k361 1650

malchren · #1 10-28-2014, 06:30 PM

I've been throwing the idea around in my head about building a k361 to drop into my 1650 that is awaiting resto. I am also thinking about adding power steering like Rescue11 did with his 1450 http://www.onlycubcadets.net/forum/s...ad.php?t=32307) i know that one has to cut the "wings" off of the block and weld in blocks to allow the correct size oil pan sit in there. I would make a new exhaust that would use the original can so that from the outside the tractor looked the same. I also know that they have problems with the rockers locking up and dropping valve seats. I am thinking that closing the breather on the side of the block with an aluminum or steel plate and then putting a breather in the valve cover. a local cub guy has one for sale for $600 which seems to be the norm for these engines and it has a gasket set. so now that you have a wee bit of background i have several questions.

1. the tractor would see tilling duty twice a year and occasional mowing so would the electronic PTO from the K341 fit the 361?

2. when putting a breather in the top of the valve cover should i route the breather into the air cleaner? put just a plain filter in the top? or make a system with an oil catch can and then a filter to let the gasses escape?

3. when rebuilding it what rod should i use? would a 341 rod work? also i would like to use a performance cam. i really like kirk engines cam but he no longer makes them so would lakota's Cast Cam Grind # 117. has anyone used this cam in a machine that sees hard yard work and needs to start when cold? does it have compression release?

thanks. this build wont start till spring when its warm again up here and I am off for the summer.

dvogtvpe · #2 10-28-2014, 06:50 PM

I've done that mod. not in a 1650 but a 122 chassis. its pretty involved. the ears on the block need to be machined off and the holes welded or epoxied in . the pto probably won't work. the 361's had 1 1/8 pto end but you can use a crank out of a 16 with a 1 inch end. the motor sits a bit higher due to the rockers and valve cover. you probably won't be able to use the exhaust shrouding. most parts are NLA now. I know for a fact the rods are, only real choice is a 16 rod. but if the rod in the 18 is good just insert it. cam you won't find one better than the 361 cam. the Kirk cam is a copy of that , the lacota cam would be a step up. biggest problems with the 361 was the valve seats falling out.

malchren · #3 10-28-2014, 08:00 PM

Arnt the crankshafts the same from 12hp to 16hp in all the k series? which means if the 18hp crank is the same as the 16, then i could use a crank from any 12,14,16 hp k series engine yes? What did you do about the issue of oil up into the valve cover? do you think moving the breather from the side of the block to the top of the engine would solve this problem?

dvogtvpe · #4 10-28-2014, 08:09 PM

12 crank is different than the 14, 16 and 18 crank. counter weights are lighter. stock I never heard of excessive oil in the valve cover. I pulled with one for years , turned it over 9000, I had breathers in the valve cover on that one but that was to get more oil up to the valve train. only way oil can get to the rockers is through the pushrod tubes

malchren · #5 10-28-2014, 08:13 PM

Ahh yes i forgot about that problem. Alright so i will have to source a 14 or 16 hp crank. I am sorry i forgot to mention that it was the problem of the lack of oil. and it wont see high RPMs really at all only the duty of tilling and mowing and driving around the yard so good oil flow up there is important. so just adding a breather to the valve cover and blocking off the one in the block will solve this problem? should i vent the breather into the air cleaner to keep the engine cleaner? or will not a lot of oil make it out the breather? how did you go about putting a breather in the valve cover?

dvogtvpe · #6 10-28-2014, 08:39 PM

I just ran long hose's down off the breathers and had them hang down below the tractor. I had a set of roller tipped rockers made for it. the heavy valve springs I needed pretty much would wreck the stock stuff so we custom made everything on top of the head casting. made our own lifters and pushrods. I found some neat little breathers that I could bolt to the sides of valve cover and slip a half inch hose on it.

malchren · #7 10-28-2014, 08:50 PM

do you remember what kind of breathers they were? would you recommend running the hose to inside the air cleaner?

dvogtvpe · #8 10-28-2014, 08:58 PM

I don't remember. might have been off of a KT17

J-Mech · #9 10-28-2014, 09:07 PM

Just out of curiosity....... WHY? Why would you go to all that work for a motor that is basically obsolete? You already know that the valve seats are prone to fall out. All that fitting and machine work... why not just put a bigger cam in your 341, rebuild it and crank 18-20 HP out of it? Far less work, parts availability is better....

I mean, what's the gain? Overhead valves, that's about it as near as I can see.

malchren · #10 10-29-2014, 04:31 PM

yeah that is about the only advantage is that i would have overhead valves. It would be a lot easier to just put a cam in the 16. port & polish and shave the head some to get the HP up. but I have done that before so was just looking to do something different. i might just stick to the 16 as it would be easier and prob last longer and be more reliable for when i need to till or mow.