» Site Navigation | | » Recent Threads | | | | | | 05-01-2014, 09:02 PM | #1 | Senior Member Join Date: Jan 2014 Location: widnes Posts: 100 | m44 what can it rev to? I have a m44, flowed head, schrich cams, m47 crank, stadnard shaved pistons, acl race bearings, standard valves adn springs. whats it safe to rev to? what is the weak point? THe rods or int he head? tahnks | | | 05-02-2014, 09:03 PM | #2 | Senior Member Join Date: Mar 2010 Location: Ottawa Posts: 579 | 7500 | | | 05-02-2014, 09:17 PM | #3 | Senior Member Join Date: Jan 2014 Location: widnes Posts: 100 | i thought so but the guy building it said 7 max LOL! | | | 05-03-2014, 02:20 AM | #4 | Senior Member Join Date: Dec 2010 Location: Wichita Falls, Texas Posts: 1,364 | Barrie, what part of the engine do you think is the weak link? Just curious. John | | | 05-04-2014, 01:24 AM | #5 | Senior Member Join Date: Mar 2010 Location: Ottawa Posts: 579 | Springs for sure in the valve train and then rod bearings IMO. I have auto cross guys reving to 7500 all day long on the M42 just so they can hold a gear Last edited by bmwconnect; 05-04-2014 at 01:27 AM. | | | 05-04-2014, 08:47 PM | #6 | Senior Member Join Date: Mar 2005 Location: Portland Or Posts: 2,666 | The M42 has better valve control than the M44. Plus a forged crank and a tick less rotating mass, I would strongly suspect the M42 will out-rev the M44 by 500 rpm.. given equal builds. Longer stroke usually means less ultimate top end rpm. If anything was going to let loose on a M44/M47 build I would guess Pistons. That build has a lot of stroke, so very high inertia on the top of the piston. __________________ Dave - PDX 1995 318ti - Active Black and Tan. 2005 330xi - Mtech 1 - 6spd - Orient Blue/Black | | | 05-04-2014, 08:54 PM | #7 | Senior Member Join Date: Jan 2014 Location: widnes Posts: 100 | im going to get it set to 7,300 then , now ist on 7,200 but stick motor with schrich cams. i cant wait to see what it goes like with the new motor! | | | 05-04-2014, 08:59 PM | #8 | Senior Member Join Date: Mar 2005 Location: Portland Or Posts: 2,666 | If your running any engine hard, not only will better valve springs be a good thing, but valve springs are a seasonal swap item, I change them every winter on race cars, and on really hot high revving engines, mid season as well. __________________ Dave - PDX 1995 318ti - Active Black and Tan. 2005 330xi - Mtech 1 - 6spd - Orient Blue/Black | | | 02-02-2015, 05:40 AM | #9 | Junior Member Join Date: Apr 2014 Location: Clemson, SC Posts: 25 | Where did you get the m47 crankshaft? I'm looking into an m42/44 hybrid build myself __________________ Using Tapatalk | | | 02-02-2015, 03:22 PM | #10 | Senior Member Join Date: Aug 2008 Location: Globally Posts: 1,162 | I would be concerned about the OIL PUMP. | | | 02-02-2015, 06:17 PM | #11 | Senior Member Join Date: Jan 2014 Location: widnes Posts: 100 | i got my crank from a guy in ireland, i live in england. | | | 02-02-2015, 08:15 PM | #12 | Junior Member Join Date: Apr 2014 Location: Clemson, SC Posts: 25 | Quote: Originally Posted by bmw2101 i got my crank from a guy in ireland, i live in england. | Dang, that's awesome. I haven't been able to find any for sale in the states. They are even difficult to come by on eBay. __________________ Using Tapatalk | | | | Currently Active Users Viewing This Thread: 1 (0 members and 1 guests) | | Posting Rules | You may not post new threads You may not post replies You may not post attachments You may not edit your posts HTML code is Off | | | |