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Discussion Starter #201 (Edited)
Thanks, doing my best.

And finally........I ended up using the Valve lapping compound on a spare intake valve, the other intake valve was kept to check the face contact with the prussian blue. It's funny because Neway says valve lapping isn't required. Well, when using their hand valve grinder.......it's required. The carbide cutter was simply riding the high and low spots like a needle on a record player and just following the existing seat profile. This wouldn't have happened on rigid setup like a CNC. The lapping compound cut thru the high spots in about 10 minutes and left the valve nearly air tight, needs a bit more work and it'll be good to go. Really amazing how fast it worked. No seat cupping or any weird issues that the experts complain about, just a dead flat surface. I'll then have to lapp again to match every specific new valve to it's own seat, but for now I'm doing it to get the big dips and valley's out. It's weird because the carbide cutter makes it look like everything is getting cut perfectly even with the prussian blue dye, so it's very misleading. The valve concentricity gauge would have detected this up and down movement from the wavy valve seat, so I'm starting to think that it's a very wise investment of $150.

Anyhow, life is all about lessons learned.
 

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Yeah I will send my head out to get redone.
 

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Discussion Starter #203
Yeah, definitely do it. I know you were asking me a ton for the intake valve pics. Man, the intake/exhaust valves and ports were so bad honestly I couldn't believe a vehicle could physically run with that much oil and carbon in the valves/runners. On the engine rebuild I was like; "Maybe the head doesn't need a cleanup". I was kinda just looking for excuses to rebuild the engine, but it really did need it. I'd think pulling the head off with the motor in the engine bay isn't a ton more work than a timing chain swap. I know Portflow have a 2-week turnaround time, they are known for being consistent on that. I'm gonna try HeadGames for my EVO X, the mitsubishi guys seem found of them.

A lot of these weird idle, fuel economy, fuel trim, power issues, etc. I'm wondering isn't a problem from the carbon deposits and valve sealing. I'm telling you I could hit 31 mpg when my car was brand new and right before the car went down for the last couple of years I'd be lucky to crack 25 mpg no matter how I drove. The only thing in the entire engine that looked terrible was the cylinder head. An oil catch can & some water/meth injection for cleaning purposes only is probably the only way to minimize it. I did the Seafoam treatments and I feel it didn't achieve much after looking at the head, but it's better than nothing. I'm gonna try BG44k next time.
 

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Well thats not gonna be for a while. Stiffer Springs would be nice to increase the RPM Limit. But that would cost as much as the Turbo Bay Turbo and the power gain would not be as much either.

I am curious how much gunk I have with only 9,100 miles. I will boroscope it one day. Maybe just take off a spark plug and see if I can get it to bend upwards in the cylinder to see the Intake valve. I want to see the cylinder gunk anyway and maybe then take off the TB and run it down the intake plenum.
 

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Discussion Starter #205
Mac,

The sure way of getting the gunk off is to run a rotating wire brush, but the various solvents might help it loosen up a bit.

Update:

I've been learning some hard lessons during this rebuild. So, what I have now deduced is that MOST of the lapping compounds.....are junk for this level of detail work. I've gone into the limitations of the Neway carbide hand valve seat cutters and won't expound much more, but to just say they need a special technique to work consistently. They definitely can give a good result though, if slow going. Now, back to the valve lapping compounds. The stuff you buy from Autozone......never ever use that stuff. This is something close to 40 grit and this cuts massive deep ugly grooves into those pretty valve seats. This will take hours of clean up and require cutting deep thru the valve seat to level out. I then tried 120 grit, then 280 grit, with varying success.

So, starting with a cleaned up used intake valve which is almost ground to a mirror finish from the factory, I started using 800 grit lapping compound purchased from McMaster Carr. This compound leaves a nice frosted surface finish on the valve seat that is dead flat once everything is worked in a bit. This "frosting" is actually the initial method of checking a good honing/lapping, if there is a break or shiny spot in the frosted finish, you need to continue lapping or apply more lapping compound on continue on. This frosting is actually the silicon carbide embedded into the steel, so it's a good idea to wire brush it off afterwards. It takes maybe 2-3 times longer than the course grit compounds, but it's so much easier to achieve a nice clean consistent surface finish. If it's lapped for too long, then the valve seat does get "cupped", not so good. This is where I again pull out the carbide cutter, cleaning the seat first of the abrasive silicon carbide, and re-dress the valve seat by applying "light" cutting pressure to sweep or "straighten" the cut profile to a perfect 45* straight line again. If the surface finish looks good, I then move on, if not I start lapping again. The end goal is to get a perfectly even circuler contact ring that the valve sits on that is maybe .055" wide (intake). Now, some of the valves need only maybe 1-2 minutes of light lapping, and they were good to go. Others required 30 minutes of heavy lapping due to a badly cut seat, thus needing to be corrected.

OK, the reason for this level of intense machining is because the valve needs to seal 180-200 psi of air pressure during the compression stroke. With any kind of valve leakages, I'd be wasting precious compression from my fancy racing pistons, so it pays to sweat the details here. This'll also pay dividends in stable idle control while also helping to prevent misfires. A good seal also provides a nice heat path to cool the intake/exhaust valves. And a polished valve seat surface that is not too thin, will knock the carbon deposits off. Lot's going on here.
 

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Discussion Starter #206 (Edited)
Got some time recently from long work hours to finish up some engine work.

Finally got the Intake & Exhaust valve seats fully cut and lapped. Took forever, had to redo it multiple times, but the valve seal is nearly perfect. The final step after lapping was to re-cut the angle cuts above and below the seat cut for the seat O.D. and width. Now, I didn't use the actual valve that's going into that particular seat for all the lapping. Too much lapping ruins the valve and the seat, but to get around this between lapping operations I lightly re-cut the 45* seat with a carbide cutter to remove any cupping on the seat surface. What's left is a seat cut without dips or valleys that also has a perfect 45* cross sectional angle. When I get the new valves I will very lightly re-lapp them into their individual seats, then clean the valve face and seat with a steel wire wheel to remove the embedded silicon carbide compound. With the correct technique it comes out perfect, or near enough. Having said all that, I will never do this job again. The amount of labor was astronomical if I include the head porting.

The intake/exhaust valves are going on order in a week or so, then I'll get the head decked by the machine shop and cleaned up. At that point the cylinder head final assembly begins. After that, I have to wait until the block is ready to do all the valvetrain checks (i.e. valve clearance, lash adjustment, cam timing, etc.). I'm looking at also getting the upgraded TD04 high flow turbine wheel from Mambatek, so the upgraded 19T turbo can breathe a bit better than the standard version.

I don't have a final completion date but realistically if I'm done with the motor & transmission installed in 6 months, I'll be happy. There is stuff going on with the transmission rebuild that is dragging things out, but it's worth the wait to do things right.
 

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I would do all the porting and send the head out to get rebuilt. Unless a shop has something to port and polish easier than hand tools.
 

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Discussion Starter #208
The porting and polishing is time consuming but otherwise straight forward, if not extremely messy. The trick is to remove just enough to reshape everything for improved flow, no more. Shops now have a CNC program to port the heads as it's impossible to do it quickly by hand. I'd say it took me about 100 hours for the head port work. The valve cutting easily another 100 hours. A professional could do it I'm sure much quicker, maybe 30-40 hours total by hand.
 

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Gotcha.

Is it worth polishing the turbo and housing ?
 

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Discussion Starter #210
Hmm, basically no. The turbo housing is thin casting, there isn't room to remove material, I checked. Same goes for the exhaust manifold, not enough material to remove. If I upgrade turbos in the future I'll just have Full Race or someone custom fab a new turbo header.
 

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Discussion Starter #211 (Edited)
Finished up some more work on the Cylinder Head:
  • Chamber polishing
  • External casting cleaning
  • Internal port runner cleaning
  • Fuel injector mounting bore cleaning
Tasks left to do:
  • Powerwash and clean the oil galleys.
  • Load valves and send to machine shop for deck resurface
  • Ultrasonic cleaning after head machining
  • Dissassemble, clean again.
  • Rebuild head with new valves, new springs, new valve guide seals, new retainer locks, new retainers.
To clean the aluminum casting, I used Dremel attachment #428 & #442 steel wire wheel brushes on LOW speed, very important for wire wheel attachment life. Then, to remove any embedded carbon & aluminum debri, a rag was sprayed with BrakeKleen and rubbed over the surfaces until the rag stopped turning black. I finished up the nooks and corners with a q-tip soaked in Brakleen. No attempt was made to polish the external casting, only deep cleaning it. What's left is a very "dry" & clean surface that can now react with the air to properly create an aluminum oxide layer without any of the flash corrosion that chemicals will always produce. This'll remove that "polished" aluminum look that I personally don't like and give it that bright OEM casting finish. By far, this is superior to any kind of aluminum etching chemical you can apply or about as good as bead-blasting without any of the mess or risk. The labor is about the same or slightly more than bead-blasting and the $3.00 dremel attachments last a good while, maybe I went thru (5) or so on the head. I'll apply the same technique on the cylinder block, lower block girdle, timing chain cover, etc.

O.K., I am NOT going to paint any of the aluminum. I tried this on the cam timing chain cover with some aluminum casting paint and it was a complete disaster. Aluminum takes a special etching primer for paint to lock onto the surface, which I didn't have and now don't want to try at this point. Everything will be a bright new aluminum casting surface per my technique like the factory intended. I'll probably just pressure wash the engine during the winter time to reduce the salt corrosion. The engine block actually looks good but I used chemicals to clean it, and to prevent flash oxidation I had to spray the surface with WD40. I'll have to redo the engine block with the wire wheel technique, then it should be good to go. The plastic valve cover is getting replaced and kept a factory black plastic finish, maybe polished but that's about it.

The pictures below show the final chambers, runners, & valve bowels with the valve seats cut to final size. Ignore those chatter marks on the valve seats, the camera exaggerates all the little surface imperfections. The engineer blue ink I use to transfer the correct valve & seat matching shows perfect imprint and zero gaps during a flashlight fitment check. I finished up with 800 grit lapping compound. The final result was polishing everything with Aluminum Mag polish (2000-3000 grit) to remove any embedded lapping compound, then cleaning generously with Brakleen again. Yes, the only aluminum I polished were the chambers, helps to reflect heat & reduces carbon sticking. The intake manifold & exhaust manifold deck surfaces were cut flat using a hand file for a perfect gasket seal, then finished with a 400 grit sanding block. The cylinder head gasket deck is going to be resurfaced by a machine shop to RMS 8 micro-in or better. As I mentioned earlier, I did not replace any of the valve guides. The intakes were well within spec, the exhaust were about at the service spec limit. The job would have been enormous, and all valve seats would have needed to been significantly recut for concentricity. Figured I'd mention that, but PortFlow recommended NOT replacing them anyway, so I didn't.

I now have a huge mess of aluminum grinding material on my workbench and basically everywhere, that has to be decontaminated before I can attempt any engine re-assembly. Clean is king.

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Looks so Purdy.

Man thats a lot of work.

With all that possible extra flow. You should go with the Turbo Bay turbo. 52mm wheel ?
 

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Discussion Starter #213
Mac,

Oh yeah, tons of work. Just got done vacuuming up all the aluminum dust and chips all over the work area, cleaned up the table and put down new towel paper. Should be ready now to do final assembly when all my parts start coming in. Looks nice and clean now. Whew......getting closer to the finish line.

Turbo bay Stage 3 (52mm wheel):
I'm on the fence, I don't actually have the $990 right now unless I sell my Mambatek and reuse my stock OEM core for the build. I'm gonna try just upgrading the Mambatek with the high flow TD04 wheel for $149. On the other hand, the GT28RS that 2J ran on their latest dyno run had a super nice torque curve, that turbo easily is good for about 380 w.h.p. or so. 2j got about 350 w.h.p. out of it. They come with a lot of turbine A/R options (i.e. 0.57, 0.64, 0.72, 0.86). Probably that turbo is my next jump when I recover financially and can plan out the design of the exhaust header, turbo specs, and downpipe.
 

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Yeah I hear ya. You have a huge build going on there.

I want to go more power and will most likely do the 52MM wheel turbo as it Bolts right on to what I have, but I need traction first. Nitto Tires and Coilovers hopefully this summer. That will be almost 2 grand there.

I talked with Matt about the 52mm wheel and he is not sure how much more flow and power the OEM housing will give the Juke. But that upgrade is not cheap either as the Turbo is around $1500 and then a Full Re-tune / re-license is needed as you have replaced the turbo. Thats a $900 venture there so thats around $4500 for power and traction. Ouch.

One thing I dont want to do is sacrifice the Cowl and wiper cover. The Big turbos get in the way and they gotta be taken off ? I like the way the OEM fits nice and snug and is more stealth.
 

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You can always go with a 20t wheel its 58/48 mm As opposed to the 19t which is 56/44
 

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Discussion Starter #216
Well, the 20t sounds interesting. The 19t is good for about 380 hp, but the turbine TD04 maybe 320. So it’s already a mismatch. The highflow TD04 turbine maybe 350 hp.

Mac, you and Matt are right though, the 5cm turbine housing is going to seriously limit power, don’t know how much more the 52mm wheel will give you but if you have the bucks, go for it. If a stock frame turbo can fit in the stock location, an upgrade can too. I think the adapter he run pushes the turbo too high up in the engine at, causing the fitment problem. A custom header could keep it in the same spot if the turbo compressor could be clocked the right way. The Blouche turbos he runs actually fire the compressor outlet in an awkward angle.
 

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My goal is to hit 300+ whp and try to keep it as stock as possible. The turbo Bay might be the way to go. How much different is the 20T compared to the Wheel TB is using ?

Either way its a serious amount of $$$ to do more power.
 

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If you guys want more options, you can send me a junk turbo and I will see what kind of wheels I can make fit. I am in my Evos turbo less than $500 and its pretty much the same as most $1700 turbos. Going custom and doing it yourself is definitely the way to go. Turbo building is really not hard and lets you customize it to exactly what you want.
 

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I've been doing the same with a dead turbo that nissan egg sent me in october so I can tinker and so far I'm only $200 deep as a 19t upgrade but I been doing research to see how much more I can squeeze in there
 

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I even contemplated drilling holes in the inlet side similar to some hks turbos
 
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