Time for me to address the 800lb Gorilla in the room.(Engine knock thread) REVIVED!

[mcgovern61]

My '81 engine was a high mileage engine that had some snot kicked out of it by one of the PO's plus it did sit for a long time out of use. My assumptions on this engine are....high mileage, found worn springs, most likely loose bearings in the lower end, and valves that were marginal. On the plus side, it has good compression, good oil pressure and starts every time! (Plus it would run right up to 8k without even thinking about it!)

I would be willing to donate this engine to anyone who would like to continue to follow up on it and continue the path of diagnosis. I do not have the money or another frame to put it in to try it out. :wave:

 

[dan filipi]

I have started my complete 1100 build.

In order to source this knock I'm having the heads done up first.
They're being completely reconditioned by a highly recommended machine shop with a lot of experience working on aluminum heads.

They will get:
1. all new stock springs
2. Valves and seats examined and lapped
3. gasket surface trued
4. Guides replaced if needed
5. New seals

When I assemble they will get the 1200 cams.
These heads will go back on as a test to see if the knock is still there.

I found $25 head gaskets online from a guy that has them made, this is a good opportunity to find out if they're any good.

This is the build thread

 

[joedrum]

only surface the head as a last resort dan thse are 0 tollerence motors dan the heads are small and warpaged s not realy a big problem ....thy could only be lighty touched.... :mrgreen:

 

[dan filipi]

As I rode down our alley it occurred to me sound bounces off the block wall pretty good so I got a new video of the knock while sitting right next to it.

I'm on a mission to solve this mystery and won't stop until I do, or I die first.

The knock is really evident at 1:05 and 1:09

[flv]https://classicgoldwings.com/forum/vids/MyKnockVid_7-22-11.flv[/flv]

 

[dan filipi]

I'm pulling the heads and installing the rebuilts today.

I'll mic the cylinders before putting the heads on but what else can I look for at this point with just the heads off?

 

[slabghost]

push the piston dome at the cylinder wall at top and bottom to see if it will rock. Any movement will indicate excess skirt clearance.

 

[dan filipi]

Left head is off.
I'm measuring the cylinders horizontal and vertical at the lowest point I can with the piston in place, cylinder center, and cylinder top just below the combustion ring.


It seems like number 4 piston will rock ever so slightly.

Will post the measurement and findings as I go along but go ahead and post any other suggestions you might have.
I'm open to every idea.

 

[mcgovern61]

Left head is off.
I'm measuring the cylinders horizontal and vertical at the lowest point I can with the piston in place, cylinder center, and cylinder top just below the combustion ring.


It seems like number 4 piston will rock ever so slightly.

Will post the measurement and findings as I go along but go ahead and post any other suggestions you might have.
I'm open to every idea.

Rocking at all is not good. My 81' pistons would not rock at all. (While I had both heads off, I was checking for loose bearings by pushing on them after TDC and rocking them.) :crying:

 

[slabghost]

While you are there try short movements of the crank in both directions. Any noise may indicate wrist pin slop.

 

[dan filipi]

No noise or feel of any slop in either direction.

K, both heads are off.

I can rock each piston VERY slightly with both thumbs on the piston and using all my force.
With only one thumb I cannot rock them.



#3 and #4 show staining on bottom side of cylinder like there was water sitting in the cylinders at some time.
I knew this from before, surfaces are smooth with no pitting whatsoever.

Both #1 and #3 have some slight scratches in the piston direction near bottom of the cylinder. Cannot feel any scoring.

Here's my measurements:

All 4 cylinders have between .002 and .004 taper, book says .006 Service limit.

#1: .9560
#2: .9540
#3: .9545
#4: .9540

Service limit: .9567

#1 is largest, makes sense since that cylinder has those scratches which would account for increased wear diameter, although #3 has the same scratches and measures smaller indicating less wear.

The numbers being within service limit make sense also because all 4 have good compression, 160-165.
New spec being 171 so accounting for the above increase in cylinder diameter wear from Standard specs of .9528- .9533, there's my drop in compression.

Here are pics of each cylinder.
I don't think any of these imperfections can result in the knock I'm searching for (or can it?) but here they are anyway:

#1

#2

#3

#4

Going to have lunch and think over what is my next step.

 

[mcgovern61]

Do not know if it will make any difference, but roll the engine so that #1 is at TDC and then ever so slightly roll the engine until #1 starts down the cylinder. At about halfway down, see if you can rock it up and down. (It looks like it is sitting low in the cylinder.)

 

[slabghost]

I'm not absolutely certain but I think if you can rock the pistons enough to see movement that is too much.

 

[dan filipi]

.... roll the engine so that #1 is at TDC and then ever so slightly roll the engine until #1 starts down the cylinder. At about halfway down, see if you can rock it up and down. (It looks like it is sitting low in the cylinder.)

I'm not following,

Do which
turn the crank so #1 piston is 1/2 way down the cylinder?

Try to rock it up and down meaning looking for any piston to cylinder clearance/rocking with piston at center travel?

 

[mcgovern61]

.... roll the engine so that #1 is at TDC and then ever so slightly roll the engine until #1 starts down the cylinder. At about halfway down, see if you can rock it up and down. (It looks like it is sitting low in the cylinder.)

I'm not following,

Do which
turn the crank so #1 piston is 1/2 way down the cylinder?

Try to rock it up and down meaning looking for any piston to cylinder clearance/rocking with piston at center travel?

Yes, turn the crank via stator bolt until 1/2 way down and using your thumbs or two fingers press at the top and bottom alternately to see if it has any movement. When you first push, take notice if the piston travels further in at all (bearings loose). Otherwise, you are looking for movement to see if the skirts are worn.

 

[dan filipi]

Understood.

Tried a couple times on all four pistons just after top and a bit lower and felt or saw no movement.

One thing I found, maybe not the cause but maybe has some relevence here.....

When I pulled the right head the odor was much like the smell of gear oil.......maybe burned or overheated oil.

The oil orifices were installed with the large end against the block.
The parts heads were the other way, large end against the head.

Microfiche looks like large end should be into the head but not certain, what is the proper direction?

 

[mcgovern61]

Haynes says, "The oil feed nozzle should be fitted with the shorter narrower end installed towards the block."

Interesting quote in Clymer, "The valves on the GL1100 must not be ground as they are manufactured with a special surface on the valve face. If the valve is rough, worn unevenly or contacts the valve seat improperly, the valve must be replaced."

Well, all of the valves on my '81 meet this criteria! :swoon:

 

[mcgovern61]

I was just looking through the PDF of the Service Manual and in section 8 page 3, it lists troubleshooting noises.

"Knocking or abnormal noise"
*Worn pistons and cylinders
*Excessive carbon buildup on piston head

 

[dan filipi]

Haynes says, "The oil feed nozzle should be fitted with the shorter narrower end installed towards the block."

Thanks, that's the way I put the left head on.

 

[dan filipi]

Rebuilt heads are on and running.

These heads were rebuilt by a machinst, 3 angle valve grind, new springs and new guides.
I swapped the rocker rods around for a new rocker race surface.

Running 1200 cams.

The valve train sounds great!
I cant hear any tappet noise at all rpms, the new springs were worth the investment.

Knock is still there :crying:

[flv]https://classicgoldwings.com/forum/vids/1100_engine_rebuild/FirstRunAfterRebuiltHeadsInstalled.flv[/flv]

Next step, put this runner all back together then pull the parts motor and rebuild it.

 

[joedrum]

whats on top of the false tank dan :mrgreen:it sure is queiter for sure ....this some pretty good evidense on the springs not lasting forever and need changing on 30yr old bikes :mrgreen: