The Stovebolt Site Forums The Shop Area Engine Shop Rebuilt engine first start

So, I started up my original 216 that I rebuilt (except cam and lifters). Once i figured out an ignition problem...points not making contact, it ran and idled well. But, it quickly proceeded to get too hot...near 220 degrees. Also pops through carb on application of throttle unless I ease into it.

So, my thoughts to check out today: Timing...I set on BB with vacuum attached to advance. Going to re-time with vacuum disconnected and a little advance dialed in. My hope is retarded timing is causing both problems. Late ignition is causing exhaust valve to be starting to open as fuel burn is still happening. Running hot i also hope is attributed to late timing.

What say you?

How did you break-in the engine (cam/lifters)? What RPM and for how long?

If he reused his original cam and lifters in the bores they came out of he didn't have to break the cam in, though it would have been a good idea to rev it little to make sure they oiled up well.

Slow timing could be some of the overheating issue, and the engine would sound like it was laboring to run if the timing was very slow.

Make sure the valves are adjusted correctly and the plug wires are on the right plugs.

Did not worry about fast idle breaking in, as I did NOT replace cam and lifters. Both measured fine and did warrant replacement. Plugs wires good. Idles well and even. Valves checked and readjusted hot. A few of the intakes were too tight...did not make a difference. I did rev her after initial start to get the oil moving well, just not for prolonged period.

New pistons and rings also would require some fast idle break in, to make sure they are getting a good supply of oil. Then take out on the road and put a good load on it to seat the rings.

Did you put a thermostat in? With mine, I burp it for the first run, otherwise it will overheat and spew out coolant. After the temperature reached 212, I shut it down and pull the top heater hose at the block. A bunch of steam rushes out and then coolant starts to come out. At this point I shove the hose back on. I then leave it for a few minutes to let the thermostat open and then run it again.

Drill a 1/8th inch hole in the thermostat as Dads50 shows here to prevent it from trapping air in the head and leading to overheating issues. thermostat

Set timing properly with a bit of extra advance and popping through carb is gone. Overheated again on initial test drive. Going to ditch old original radiator (that I had "professionally" cleaned and checked. Upon opening cap to add coolant, found literal hairball struck to ( inside of) cap. Getting new radiator. Will check thermostat as well.

Maybe so, but I don't necessarily agree. Pistons like a varying engine speed and load for break-in, IMHO. I avoid excessive rpm and luging engine during break-in.

Received new radiator last night and have it installed. The holes in the mounting bracket/flange are in the wrong location, but other than that, it was similar to the original (purchased from LMC Truck). It appears that the mounting brackets/flanges were installed upside down. If they were flipped 180 degrees, the holes would be in the correct location.

Did not have time to fill and test. Have to save that for another day...headed to the lake this evening.

Update: Filled with Coolant, warmed her up...temp stayed at about 185 degrees with 160 t-stat installed.