel is being sprayed past the gaskets anyways. If you feel it is a concern, Permatex also makes a sealant used for intake gaskets that's fuel safe, and it never fully hardens so it's easy to work with when you dissemble again. It's just messy, lol.

[float_6969]

I used a LIGHT coating of RTV. I don't see any sense in the lower-to-head gasket since the thermostat housing is in there anyway, and the whole thing is going to heat up regardless. The plenum to lower gasket would NEVER see fuel, so I wasn't worried about the RTV dissolving.

I replaced it during a rebuild, so it took no time, but doing it with the motor in the car would take 2-3 hours.

[sjbsuperman1425]

I used a LIGHT coating of RTV. I don't see any sense in the lower-to-head gasket since the thermostat housing is in there anyway, and the whole thing is going to heat up regardless. The plenum to lower gasket would NEVER see fuel, so I wasn't worried about the RTV dissolving.

I replaced it during a rebuild, so it took no time, but doing it with the motor in the car would take 2-3 hours.

my thought for the lower tasket is even though the coolant is hot and flowing through the lower manifold there is still the heat being transferred from the head itself.

[float_6969]

Yea, but the head and the thermostat housing are all the same temperature. If anything, being bolted to the head is going to even out the temperature so that all the runners are the same temp. My concern with using the thermal on the lower was not only heat transfer from the thermostat housing, but also the fact that if it's thermally isolated from the head, then the 1st runner would be WAAY hotter than the 4 runner. That would make that cylinder a bit more prone to detonation. I'm HYPOTHESIZING though, so I have no evidence to prove that. I guess if somebody was rambunctious, they could use both, and use an IR temp probe and see if there was a variance in the runner temps.

[sjbsuperman1425]

hmmm that's a valid point Ryan. Time to do some research...

[float_6969]

Keep this thread updated if you find anything definitive.

[sjbsuperman1425]

Ryan, even if the lower thermal gasket was installed, it wouldn't necessarily RAISE the intake temperatures for cylinder 1. It will either lower them, or keep the the same. If you are not having detonation on any cylinder prior to this gasket, I don't think post install that there would be an increased risk.

[float_6969]

Yea, I should have worded that differently. My concern would be a VARIANCE in temperature of the submanifold between the #1 runner and the #4 runner. When it's in contact with the head, the heat is evenly distributed. If the lower manifold was thermally isolated from the head, then the heat source will be from the thermostat housing only. The #1 cylinder is separated from the thermostat housing by a few mm of aluminum and I would GUESS that it would run considerably hotter than the #4 cylinder. That could potentially create a variation in the inlet temperature of the air going into those cylinders. If the variation was great enough, there could be an imbalance in air volume, creating an imbalance in power output per cylinder. This could setup harmonics inside the crankshaft and cause bearing failure or crankshaft twisting. It would also mean that the #1 cylinder might be more PRONE to detonation, but you're right in that if you're not experiencing detonation with the stock gasket, that shouldn't increase the risk.

[sjbsuperman1425]

So Ryan, I e-mailed Gizzmo yesterday before leaving work and this is their response I received this morning before coming into work:

""Hi Zak,

We have not had and direct experience with this particular concern, however I can provide our own prospective on the situation. It just so happens that my background is in thermal engineering and engine design. I just want to make sure I understand the question and engine layout. I’ll attempt to explain the concept without going into the boring details though.

My assumption is the thought is as follows: Now that the manifold isn’t soaking and forcing the metal in the runners to the same temperature that the air in one cylinder may be warmer (or cooler) as the port on the head is cooler in that location.

This should not be a concern due to the velocity of the air in the runners. The manifold has a large mass of air in it at a (relatively) low velocity. The runners on the other hand always have a charge of air moving either towards the valve when open, or “rebounding” from the valve after it’s shut and traveling back towards the plenum/manifold. The point here is that the air in the runner is never really stagnate. Heat transfer is a partly time dependent function (depending on the mode of course). Since the particle of air never spends a significant amount of time in the area of heat differential the heat transfer is relatively insignificant.

The idea of the thermal gasket is to prevent heat transfer to or from the manifold, promoting cooler temps in the manifold. The manifold overall will still seek to reach a steady state temperature, the same with the air in the manifold. There just isn’t enough time and surface area in the runner and local area to heat the air in that local location. As the intake manifold is mostly isolated from the effects of the head and the engine it will reach a fairly even and steady temperature driven mostly by the under hood temperatures and temperature of the incoming intake air.

It take a surprising complex design to create a significant impact on air temperature in a moving air stream (think of an intercooler design, or of radiator design for example).

Of course the chance for a little variation always exists, and no system can truly be isolated from the surroundings. From a basic concept though I would say that there is no significant concern for a significant heat imbalance across the cylinders.

Let me know if you would like to discuss this topic further or if there are other concerns. Hopefully this has been the helpful answer you were looking for.

Thanks and best regards,
Brian Barnhill""

[float_6969]

Makes sense. But if that's the case, then why bother with both gaskets anyway? I would still think you just need one or the other. What gain would there be from both?

[sjbsuperman1425]

I guess technically if they still do allow a small amount of heat to be transferred, the upper to lower manifold gasket would decrease the heat soak that much more, but you are right Ryan. The amount of heat you may be dropping the intake with the two gaskets would be offset by the heat soak from the engine bay temperatures. I think I'm going to run the upper-to-lower manifold gasket that why I know I shouldn't leaks or anything like that. But at least the information is there for the future person! I will still post actual intake runner temperatures later on as well.

[float_6969]

I can tell you from experience that gasket makes a HUGE difference. It's pretty amazing. If I beat on the car, or drove on the highway for a while, the intake would be so hot you couldn't keep your hand on it. Now it doesn't matter what you do. You can keep your hand on there all day long. It's still warm, but no where near hot anymore.