Poor old engine... - Page 2

johncub7172 · #11 01-17-2010, 06:33 PM

looking more carefully, its eazy to see that the piston is damaged.

johncub7172 · #12 01-17-2010, 07:08 PM

the old head gasket on left, new carbon gasket on right. looks like the old ones were made pretty well. the carbon worked good.

johncub7172 · #13 01-17-2010, 07:24 PM

yes i do, and prep'in for paint starting this tuesday. i'am hot married yet, so i have my own home. paint job might turn out good.

Merk · #14 01-17-2010, 07:43 PM

I would consider replacing the governor gear (if it is a plastic gear) while you have the motor apart. The gears get brittle with age.....trying to save some aggervation down the road.

Matt G. · #15 01-17-2010, 11:45 PM

Is that new gasket aftermarket? The reason I ask is because the Kohler gaskets have a "fire ring" like the old one on the left in your picture. Most aftermarket gaskets don't have that, and I don't think they work as well. It's difficult enough trying to keep head gaskets from blowing on these because the head and block are different materials, so it needs all the help it can get. Kohler's gasket is best...I would get an OEM gasket with the fire ring.

johncub7172 · #16 01-18-2010, 01:42 AM

the bag on the left was what the new head gasket came in. it is totaly identical to the gasket on the right in the last picture,which came in the bag on the right in this picture. looking at the old head gasket, is why i replaced it for the new one. my local cc.dealer said that they dont make the old style anymore. they are carbon fiber now and are rather soft, as i was told by him not to bend it. both part numbers are the same [41 041 10-s] for the k161. i ran the gasket all summer and no leaks were seen again. when i built my 383 stroker, it was recomended that i use a carbon fiber head gasket when useing aluminum heads on an iron block, but cost more than the copper that i went with. as far as i can tell, yes, now they are Kohler Genuine Parts.i have no idea why my old gasket leaked, it realy does look good.

johncub7172 · #17 01-18-2010, 02:23 AM

your advice is wonderful. left pict. shows a steel gov.gear! next shows a clean and inspected inside components.

Matt G. · #18 01-18-2010, 07:04 AM

Oops...I forgot we're talking about a K161

I think the only gasket you can get for those is the kind without the fire ring. Never mind then...

johncub7172 · #19 01-19-2010, 03:55 AM

here is a picture of the 71 k161 all put back togeather. was thinking a bit about what the heck happend here. i'll admit, i was running her hot and hard. after a bit, we started to loose power, had to use 1st. gear to get it in the shop. on our way up the drive, a flame appeared out from the muffler, then came the knocking. i shut it off right there. about a hour or so, i started it up and the knocking was still there but no flame this time. and just that quick, she went silent, only the s/g on and running. so there was very minimal time from the power loss, to the flame, to the knock. now i know the crank is super strong v.s the piston and connecting rod. no bearings in the c.rod, as made. guess the rings went, then the piston. looking at the picts. i've all ready posted, its funny to me how that c.rod buckeld and the big scuff on the piston. so my question is: would it be possible at all for the crank not to be damaged too bad, given the time it all went down, the big difference in the two materials. if i can get an "out of round " reading of the journal with out removing from block, having the cyclender honed and new hardware, i would be in good shape. but i never broke stuff like this and dont realy know the very extendent of damage caused by. i'll clean with emery cloth and go from there.

ol'George · #20 01-19-2010, 09:04 AM

It has been my experience over the past 50 years is that the scuffing above the top ring is caused by heat build up,
carbon deposits, and wear.
Combustion temperatures get high, add some carbon, and the aluminum piston is near the melting point.
so it tends to gall the piston to the wall at the top of the bore.
By design, the piston is slightly smaller at the top, above the ring, but as the piston wears, and the bore wears farther down, the galling takes place on the piston as it rocks in the bore when it is at top dead center.
On repairing the crank journal:
I have used a flat file to CAREFULLY remove the aluminum that is galled on the journal, successfully many times.
but it has to be done carefully so you are only removing the alum, not iron journal .
if you use emery cloth you will remove both, --not good
another trick is to use acid, it will eat the alum. but not the iron journal ( wish I could remember the name of the acid) but they use it to clean alum. wheels. ( sulfuric acid works also)
acid takes a little longer to do, as I dab it on and go do something else, checking back periodically.
---the acid works well on cylinder walls to remove galled alum. in 2 stroke applications.

On the head Gskt:
They usually blow right above the exhaust valve as that is where the most heat is.
check your head for flatness, and if need, surface it and proper torque is very important on those engines, retorquing several times after it has been run @ operating temp.