Oil Separator

Briann1177

Goblin Guru
After reading quite a bit about direct injection and the problems with it, I took my intake manifold off today just for fun to take a look at the valves. While the valves weren't terribly caked up with carbon(only 48k miles), there was definitely a lot more than I would have liked. A couple of pretty big globs on the stems and a crusty layer on the seats. So I spent the majority of the day cleaning it off. Yuck!

Now that they're cleaner than they were before, I'd like to be able to not worry about this in the future by installing a catch can. There's not many pictures of the Goblin's turbo plumbing so I'm not sure how it would be integrated into the intake stream. I'm assuming there is a PCV bung somewhere in the plumbing, right? I can't seem to find any pictures of that in Lonny's build thread.
 
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David

Well-Known Member
I'm thinking about the same thing but I was looking into replacing my manifold with a TTR intake manifold which takes care of the factory pcv port but not sure what else has to be done to the pcv system
 

Bill

Member
There is really only few ways to eliminate the carbon issue with direct injection. One you can add an additional injector in the to the air path but this can be problematic or the easiest solution is a water/meth injection system to keep the valves washed clean. I work on direct injection engines all day long and ive seen every type of catch can tried and at least with the Mini engines I work on having some sort of fuel running thru the intake tract is he only way to avoid having to periodically clean the valves with a walnut blaster. I'm planning on doing a meth system for that issue and the added benefit of cooler IAT
 

David

Well-Known Member
That's also in my plans that's also another reason I like that manifold it has a tap for meth but let me ask you a question maybe you'll know I'm not a mechanic I just do things here and there if I would install the TTR manifold which plugs the pcv port is there any special thing I would have to do extra since I believe the oil would have to go somewhere mybe im not thinking it all the way through
 

Briann1177

Goblin Guru
Agreed on the walnut blaster. I thought I could cheap out with a couple cans of Chemtool B-12, carb cleaner, and a tooth brush. It works, but not nearly as easy, thorough, or timely as a media blast would have been. Lesson learned.

Does the water/meth injection help the problem of the oil getting into the turbo, charge pipes, and cooler?
 

Bill

Member
I'm not sure what the effect on the cobalt engines would be plugging it but on 2nd gen Mini engines its causes the crankcase systems which are internal to the valve cover to fail and you end up with an extreme vacuum issue internally and you start sucking in unmetered air past the valve cover gasket and the front and rear mains causing mixture issues and a "hunting idle issue"
 

Bill

Member
Its been my experience that some oil is going to make it thru the turbo system but a very small amount. I think a properly installed catch can can help with cutting down the oil going thru the intake trac but I personally wouldn't block off any crank case ports and don't expect a catch can to help with the carbon issue. Its a product of valve over lap and no fuel with detergents flowing over the valve stems.
 

Briann1177

Goblin Guru
I didn't take any pictures of my valves, but here is a very close image of what they looked like. It was probably not even enough to really worry about. It's a ripped off picture from cobaltss.net. :)


20131110_141932.jpg
 

Bill

Member
Yeah that's actually really light and I doubt you would notice any drivability issue, we get engines in where you cant even see the valves only to top half of the stem. like I said I'm not even sure how prevelant the issue is on the lnf engines but I want the lower intake air temps and additional power from it with the added benefit of keeping the valves clean.
 

Briann1177

Goblin Guru
I think you made up my mind, Bill. For now at least. :) The car went 48k miles for the valves to get to that point. After mostly cleaning them, if I can get another 45k or so before they look like that again, I'd be happy. That would be a lot of miles in a Goblin.
 

Brian74

Goblin Guru
I'm a big advocate of catch cans, especially on turbo/SC engines. I did a fair amount of research on them a while back before installing one on my sandrail (NA Honda J series 3.5). My intake runners had a fair amount of sludge, although the engine has excellent compression and leakdown is well within factory specs. I went with the Moroso 85472. Its small, lightweight, and looks good. This is what I had in it after a few weekend rides of rather hard driving (this engine spends most of its time at 4-6k RPM). I plan to run the same one on my LDK.
IMG_2555.JPG

I do remember reading that some engines characteristically have more crankcase blowby than others; also some engines are more prone to blowby with synthetic oils. I do know that carbon buildup is a characteristic of DIS motors, but running decent fuel and a catch can is certainly a mitigator.

I also read that some of the earlier Ecoboost and European DIS engines were horrible for carbon buildup, but I have not found anything yet that has classified the Ecotecs as being known as problematic in that respect.
 

Bill

Member
That's seems pretty normal, just condensed vapors being separated. The puegeot motors mini used for the 2nd gen turbo models were horrible for carbon buildup until a redesign on the crank case system and some programming updates addressed some of the valve overlap thru the vanos system which is just our version of variable cam timing
 

Brian74

Goblin Guru
That's seems pretty normal, just condensed vapors being separated. The puegeot motors mini used for the 2nd gen turbo models were horrible for carbon buildup until a redesign on the crank case system and some programming updates addressed some of the valve overlap thru the vanos system which is just our version of variable cam timing
Yeah, my only concern now is running a tune on these LNF/LDK motors, if that will cause an increase in the carbon buildup due to changes in the VVT intake overlap. I know the GM factory tune is rather conservative and this may be one of the reasons? lol...
 

Goblin-SS

Active Member
Hay guys. The carbon build up on intake valves of direct injection engine is something I deal with almost daily. Im a master technician for VW and there turbo Engines are some of the worst when it comes to carbon. Even seen it with after market brather systems and catch cans installed. The only true way to fight the carbon other then Manuel cleaning of the valves is with Meth injection, Or a 5th fuel injector in the intake manifold. Need to have something actively cleaning the valves during engine operation.
 

Briann1177

Goblin Guru
I changed my mind on installing a catch can. The Powell system I was going to get costs a few hundred bucks, and I just couldn't see myself spending that much on something that is just a band-aid. I got them mostly clean so I'll probably just suck up a can B-12 once a year or so as up keep. On a side note, that stuff works surprisingly well at dissolving the built up gunk.
 

PHerder

Well-Known Member
FYI, the engine I got (LSJ out of a Ariel Atom) has a quite large oil vapor separator bolted to the top of the engine.

I don't know if I will (or even if I CAN) use it and will not know until I attempt the engine install into the Goblin frame.

IMG_20170923_160550.jpg
 
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