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

[GhostMerc]

The only type of head work I've ever done was on my car.  When I put stuff back together I used lots of new oil on all the parts.  Looks like you've coated the head as well.  Even though it's thin it could provide interference on some of the moving parts.
I haven't been inside the top end of my bike too much yet, but those are my two thoughts on the matter.

[skymasteres]

The only type of head work I've ever done was on my car.  When I put stuff back together I used lots of new oil on all the parts.  Looks like you've coated the head as well.  Even though it's thin it could provide interference on some of the moving parts.
I haven't been inside the top end of my bike too much yet, but those are my two thoughts on the matter.

Well, you're half right. I sort of panicked and called Randy because, well I was panicking. (Duh) Sort of
answered my own question, but didn't realize it till I actually looked at the spring cups that the cup and
their corresponding pockets are frictions surfaces. Of course you know what that means.... Off to the
garage for more cermalube! (But we'll get to that in a little bit) 

No I had to go through the whole process of disassembling the cylinder head yet AGAIN. Well after I used
the spring compressor to remove the first valve I realized I really didn't want to do them all that way. So
I took one of my scrap 1" PVC sections, a mallet, put it over the keeper and gave it a good whack. (Of
course this resulted in sending the valve locks flying, landing in my miserable poo brown shag, and frantic
searching ensued.) Not to be deterred I figured there had to be a better way. Bingo, how about putting a
used plastic bag over the PVC? Works like a charm.

My high tech valve removal kit.



I ended up using a flap wheel from my porting kit with a piece of skotchbright pad wrapped around it to
clean up all of the spring cup bores.



With the scotchbright.



It turns out that when I put the wax and paper towels in the spring pockets I ended up with leftover
wax that was jamming the spring cups. After I ran the pad through it the buildup was removed.



Of course now armed with the rapid valve removal capability progress on the rest of the bores was fairly quick.



Here is a comparison between new springs and the stockers with 120K miles on them.
(I guess it's fairly obvious which is which...)



Back to the garage. (Sometimes I think I spend more time in here than at work...)
Here you can see, if you look carefully, the shiny parts of the spring cup.
This is where the contact was being made with the cylinder head.



And here are some of the spring cups coated.



With the parts curing in the over the grueling process of now RE-assembling the cylinder head continues...




Although on the bright side, it turns out I was only missing one spring seat. The other two were doubled
up in the bottom two different spring pockets and I didn't notice. Turns out I only lost one.
(It's a good thing I found that out before the engine was run. But finding stuff like that makes me nervous)

[fj1289]

Did you put (new) stock valve springs back in it?  Pretty sure that's something you want to go aftermarket with -- even with stock cams and valves. There were some discussions a few years ago about how the stock springs lost a lot of seat pressure after just one or two heat cycles with a drastic HP drop that was verified on the dyno. I'd get Randy's opinion on this if it were me. I'd also like to hear his opinion on this...

[Dan Filetti]

Did you put (new) stock valve springs back in it? 

Am I missing something? ...doesn't this photo answer that question?



Dan

[Pat Conlon]

Dan, I think Chris's question was about replacing old with new oem Yamaha springs.
The aftermarket KPMI springs are superior to the oem Yamaha springs.

[fj1289]

Exactly -- I "think" it takes a LOT less than 120K miles for a set of stock valve springs to be sacked out like those are.  With all the care and attention to detail being put into this build, it would be a shame for the new valve springs to give up early.

[JMR]

I don't like pulling the valves out of new seals. The upper keeper lip is sharp and can cut the sealing lip. Just my experience.  Hope it works out.

[fintip]

Right, not, "Did you put new valve springs," but, "did you put new *stock* valve springs".

I can't wait to rebuild my engine some day.

[andyoutandabout]

I really hope this re-assembly goes well. Surely the karmic gods will ensure the safe return to the road for this project. Who needs a workshop manual with this detailed restoration going on?

[skymasteres]

Well it's good to know that everyone is paying attention. You can all rest assured that I have new aftermarket
valve springs in this cylinder head. Unfortunately I do not have the specs on what exactly these springs are
because they came with the cylinder head. I can say that the inner spring is definitely slightly larger in diameter
than the stock inner spring.  I can also tell you that the old keepers are 7.8g while the new ones are 6.6g.
(Looks like stainless steel too)



A 1.2g weight savings on something that completes its open and closed cycle in less than 270* of crank rotation
is pretty significant. (360*/Rev)x(6000Rev/min)(1min/60sec)= 36000*/sec of crank rotation or 100 revolutions/sec.
So if you figure that the crank makes two twice for every time the cam goes around then the cam is spinning at
50 revolutions per second at 6k RPM. If the lobe on the valve for about 270* then let's assume half of it is opening
and the other half closing. 270* is 3/4 of rotation. Half of that is 0.35 of a rotation to open, and 0.35 to close. At
1/50 of a second for a revolution that's (1/50sec)*(0.35)=0.007sec for the valve to travel it's 0.4" from closed to
open, or open to closed. I don't have time to dig further into it than that right now, but that's a lot of acceleration
for a little part.

On another subject. It's amazing the difference it makes when you polish up this coating a little.

[Pat Conlon]

If those are the Hank Scott 82mm pistons (they look like it) left unshaved, your compression ratio will be over 13.5:1. Remember with the added displacement, you are compressing 22% more air in the head's squish area.
You should consider shaving down those piston crowns if you want to run pump gas.
Especially the piss water we get in Calif.

Just a suggestion.

[skymasteres]

If those are the Hank Scott 82mm pistons (they look like it) left unshaved, your compression ratio will be over 13.5:1. Remember with the added displacement, you are compressing 22% more air in the head's squish area.
You should consider shaving down those piston crowns if you want to run pump gas.
Especially the piss water we get in Calif.

Just a suggestion.

Well, Hank Scott told me that I should be in the 11 to one range with these pistons because he opened up
the combustion chambers a bit for the bigger bore. That and the larger valves have been unshrouded.



Here is a comparison of the old cylinder head.



I figured I'd try and see where I was CC wise so I taped over the spark plug hole and filled the combustion
chamber with water. I didn't have a burette handy (Broke my last one) to I used a 3ml graduated dropper
and just counted how many times I had to empty it into the cylinder head.




I ended up with 14x3ml for the new head and 12x3ml for the old head.



Hopefully a displacement difference of just 42-36=6cc will make enough of a difference.

Here you can see the valve releifs...

[skymasteres]

Well, I caved after a conversation with Hank Scott about the possibility of running the motor I'm building
with the pistons stock. Turns out that when he assured me that it would run fine on "pump gas" that he
was under the impression that I had access to the 94 octane fuel that they have back east. Not this
piswater 91 being the best available without having to buy it from a race shop. Of course I should count
my blessings. There were places in Texas where the best I could get was 87. (Played havoc with the car
since I was towing a trailer and the minimum is 91) So, it was decided that I would take 50 thousands off
the domes to drop the compression to about 11 to 1. (I asked randy to shave 60 just for a little extra margin.)

And here they are.



Of course while I was waiting for the pistons I decided to open the clutch back up and make that right.

I'll have to get to that a little later. Jumping ahead though. (Spoiler alert)
























I crushed the crap out of this connector. Does anyone have an extra handy?



( I Don't know why the links are broken. But here is the crushed connector)

http://img.photobucket.com/albums/v127/skymasteres/Motorcycles/FJ1200%20Rebuild/Engine/13697557029848_zpscaaea9ca.jpg

It's the one for the clutch grip controls. (Lights, horn, and turn signals)

[fintip]

Yup. Mostly see 91 in Austin at the top. Of course, my question is: is this bike going to be a daily rider? If not, is it really that much of a hassle to run an octane booster? And with the cost you've spent on the motor at this point, I can't imagine the cost would be unbearable for you (again, unless it's your daily rider).

Hard choice, but I feel like if I were this far in I'd just want to go all the way.

I feel like most people are generally misguided about octane numbers... In this case, I understand, but what towing vehicle were you running that had a high enough compression ratio and wasn't fuel injected that required 91 octane?

I run the cheapest octane (83? 87?) on my stock FJ engine. Compression ratio isn't enough to cause pinging. When I hear people here saying they put premium in their stock engines, it just sounds like money wasted to me.

[RichBaker]

I don't like pulling the valves out of new seals. The upper keeper lip is sharp and can cut the sealing lip. Just my experience.  Hope it works out.

Never mind, misread the post.....