Burnerman 759 #1 Posted August 10, 2019 We pulled the 8hp off my sons C85 tonight. I knew the rod was broke but we found a chunk of the lower cylinder wall got busted out also. They’ll only be about a 1/2” of cylinder wall below the oil ring on one of the skirts. The rest of the block is fine and there’s even crosshatch visible in the cylinder. Is it worth throwing a rebuild kit into or should we look for another block? Share this post Link to post Share on other sites
ri702bill 9,454 #2 Posted August 10, 2019 I have seen the same with one of a pair of C81's I bought a few years ago. When the rod broke it took out the bottom of the bore, along with the skirt on the piston. Time for another block. It is not worth the gamble that the block is now cracked and would fail after being rebuilt. A rod usually breaks due to a low oil level and the rod binds up on the crank journal before it snaps. The cost of a new rod, turning the crank journal (or a new crank) along with a gasket set gets pricey - better to find a donor block. Bill 3 1 Share this post Link to post Share on other sites
Burnerman 759 #3 Posted August 10, 2019 Thanks. That’s kinda my thought also but I wasn’t sure. Share this post Link to post Share on other sites
richmondred01 2,307 #4 Posted August 10, 2019 I just took about six blocks to the scrap yard with the same issue. There is another alternative, it can be sleeved. But you are getting into some money. Share this post Link to post Share on other sites
Burnerman 759 #5 Posted August 10, 2019 No big money into this tractor. Well clean up the chassis and find a new heart for her. Share this post Link to post Share on other sites
Shynon 7,482 #6 Posted August 10, 2019 Cam may be broken too, common when the rod breaks Share this post Link to post Share on other sites
peter lena 9,280 #7 Posted August 10, 2019 don,t stay locked into the 8 hp mind set, that c 85 is the basis for the tractors of the era. you can easily find a 10 /12 hp engine and it will be a good upgrade , with matching bolt in locations. i hunted around for mine , with the same c 85 chassis, picked up a 12 hp magnum on ebay . aside from the electrical change over , new switch and plug in wire harness , the change has been so worth it. you will have a great black hood series tractor with updated power , whats not to like , pete 2 1 Share this post Link to post Share on other sites
Burnerman 759 #8 Posted August 10, 2019 This was a scrapyard rescue. Chassis is solid and the 8 spd is all good. It’ll become a plow tractor and pulling stuff around. It’ll get whatever good engine we can get cheap. It’s kind of a side project. They thought he was nuts when he asked about it. Got it and a 5-2362 mower deck for basically free. 😁 1 Share this post Link to post Share on other sites
peter lena 9,280 #9 Posted August 10, 2019 you can do this, pete 1 1 Share this post Link to post Share on other sites