Engine Update

[Corvair1]

Waiting for the electric fan conversion kit...

IMAG0085.jpg (58.69 KiB) Viewed 2923 times

[Bobby65]

looks nice! I'm curios to hear how the electric fan conversion goes

[Corvair1]

Hi Bob, YA you and 100 other people... . I'm having a
custom low profile oil-pan fabricated out of stainless steel
of my own design, which will ad an extra 2 quarts of oil. that
should help keep her cool. Some will say don't cool her to much.
To cool her can be expencive but to heat her up is easy.

[Bobby65]

I would go with a remote oil cooler as well as the bigger oil pan, if it were my car, thats where most of the oil cooling is going to happen

[Corvair1]

Way ahead of you , got a new external oil cooler with a oil stat and all those fancy braided lines.

[Corvair1]

Once I get my electric fan system working proper,
then I'm relay going to plow everyone's mind and
convert it to a hybrid, running on gas and hydrogen...
PS: This is going to be a one of a kind Corvair.

[bbodie52]

I'm not sure that more oil volume equals cooler oil. It may just mean more hot oil. Black valve covers with more heat transfer surface area -- both inside and outside (not polished) can help to transfer heat to the outside air. The Otto Parts oil pan and valve covers were designed with these engineering principals in mind, and I believe that this was discussed in the original edition of How to Hotrod Corvair Engines by Bill Fisher, if my memory serves me correctly. The posts and baffles help to transfer heat by providing more surface contact area with the oil and aluminum pan. The baffles serve a dual role in preventing, or reducing oil sloshing at racing speeds, to keep the oil pickup covered in oil so that the potential for engine oil pump starvation is reduced. As mentioned earlier, an external, properly vented oil cooler would also transfer more heat to outside air, but a larger volume of oil within the crankcases and oil pan will only provide for a larger volume of hot oil, with no place to transfer it out of the engine. If you want to ask more of the oil, to utilize the oil as a coolent, you will need to give it additional radiator surface area -- either with a special oil pan and valve covers -- as with the Otto Parts units -- or with an external oil cooler and good air flow.



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[Corvair1]

Hi Brad, OK lets just make a simple test. Take 1 quart of oil and 3 quarts of oil. Put it on the stove at 375 deg. for 5 min. then take the temp. of the oil. Know put the 3 quarts on the stove for the same length of time and take the temp. What do you think the result will be?...

[sam60]

I'd need to try that while my wife is at work, like when I use the diswasher for auto parts......

[Swngaxl]

Hi Brad, OK lets just make a simple test. Take 1 quart of oil and 3 quarts of oil. Put it on the stove at 375 deg. for 5 min. then take the temp. of the oil. Know put the 3 quarts on the stove for the same length of time and take the temp. What do you think the result will be?...

???

You have me confused here. You heat one and three quarts on the stove, then heat three more quarts on the stove, then measure the temp. Sorry, just can't quite get my head around it, am I missing something?

[sam60]

I think what Herb is saying is that 1 quart heats up faster than 3 quarts.

I just wonder how short of a drive one would need to take to reap the benefits.

[Corvair1]

Sorry I should have put it a little better. Heat the one quart first take the temp. then heat 3 quarts and take the temp. and see what the deference is. You will fined that the 3 quarts is lower in temp. because of volume, in other words the more oil you carry the longer it takes to heat it.

[Swngaxl]

OK, that makes sense. But here is something to keep in mind. Basically, this is a heat transfer problem. The oil is a heat sink that is used to take heat out of the engine, and how effective it is depends on the temperature difference. And one problem with oil is that it makes a tremendous heat sink. In other words, once it gets hot, it is not so easy to cool back down.

I remember when I first put an oil temp gauge on my car. It took the oil a long time to heat up, but once it got hot, it stayed hot! So for short trips, more oil might be a big help, but after an extended drive on the freeway, it might be a hindrance, if you see what I mean. It's an energy balance problem. You put heat into the oil to take it away from the engine, then what? Theoretically, if you can take that same amount of heat back out, you can maintain equillibirum. If you can't take it all out, it stays in the oil.

I think all the extra surface area on those finned oil pans will help.

I'm curious to see how this project turns out!

[miniman82]

It takes longer to heat more oil, but all you end up with is more hot oil. The best solution is the stock amount of oil, and a cooler large enough to keep temps in check. Remember that the longer the oil takes to get to operating temp, the longer it takes for deposits like water and hydrocarbons to boil off. That's why the best solution is an oilstat, engine gets up to temp fast and stays there.

[scottydont]

Growing up in sunny Phoenix and driving a hopped up VW in 120 degree heat, this is an issue that I had to deal with for years. Deep sump oil pans are a standard modification for aircooled VW's. The claimed benefits are two fold. First is the greater volume (and therfore greater thermal mass) of oil. As has already been pointed out, this is a benefit on short drives, but the benefit disappears under extended operation since the extra heated oil eventually becomes a hindrance to cooling (reversing Herb's experiment, run 1 qt of 200 degree oil through an oil cooler for 3 min compared to 3 qt for 3 min and compare the temps). The second benefit for the VW deep sumps is maybe a more important lesson here. Because the VW sump has a very small contact area with the case the entire extra volume of oil is out of contact with the engine and even when hot is not transferring heat directly to the block, but rather radiating it to the air. In essence, the deep sump performs as a very rudimentary external oil cooler. Remember that the whole purpose of any cooling fluid (oil, air, or antifreeze) is to absorb heat from the engine and radiate it to the atmosphere. Absorbing heat and keeping it in the engine is counter productive in the long run.

For my own purposes, ran with this basic principle and skipped the deep sump in favor of a remote oil cooler mounted behind the front apron of the car and plumbed with copper lines with a thermostatic bypass near the engine. This added about 1.5 qts of extra oil which was always out of contact with the block and radiating heat to the atmosphere. This a) took advantage of the thermal mass of the extra oil on short trips, b) dramatically increased the cooling capacity of the engine to keep up with the extra oil capacity, and c) avoided a situation where a large mass of hot oil could act as a heatwell for the engine block.

Anyway, just food for thought. There's definitely more than one way to skin this cat, but it seemed like my experience might be worth sharing.

[Scott H]

scott