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Oh wow you are a patient man.
 

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Discussion Starter #162
Lol.....I'm actually fairly impatient. What is the most frustrating is waiting on parts. I get really anxious waiting on critical parts. I spent most of my time cleaning old parts.......that engine block was an intense amount of labor.

Anyway, I expect I'll get the Juke running by April or so. I wanted it for December but I just realized how deep I'm going with the cylinder head which threw off my schedule. I'm pushing hard now but it looks like everything will take the time it needs to for it to be right.
 

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Well with the Chicagoish winter weather. Maybe sooner.
 

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Discussion Starter #164 (Edited)
Couple pictures of the final product. I have (3) of (16) modified retainers completed now. It's taking me about 4 hours to lighten/polish each retainer. The final retainer weight is 9.0 +/- 0.1 grams. I'm a bit anal about precision. For reference, the Supertech SPR-FE20BE springs are coming in between 24.9 to 26.3 grams. I have (12) springs in the 24.9 to 25.4 gram range, then another (4) well outside those values. The heights are roughly 49.7 mm, but I still have to measure each one as it will become critical later on.

So why is all this important? Well, because the spring weight affects valve float rpm, so does the install height as it directly affects spring seat load/force. These (2) determine how much force is available to keep the valve on the seat @ rpm. This is where the blueprinting process begins. Now, the full spring weight is important, but more important is the weight distribution. The reason for this is because only a fraction of each spring coil contributes to the highest mass acceleration. Since the Supertech springs have roughly (6) active coils, the 1st coil sees the full mass acceleration, the 2nd sees 5/6 of this, the 3rd 4/6, the 4th 3/6, the 5th 2/6, and the 6th sees only 1/6. Additionally, the spring is tapered so the 1st spring coil also happens to be the lightest......and so on until the last which is the heaviest. This is the magic of the conical springs, the coils that see the most acceleration are also the lightest. In addition, each spring coil being slightly different diameter also snubs the other's resonance frequency amplitude. All things being equal, a conical spring would have a minimum 500 rpm float advantage against an equal rated cylindrical spring. A beneficial side affect is that the smaller top spring coil also has requires a smaller retainer. I can get away with a tool steel spring retainer vs. titanium just because of the smaller top spring coil diameter of the conical spring design. It's a win-win-win.

Getting back to the blueprinting, each spring is then weighed and height is measured. Then it's pre-loaded on a spring force gauge to the exact install height. Finally, the spring force is measured at seat height and final opening heights. The idea is to get all springs equal. Since the heights and weights are all slightly different, what can be done? Well, I can simply adjust the install height with shims or grinding of the springs seats. I'm making a .070" tall custom spring seat, so there is some room to pull material off there. I would have to plug all this into my spring float spreadsheet calculator to balance everything out so every valve assembly would essentially have equal F/m (i.e. force divided by mass). This means some springs that are heavier weight, might have more spring force needed. The lighter springs would require less spring force/install height. This might mean as little as 1 lb difference in seat pressure to balance out a heavy vs. a light spring. So the precision is going to have to come from an accurate spring force gauge as well. It's the details that make the difference.

Is all of this effort worth the time? Well, lets assume the intake valves and spring retainers are all coming in at perfect nominal weights. If I take worst case scenario of a 26.4 gram spring with a seat pressure of 78 lbs. Then a best case of a 24.9 gram spring with an 82 lb seat pressure. The difference in valve float rpm, using OE valvetrain weights and 7000 rpm @ float, would be something like 8100 rpm vs. 8650 rpm. Imagine (1) cylinder with valve float loosing significant power, while the other's are not. The engine tuning might be seriously affected. The tolerance stack-ups are hugely significant. I'm targeting an average 8350 rpm @ float. On a racing car, this might be significant.

Now it becomes evident why race teams blue-print the valve-train on a cylinder head. Anyway, this is typically how a cylinder head is blueprinted.

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Man thats a lot of work and looks well done.
 

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People wonder why we charge at least $500 just to assemble heads (no machine work) and this thread shows exactly why. Whenever someone complains, I am going to link them here just to show how much work goes into a head to make it right. Sure you can just slap it together but everything here shows the RIGHT way to do it. Keep up the good work Gene.
 

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Discussion Starter #167
People wonder why we charge at least $500 just to assemble heads (no machine work) and this thread shows exactly why. Whenever someone complains, I am going to link them here just to show how much work goes into a head to make it right. Sure you can just slap it together but everything here shows the RIGHT way to do it. Keep up the good work Gene.
Thanks, much appreciated. Absolutely agree. Slap a head together and it'll probably work if the deck is flat, but doesn't mean it's optimal.
 

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Discussion Starter #169
Man thats a lot of work and looks well done.
Thanks Mac, it's coming along slowly but surely.

Really enjoying this thread. Keep up the good work. This has been fun to watch.
Thanks, I'm trying to make it entertaining with more pictures.
It'll get interesting in the next couple of months when it all starts coming together.
 

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Discussion Starter #170
Update:

Crower contacted me regarding the cams. Looks like the stock cams are 198/194 deg duration and 0.365/0.335 lift. I assume these are at 1mm or .050” lift. Now they are going to bump that to around 208/204 deg duration and maybe 0.375/.345 lift. Cost is running around $250 or so with shipping. They should take 1 week to regrind and then 2 days to ship. I’ll have to check how much the lash adjustment I’ll need to make when they come back.

That’ll put them at about 5 weeks lead time if any of you are interested in sending out for the process yourselves.
 

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1.Cams. Installed

2.Springs Installed

3.Turbobay Turbo upgrade

4.Cams and Springs

5.Springs and Turbobay Turbo.......

6. All 3.

7. E30+++ tune.

I think for me the E tune, 20+whp easy, will be the most cost effective then the Turbobay with the E tune. Replacing the turbo will require a tune anyway.

I am on the sidelines til there is more out there on Cams and Springs. Although I would love a 8,000rpm redline.
 

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Discussion Starter #172
Go for all (3)....lol. That Turbobay turbo looks very interesting. How much is it?

I picked up some toys today for my cylinder head work. Best attachment for the dremel are the sanding flapper wheels, I bought (3) 120 grit 0.750 dia. sanding wheels from Mcmaster Carr. The diameter had to be small to fit into the valve bowels and intake/exhaust ports. These things last forever and are worth the $5 ea. They don't gouge into the aluminum, yet are extremely resistant to wear. I then finish off with the Dremel scotchbright soft pad wheels which give a beautiful finish. These things don't last super long but used correctly you can get good mileage and a pack of (2) are like $4.....not too bad. I have the Dremel stone wheel but for this type of work that is done almost blind, the stone wheel is not optimal to use. For the valve bowel port work I used the stone grinding wheel and a carbide flame burr to remove material quickly. I then picked up a new Dremel engraving flex shaft. These things are required to get deep into the intake/exhaust ports. I'm using my 20 year old Dremel 0.8A for all the port work and it's still going strong. The flex shaft seems to have some additional torque drag, so a higher amp rated Dremel would help out here.
For this type of delicate work, a full size die grinder is definitely not wanted or needed. Dremel also has a 1.8A version which I'd say would be perfect with some decent horsepower, but I'll wait to drop $120. Damned dremel and their expensive bits but they do work effectively. I buy 1/8" shaft bits that will work on a Dremel at maybe 60% the cost at McMaster vs. Homedepot.

Anyway, you can see the detail work I'm doing on the cylinder Intake ports. Mostly.......it's for show. The casting flash parting line has been removed. The flow divider is critical not to mess with it, and it's simply smoothed down. The valve bowel port-work is the critical portion to reshape the airflow firing into the intake/exhaust valves. This intake porting was to smooth out and match the runner to the valve bowel port-work I did early. This is because I'm porting from (2) different directions, so I need to blend the transition where they meet. The main problem with the cylinder head is the thin casting walls, it's not possible to take too much material out for port work anyway. It does look pretty though, still have cylinder (1) and (4) to port.

The intake flange surface I resurfaced by hand with a file checking with a straight edge, then I finished with 400 grit sandpaper. Yeah, that took (8) straight hours, the surface was badly cupped and to make a reliable intake manifold seal it has to be relatively flat. The trick is to file the surface on a diagonal to avoid creating any low spots. This technique is straight enough for anything other than a headgasket surface. The head gasket surface will be fly cut by a machine shop for a perfect head gasket seal, they only time it'll see a machine shop.

The exhaust runners and exhaust flange surface will get a similar treatment. Then (8) brand new exhaust studs and it'll be as good as a brand new head, but with a decent bit more airflow.

It's getting there.

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Oh very nice home done port job.

Turbo is $1500 with a core sent in.
 

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Gene, we just got a new toy in today. If you need me to do some precise spring testing for you, I can make it happen now. Just let me know.

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Discussion Starter #175
Hmm,

That is very very cool........damn....lol. Thanks for the offer. Let me see what I have I can put together, send me a PM with your contact info. I can accurately measure the seat pressure on the Chatilllon which is digital, but it's limited to 100 lbs and I'm going to be over 150 lbs on the open pressures.

Nice, things seem to be coming together.
 

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Discussion Starter #176
Here's a few pics of the intake bowels and ports which are now finished. I used a 60 grit stone wheel, then 120 grit flapper sanding wheel, then a 180 grit buffing wheel. The finish is fine enough without having to polish it which is a huge waste of time, yet I think it looks better with a brush finish anyway. It's takes a lot of back and forth between ports to balance them out. The dremel had to be turned down low speed for the buffing sander, so it was bogging down. This is where the 1.8A Dremel would really have helped on the low rpm torque. Still a huge huge fan of the dremel for this type of job. I also check with inside calipers in several locations to make sure the ports are equal size. I have no idea what this porting will actually flow, now that I don't have a reference stock port to compare it to. The difference should easily be 10-20% improvement though. As I mentioned before, I didn't so much hog out material as I improved the short radius and especially the long radius turn into the intake valves. A racing head would also increase the valve seat "throat" dia. from 1.030" to about 1.060" and this would hit that magical 86-88% of intake valve diameter for the throat. Since I don't have a proper valve grinder to cut a perfect circle of this size and angle (i.e. 75-80 deg), I'm not doing this mod. I would need a 75* or 80* angle carbide seat grinder and although it's possible, the downside is that once I do this I really am thinning out the valve seat width and there is no room for another cleanup on future rebuilds. So it's kind of a race only modification. If I have time I might get the head flowed. I'm thinking stock it's be around 150 cm or so, modified I'm hoping closer to 180-200 cfm.

The combustion chambers have also been polished, a little more work on those to get them mirror smooth. This also knocks the edges down on the top valve cut angle, helping to flow radius everything. The exhaust ports still need touch up but the porting required is minimal from the factory, the intakes were the restrictive areas. Valve seats still need to be cut, the pitting on the exhaust seats are pretty bad.

I checked the price on the valve guide replacements and they are like $30 ea., so I'm not going to replace them. It'd cost $450 just for valve guides from Nissan when an entire head is $1000.

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Yeah you can see the pitting just in the pic.
 

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Crower Cam update:

Cams came in finally. Impressive to say the least. The duration Crower provided is a LOT more than what they mentioned on the phone. They said they could only get about 10*, they got about 20-26* more duration. Specs are 250* @ 0.363" intake lift, 254* @ 0.375" exhaust lift. Stock is something like 228* @ 0.363" intake lift, 228* @ 0.335" exhaust lift. This is a huge difference. They were basically able to get a duration increase and exhaust lift increase as well, with only the intake lift remaining stock. For comparison, my EVO X is running something like 252*/224* duration @ 9.7/8.58mm lift. That setup will easily spin to 7500 rpms even on stock springs. Price came in at around $215 + $38 shipping back and $28 shipping there, total about $281. Lead time was about 5-6 weeks, so factor that in.

I should have taken some dimensions on the cams before the regrind, might have it around here. But they got the exhaust lift by taking .040" off the base circle for sure. I'll know more once I start measuring the valve lash.

So, if I were to price out a fully built Juke cylinder head it would look something like this:

Cylinder head (ported, 3-angle valve job, new valve guide seals, etc.): $800-1200 (free for me)
Crower Regrind cams: $281
Supertech springs & upgraded keepers: $387
Ford spring retainers: $65
Custom Spring seats: $385
Intake valves new (8): $106
Exhaust valves new (8): $166
Supertech Lashcaps (16): $96
Total coming in around: $2686






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Discussion Starter #179 (Edited)
Did some more port work on the head. I still have (2) exhaust ports to go but then I'm done. It's hard to show in pictures, but looking inside the water jacket, it's easy to see inside the cylinder head cooling jacket. There is very little room for port work on these heads without cutting thru a water jacket wall. The Juke can tolerate high compression and boost without knocking because IMHO the heads are so well cooled with water flow, including the engine block as well. Pro's and cons to the open deck block, but engine cooling is outstanding on these cars.

The pictures show the final chamber polishing which will reduce detonation and carbon build-up. I didn't want to remove too much material, so there is a little bit of casting roughness left behind, but all the sharp edges are knocked down. The final operation is to then re-cut the valve seats to get everything perfect. The exhaust valve bowels had an odd flat ramp that I smoothly blended into a 90* bend. The exhaust runners are shown ported, again mostly to remove casting flash. I had to buy those sanding cartridge tapered rolls and a long 2" mandrel to get into the exhaust runners, the valve guide bosses were making it difficult to get in there. The term "valve bowel" comes from the fact when looking straight into the chamber without the valves installed, the cavity should look just like a cereal bowel. The power gains mostly come from the valve seat angle cuts and the valve bowel blending work. The port runners are mainly cleaned up for cosmetic reasons.

Finally, the exhaust manifold mating deck surface. This took about 16 hours to get a flat surface using a hand file, probably .0005" flatness over the entire face using my machinists straight edge. I was surprised by the hardness of the aluminum casting, it's very hard material actually. A machine shop could have done this with a fly-cutter, but I wanted to get some practice. There is some minor pitting that would take forever to grind down, but the rest of the flange face is dead flat. This is required because it provides a very tight gas seal for the exhaust manifold gasket, and it takes stress off the exhaust manifold preventing cracking due to warpage. I've seen a few guys attempt to use high temp RTV to seal up these areas........very messy and not very professional looking. The best seal is made on a perfectly flat machined surface with a multi-layer soft stainless gasket. OEM know best. I'll be running a brand new OEM exhaust manifold for improved reliability as well.

The head gasket deck surface is just cleaned up for now. It's flat, but it needs a few thousands taken off to remove the gasket impression and provide a perfect RMS surface finish that'll stick to the viton head gasket. The machine shop will take care of that operation. I'll then probably have them put the head in an ultra-sonic parts washer since it's completely filthy with aluminum grinding dust. I should be wrapping up the head rebuild in the next 2-3 weeks or so. If I had to put the number of hours I have into it, I'd say maybe 80-100 hours. The risk of screwing something up........very high. I'm going to say worth the $600-1200 to let a professional do it for you.

The difficulty will be in degreeing the Crower camshafts when the head is bolted to the engine. I'm going to see how much I can clock the cams to achieve the cam card specifications just by advancing (1) tooth at a time. Unfortunately, no cam gears available. I can at a later date possibly just do this with the cam phasing option on the flash software when I switch-over to UpRev. I'm going out on a limb and saying they should idle fairly well since there is about -8* valve overlap on these cams, we will see though.


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Looking great. Smooth is fast.
 
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