cjsdad 18 #1 Posted June 28, 2012 I have learned from some hard earned experience lately that the camshaft in a K-181 engine tends to get broken when the connecting rod comes apart. I learned the unfortunate truth when I bought a parts engine for the camshaft. I am sure the seller never knew the cam was damaged because the break was virtually invisible until I tried to remove the cam from the block. The cam fit so precisely in the block that the crack was impossible to see and the two halves were "keyed" together by the ragged fracture. The cam turned with the crank perfectly. After removing it I found the shaft to be broken and a small, almost invisible dent in it from where the connecting rod impacted it and obviously that is what broke it. As a parts engine it was well worth the price though. All this leads me back to the thread title! I need a good usable camshaft for a Kohler K-181 engine. I need one with good sound lobes for the valves as well as the points pushrod. Obviously the better shape the more I would appreciate buying it. Can anyone help me out with this? Share this post Link to post Share on other sites
Fordiesel69 235 #2 Posted June 28, 2012 http://www.ebay.com/itm/John-Deere-110-112-Kohler-8HP-K181S-Camshaft-AM34912-/220945821979?pt=LH_DefaultDomain_0&hash=item337165b11b A bit steep but would do if you were in a hurry. K181 for whatever reason seem to break cams. Not sure why. At least all of us here know when it starts knocking to rebuild it before it blows. But hey, if everyone was smart we would not be finding good deals....................... Share this post Link to post Share on other sites
cjsdad 18 #3 Posted June 28, 2012 http://www.ebay.com/...=item337165b11b A bit steep but would do if you were in a hurry. K181 for whatever reason seem to break cams. Not sure why. At least all of us here know when it starts knocking to rebuild it before it blows. But hey, if everyone was smart we would not be finding good deals....................... The reason the cams break is because the sweep of the connecting rod is so close to it. The cam is even clearanced to allow for the longer stroke of the K-181. It doesn't allow room for anything out of shape swinging around on the crank. The two broken camshafts I have seen have a little shiny spot that indicates where the con-rod impacted and snapped it. The problem is that the cam fits the block so nice and tight that the break is difficult to see. So yeah, if your K-181 is knocking, take it apart before it comes apart on it's own! Save a few bucks on parts that don't actually need to be replaced! Share this post Link to post Share on other sites
Fordiesel69 235 #4 Posted June 28, 2012 I wonder how long a cracked cam would work if it is shimmed proper and tight? Sometimes they crack very jagged and I would think it would still work for a long time...... Share this post Link to post Share on other sites
MarkPalmer 80 #5 Posted June 28, 2012 http://www.ebay.com/...=item337165b11b A bit steep but would do if you were in a hurry. K181 for whatever reason seem to break cams. Not sure why. At least all of us here know when it starts knocking to rebuild it before it blows. But hey, if everyone was smart we would not be finding good deals....................... The one in this ad is the older style two piece non-compression release K181 cam. The older cam will interchange, but the picture isn't showing the small piece for the end that is the cam for the points, which is needed for it to work. Instead of exhaust valve compression release, this cam retards the ignition timing during startup to prevent kick-back. I am actually in the process of putting one of these older style cams in a K181 I am working on at the moment. -Mark- Share this post Link to post Share on other sites
Fordiesel69 235 #6 Posted June 28, 2012 Yep, I didn;t see that. It is useless unless you / them have that piece. Share this post Link to post Share on other sites
cjsdad 18 #7 Posted June 28, 2012 I wonder how long a cracked cam would work if it is shimmed proper and tight? Sometimes they crack very jagged and I would think it would still work for a long time...... Mine actually ran and I don't know how long the cam was cracked. I am just guessing here but since the reason for the first tear down was the con-rod breaking the cam was probably broken too. It ran that way for probably 10~15 hours. It was still running when I took it apart this time but the cam was jumping forward and backwards. When the cam jumped forward the valves would slam shut causing a knock that sounded like the rod was going bad again. Fortunately the way my cam broke the advance weights were keeping the cam relatively close in timing. You can see in the pic below how the leg of the weight was "keyed" into the cam casting to keep it rotating. If it cracks in the middle I imagine it could be catastrophic to the engine block. If the engine is running when the cam finally separates the crank counterweights could impact the cam. If the block isn't strong enough to stop everything, it's gonna crack somewhere! Share this post Link to post Share on other sites
MarkPalmer 80 #8 Posted June 28, 2012 The original cam in my K181 broke near the middle, but it wasn't from the rod being worn rather the lower end of the dipstick broke off and must have got lodged between the cam and the rod when the engine was running. The cam, rod and piston all had to be replaced, but there was no damage to the block or crank. The piece of dipstick also took off the fuel pump's actuator lever. This was my father in law's engine, it must have been interesting when all this happened. Share this post Link to post Share on other sites
