FJ1346 from ashes to... Well, we'll see...

[skymasteres]

I'll admit that I am waaaaay behind in catching up with this thread; however, I cringed when I read the bolded statement above.  If the something felt ~sticky~ and burnishing the coating ~fixed~ it, then I would think it might have been a clearance problem.  Too little clearance would not allow enough oil film to support the rod/crank loads.  Metal to metal contact could have caused the rod to seize and snap.  

If the bearing surfaces are not scored and look okay, then I'm off base.  But, I've seen more than my share of engine failures and most of them were due to catastrophic part failure or oil/bearing failure.

I'll tell you when I get it taken apart and take pictures. But the coating itself is really like graphite in texture. It burnishes down even thicker than I can polish it with scotchbright under load so I am REALLY dubious as to whether or not it could have been a problem for the bearings. If it was I'd be really surprised...

Anyway. Progress is being make on the "new" lump. (Kind of had to take a break from things because it was just too stressful)

Also, just FYI. I'm on the lookout for a used crankshaft.

[skymasteres]

Okay, so I know it's been a while. There has been lots of movement on this project. I just haven't had any energy left over to share because like keeps kicking me in the balls.

So, I guess I'll just put up the picture rich version and narrate.

I guess I'm kind of sold on these coatings.  As with any process, as you do more of it, you tend to get better at it the more you do it. Or at the very least you pick up little techniques that make life much easier.  Case in point, when prepping pistons for coating, I know cook the heck out of them in the oven to burn off or carburize any oil and grease left on them.



Another IMPORTANT new trick is to leave the rings IN during the prep, coating, and curing. This makes sure that the ring groves don't get too tight and lock up the rings. (When I did the assembly the first time around there was a lot of time spend with old rings making sure that the rings could move freely.) Now I have the coating, and I don't have to spend all kinds of hand labor time getting the coating out of where it shouldn't be anyway.

Here the pistons are all dressed up but before getting new rings.



At first I had this kind of misguided notion that I would be able to simply mask off the areas that I didn't want to get grit in and be able to avoid having to totally strip the head and clean it.



I was sorely mistaken. I mean, you know these things, but dang if 120 grit doesn't kind it's way in everywhere when It's at 90 PSI... Oh, and sometimes you really need to give steel bolts in the head a really good whack to get them dislodged. And other times you break your impact bit and you have to put a wrench to a screwdriver after cutting a slot in the bolt with a dremel...



I'll tell you this. For blasting cylinder head castings with all of their nooks and crannies they are a real challenge for a cabinet set up with a siphon feed system. It was amazing the difference in how long it takes to process a cylinder head by switching over to a pressure pot system.  It makes it SO much easier to get into those tight spots. Plus it runs at a lower pressure while maintaining the same grit volume.
It makes for a nice clean casting.



And duct tape doesn't hold up under sandblasting very well.





Of course the reason for all of the cleaning is stuff like this...

[ribbert]

Welcome back Mike and good luck with engine build #2.

Just an observation, if it was me, I would not be trusting the old rings alone to keep the landings free of coating.

I use one of these:




They are not very expensive and give you a nice clean, square, uniform ring groove with the proper clearance.

Noel

[skymasteres]

Welcome back Mike and good luck with engine build #2.

Just an observation, if it was me, I would not be trusting the old rings alone to keep the landings free of coating.

I use one of these:




They are not very expensive and give you a nice clean, square, uniform ring groove with the proper clearance.

Noel

You know, this is one of the reasons forums like this are great. I had never even heard of this tool before. I was just using an old ring and scraping away, over and over again. This would have saved quite a bit of time.

Speaking of saving time. Before I ended up stripping the whole head and blasting it, I tried using some gunk degreaser gel in the combustion chambers to get the carbon deposits off. It actually worked pretty well. I just needed to use a nylon brush to scrape it off. (Of course this was after letting it sit for several days with a piece of plastic covering it)

[skymasteres]

You know, honing cylinders is certainly a messy business.  Between trying to keep a consistent rhythm and not
going too far out the end of the jug it's kind of challenging. That and the honing oil flying all over.
Doing the whole process in a box certainly helped.





Although, the bit that really did me in was realizing that I had tapped number 1 and 4 cylinder sleeves out of the
block by a few millimeters. At first I figured that the clamping pressure from the cylinder studs would seat them
back down where they belonged, but then I had a came back to reality and realized I'd have to press them back in.
Off to the local motorcycle shop to borrow their press.

(This was probably the single easiest screw up of mine to fix in this whole project)

[Capn Ron]

Speaking of saving time. Before I ended up stripping the whole head and blasting it, I tried using some gunk degreaser gel in the combustion chambers to get the carbon deposits off.

I used some oven cleaner on the pistons...let it sit for an hour or so and the carbon deposits came of pretty easily.  Here's a shot of piston #1 cleaned and about to work on piston #2:



Cap'n Ron. . .

[ribbert]

You know, this is one of the reasons forums like this are great. I had never even heard of this tool before.

You're right. The diversity of subjects that are raised and the wealth of knowledge and experience that flows is terrific.

Perfect example is the recent PH screw driver discussion and the link to the electrical terminal etc site.

Great stuff indeed.

Noel

[skymasteres]

Well holy crap. I am soooooo far behind this is crazy.




Finally got all of the pieces together and ready to put the jugs in. What a pain in the rear. I had a terrible time with the oil support rings.




This part actually cost me a few oil support rings so I had to reuse the old ones.







I'm telling you between all of the stripping and coating you really need to make sure you have your PPE. Especially when the temperatures get up there.





Okay, major dumb ass moment. First off I was setting up the shims on the new cylinder head and found that I didn't have shims thin enough to get the proper valve clearances. Ended up having to take it apart again to grind the valve stem tips to open them up.





The dumb part is that I set of the first motor using English units. NOT metric. So I was running 0.02" on the exhaust and 0.015" on the intake initially.
Reminded me of NASA....

Since I had the thing all disassembled anyway I figured I'd get rid of that major ridge at the base of the valve seats.





I also actually found a practical application for that class that I took on hypersonic flight.  Interestingly enough the "speed limit" for air flowing through a tube is the speed of sound. But that's not the end of it. The cross sectional area of the tube has direct impacts on air density as it goes from smaller to larger or vice versa. As the density changes so does the speed of sound in the tube. That throat at the base of the valve seat actually creates a shockwave when the cylinder stops filling providing a momentary stagnation point  before the valve closes. I mean, I just smoothed things out. But it would be cool to do some FEA on it.






And of course I sanded the ports to smoothe them as well.



And all of it was washed out before doing the reassembly.

[JMR]

How did you grind the valve stem tips?

[skymasteres]

So what I did was measure all of the valve clearances and put wrote them all down with the
respective valve clearences and did the math on the shims to determine how much needed to
be removed. The numbers on the shim are millimeters times 100. So a 230 shim is 2.3mm.
So if I want to get into the 270-290 range I have to take (280-230=50) 0.5mm off of the stem.


 

I just used my sander and held the valve perpendicular to it and rotated it as I removed the material.
(I tried to use that tungsten carbide cylinder in the bottom right to hold the valves, but it was
impossible to be precise with how much material was being removed)

[skymasteres]

Okay, I have to jump ahead here...
Cue 2001 Space Odyssey music....
2001: A Space Odyssey Theme song

















































First Start

https://www.youtube.com/watch?v=Hgm1l_EmAKw&feature=youtube_gdata_player

[ribbert]

So what I did was measure all of the valve clearances and put wrote them all down with the
respective valve clearences and did the math on the shims to determine how much needed to
be removed. The numbers on the shim are millimeters times 100. So a 230 shim is 2.3mm.
So if I want to get into the 270-290 range I have to take (280-230=50) 0.5mm off of the stem.


 

I just used my sander and held the valve perpendicular to it and rotated it as I removed the material.
(I tried to use that tungsten carbide cylinder in the bottom right to hold the valves, but it was
impossible to be precise with how much material was being removed)

Mike, I'm a bit perplexed as to how you kept the valve stem perpendicular to the sanding wheel by the method shown. The valve doesn't allow the stem to sit flat on the bed.

[JMR]

So what I did was measure all of the valve clearances and put wrote them all down with the
respective valve clearences and did the math on the shims to determine how much needed to
be removed. The numbers on the shim are millimeters times 100. So a 230 shim is 2.3mm.
So if I want to get into the 270-290 range I have to take (280-230=50) 0.5mm off of the stem.


 

I just used my sander and held the valve perpendicular to it and rotated it as I removed the material.
(I tried to use that tungsten carbide cylinder in the bottom right to hold the valves, but it was
impossible to be precise with how much material was being removed)

I'll be honest with you....you should have taken the valves to a machine shop and had them do it on the valve grinding tool. It would have been very inexpensive and would have insured the tip is perpendicular to the stem. If the the tip is not you will  see wear on only a portion of the stem tip and the bucket. You may experience some funky clearances after running it a while. Somethings really should be done with the proper equipment

[FJmonkey]

Okay, I have to jump ahead here...
Cue 2001 Space Odyssey music....

Does this mean you are up for a ride this weekend?

[CatTomb]

 

Dying to watch the video, but it says it is private...   

Congrats on getting back together. Can't wait to hear it run. 

Jeff