Desko 552 #1 Posted March 23, 2014 Hello. I have an onan block with crank no rods its 20 hp but I don't have the money for rods $200!!! I have 16 hp rods but no crank will a b43m crank work in a p series block or no. Thank for the info Share this post Link to post Share on other sites
Martin 2,130 #2 Posted March 23, 2014 I'm sure you could find used 20 hp (P220G?) rods for less than $200. new rods run around $85 ea. but the thing that concerns me is rebuilding an Onan engine is not cheap and if you are already not happy with the price of the rods then you will fall over by the time you purchase gaskets and any other parts you need. timing gears shouldn't really be mixed either........ most parts of the smaller hp (16-20) B and P Onans interchange hp for hp, but there are always machining and tolerance issues to deal with. the rods on the b43m are the same as the P 216G, but as far as the cranks, I'm not sure. they use the same crank gear, main bearings etc. you are better off finding a matching rod/crank combo to start with and hopefully you can cut down on some machining costs. Share this post Link to post Share on other sites
Desko 552 #3 Posted March 24, 2014 Alright but it might be the German in me but I'm not buying another crank gear LOL. I'm building this engine form the ground up joes has p220 rods and pistons but used rods scare me as the might be egged out or scored and destroy my crank then I'll really be sol. Share this post Link to post Share on other sites
woodchuckfarmer 333 #4 Posted March 24, 2014 I think Joes Outdoor Power had a set of rods and pistons on ebay ...$125 bucks Share this post Link to post Share on other sites
Desko 552 #5 Posted March 24, 2014 I have already looked I'm not saying nothing bad about Joes but the races look scored on them thanks for letting me know though. Share this post Link to post Share on other sites
ericj 1,576 #6 Posted March 24, 2014 i have heard that you can machine out the rods and use a shell bearing maybe out of an older style onan motor check it out its is possible eric j Share this post Link to post Share on other sites
Desko 552 #7 Posted March 24, 2014 Thanks for all the great info I will have to look further into it Share this post Link to post Share on other sites
Desko 552 #8 Posted March 26, 2014 Update I have bought used rods off dennist. No on to my next question why did onan go to the solid I-beams were there any advantages? Share this post Link to post Share on other sites
dennist 139 #9 Posted March 26, 2014 Check this out... http://onanparts.com/index.php?main_page=page&id=6 Share this post Link to post Share on other sites
Desko 552 #10 Posted March 27, 2014 So my thought is that all it does is give the motor a little better balance yes or no? Share this post Link to post Share on other sites
