So in another installment of K101 (that is karting 101 for those not in the know)...

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Mario_d &raquo;</TD></TR><TR><TD CLASS="quote">
Alas, I think I have found the bane of my power issues...



If you look at the edge of the cylinder, it is not smooth. Those jagged edges don't belong there. SVH believes that when my head was leaking @ Dixon, the engine tried to compress the water. Water - 1, Engine - 0. So my head and cylinder are 99% toast. I could try to have the machined, but I will be on the look out for a new combo.

Another angle:


But this is racing. This motor wasn't going to last me forever. Well, my wallet was hoping for it.
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That was from last year...fast foward to now....My new Swedetech setup ended up compressing water as well. Faulty o-ring FTL.

The damage to the piston when trying to compress water:


Another angle:


The intake side of the piston took a beating. The interesting thing about this is that the motor was still running strong.

Here are some pics of the Woltjer head/cylinder that were repaired.

Cylinder:






Head:




Many thanks to Derek G. for fixing this engine setup. He also fixed my Swedetech setup that decided to compress water at Buttonwillow as well. I feel so racer like when I say I have a race motor and a practice motor.

I need to set the proper squish, check jetting, and remount my pipe. Then I can hit the track again. Hmmm, love the smell of 2 stroke oil and race gas in the morning.

m-


Modified by Mario_D at 9:53 PM 4/3/2008

 

if you need that motor ported, PM me.

 

Love how it has o-rings to seal the head on, haha

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">love the smell of 2 stroke oil and race gas in the morning.

m-</TD></TR></TABLE>

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by sporkcrx &raquo;</TD></TR><TR><TD CLASS="quote">Love how it has o-rings to seal the head on, haha
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When I first saw the o-ring setup I was a bit leary of it. But when I found out that engine builders went to the o-ring due to head gasket failure due to high compression, I wasn't going to argue.

Rule of thumb, if you have to split the head and cylinder, replace the o-rings.

m-

 

I'm no expert on 2 strokes, but that doesn't look like water damage to me. How many hours on the motor?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by solo-x &raquo;</TD></TR><TR><TD CLASS="quote">I'm no expert on 2 strokes, but that doesn't look like water damage to me. How many hours on the motor?</TD></TR></TABLE>

Top end had all of 50 minutes on it.

It was water. I had water in my overflow tank. Steam was coming out of the spark plug hole. That is a big no no. With water in the o-tank and steam coming out, the cooling system was getting pressurized by the compression stroke as the compression leaking into the water jacket forcing the water into the overflow tank.

The cooling system is big enough on my setup to not overheat.

m-

 

Wow, that sucks. I've always been a big fan of shifter karts.

 

Water in the cylinder (assuming the volume of water is greater than chamber volume @ TDC anyways) will bend the rod or wrist pin or break the piston. That looks like a lean burn or sandblasting from running no filter.

 

regardless of the amount of water, it cant be compressed and will damage the crown. but i would say if it did that much damage to the crown, it probably needs more than just a new piston. id say more a new rod/crank.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by nfn15037 &raquo;</TD></TR><TR><TD CLASS="quote">Water in the cylinder (assuming the volume of water is greater than chamber volume @ TDC anyways) will bend the rod or wrist pin or break the piston. That looks like a lean burn or sandblasting from running no filter.</TD></TR></TABLE>

Pilot jet was spot on and I was running a bit rich on the main. The engine builder also agreed on water damage. With a faulty o-ring setup the water, when compressed, leaked into the cylinder and back out.

As for the damage to the rest of the bottom end, I didn't see anything. Once I set up the squish, I'll be able to get the final picture on it.