PT Rises from the Ashes

Sedgewood · Sep 17, 2003

Here's a picture of the filter after the 1-1/2 hours of brush hogging. There is no accumulation of chaff on the screen (no intermediate cleanings were needed) but there is a fair bit of light stuff inside on the furnace filter. Whether that light stuff would pass through the cooler or become lodged I don't know.

Sedgewood

bmkar · Sep 17, 2003

( I think there is a good chance the temperature of the air there would be increased by running the fan backward )

It might seem so, but when I hold my arm over that "radiator", it's not uncomfortable even on a hot summer day, much less so than in proximity to that muffler or block...
... /forums/images/graemlins/wink.gif This is begging for a thermocouple test, isn't it??...
Wish I had a laptop right now(hmm, my wife does /forums/images/graemlins/grin.gif) ...
I'll think about how I can test this...

bmkar · Sep 17, 2003

Pretty close...here's the way I saw it... take off the top plywood and replace it with screening, 2) take off the "venturi" 3)take off the furnace filter over the fan and apply it to the 5 surfaces of your "box"(increased surface area=increased flow rate) and replace duct tape with "strip" magnets under box to hold it to the hood(in it's finishing stage,not for testing's sake)...

If I can figure a way to wrangle a laptop, I'll try to get some temp measurements

Bob999 · Sep 17, 2003

It might seem so, but when I hold my arm over that "radiator", it's not uncomfortable even on a hot summer day, much less so than in proximity to that muffler or block... 

In checking your bio I note you have a 422. I think that the engine cooling air flows are different for the 422 as compared to the diesel models.

bmkar · Sep 17, 2003

In support of John's fan reversal--I thought that the blowing of filtered air might help to keep the engine "room" cleaner because of the "positive pressure"(less dust, chaff, etc.)...
Any "cooling" effects would be a secondary "benefit" because they're anticipated to be small...
In the case of my 422, on a hot summer's day, I have not found the heat rejection off my oil cooler to be that uncomfortable, and in fact, way more comfortable than under hood temps. So I thought, in theory, that air blowing over the (too hot to touch) surfaces(even if warmer than ambient) would have a beneficial effect rather than no forced air...
Still in theory mode, here, and still relevant(400/1400/1800) ... unless the 1800 series oil cooler has a much higher efficiency and is putting out a great deal more heat.

It's true that any measurements I make will only be useful to other 422 owners (maybe 425, too) but that gives me hope that the theory works... as always, your results may vary...
/forums/images/graemlins/smile.gif

smartguyz · Sep 17, 2003

Well, on the subject of 'positive pressure', why don't we look at some other solutions - for example, we can leave the 'oil cooler fan' alone, and just look at putting fan(s) on the sides of the PT - With filtration material on the intake side, and with some kind of flow path, there's nothing to say that we can't put multiple fans into this system. Let's say you want to have air come in on the sides, and exhaust out the top and back - (on my PT425, the muffler/exhaust is on the back end, but shoots out the sides). Suppose I make air come in around the front half of the engine bay, and rely on the existing fan (and perhaps one more on the back of the unit) to channel the exhaust. I realize that this will make the thing look like it has a series of fans all over it, but it seems that with proper design, this could be quite efficient, and keep things a lot cleaner and cooler in the engine bay.

What do you guys think?

-Rob /forums/images/graemlins/grin.gif

bmkar · Sep 18, 2003

( leave the 'oil cooler fan' alone, and just look at putting fan(s) on the sides of the PT )

For the question of cooling, your idea probably has much merit... I find myself reaching back to the values that drew me to this beautifully simple machine from heaven /forums/images/graemlins/confused.gif /forums/images/graemlins/crazy.gif ...in that I'm willing to add a toggle switch but not much more effort than that...(I started with a whole dream list of mod's, but after running my own benefit/effort analysis, I've done pretty much none of them and I'm fine with that /forums/images/graemlins/grin.gif )