47-55.1 Catch Can

[mobileortho]

Where’d you mount your catch can on your LS?

[dsraven]

best to mount high if possible, stuff runs downhill.

[Kevin_C]

I think im going to mount mine to the left of the engine on the firewall. for the dyno tune i'll probably just run mini filters temporality

[e015475]

This is a cheapie ebay catch can on my LS.

I took out the supplied nipples and threaded it in pipe so I could use AN fittings with hard lines. A simple bracket hold it onto the right cylinder head.

[Dan in Pasadena]

Hmmm, I don't think my LQ4 has one. Must it?

[mobileortho]

Originally Posted by e015475

This is a cheapie ebay catch can on my LS.

I took out the supplied nipples and threaded it in pipe so I could use AN fittings with hard lines. A simple bracket hold it onto the right cylinder head.

That's a perfect location for it, but my AC compressor is in that spot. I saw a guy mount his on the frame on the drivers side. I kinda like that to cause it wouldn't clutter up the engine bay, but it also limits access.

[mobileortho]

Originally Posted by Dan in Pasadena

Hmmm, I don't think my LQ4 has one. Must it?

I don't think it's required, but they're supposed to help keep the engine cleaner and reduce carbon buildup.
https://www.roadandtrack.com/car-cul...tch-can-works/

[dsraven]

catch cans are more advised for the direct injected engines than the port injected engines. the port injected engines have the injectors in the intake ports close to the intake valves and they spray the fuel at the back side of the intake valve. this cleans the back of the intake valve with fuel and tends to keep the valve clean. the direct injected engines dont benefit from this cleaning effect because the injectors spray fuel directly into the combustion chamber. this means there is no cleaning effect going on so the back side of the intake valves tend to build up with the deposits.
on my old avalanche 5.3 I needed to replace the knock sensors so the intake was removed to get access. I was pleasantly surprised to see the intake valves and the bowl area around them were as clean as new. I contribute this to using Seafoam motor treatment in the fuel tank after every oil change or before a long highway trip. the spark plugs were equally as clean as were the visible faces of the injectors. the pics are before any cleanup was done.

[dsraven]

the black stuff in the ports, before the clean bowl area around the valve, is what would be building up on the back side of the valve in a direct injected engine. add to that any oil that may be coming down the valve stem as well, which probably wouldn't be much unless your engine is worn. with the tolerances of the newer engines they use a light grade synthetic oil so there is possibly more oil mist inside the engine to get sucked up through the pcv system and drawn into the intake. old engines simply used a vent tube that dumped out below the engine, a reason why there would be a spot of oil on the ground where they parked sometimes. on some newer engines, not necessarily the LS ones, the ventilation system is lacking on one cylinder head and the sludge builds up on that side and causes issues with cam phasers etc.
anyway, a pic is worth a thousand words so hopefully somebody benefitted.

[dsraven]

a lot of shops will sell an intake cleaning or flushing. this is usually done with the engine running and cleaner sprayed into the intake upstream of where the throttle valve is situated. there have been cases where the cleaners have done their job but it was done fairly late in the game so a lot of gunk was sent down the pipe, contaminating the o2 sensors and causing the cats to heat up a lot and plug partially. just saying, regular maintenance can be better than leaving it too late.

[mobileortho]

I ended up putting it on the firewall.