Question: Oil Catch Can

[Doc Watson]

Does anyone have experience with installing an Oil Catch Can on an L98 / C4 ?? There are several on market Moroso has a few as does Matimoso (Summit Racing) . With the Ethanol the Plenum & Runner CAN get really tarred up. The Chev dealer has actually had some Valves Stuck down... Which Can / system is the best !! All Comments appreciated !! Thank You ! Doc

 

[Vettehead Mikey]

E10 fuel was around for at least 10 years before your car was built. Why would it suddenly cause such issues?

 

[Doc Watson]

Sludge Issues

E10 fuel was around for at least 10 years before your car was built. Why would it suddenly cause such issues?

The Plenum and the runners have an unhealthy coating of sludge / grease. On this particular C4 by removing the T Body and reaching into the plenum I "contacted" a load of coated on goo. The cars I raced (c4's) used high test with only a slight misting inside the plenum & runners. The Mechanics installed catch cans to eliminate this. Now I'm looking for advice on what catch can I should get for this show / driver C4. A mechanic, I'm not. Though the Ethanol has been with us for some time, I really don't know why the sludge buildup situation is worse. The Local Dealer Service Mgr. assures me it is a real problem of late. ?????

 

[Vettehead Mikey]

The Local Dealer Service Mgr. assures me it is a real problem of late. ?????

Th sludge and carbon build up can be a problem on direct on the new direct injection engines, but has nohing to do with ethanol content and is not applicable to your engine type at all.

 

[LLC5]

Does anyone have experience with installing an Oil Catch Can on an L98 / C4 ?? There are several on market Moroso has a few as does Matimoso (Summit Racing) . With the Ethanol the Plenum & Runner CAN get really tarred up. The Chev dealer has actually had some Valves Stuck down... Which Can / system is the best !! All Comments appreciated !! Thank You ! Doc

Your Chevy dealer told you that he had some valves stuck down, as in not closing to the valve seat?

And this was because there was no catch can on the vehicle?

 

[DonB]

Your Chevy dealer told you that he had some valves stuck down, as in not closing to the valve seat?

And this was because there was no catch can on the vehicle?

LLC5, WTF is he talking about????The L98 is a DRY intake system? Somebody is Bullshitting somebody here.

Unless he has a really bad intake valve(which I doubt too), how is sludge getting into the plenum? The only source of possible(NOT probable)liquids connected to the plenum are anti-freeze to the throttle body, some vacuum lines and the vacuum line from the brake booster. The PVC if I remember goes to the base of the manifold.

I'm at a loss here!

 

[Doc Watson]

I agree

LLC5, WTF is he talking about????The L98 is a DRY intake system? Somebody is Bullshitting somebody here.

Unless he has a really bad intake valve(which I doubt too), how is sludge getting into the plenum? The only source of possible(NOT probable)liquids connected to the plenum are anti-freeze to the throttle body, some vacuum lines and the vacuum line from the brake booster. The PVC if I remember goes to the base of the manifold.

I'm at a loss here!

I couldn't figure out why the tech wanted a catch Can. I had one on several of the race cars but never on this. It IS a dry system, but there was quite an accumulation of crap inside the plenum. At any rate I will be down to investigate what I was told and get to the bottom of this. So far several different answers, and the mechanics version is looking like it's the confused one. I'm NOT a mechanic and really appreciate all of you that have responded. What you have stated makes sense & seems pretty obvious. Thank You!!

 

[kpic]

Although this has nothing to do with E-10 or stuck valves. In today's vehicles, the PVC vents into the intake and the vapor contains oil..

 

[L over D]

Throttle bodies especially around the blades need some attention as motors get lots of hours on them. Use an aerosol product to clean up the mess. As the motor ages there is more mist flying around in the upper and lower internals of the engine. ...and guess what. Some engines are prone to sludge just by their design. Look in your shop manual or the glove box book. When you r&r your air filter, thats the time to take a look at the throttle blades.

Even if the motor has very good ring seal and the valve stems and all the venting or positive crankcase vent(s) are working as they should, you might get get a bit of blowby.

You may or may not have a loose motor due to age but possibly there is clogged hoses/lines and so on. An aftermarket "catch can" may or may not alleviate your problem because of the condition of the motor. Actually these "cans" are not a catch can but an oil separator. We are talking here about leak down numbers well into two digits on loose motors.

 

[Hib Halverson]

Typically L98s have not had as much of a need for a "catch can" has have other engines.

I'd say if you have an L98 with a plenum that all gooked up with "sludge", then you have a problem somewhere...

Either a high mileage engine that's got some blowby and, over a period of time, the oil vapor has deposited a mix of oil residue and combustion residue in the plenum. If that's the case, stuck valves are possible as are intake ports all gunked up, too.

You may need to rebuild the engine.

Do a cylinder leakage test and a blow-by test to know for sure.

 

[kpic]

Where does the PVC vent is the question. As it is venting, what the PVC passes has oil vapor in. Mine vented into the TB or the red circle. When I swapped the LS1 intake manifold out it was nasty inside.




The picture is my old setup or one side venting to a catch can. Now, I'm running a Nick Williams TB and FAST and both VCs are vented to catch cans to lower crankcase pressures. Dual PVC is overkill unless you're running some form of forced induction.

 

[LLC5]

Where does the PVC vent is the question. As it is venting, what the PVC passes has oil vapor in. Mine vented into the TB or the red circle. When I swapped the LS1 intake manifold out it was nasty inside.

View attachment 25157


The picture is my old setup or one side venting to a catch can. Now, I'm running a Nick Williams TB and FAST and both VCs are vented to catch cans to lower crankcase pressures. Dual PVC is overkill unless you're running some form of forced induction.

Am I just getting old or something, your picture looks to me like your oil cap vent runs directly to your radiator. Tell me I'm wrong.

 

[ken mohr]

Does anyone have experience with installing an Oil Catch Can on an L98 / C4 ?? There are several on market Moroso has a few as does Matimoso (Summit Racing) . With the Ethanol the Plenum & Runner CAN get really tarred up. The Chev dealer has actually had some Valves Stuck down... Which Can / system is the best !! All Comments appreciated !! Thank You ! Doc

Change oil on proper intervals, use good oil and gas. 120K just as intake was pulled. Shell premium, Mobile 1 15000 mile oil.

 

[kpic]

Here's a better angle.. The one goes from the radiator to the expansion tank. The other goes from the oil filler to the can.. I looked at the picture I posted; no I won't tell you that you're getting old; I will say your the first person who noticed..

 

[LLC5]

View attachment 25167

Here's a better angle.. The one goes from the radiator to the expansion tank. The other goes from the oil filler to the can.. I looked at the picture I posted; no I won't tell you that you're getting old; I will say your the first person who noticed..

Good, all is right again.

 

[kpic]

LLC5: I never looked at the picture critically.. The other side is easier, but it was a lot harder for me..

For some reason, this site has a lot more latency with Hughes satellite internet than others..

 

[vetteoz]

, how is sludge getting into the plenum?
The PVC if I remember goes to the base of the manifold. I'm at a loss here!

Correct.

BUT under low intake vac conditions like WOT , the crankcase fumes are pumped back up the PCV intake line from the pass side valve cover to the port on the TB ;
Hense the crud in the intake ( if engine is dodgy )

 

[LLC5]

Correct.

BUT under low intake vac conditions like WOT , the crankcase fumes are pumped back up the PCV intake line from the pass side valve cover to the port on the TB ;
Hense the crud in the intake ( if engine is dodgy )

The engine doesn't have to be "dodgy" for oil accumulation in a dry style intake manifold it is normal, but there will be more oil with a loose engine. Without fuel going through the intake manifold like carburetor and throttle body systems, there is no way to wash the oil off the inside of the manifold. Some oil accumulation is normal.