RomRaider

wow thats what 20 minute old parts look like? interesting to see since i figured that kind of carbon buildup only happened over a long period of time.
i'm rooting for ya on getting this thing back together quickly and painlessly...

The heads had about 14k on them. There was a ton of carbon buildup on the exhaust valves and some rust. My 240SX heads had 130k on them and those valves looked better, only a few had some rust spots from sitting so long . Of course, I never took the valves out, I just sprayed them down to clean them off and the exhaust valves looked like they had rusted some. That is only something I have seen in a very old car. Even my 240SX had sat for a year and a half before I picked it up used (to rebuild). Those valves were in better shape. I guess hind-site is 20/20. I will know for sure when I do the leakdown, but everything points to exhaust valves (the guides as they were all seated at least).

It is not the headgasket for sure either. Nevertheless, I am going to do a leakdown to pinpoint if it is just exhaust valves or both intake and exhaust.

A friend is coming over tonight, we think it may be the used turbo I bought. If oil is in the IC and since it is not in the catch cans, then it is the turbo. If it is dry, then it is the exhaust valves. The turbo would be easy because it is under warranty (it is used, but my friend sold it to me). That would be good news. It did have some front to back shaft play, but my friend who sold it to me said that was normal for a 20G. My VF43 had no front to back or side to side shaft play.

Im very sorry that things turned out the way that they did... I know that things happen but damn... Just know that when your done with everything that you will have a pretty bad ass setup... I wish I had that kind of money laying around

Well, I am going to do a leakdown to make sure, but everything was bone dry. This means a head problem and Subaru heads are not supposed to break. They were never mis-shifted, etc. It may just be a valve seal, that would be the only hope, but I was worried about them because they looked pretty bad (carboned up exhaust valves, loooked burnt and rusted, hell the last motor I built was a KA24DET and it had sat for 1.5 years undriven, it's head looked better, but I rebuilt it and all the exhaust valves and guides were good). My friend with his broken 07 FXT had 8k miles on his and 3 broken valve guides. He is getting them rebuilt for around 4k. I don't think that is the right way to go as it is almost a crapshoot now.

Do I make the decision and go with one of these:

http://www.raw1performance.com/index_fi ... e1875.html

or get used V8 JDM heads? Which I can't find anywhere,

or send my heads off to be rebuilt for 2-3k?

Now that my head (pun intended) is a bit more clear, and I am pretty sure it is the heads (will know this weekend sometime), do I go ahead and do the painstaking process of re-building the heads myself? If so, I would become a master Subaru engine builder. Of course, pressing the new valve guides in is the biggest problem, I would have to get those done by a machine shop, but I sure can do the rest. I don;t need a 3 angle valve job, etc, etc... I just want a stout motor. The consensus last night was that the bottom is built stout. The problem has to lay in the top end. Unfortunately I knew this might be a problem traveling down this path, so I was a tad prepared. At least I already have some of the tools.

Judging from the roughness monitor, the same piston (labeled #4 in the logger, 785 beta) that had the broken ringland (which is actually on the opposite side, it is in reality piston #3, but I will have to verify once I get home and look at my old logs when the engine went just to make sure I am remembering correctly), has a burnt exhaust valve I am betting as it is the worst as far as roughness, which is just a missfire counter. It goes up to 10 count at times and the others are around -1 to -3 when cold, and at 0 when warmed up (but not the one labeled #4, it goes to 10 when I rev it up with the engine completely warmed up) that I burnt a valve and it has damaged the valve guide now. So I am going to do a leakdown, and if I am correct, the leakdown results will show that everything is fine, then I will know it is the guide. There is a slim chance it will be a valvestem seal, but judging from the missfire counter and how it lines up with the same piston that went, I bet the guides are bad on that side of the head. At least the heads are not warped. There is no coolant in the oil and vice versa and it is strictly burning oil. I had some fear about the heads like I said earlier, there was so much carbon buildup on the exhaust valves, that they must have some kind of damage and ate away at the valve guides. #4 probably just got the worst of it because it was running 5% leaner, but they all looked bad. Boy howdy did I burn that motor up or what? Oh well, just more work to do and some more money. Probably be down another 2-3 months at least. It is really smooth when it is not missfiring though and with it smoking that bad out the tailpipe, the oil would have to have turned black and I would have to have had some blowby for it to be the bottom end. Nevertheless, I will know for sure this weekend after I do the leakdown test. You would never think that 11:1 AFR would do that, but with the car running the stock map for 5k miles, one blown piston from a bad injector, and another from running 5% leaner than the rest, the nice new non sodium filled exhaust valves could not take it. Of course, if the logger is labeled correctly, then the damage was done by the original failure with the injector that only flowed 45% DC. Time for new guides, valves and probably springs. I think I discovered every single weakness in the 07 STI motor from that particular plant. I wish I had an 06 motor. Oh well. At least the bottom end is solid now.

Hopefully my car wasn't made at that plant...

I say buy the Raw Performance heads and be done with it. It'll probably take a lot less time to get the car back running and you'll know if things are right. It is costly though...

Well, my heads are not warped, so the head cost of 2k I would just be throwing away pretty much. The parts to rebuild it myself are much cheaper. I have done heads before, I just take the heads to a shop to get the guides pressed in. I can install the rest as I have the tools.

It would be about 1500 to 2000 to do it myself with all upgraded parts (but no 3 angle valve job or porting).

It really is going to depend on how bad the heads are and funds available.

Hey gabe,

let me know if you want some version 8 heads... I know where you can get some... Not sure on the cost but I know where you can get some and some other goodies too

-Wes

Any chance it's something "simple" such as a stuck ring? Does it get better or worse as it warms up? Had a chance to pull the plug(s)?

Hoping for the best for ya

The only chance it is something simple is either I put the lifters (buckets) in the wrong spot and one of them is holding an exhaust valve slightly open, but that is probably not it as they were so close in size. Anything to do with oil slipping into the combustion chamber is going through one path. That path cannot be the rings or a slightly stuck open vlave because the oil is not contaminated and there is no oil in the IC, turbo, catch cans or intake tract. There is virtually 0 blowby, but it is constantly smoking out the tailpipe and the car is missfiring, especially on startup and in one cylinder (the same one that had the broken ringland) up to a 10 count when warmed up and revved. The oil must be seeping in through the heads which (once I do the leakdown, decided to take the weekend off), if it shows all cylinders ok, then it is the heads. It could only be one of two things in the heads. That would be a valve guide or seal. I am hoping it is simply a seal, but I am not going to rip it apart before first verifying that it is a head problem with a leakdown.

So the plan is this:

If leakdown shows that no air is escaping past any valves or cylinders, then it is time to pull it and redo the heads, at least replacing the seals (hoping that a guide is not scored). If a guide is scored, then they all are getting replaced with new after market valves and Subaru guides (contemplating replacing the exhaust valves with 06 sodium filled valves as I do believe they fit). The exhaust valves looked really bad, they had carbon and rust all over the stems.

If leakdown is showing air is escaping through the head and into the tailpipe (open exhaust valve), then I will re-do the buckets and try that. While I am in there, I will replace all the seals and check the guides.

If it shows it is escaping through the throttle body, then it is an intake valve.

If it shows it is escaping through the breathers (which it isn't I know) the it would be the bottom end.

Hey Gabe,

Just getting caught up on your rebuild... A very good read. Nice work, might I add.

We were talking about your 'project' here at work, and we're leaning towards Turbo seals - which would be a relatively easy 'fix' in terms of your labour and expense.

Hope you get some (relatively) good news on your measurements.

Dave

I was thinking turbo seals at first, but there is no oil in the D/P and no oil in the output to the IC. Bone dry. I have my leakdown tester now and an air compressor. My bet is that the leakdown will get 100% pass, which means the valves are closing, but when open, oil drips down into the combustion chamber due to valve stem guides and/or seals. The head is true, not head gasket leaks, so I am just looking at having new valves (Ferra) and guides installed all the way around. I have the tools and experience to put the rest back together (lap the valves, etc), but will have a machine shop replace all of the guides with new OE ones. If money permits (it probably will not though), I should upgrade the springs while I am in there in case I decide to go GT35R later.

Head work has always been kind of fun anyway, and I know the bottom end purrs nicely (it did for 20 minutes, it was so smooth and quiet at low idle). The fact that no smoke or oil is in the catch cans and none comes out of the filler cap leads me to believe the bottom end is fine. I checked and rechecked those pistons, so the should be fine.

I have only built one engine where I did not do any headwork. That was a smallblock chevy, but after a year it started burning oil in one piston, fouling out plugs. I was running it very lean too (carb tuned, no EFI), so I bet I burnt a valve on that one and scored the guides. Still it was a 14 second Monte Carlo (78 model before they had the SS trim, but it had the SS goodies and newer lighter 3300lb chassis). That car was much cheaper to rebuild. It seems my projects are just getting more and more expensive, but I love this car so much, I am totally willing to do whatever it takes to get it running perfect. Of course I will be doing my own work on it as I do not trust many other people.

The only other slim hope is that it could be a folded over oil control ring. It would then act as a check valve and not let gasses past into the crankcase, but would let oil slip through into the combustion chamber. The leakdown test will tell me and I can always pull the piston to inspect it once the heads are off too.