2000 Honda Insight - Heating the manual trans with engine coolant

[Daox]

Thanks for all the suggestions guys. I appreciate it!

This past weekend, I got the transmission case removed from the bellhousing. I got a bunch of shots of the case. Creating the water jacket around this will be interesting. I don't want to make it in a million pieces, but I don't want to largely increase my coolant capacity either. I'll have to try to find a happy medium. It is also going to need a very good cleaning and sand down job to make sure things bond properly.

[Daox]

I gave the aluminum brazing a shot with the aluminum oil pan on my sister's Jetta TDI. I replaced the engine last year, and am parting out the engine right now. It seems to work pretty nice. Doing it around the diameter of the transmission housing will definitely be in interesting though. Once that stuff turns to liquid, it definitely runs.

https://www.youtube.com/watch?v=KxLJ...ature=youtu.be

[ar5boosted]

I think that was just the ice-breaker :-) me thinks there is going to be more aluminium projects to come.

[Baltothewolf]

Welding aluminum is a *****. And magnesium is a ***** to weld as well (looking at you, insight oil pan).

[diesel_john]

What are the pros and cons between hot thick oil and cool thin oil like john deere hy-gard?

[Daox]

I'm not sure what you're asking, but I'll give a shot at explaining why I'm doing what I'm doing. Oil always thins out as it heats up. In essence, we don't really care about the temperature of the oil, we just want it to be as thin as it can be without damaging the transmission. Since the transmission was designed to work with Honda MTF, that is what I will be using. But, I will heat it up to thin it out a bit.

[dancam]

Hi. Your idea is good, i like it. Your not using your car hard so the transmission should be able to handle the thinner fluid in the summer, winter will be the biggest benefit. However with a 7 mile drive i would say there is no way that this will heat your transmission oil any benificial amount before the end of your 7 mile drive. Farther sure, but not 7 miles in the winter. Your engine first has to heat up, then your valve opens and the engine has to heat all the cold coolant in this secondary system. Then once its warm convection through the wall of the jacket, theough the wall of the transmission to the trans oil has to be higher than the cooling effect that winter air has passing over the jacket your making and the rest of the transmission.
Just imagine a stovetop. Have you ever used a double burner? Just imagine a pot of water thats not boiling- 190f instead of 212. Then 2 thick sheets of aluminum on top of it. Then on top of that a 2-3L pot of oil with 5f wind blowing on it. Its going to take more than the time it takes to drive 7 miles to warm that. It can get warm this way but i think it needs much more time.
The best way i think to do it quickly is to buy a heat exchanger-probably one thats already meant to exchange heat between engine coolant and engine oil- and use it to transfer heat between the coolant and transmission oil with a pump for the transmission. All that stuff is readily available to buy and if the pump quits nothing bad happens. No added weight and minimal coolant capacity added. Quick and more importantly efficient heat transfer. The way you plan to do it i think you will loose a lot of heat to convection to ambient air.
Were you able to take transmission temperature readings before you started this to compare to after?
Looks like your comitted to doing this jacket though, so what about insulation over the jacket to not loose as much heat to ambient?

[jrnsr]

I don't mean to rain on your parade, but...

First off, automatic transmissions use engine coolant for cooling, not to heat up. The torque converter can generate a lot of heat. I had an old DeSoto and it was ventilate for cooling.

If you try to "braze" the casting, you risk the chance is screwing up tolerances. It is a real pain to sweat and the attachment can be iffy, especially if you want it watertight. If you succeed on the bench, you might find after numerous thermal cycle, a leak could become a catastrophic overheating episode on the road.

When I "braze" aluminum, I use a fattened piece of stainless welding wire and scrape the molten "solder" and basemetals to coax bonding. Unless you grind the casting down to new metal, the contaminants are going to be a real issue.

50 psi air pressure would likely destroy your work. 15psi is all it'll encounter.

In the good old days, 90 weight oil went into the rear end and transmission. A Honda was the first car I had that used 10W30 in the manual trans, so they already have built the transmissions around thinner oil. Not sure what the newest cars are using. Heating it thinner may jeopardize the trans.

About a month ago, I discovered a previous owner used gear lube in the trans. iI changed it back to motor oil.

If you want thinner oil, toss in a cup of diesel and then cross your fingers.

[jojogunn]

Another way to heat the fluid is to get a cooling tube that resides inside the lower radiator tank.
I ran a copper tube inside the cooling tube and plumbed it into my heater line. I was using this as a fuel heater at the time.
It might also be possible to source a fuel heater from a diesel engine for this.

[jrnsr]

If you want to run thinner oil, you might look into Red Line oils. They promise your car will be more powerful, run faster, shift easier and get better fuel mileage.

I put it in my wife's 1950 MG in hopes it would shift smoother, but the only thing I noticed was the transmission was louder. Within 1000 miles, about a year's time, the trans selfdestructed and locked up. Coincidence? Careful what you wish for.