Oil Catch Can FTW (10k mi amount)

[SheepDog]

It's not just about carbon buildup. Oil vapor and water vapor going into the combustion chamber can contribute to detonation. Catch can on an NA car- not really needed. Catch can on Forced induction - definately needed.

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[NightmareMoon]

I have yet to see a GT do that on track... also I said if you're really pushing the car or its a track only car it might be worth it. It is uncommon for a car to blow that much smoke out the back because of the PCV lines. Hence why most of the other drivers thought you blew your engine. Also which track were running at? I only ask because the track stations would absolutely give me the meatball if I was blowing that kind of smoke out.

Uncommon yes, but not unheard of. Track was Circuit of the Americas which are run very professionally by dedicated CotA crew (in addition to the HPDE people there running the HPDE event). The control room has like 50 screens watching every inch of track and yes its manned even for HPDE days. It took more than stock grip and it took very aggressive driving to trigger it. If I let off and drove at 8 or 9/10ths leading up to the two specific corners in question it wouldn't do it. Both corners were proceeded by long sustained left hand corners which hit the weakness in the drivers side valve cover baffles.

Point is that when you do get significant oil in the PCV lines, it can be a lot at once, and a catch can would have helped a ton (until it got full). For a mist of oil over thousands of miles, no big deal.

 

[junits15]

It's not just about carbon buildup. Oil vapor and water vapor going into the combustion chamber can contribute to detonation. Catch can on an NA car- not really needed. Catch can on Forced induction - definately needed.

I hear this argument a lot, but I have an issue with it.

Namely that it isn't what we observe in practice, the primary contributor to knock on FI and NA cars (because all s550's are knock limited from the factory) is the fuel itself. If the effective octane was actually being reduced by blow by oil, we would be able to reliably pick up power by adding a catch can to any car (FI or NA). However we don't see that.

 

[SheepDog]

I hear this argument a lot, but I have an issue with it.

Namely that it isn't what we observe in practice, the primary contributor to knock on FI and NA cars (because all s550's are knock limited from the factory) is the fuel itself. If the effective octane was actually being reduced by blow by oil, we would be able to reliably pick up power by adding a catch can to any car (FI or NA). However we don't see that.

It depends on the amount of oil entering the combustion chamber, which is why I believe it is necessary to have on a F.I. setup, especially with forged pistons that generally have looser tolerances but even with stock internals. The more boost, the more blowby

 

[Jstang23]

I mean, I had so much smoke other drivers thought I blew the motor, but the flag station workers didn’t flag me, they’ve seen it before, its not uncommon on track for a car to sip enough oil through the PCV lines to blow significant smoke out of the tailpipes.

Uncommon yes, but not unheard of. Track was Circuit of the Americas which are run very professionally by dedicated CotA crew (in addition to the HPDE people there running the HPDE event). It took more than stock grip and it took very aggressive driving to trigger it. If I let off and drove at 8 or 9/10ths leading up to the two specific corners in question it wouldn't do it. Both corners were proceeded by long sustained left hand corners which hit the weakness in the drivers side valve cover baffles.

Point is that when you do get significant oil in the PCV lines, it can be a lot at once, and a catch can would have helped a ton (until it got full). For a mist of oil over thousands of miles, no big deal.

I've driven COTA, great track! I'm shocked they didn't meatball you, did they know you beforehand? Maybe you told them it might happen? Normally they meatball you just to be on the safe side, worst case you miss a few laps. Anyways, I think for someone pushing as hard as you it definitely helps, but I've never heard of anyone having this issue on track. I know some pretty fast people on the forum and they've never mentioned it

 

[luc]

Even on the track, I doubt a catch can would serve a super useful purpose. Maybe if its a track only car, you're running 5w-50 oil and are running a built engine sure. But for most running HPDEs and 20 min track sessions, the amount of oil blowing by into the intake manifold should not cause many issues if at all.

I totally hear the better safe than sorry argument as well though. Especially since its relatively cheap and not likely to cause many problems itself. I haven't installed one on mine yet, but its something I've been thinking about... might bite the bullet and get one. Haven't been entirely convinced yet.

Once again, regarding track, it all depends on how fast you are and how much you rev the cars
On my 17, not only do i have to run cans on both sides but also had to add the aluminum gt 500 valves covers to solve the problem

 

[vaeevictiss]

wish i did mine sooner. put it on around 9k and I'm at 12k now and have already gotten a decent amount out of it. Only did the passenger side as I was reading somewhere, maybe here, that with them being connected you don't actually need both and that's why people with both usually only have oil in one of them.

Planning to boost soon so its good have but I'm not sure I have the right one for a boosted application.

 

[luc]

wish i did mine sooner. put it on around 9k and I'm at 12k now and have already gotten a decent amount out of it. Only did the passenger side as I was reading somewhere, maybe here, that with them being connected you don't actually need both and that's why people with both usually only have oil in one of them.

Planning to boost soon so its good have but I'm not sure I have the right one for a boosted application.

Street,passenger is all you need. Track, you definitely also need the driver side. Will get oil in it

 

[NightmareMoon]

I've driven COTA, great track! I'm shocked they didn't meatball you, did they know you beforehand? Maybe you told them it might happen? Normally they meatball you just to be on the safe side, worst case you miss a few laps. Anyways, I think for someone pushing as hard as you it definitely helps, but I've never heard of anyone having this issue on track. I know some pretty fast people on the forum and they've never mentioned it

I had no idea either, but after encountering it and researching it I found some info from other track guys, which is why I knew to look at the GT500 valve covers, but FWIW the valve covers were different on 15-17 GTs versus the GT350s and changed again on the 18+ models, and I don't think its as likely on newer cars.

I didn't encounter it for years, but I'm quicker now. Better suspension and good aero. IDK if valve cover age had anything to do with it, but it sure caught me by surprise at CotA, and it was repeatable. My other local track which I run at more often just didn't have the sequence of G forces that would cause it. \

 

[ice445]

I hear this argument a lot, but I have an issue with it.

Namely that it isn't what we observe in practice, the primary contributor to knock on FI and NA cars (because all s550's are knock limited from the factory) is the fuel itself. If the effective octane was actually being reduced by blow by oil, we would be able to reliably pick up power by adding a catch can to any car (FI or NA). However we don't see that.

Depends how much blow by your particular car has. I don't think it would make much of a difference, but if you're running the car hard, blow by + oil vaporization might cause some knock.

At the end of the day the can is only going to catch a certain percentage of the blow by. I still think it's worth it if you're going to run the car hard regularly. For street use it's optional.

 

[13GetThere]

I don't have a catch can, and I'm not sure I need one, BUT Ford Performance does have one for the Mustang if you think you need one.

 

[Ford Guy V8]

I've been having a similar issue. Gingerman raceway has a high g harpin that seems to be causing misfires for me from oil getting into the cylinder. Does anyone have a link to a specific product they recommend?

 

[Gargoyle]

Research leads to this:

DI injected : Yes
Turbo : Yes
Mustang GT is Port and DI: No need.
Unless Beat it to hell?: maybe
Daily with mild track : No
Still on warranty: No

Gonna leave this here:

“The PCV system includes an oil separator, designed to catch oil before it it drawn into the engine, and return it to the sump.

When these systems work properly, there’s no need for a catch can.
(Fitting a catch can is like taking Panadol for a brain tumour. It’s ineffective, but might make you feel better.)”

“All modifications come with what engineers call ‘feedback effects’ - inevitable changes to the system’s response flowing from some modification to the system.

(For example, upgrading to stiffer springs and stickier, low-profile tyres improves grip - the primary benefit. The feedback effects might include reducing the margin between grip and slip - meaning a sudden transition from grip to sliding, with less warning. Especially in the wet.)”

“For this reason, curing ‘maybe/nonexistent’ problems is a bad idea. Curing the nonexistent problem of oil blow-by with a catch can, which pressures up the system and blows a seal, allowing sump oil to escape could have the nasty feedback effect of catastrophic engine failure, and you will not be covered by warranty. In fact, engine modifications generally (and modifications to related systems) are a great way to give the manufacturer justification to deny a warranty or consumer law claim in the event of a major engine failure.”

 

[cerbomark]

and yet Ford makes an OEM one???

 

[WildHorse]

Oil vapor and water vapor going into the combustion chamber can contribute to detonation.

Oil yes, water vapor is really good at preventing detonation/knock.

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