1100cc Chery Engine - Need Help

[Williamson]

First I’m going to start off by telling you how the problem started. 

I have a XY Ground Pounder with the 1100cc Chery Engine; I sunk it in a mud hole and had water up middle ways of the muffler; about 10 seconds of being stuck and hitting the gas all of a sudden the motor started making a tapping noise that sounded like it was coming from the head (the buggy never died while I was stuck on the mud hole). I finally got pulled out and had to proceed to drive the buggy out the rest of the trail back to my truck (buggy still making the tapping sound and I lost about half of my power and had to keep the buggy going at around 4,500RPMS).

I got the buggy home and first thing I drained the oil and dropped the pan to find water, dirt and metal shaving in the oil. I proceeded to check the rod bearings and mains; they had very little play but had a lot of wear; I also took the head off and inspected everything and took the pistons out everything looked fine up top. So I ordered a new crank, main bearings, rod bearings, head gasket and bolts; after waiting for a month for the parts to come in I finally got the block and everything clean and put the new parts in and torqued to spec. I got it all put back together and new fluids, plugs and filter put back in and everything aligned and put back in time while TDC. I started the buggy and instantly it’s still doing the same thing; so I took the head off and inspected the springs and valves but everything seems to be good. I also did a compression test on each cylinder with great readings. 

Has anyone ever had the same problem or know anything?

 

Thanks for taking your time to read. 

[Travis]

What does your camshaft look like? Does it have hydraulic lifters?

 

[Williamson]

Yes; the 1100cc Joyner’s have the same motor. I know the problem is probably in the head but I’m not seeing anything. A new complete head is $450 from China; and that’s not including shipping.

[Travis]

Hydraulic lifters use oil pressure, and should be full of oil to perform properly. It's possible water or dirt got in them and that's what is clacking/causing them to clack.

I know when cars get old and start to click is usually due to the lifters not holding good hydraulic pressure.

[Dan B]

I agree with Travis.  Check valve lifter to camshaft clearances with the valve for the cylinder closed (cam lobe not in contact with the lifter).   Dirt may have worked its way into the lifter.  I'm not sure if this engine has hydraulic lifters (I don't know).  If they do, I don't see where shims are needed to adjust clearances.  But a lifter could be binding due to dirt whether a solid or hydraulic lifter.  Were you able to determine where the metal shavings came from?

[Williamson]

Metal shavings came from the rod bearings; everything below is new besides pistons and rings which are in great condition. Attached are some pics. The valves seem to open all the way a close all the way too.

[Dan B]

I would still check the valve clearances (cam to lifter clearance).  Can't really tell clearances by looking at the valves.  Lacking any other info that might say otherwise, the intake is 0.18mm/0.007"±0.05mm/0.0019", exhaust 0.25mm/0.0098"±0.05mm/0.0019".  Excessive clearances will cause the cam lobe to "slap" against the lifter causing the clicking/clacking noise.

[Williamson]

I’ll have to  check them tomorrow. Would that cause it to loose a lot of power? If it was off by a little.

 

[Dan B]

My theoretical analysis of incorrect valve gap.  I wouldn't say a lot of power if one cylinder, but more pronounced if on all cylinders.  A larger than normal gap will cause the intake valve to open late and close early.  The compression will be a little lower (less fuel/air mixture gets into the cylinder on the intake stoke) and cause some loss of power.  Does the engine othewise runs smooth (not missing)?  Your compression should be near 130 psi at sea level (based upon 14.7 psi atmospheric pressure and a 9.5 compression ratio minus a few pounds due to other factors).

A larger than normal gap on the exhaust valve will also cause it to open late and close early which, in turn, keeps more burned fuel in the cylinder on the exhaust stoke, prevernting a full charge of fresh fuel/air mixture from being fully injested into the cylinder on the intake stroke.