Break in gone bad... 360

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Mopar92

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Got my LA360 with J heads on it in and fired up for breakin. Running a new 3 row champion with new water pump. Running basically a 340 cam. 9.4:1. Holley 650 stock out of box to start with. MSD 6AL, new MSD billet mech advance distributor. Had 2 squirrel cage fans in addition to my 20” Mopar 5 blade. It was moving a ton of air. Anyway, it cranked right away and took it to 2000-2300 rpms. Within 1/2 minutes it was at 190, then 200, then 210, took a touch of timing out, didn’t help.... no matter the timing we shut it down as it was nearing 230. 8 minutes in. The last 4 seconds ONLY it was blowing smoke. As in something let go. The pass side manifold and head seemed to have been HOT. It was running very crispy the whole time.
Pulled some plugs and saw what appearing to be a speck of brass. Pulled the engine and a head.... didn’t see a gasket blown. No coolant in the oil. The top 1/2” of the middle cylinder bores has dark brown rings about 1/3 the way around the cylinder where the cylinders are closest. Taking it to my motor guy tomorrow to see what happened. Coolant was topped off at the 190 degree mark then cap installed. Brad Penn Break in oil per the engine builder. What are some opinions on how it ran that hot that quick after startup in 50 degree shop temp? I’ll know more after they pull it.

Also,every single Intake valve guide orange seal was up in the springs. Ughh. Never had any trouble with his stuff. He’s done some race stuff for me for a while. Knows Mopars pretty well too. Actually very well.
 
10 min of breakin. Cam looked ok though!

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When I broke in my stroker I remember getting up near 230 and took the hose and poured water over the radiator and of course water splashed everywhere but it cooled it right down and never had a problem after that.
 
Yeah. We thought about that. Had the front way up and filled it. Let it back down. It took a bunch of coolant on fire up like it filled itself up. Not sure what or how. I’ve never had much trouble with air locks on my small blocks.
 
When he goes to fire it again would it be smart to remove the thermostat and leave the cap off the radiator as long as possible then put it on?
 
What type of vale guide was used for the reconditioning of the heads? If it was "Bronze Liner" type, this could be the residue that you see on the plugs and the fact it started to smoke they were deteriorating from the overheating and may also have shifted the seals out of place.
 
took a touch of timing out
Where did you have timing During break in rpm...and whats your definition of "took a touch of timing out" ? That reads to me as you went back toward zero degrees to try and cure overheating...?
 
And put more timing in instead of taking it out
We must have been typing at the same time...im with you. The way I read it he did the exact opposite of what was needed. Some distributors aren't fully in by the 2000 rpm that some people try and break their engines in at... instant meltdown
 
Not enough timing will make them HOT.

When breaking them in, I always suggest get it up to rpm quickly and then time it right away to 36-40* BTDC.

Once you get the heat monster going, especially on break in, it's hard to get it back under control.

I also always check new themostats in a pot of water to make sure it opens.

Hope things aren't hurt.
 
Pulling timing out killed you trying to get to run cooler. You should have been pulling more timing IN. How much timing did you have in it?
 
Since I usually have done engine work in the Summer, I have had engines get too hot during break in...and just did the break in in 3 sessions of 10 minutes each. The last 2 times were with my 440/493. I have not had a failure.
Good luck.
 
I personally run a gutted thermostat in my race motor and pretty much that's the only one I've had to break in. I just started a motor last night for the first time since I've had it and I did drill a small hole in the thermostat.
 
How tight were the bearing and ring clearances? Any real friction on 1st startup are from those two components. Tining and air pockets in the cooling systems are the other possible issues. Oil pressure good and plenty of oil up to the valve train?
 
On a side note, may not be the problem.....I have ALWAYS left the intake manifold heater hose connection open when filling with coolant. NEVER had an air lock
 
I have no idea what the op ran for timing and would sound kinda lame telling him he needed more or less timing.
Too little timing and it fires late and makes the motor the hot , too much can be hard to do without any load on the motor...but things arise from too much if not adjusted on the mixture end.

Dry stems pulled the seals up, can happen, usually the seals just burn and then the guides suck oil. I have seen the wrong seals used and them riding the stems.
The dark rings...oil rings ,well ....you did say it smoked just before shutdown...so I bet A. the intake manifold gasket leaked and sucked oil from the valley... or B. You have a ring problem in those 2 cylinders.
 
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