LS7 Intake--Foam Pads

[sjaroslo]

Hello, stupid question here.... I just received my new GM LS7 intake manifold (and injectors and throttle body) and I notice on the underside of the manifold, there are 2 gray, foam pads that appear to be glued on. Do these stay with the manifold for the install? I guess that the underside of the manifold is clean due to the valley cover on the engine, but this is definitely a new one on me. Tried to do a search, didn't turn up anything obvious. Thanks in advance!

[Ron.in.SoCal]

Pulled an intake off my LS7 before rebuild and there they were. This was off a Vette that saw track use, so yeah they belong there. I would like to know if they are a replaceable part because they were pretty worn...

[68sixspeed]

They are there to (get this...) soak up excess oil from the pcv system... Not kidding. Occasionally they have been known to come loose and get digested but that is very rare. The ls7 doesn't have a true pcv valve, just a restriction in the connection on the valve covers. The intake pulls some vapor in from the lifter area cover fitting. That pulls a slight vacuum on the engine. The valve cover vent lines connect to the dry sump tank, then another hose connects the dry sump tank to the air intake tube/housing to act as a filter for the "inlet" of the crankcase vent system. Hope that makes sense.

Short story, ok to leave them, gm still does.

A PVC catch can might be a good idea if you remove them, or even if you leave them.

Dan

[69cutlassrkt]

When I bought gaskets or o rings I mean for swapping to a ls6 from ls1 intake It came with the new foam pieces. I think they are to keep debris from getting under there or to reduce noise some how.

[Rod]

When I bought gaskets or o rings I mean for swapping to a ls6 from ls1 intake It came with the new foam pieces. I think they are to keep debris from getting under there or to reduce noise some how.

correct there just there to reduce the dust and dirt that gets under the intake that's it, its used on the truck manifolds also, and they add a little vibration dampening on the coolant tubes that pass rear to front under the intake as a by product (not planed that way but) they were just for dust and dirt

[68sixspeed]

my bad, I thought he was asking about the strips/pads inside the intake... not the fillers under the intake. D''oh!

[sjaroslo]

Thanks for the responses, folks. I didn't tug on them but they seemed as if they were "supposed" to be there as opposed to something that stuck there during shipping :-)

[JEFFTATE]

The foam pads under the intake are GM pn - 12560251