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Crankcase evacuation kit

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Morris

Morris

Yoda
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I am kicking around the idea of installing a crank case evacuation system similar to this:

https://www.summitracing.com/parts/SUM-120108/

But what I am wondering is, do I really need to buy the kit? I mean, its basically just a tube welding onto the exhaust line at and angle in order to create a venturi. I can do that easily without an expensive kit.

I already have a check valve by the way.
 
I just received the Summit kit and it will need some work to be suitable for an A-series. The tubes (two since it's a V8 kit) are very large OD to accomodate the gas flow of a big inch racing engine. It looks like it would be a pretty good exhaust restrictor in a LCB spridget header!! I also wonder how effective the big tube would be in creating a vacuum. I plan on using the stock tube as a mount for the checkvalve and then welding a smaller tube into the header and then to the threaded portion of the stock tube. I hope this will give good vacuum and lower restriction by using a more appropriate sized tube.

The next part of the fight is to seal up the engine so that there really is a vacuum, or at least low pressure in the engine. This means finding a seal for the dipstick, venting the timing chest (I have a belt drive), venting the crankcase, venting the valve cover and sealing the oil filler cap then connecting all the vents and running a hose down to the header/check valve.

I am getting ready to start this installation this week, so I can keep you posted.

Does anyone know if this will pull a vacuum at idle or does the engine need to be at racing rpm's to be effective? Just wondering if this would work on a street car.
 
I have heard different reports on vacuum at idle. I think the amount of pull you get at idle is relative to how far down the pipe you place your pick up. It seems to me that the time you need crank case evacuation the most is when you are running at speed.

Check out this write up it's pretty thorough.

https://www.honda-tech.com/showthread.php?t=1199935
 
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