[T3] Generator ... Again

[Jim Adney]

On 18 Sep 2012 at 21:40, Max Welton wrote:

> The engine is FI, using the stock type-3 manifolds and oil-bath
> air-cleaner. The engine is a mild 1776, limited by the stock intake.
> Exhaust is the ISP over-the-top system. Works well. 
> 
> The hose from the breather to the air-cleaner is present, but is
> always wet with oil. And there is always a bit of oil around stock
> breather. The breather only has one cap, not two. 
> 
> Perhaps you can offer suggestions on making the breather work better?
> 
> http://www.maxwelton2k.net/squareback68/1776/IMG_7519.jpg
> 
> http://www.maxwelton2k.net/squareback68/1776/IMG_7520.jpg
> 
> http://www.maxwelton2k.net/squareback68/1776/IMG_7521.jpg

That's a pretty clean looking '68 engine. I don't know anything about 
the Megasquirt system, so I wouldn't mind a bit of an explanation. 
Where does it get its inputs and feedbacks?

As far as improving the breather, is there any chance that the little 
louvered plate that's supposed to go between the case and the 
breather stand got left out? That's important, and it has to be 
installed in exactly the right way.

Other than that, it may just be that you're just getting more blowby 
than the breather can handle. What's a 1776, 69 x 90.5? That comes 
out to 1775 on my spreadsheet, but that's as close as I can find. I 
think Berg thought Type 3s shouldn't go larger than 88s, but I don't 
know how he came to that conclusion.

I generally pull off that breather hose while the engine is running 
and watch it at different throttle levels to see how much blowby an 
engine is getting. That's a decent measure of condition.

'68-9 engines came with a sort of "filter" that lived under the 
single breather cap. That was a sort of wad of nylon netting that 
served to coalese any oil mist that came up there. Then the oil could 
make it's way back down the pipe into the crankcase. That "filter" 
has been removed from most of these engines because it used to fill 
up with water droplets and freeze closed in cold weather. You could 
try adding something there. The OG part looked like a blue plastic 
kitchen scrubber.

Another thing that might help would be to try to wash out the 
breather box. I do this on every engine I rebuild, and I'm often 
surprised at how much crap comes out. It takes a lot of time, because 
you have to use a piece of wire to scrape all around the inside. It's 
common to find 1/8-1/4" of solid sediment covering the whole bottom. 
You want that volume to be as open as possible, to give the oil mist 
a chance to settle out.

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Jim Adney, jadney at vwtype3.org
Madison, Wisconsin, USA
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