Bent Valves or No?

[BobCo]

note: the #4 cams are 180 degrees opposite of #1's on each cam shaft, so they can't be anywhere else when #1 is correct

The reason for the #4 valves to be slightly open at #1 tdc is cam overlap. Which allows for exhaust scavenging to take place during #4 exhaust stroke. Both the intake and the exhaust valves should be slightly open from a few degrees before the top of the exhaust stroke (where the intake valves start to open) to a few degrees after the top of the exhaust stroke (where the exhaust valves close). Sorry if this comes across as pedantic.

 

[Redfish Hunter]

Very good stuff in this thread. I may never do it myself but I am certainly learning a lot here.

 

[audiowize]

At the speed available from your wrench and the minimal torque you applied to the crank, I would go back in there and attempt to reset the cams before dropping it off at the dealer.

 

[BobCo]

Very good stuff in this thread.

I've bookmarked this topic for future reference.

 

[RaYzerman19]

Out of all this comes some positive learning from a negative experience........ one knows what to do next time or on your first valve check/shim change. While checking your valves, you're spinning the engine, taking your readings, or perhaps taking a second set of readings. If you are going to change shims, it is best to spin your engine to leave #1 at TDC, crank and cam timing marks aligned, cam chain tie-wrapped at crank and at sprockets, loosen CCT, proceed with shim changes. With the cams back in, it is then easy to verify the timing marks are all still OK at a glance.

 

[Intech]

I read through this thread and had a major deja-vu! Pants, you did exactly what I did with LCB's bike. I ended up learning a trick to skip a link to adjust with the cams installed too.

 

[PhilJet09]

Out of all this comes some positive learning from a negative experience........ one knows what to do next time or on your first valve check/shim change. While checking your valves, you're spinning the engine, taking your readings, or perhaps taking a second set of readings. If you are going to change shims, it is best to spin your engine to leave #1 at TDC, crank and cam timing marks aligned, cam chain tie-wrapped at crank and at sprockets, loosen CCT, proceed with shim changes. With the cams back in, it is then easy to verify the timing marks are all still OK at a glance.

I also made sharpie marks where a tooth sat in the chain for each gear and only removed one cam at a time. After both cams are torqued back down and the tensioner is re-installed, a double check of the marks in all 3 places ensures it's back together right. More of a sanity check really.

 

[hppants]

Wonderful support on this, friends. Much thanks to everyone.

Mike came over today - we are probably going to give it another shot next weekend. Yesterday in our deepest frustration, we threw our hands up and started buttoning up the bike to ship off to the dealer. Looking back, we probably should have just stopped, started this thread, and slept on it. Things would be much clearer today (as they are).

If it's broke, I don't think we can break it any more by trying again. Ray's series of steps seems logical. Take the cams out, spin the crank and verify a couple of knock free revolutions, put the cams in time and install. If we are able to get the cams to line up in time with the crank, we can spin the crank and verify nothing unusual and the timing marks re-align on time. Then we can take a compression test on the motor and if we get that far, I think we will be home free.

One way or the other, I will be updating this thread.

 

[dcarver]

Attaboy Pants! Keep after it.

 

[wfooshee]

Oh **** - bingo!!! We have a winner. I'm almost certain we were using the marks with the arrow for both the intake and exhaust.

If that's the case and I've cleared it up for you, then it's a bit of karma!!! I'm shifting that transmission you salvaged from Patriot's bearing-failure motor, so if I helped with this, then it's kind of a payback!

 

[Pterodactyl]

This has been like watching one of those serial adventure shows they used to show before the matinee movies when I was a kid. Our current show leaves us with our stalwart hero resolving to pick himself up and make another charge at the evil forces of Dr. Doom.

Can't wait until the next installment.......

 

[Fred W]

Pants, after you get everything in time and back together, you'll also be re-measuring the clearances. If any of them has become very large, that's your sign that a valve is bent. A bent valve will not be able to close fully, so the clearance will be increased

If they all measure good and what you expected to hit after the adjustments you made, then you are good to go.

 

[hppants]

I for one hope that we have reached the peak of this particular drama (or the rock bottom depending on your perspective).

It was very good for us to take a break yesterday and simply calm down.

I went back today and re-read everything, including a very detailed email from Ray (Thanks much, my friend) and I really think things are much clearer now. I do have a few follow up questions:

1. Ray - in your post #11 - is it your understanding that the orientation of the cam lobes pictured is what the #1 cylinder should look like. IOW - the view of that drawing is looking at the motor from the left turn signal side? If that is true, then the #4 cam lobes would be facing inward toward each other (as in Fred's picture).

2. Woofooshee - I'm still trying to understand the "lead" the cams part? If I understood you in post #16, by "forward" side, you mean the side of the chain that is closest to the exhaust header? Keep that side tight when installing the exhaust cam. Then keep the chain between the cams tight as we install the instake cam. Have a got that correct? I'm also thinking that I will zip tie the crank at TDC, then zip tie the exhaust cam after it is installed, then zip tie the intake cam after it is installed, then (and only then) release the cam chain.

3. In the same drawing shown by Woofooshee in post #16, there are cam lobes drawn in hidden lines behind the cam gears. Are those the cam lobes for cylinder #1 (I'm just backing up question #1 in this post)?

4. Also in the same drawing, on both cam gears, there appears to be some small notches or marks identified by an "A". May I assume that the orientation of the "A" marks ensures that we don't get the cam gears 180 degrees out of sync?

5. Trivial question - what does the "E" mean that is stamped on both cam gears?

6. Can anyone confirm that when the crank and both camshafts are oriented correctly for timing purposes, that at this instant, there are NO valves open (partially or fully)? IOW - are all of the lobes off the buckets? I think this is important. The reason we had trouble in the first place was because we were trying to over come the valve spring(s) to set the camshafts down. This very little amount left no slack in the chain to work. We were able to use the bolts (4 of them) on the cam bearing/block (the one with the lateral camshaft guide built in it) to overcome the valve spring. But it would seem to me that it would be a whole lot easier to set the time if we didn't have to fight a valve spring. If one (or more) of the valves is open (or partially open) when the cams are in time with the crank, can anybody indicate which (and by how much)?

7. Bob - in your post #25, you indicate that you learned a trick by "skipping a tooth". Can you elaborate on this, please?

8. Finally, thinking positively that we can in fact DO THIS, can anyone provide the torque spec for the crank rotor bolt? There was no lock tight on that bolt, but should we use some and if so, which kind (blue or red). Anybody have a problem with my previously proposed method of torqueing this bolt (bike on the ground in 5th gear, front wheel against a wall, rider sitting on the bike stomping on the rear brake)? Of course the compression of the pistons won't provide enough resistance for me to torque this bolt. If I meet a stop on a stroke, then we know there are much bigger problems than torqueing that bolt. I could use my impact wrench and hunk down on it, but the last thing I need now is a stripped or sheared bolt in a crankshaft. LOL.

At least for me - when dealing with any challenge, it's very important to fully understand where you came from and how you got here before you start moving forward.

Based on this, my best guess is that we had the intake cam out of time by about 45 degrees (lined on the arrows, not the straight marks - the difference in the drawing post #15 is about 45 degrees), and this caused the #4 intake valves to push open against the TDC of that piston. The valves moved the piston clockwise about 10 degrees. I know this because after assembly, I could rotate the motor clockwise about 150 degrees before a stop, followed by counter clockwise in the same amount. Upon stopping after the counterclockwise movement, the crank was about 10 degrees clockwise from TDC.

Of course what we don't know is if I bent #4 intake valves during assembly, or some other valves when I hit the stop 150 rotational degrees later. A set of tests should confirm this one way or the other.

As for the rest of you (including those of you that have sent PMs with well wishes), I am indeed humbled by your encouragement. We will give it another go and hope for the best. This thing is not the boss of me. I'm the boss of it!

 

[Fred W]

Yes, in that drawing of the cam sprocket and the timing marks, the dashed lines showing cam lobes would be the #1 cams, way on the opposite end of the camshaft.

Yes, when the #1 cams are in that position, the #4 cams will be in the position shown in my photo. The #1 and #4 cylinders are 180 degrees apart.

The FJR engine;'s firing order is 1, 2, 4, 3 so the #2 and #3 cylinders will be exactly 90 degrees and 270 degrees retarded (located CCW from the chain end) from #1's cams. They will be depressing some valves slightly at #1 TDC, but do not want to rotate the cam shafts as I recall.

What Intech was saying is to intentionally skip a tooth in the CW direction when putting the slack chain on the crank sprocket so that you will be on the right tooth when you tension the chain tight. This is easiest accomplished if you turn the crank backwards a few degrees (CCW) from the timing mark when fitting the chain. It is impossible to fit a tight chain over the sprocket teeth with everything exactly at the timing marks..

 

[Intech]

What Intech was saying is to intentionally skip a tooth in the CW direction when putting the slack chain on the crank sprocket so that you will be on the right tooth when you tension the chain tight. This is easiest accomplished if you turn the crank backwards a few degrees (CCW) from the timing mark when fitting the chain. It is impossible to fit a tight chain over the sprocket teeth with everything exactly at the timing marks..

I was moving the position of the exhaust cam not the crank, so to give me a little more slack I pushed the chain guide up and away from the crank sprocket. I was doing this to move the exhaust cam CW as you look at the sprocket end. It gave me enough slack to take the chain off the cam and rotate it to the right position. The only thing you have to be careful of is to keep the slack at the cam, so it doesn't drop off the crank. It actually was easy to do after I figured out how to position everything. If I had someone else there with me I could have taken a video as it is almost impossible to describe.

I am not sure what I did wrong in the initial process, but it is likely that the chain moved on the crank as i didn't take that cover off initially. I had it off for the final install, so I could see all the marks. The hardest ones to see are on the cam sprockets. A good light and a straight edge were helpful. It is also helpful to know that the marks you reference are different on the sprockets (noted earlier).

 

[Blind Squirrel]

Bob,

You should hold a clinic on this at your upcoming tech day https://www.fjrforum.com/forum//index.php/topic/165784-intech-day-iv-may-67-2016/?p=1270366. There has to be someone that wants to do a valve check!

 

[RaYzerman19]

Best keep it as simple as possible....... taking the cams out is like rebooting your computer..... fresh start..... now you place the cams as shown in the diagram(s), ensure timing marks are aligned as best you can get them, snug down the cam bolts (I do a progressive tightening to avoid any pressure in one spot that would crack/break a cam, even though there may be little danger). If all is aligned to #1 TDC, etc. then everything else is going to be in the right place. Verify the timing marks again, and if you have to tweak a cam's position by one tooth, you'll either remove that cam again or use the "skip a tooth" method... verify again once you've released the CCT.......... keep it simple.

Fred brings up a good point to check the clearances again to let you know if there's an issue with the valves seating....

 

[Fred W]

The reason that I mentioned turning the crank backwards slightly while slipping the chain on that crankshaft sprocket is because it is easier to back the crank up than it is to move the cams forward since you'll then be fighting the valve springs.

The reason they warn you in the FSM to only rotate the crankshaft in the forward (CW) direction is because that keeps the chain tight on the forward run down from the exhaust cam down to the crank. Rotating the crank CCW can pull the slack out of the rear chain run and compress the CCT, and would allow the chain to start skipping teeth on the crank or cams. Since the chain is not yet connected, there is no problem with backing it up a few degrees to slip the chain on. Then rotate the crank back CW to the timing mark and check the timing marks.

Like Bob said, it's easier to do than to describe.

 

[Intech]

The reason that I mentioned turning the crank backwards slightly while slipping the chain on that crankshaft sprocket is because it is easier to back the crank up than it is to move the cams forward since you'll then be fighting the valve springs.
The reason they warn you in the FSM to only rotate the crankshaft in the forward (CW) direction is because that keeps the chain tight on the forward run down from the exhaust cam down to the crank. Rotating the crank CCW can pull the slack out of the rear chain run and compress the CCT, and would allow the chain to start skipping teeth on the crank or cams. Since the chain is not yet connected, there is no problem with backing it up a few degrees to slip the chain on. Then rotate the crank back CW to the timing mark and check the timing marks.

Like Bob said, it's easier to do than to describe.

Well I must clarify that the technique I was describing was to rotate the exhaust cam with it INSTALLED. That is why I did give the slight CCW turn on the crank AND push the chain guide up enough to get the slack required to disengage the chain from the cam sprocket.

 

[hppants]

Very good descriptions regarding the "leading" portion of my concerns. I do understand what you are writing and will hope to get everything correct. Regardless of how I do it, as long as I get all of the CORRECT timing marks aligned with the chain tight, and the rotate the crank two revolutions and verify all marks re-timed, then I guess I'm good to try a compression test and hope for the best.

Anybody wanna take a stab at the torque for the crank bolt?