L-134 break-in.

billybob · Post by **billybob** » Tue Feb 28, 2017 7:50 pm

Does anyone want to give me any advice on the proper break-in procedure after the start up of a completely rebuilt L-134? I found a good article a while back but I can't find it again. Thanks for any advice.

oilleaker1 · Post by **oilleaker1** » Sat Mar 04, 2017 6:57 am

Re-torque the head if you haven't. Change the oil in about 500 miles. If your idle changes, re-adjust the valves. Make sure the thermostat has the 1/16 inch by-pass in it or drilled. Without it, it opens late and can get your engine quite hot------not good. Hope she runs good for you. John

billybob · Post by **billybob** » Sat Mar 04, 2017 7:24 am

Thanks oilleaker 1 for reminding me about the thermostat. I'd forgot about that.

strathdaigeil · Post by **strathdaigeil** » Wed Mar 08, 2017 9:33 am

oilleaker1 wrote:Re-torque the head if you haven't. Change the oil in about 500 miles. If your idle changes, re-adjust the valves. Make sure the thermostat has the 1/16 inch by-pass in it or drilled. Without it, it opens late and can get your engine quite hot------not good. Hope she runs good for you. John

I am having an engine rebuilt for me but I have never heard about the bypass of the thermostat. Can you explain more? If I am running an M38 engine with the bypass hose, will I still need to drill the thermostat?

Post by **wesk** » Wed Mar 08, 2017 11:01 am

Here's a good read:
http://www.thecj2apage.com/forums/drill ... 24761.html

skyjeep50 · Post by **skyjeep50** » Thu Mar 09, 2017 8:13 am

You asked about engine run-in - look at page 98 in TM9-1804A (in the "Downloads" section of this website) - it details a rather thorough procedure to follow to break-in an engine. While you may not have all the equipment mentioned, you can follow a similar test cycle.

dpcd67 · Post by **dpcd67** » Sat Mar 18, 2017 11:03 am

I just drive them; but I do keep the revs down for the first couple hundred miles. And I have built several L134s and Dodge 230 flatheads. No issues noted.