Crank case breather options

[stuartrubin]

For some time, I've had a pretty bad "old car" smell in my garage even for just the few moments from when I pull it out or in. If I'm working on it - forget it - the whole house smells! I suspect it MIGHT be from the crank case breather hose. You can see from the photo below that I have routed it back into the air filter. You can't tell from the picture, but the "seal" (or lack there of) between hose bracket and air filter is very poor, wobbly, etc., and exhaust might be escaping into the air and not going back through the filter.



You can see from this picture that there is a plugged hole in the base of the air filter. (Note that this is an old photo with my old "Frankenstein" carburetor. The new one is a Chinese 34 ADF copy.)



And the metal fitting for the hose has a second, smaller connector which is presently not use, and not plugged.



So, here are the questions:

• 1. Should I try to route the hose through the plugged hole under the air filter base plate? This would have it skip the filter entirely and dump the hose exhaust right into the carb. This would hopefully most likely eliminate any exhaust from leaking into the atmosphere.
• 2. As suggested in previous posts (from my old carburetor, which was a Frankenstein model with weird stuff going on), should I connect the "other" connection of hose bracket into one of the currently plugged port in the carb? See http://www.fiatspider.com/f15/viewtopic ... er#p241899. (Again, note that that post referred to my old carb which was ported differently.)
• 3. Can I skip this entirely and connect the breather to a filter like this https://smile.amazon.com/62-1600RD-Vent ... J4C98WFNFS?
• 4. Am I barking up the wrong tree here?

Thanks!

[phaetn]

That hose from te crank case looks pinched and might restrict flow. Mine has a metal 90 degree elbow.

Also, as with your Frankencatb, mine ports right into the filter at its base,, so straight to the carb. It's oriented 180° though – so the port is closest to the fuel intake hose.

Cheers,
phaetn

[stuartrubin]

Phaetn, thanks for your reply. I'm not totally clear about how your breather is ported into the carburetor. You said that your is connected right into the base of the air filter assembly, but that there's a 180-degree connector. So, is your connection bypassing the actual filter?

Do you have a photo?

Also, to the others, any thoughts on using a dedicated crankcase breather filter and not plumbing it back into the air filter or carb at all?

Thanks!

Stuart

[kilrwail]

Mine is vented to the atmosphere through a small filter similar to the one you showed. I'm not burning oil fumes any more, nor am I burning exhaust fumes since the EGR has been removed. I get poorer fuel economy and more horsepower. The oil breather output does not stain the under side of the hood either.

[stuartrubin]

Peter (kilrwail) thanks for your input. After reading more, I'm still not sure what to do. You have had good luck with the external filter (with the minor drawback of fuel economy), but others have gone straight into the air filter assembly (ref http://ww.fiatspider.com/f15/viewtopic.php?f=5&t=19124).

Neither solutions are particularly difficult or expensive, so I suppose I could try both, but I'd like to understand what's really going on and make an intelligent decision.

My main goal is to eliminate the smell.

More input (and photos?) welcome!

Thanks

[kilrwail]

When my car is running in the garage, I smell nothing with the hood open. I wonder if your "old car smell" is from the exhaust - like maybe you're burning a bit of oil? Have you seen bluish-white smoke, especially when shifting?

[phaetn]

Peter -- so I can just terminate the crank case breather hose to a filter? Should i bother with an oil trap? More power is always good! My head (actually two so he can pick the best) are at a machinst's right now to get decked and seat new valves and guides, My days of burning oil on lift-off are hopefully over with new valve seals. . Hopefully this won't mean that the bottom end is going to give out now.

Stuartrubin, here's a pic:

The elbow is to help with the bend in the hose, It connects directly to the base of the air filter plate, so the gases go straight in since it's inboard of the filter.

Cheers,
phaetn

[kilrwail]

Yes. I just disconnected the oil breather hose from the air cleaner (and plugged the inlet port), and terminated the hose on a lawn mower type air filter - seen here behind the air cleaner. The rotation of the crankshaft pulses oil vapors through the hose - in very small quantities - and out through the hose and filter. You still have crankcase ventilation, but not encouraged by vacuum.

[RRoller123]

I am curious and have no knowledge on this topic. Does terminating the sump breather to a filter, and not running it back through the intake to be burned, actually increase HP? Any idea how much of a gain this provides? Eventually that filter is going to become saturated with oil from the vapor, even with the separator back at the exit to the block, and need cleaning. My FI system always has a very slight sheen of oil inside the intake plenum where the breather terminates, but it is never enough to be of worry.

[kilrwail]

I don't know how much power is gained, but by burning only gasoline and neither oil vapours nor exhaust gases (due to the removal of the EGR), the engine is producing more power - you can feel it. When the little filter gets dirty, I just replace it - it's inexpensive. I had to do the same thing on the Porsche because the new carburetors don't have a PCV port.

[RRoller123]

So you saw a noticeable difference in performance by just removing the crankcase vent recirculation? Wow, worth a try.

[kilrwail]

So you saw a noticeable difference in performance by just removing the crankcase vent recirculation? Wow, worth a try.

As well as the EGR - done at the same time.

[DUCeditor]

When I used to live in Boston I had a mechanic from Rome do all the work on my Spider. He early on removed all that crap. (Yes, the car still passed the stiff state inspection -- as long as it was warm.)

As I remember he said it'd make a minuscule difference in actual power, but run more evenly and trouble free.

That was nearly thirty years ago and she's still running strong!

They way I reasoned was this: The car could be "tuned" by a lawyer, of a skilled and experienced auto guy. I chose the later.

-don

[RRoller123]

It wasn't Mario, from the former Framingham Fiat, was it? He was excellent, and loved my '79 X and kept it in great shape for me. I remember bringing it in for a head torqueing (I did it every 30,00 miles, he used to say it was unnecessary but he humored me). He would walk around the car and mutter, "this is a good one."

[stuartrubin]

Thanks everyone for their help. I ordered a filter to use in lieu of routing the breather back through the carburetor. (In my particular case, the way the filter housing was oriented, doesn't have the any coupling tubes, etc., it also happens to be easier and cheaper to just slap on a filter!) I don't mind a little loss in fuel economy. Hopefully this will knock out the smell (or at least rule out the cause). I'll post when it's installed and tested.