JStevens120 Posted February 14, 2012 Share Posted February 14, 2012 (edited) So this weekend i was going to drag the race trailer out of its storage spot and get some work done. I plugged in the old B and let her warm up for a couple hours. When I turned her over she fired almost instantly but I had a nasty popping coming from the intake. I shut her down right away and pulled off the valve covers. The pic shows what I found. #6 exhaust valve is very sticky in the guide, if I force it open, it takes about 30 seconds to a minute to come all the way closed again. So, the heads are off to the machine shop tomorrow, and the injectors as well. Anybody know where I could get a couple pushrods, the intake is bent too, just not as bad? I knew I should have gone through the top end before I started running her..... Edited February 14, 2012 by JStevens120 Quote Link to comment https://www.bigmacktrucks.com/topic/23242-hurt-the-old-673-this-weekend/ Share on other sites More sharing options...
220cummins Posted February 14, 2012 Share Posted February 14, 2012 When you started up did you let it warm up before you rev'd it high? Or did you rev it high out of the gate? On start up on these, the 237, 285, 300, you gotta let the engine warm up some before revving it or they will drop a valve or bend push rods. Quote Link to comment https://www.bigmacktrucks.com/topic/23242-hurt-the-old-673-this-weekend/#findComment-102216 Share on other sites More sharing options...
Brian Blaylock Posted February 14, 2012 Share Posted February 14, 2012 I would try the local Mack dealer first, if not I think Iight have a couple that are used, get back with me and let me know where you are located. Quote Link to comment https://www.bigmacktrucks.com/topic/23242-hurt-the-old-673-this-weekend/#findComment-102236 Share on other sites More sharing options...
JStevens120 Posted March 17, 2012 Author Share Posted March 17, 2012 It has been quite an ordeal, but I got the old girl up and running again. Turned out both heads where cracked, and all the valve springs and valves where worn out. found a couple heads that where already repaired and machined and a couple new push tubes(Thanks Fifth Wheel...). While I had it apart I had the injectors all rebuilt, built a new wiring harness(maybe the lights will stay on this year), and replaced every piece of hose in the truck. She will now hold some air pressure overnight! I'm off to go get some heat in the motor so I can re torque the heads... Quote Link to comment https://www.bigmacktrucks.com/topic/23242-hurt-the-old-673-this-weekend/#findComment-108185 Share on other sites More sharing options...
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