1166 Kit Engine Knock

[Boozy Creek Beast]

Piston to wall clearance was done by a Pro that used the specs provided by J and E to complete the bore. The gaskit used for the bottom end was very thin. It is the same one that I have used in the past to clean up an oil leak. I belive that there may be a problem with the Cam Chain tentioner. I am going to replace it and see what happens. I will let everyone know how it turns out.

The Beast

[Boozy Creek Beast]

Still have that engine knock.

Well I have replaced the Cam Chain Tentioner and my knock still knocks. I will be taking the top end back off tonight. If I see no cylander damage I will stop at the head. I do not have a mic. so I will not be able to check the tolarances between the pistons and the top of the cylander unless I can check it with a feeler gauge. How much space should you be able to see between the pistion at TDC and the top of the cylander walls. Is there a specific amount of clearance. I will have to eyeball it right if the feeler guage is not good enough but as long as the piston dose not come out past the cylander walls shouldn't it be good? I still belive that I some how have a problem with my timeing as it sound like the knock is coming through the head. I have checked the timing and the valve clearance again and it seams to be correct. I have not replace the Cam Chain and since the bike has more than 60,000 miles on it could the cam chain have streched enough to throw of my timing. It may sound crazy but I just seam to think that is some how in my timing. I will post the results of my tear down tomorrow which may shead some light on this painful subject.

The Beast

[hungryman]

I hate to be the bearer of bad mews, but you can't check piston to cylinder clearance with a feeler gauge.

[Boozy Creek Beast]

That was more a joke that a serious comment. The piston to cylander clearance is good. My question is about the piston at TDC clearance to the top of the cylander.

The Beast

[Billy Ricks]

That was more a joke that a serious comment. The piston to cylander clearance is good. My question is about the piston at TDC clearance to the top of the cylander.

The Beast

If you want to check piston to valve clearance it means a disassemble and reassemble or two. You have to use Silly Putty or some other type of clay. Place a little across the valve reliefs in the piston and assemble the topend. Turn the engine over by hand a revolution or two and disassemble and see what the clay looks like.

[zooke-158]

To check Piston to Head clearance. I have removed the plugs and using very soft solder, maneuvered it around the valves and rotating the crank pressing the solder. Then take a measurement. I did this on three different areas in the combustion chamber, kind of like a triangle.

[rosco15]

If your pistons are set level with the top of your block. "0-deck height" Your piston to head clearance should be fine. Using the supplied gasket. Also assuming this is low compression motor.

To check piston to valve just us a screw driver. Put the screw driver under the cam and leverage down on the rocker arm. I use a little duck tape where the screw driver hits the adjuster. Helps avoid damage. You need to check it around 8 deg plus or minus a bit.

Just a thought, but did you use one of the unbreakable cam chain guides. The stock ones can break pretty easily. Make a terrible racket.

[Boozy Creek Beast]

Last night I planned to take apart my top end but had a family issue and was unable. I will do the work tonight. I started the bike again and by using a screw driver pressed to my ear (showed to me by a Suzuki tech) I was able to better understand were the knock is coming from. I now belive that it is not in the Timing but it seams to be a valve tap and I may need to purchase a cylinder spacer. A.P.E sells them in 9 different sizes from .020 through .750. The only problem now is which one. How would I determin the size I need? Any the biggest question is what should I check to make sure that I did not damage any components such as the Valves of the pistons.

Thanks for everything!!! I do not know what I would have done with out all of your help.

The Beast

[rosco15]

Before you take it apart make sure you adjuster screws are set right. You should have 6-8 thou from the adjuster to the tip of the valve. Don't check between the cam lobe and the rocker arm. Check between adjuster and valve. I had to make a custom tool to get down in there. A loose one will also make a bit of noise.

I'm assuming your talking about a spacer to space the block up. When you get the head off put the #1 and #4 pistons to top dead center with the block still on. Check to be sure the piston is level with the top of the block. Down in the hole is bad and sticking out over the top of the block is also bad. If the piston is sticking up past the block then you need a thicker gasket. I think cometic can hook you up to about .060. I would think a thicker gasket would be better than a spacer plate. If the valve is hitting the piston you should see marks from the valves on the piston. The vlave is harder. I have pics of that if you want.

I had my valves touching pistons and it didn't make any noise I heard. heck another guy I race with had his pistons actually touching the head. It also never made any noise. If you can hand crank the motor around then I would suspect your problem is someplace else.

Now have at it and keep us updated.

[Boozy Creek Beast]

Well I have taken the head off and I am very pleased to say that there seams to be know damage to the pistons, cylander's or the valves. The only thing I can see is a very very small almost unnoticable half moon ring in the 3rd and 4th cylander, right side exhaust, piston valve port. The ring is so small that I almost didn't even notice it. As for the piston TDC cylander clearance, the pistons at TDC are completly flush with the top of the cylander. I checked it the only way I could by rubbing my fingers over each piston as it was set at TDC and they all were smooth as a baby's rear end.
So where do we go now. I was talking with a tech at A.P.E. and he thinks that my cams are out of time. I would also like a little more information about the adjuster screw idea that Rosco15 brought up as I am not really sure what he is talking about. I don't belive I need a spacer or even a thicker gaskit to stop the knocking I just need better adjustments on my cams and timeing. I have been told a couple of different valve setting and I would like to know what you all think. I set my Valve at .005. Should the be .006 through .008? What seams to be the best setting.

[Big Jay]

If you have a big bore kit and stock cams, there is no way you will have piston to valve contact unless you have the cams out of time.

Jay

[RacingJake]

So you are saying the halfmoon marks are on the pistons at the valve reliefs?? And there is no marks on the combustion chamber area where the top of the piston could be hitting the head.

Usually it's the intake valve's that make contact with the pistons due to too much advance intake cam timming. What type of cams are you running. If 3 and 4 have touched most likely 1 and 2 where touching too not unless you where running more valve to rocker clearence.

Also check the valve guides for cracks or missing pieces inside the ports since the valves hit the pistons the valve stem will flex and could break the tip of the guide off.

Another way to tell if the valve's are making hard contact with the pistons is to check the area between the valve tip and rocker arm adjustment screw. If it looks like a jackhammer has been in there that could be a warning sign.

So it sounds just like a cam timing issue, maybe it jump a few teeth when you where trying that other tensioner. Install a new head gasket, set cam timing and tensioner at TDC, set valve/rocker clearance, check valve to piston clearance 50thou on intake and 75thou on exhaust at 15 degrees before TDC working your way to 15 degrees after TDC. Just make sure your on the intake stroke and exhaust stroke.

Good Luck

[Boozy Creek Beast]

Sorry I was very tired last night when I sent that post. The half moon rings are on the intake valves. Sorry for the confussion. I will start working on the Cam timing tonight. With all of the Cam chain tensioner problems I have had I more than likely skipped a tooth there for throwing off my cam timing. I will put it back together and let you know the results.

The Beast

[RacingJake]

Hey that's not a problem, forgot to asked if you are using adjustable cam sprockets.

You can't really trust the notches on the end of the cams, they could be off alittle. That's why I use a degree wheel, dial indicator just to make sure the cams are openning and closing at the right time.

[Boozy Creek Beast]

Jake,
I have a set of adjustable cam sprocket but I am useing the stock ones at this time. I am a good novice tech and would love to use the adjustable sprockets but I have never done the work and I do not have a dial indicator. Are they expensive? I am a little nervious doing the work for the first time by myself and would appreciate it if you could let me know the basics. It can't be that hard and with everything that I have done so far it would be a shame to not complete the job.

The Beast