1166 Kit Engine Knock

[Boozy Creek Beast]

I have a 1980 1100E. I have just completed my 1166 kit upgrade and she starts with no problem. For some reason I am experianceing an engine knock and or a valve chatter. I have checked the timing and valve clearence and everything seams to be correct. I am at a loss for words at this time so any information you can offer would be helpful.

Thanks
The Beast

[Billy Ricks]

I have a 1980 1100E. I have just completed my 1166 kit upgrade and she starts with no problem. For some reason I am experianceing an engine knock and or a valve chatter. I have checked the timing and valve clearence and everything seams to be correct. I am at a loss for words at this time so any information you can offer would be helpful.

Thanks
The Beast

With the bump in displacement it could be jetting or octane causing the knock. At least let's hope it's as simple as that. How closely did you check the rods?

[hungryman]

With the bump in displacement it could be jetting or octane causing the knock. At least let's hope it's as simple as that. How closely did you check the rods?

I think they have 2 different compression ratios on this kit - which one did you get?

[rosco15]

Is it banging at an idle. Mine would kind of bang or knock when the idle was really low.

If not that I would check valve adjustement and piston to valve clearance.

[ronin1166]

Detonation due to increased C/R?
I assume you have the 10.25:1 'Street' Kit?

If it's the 13:1 'Drag' Kit, no way it's gonna live on the street.

Definitely check the timing at idle.

Pray it's not valve-to piston crown interference. What cams are you using?

Various drag shops (i.e. APE, Orient Express, etc.) can provide thicker base gaskets, to drop the C/R if necessary. Unfortunately, that means pulling the block...again...

I'll be doing an 1166 upgrade soon also. Keep us Posted.

Ted

[jgordon]

We hope that your machine shop didn't give you too much on the piston to cylinder wall clearance. Wiesco has a clearance of about 1-1/2 to 2 thousands if I remember correctly. If they are Wiesco street pistons they are 10.25:1 and the ones that I put in my street bike are just as quiet as stockers and it doesn't ping.

[RacingJake]

What about the cam chain tensioner?

[triffecpa]

I built a TT600 Yamaha dirt bike with an oversized Wiseco piston. It knocked also. I thought that it was valves, but that didn't fix it. Tore the engine back apart and found that I had incorrectly installed one of the piston pin circlips. It had popped out and the wrist pin had slid over to the side until it gouged the cylinder wall. In the meantime, the piston was held in place with only one side of the wrist pin and the knocking that I heard was the piston cracking. Needless to say, the piston and cylinder were toast. Maybe you're luckier than me though. The only way that you're going to be able to tell is to tear the engine back apart. TR

[Boozy Creek Beast]

I appreciate all of the input. I baught my set of pistons from J and E through A.P.E. and made sure that I got the 10:25:1 street kit. I was checking out some information from Biker 66 on how to make an adjustable cam chain tentioner but am not very happy with the results. I am going to purchase a new one from A.P.E in the morning to see if it makes any difference before I go through the trouble of breaking it down again. At this time it starts and runs better than it ever has with no smoking and it even ideals cold better than ever. I am afraid that there may be a small differance in the piston higth that may be causing the knock. If so wouldn't I see it in the plugs when I take them out. The pistons that I purchased at J and E are for and 81 as they do not list any pistons for an 80. I spoke with the Tech at J and E about the difference and they confirmed that the engines are the same. I am useing the stock cams at this time to cut down on cost.

The Beast

[Billy Ricks]

If you're running stock cams I doubt that clearance is a problem. Piston heighth shouldn't be a problem either. Could be the small end of one or more rods is worn beyond spec. The tensioner could be the culprit. At least it's a relatively inexpensive and easy place to start.

[Boozy Creek Beast]

So to try and answer all question the only thing that I changed were the pistons. Everything else is stock except for my V and H header and my stage 1 jet kit.

The Beast

[pano]

When I installed my manual cam chain tensioner it made a heck of noise before Racing jake suggested I tightned it up. It may be that simple.

[Boozy Creek Beast]

I sure hope you are correct. I would hate to have damaged the engine because of something stupid I did. I will let everybody know how it comes out.

The Beast

[RacingJake]

Also did you check the deck height, ie piston at TDC and is it level with the top of the cylinders without the head gasket. Some base gaskets are .005 (paper thin) and some are .020 and some are even thicker.

If you got one that's too thin it could be causing the knocking as the piston reaches TDC, it's higher than the head gasket hitting the bottom of the head. Sparkplugs won't show you anything as they are too high in the head with 10-1 pistons. Now if they were 13.5-1 pistons the sparkplug electrode can touch the top of a dome piston if a base gasket is too thin.

[jgordon]

What do you have for piston to wall clearance?