Cam break in during cold weather?

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David66dart

David66dart

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I have a very mildly built / freshened 360. (FLAT TAPPET cam + intake, 30 over pistons and a few other little things) I want to break in my motor tomorrow or Monday. The day time high is predicted to be 35* F. My friend told me that this may not be a good idea but I wanted to get more experienced peoples opinions. Is there a larger chance of failure?
Thanks
David
 
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What do you plan for break in oil? If I was going to do that, I would run "some kind" of 5/20 with plenty of zinc additive.
 
IMHO, that 5W at 35F is gonna be a bit thicker than 10W at 50F. I'd probably put a milkhouse heater under the engine and a wind block under the car and let things get as warm as I could. iMHO, it is just a matter of getting good oil flow right away.

And if you have the stock valve springs, the issues tend to go way down anyway.
 
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nm9stheham said:
IMHO, that 5W at 35F is gonna be a bit thicker than 10W at 50F. I'd probably put a milkhouse heater under the engine and a wind block under the car and let things get as warm as I could. iMHO, it is just a matter of getting good oil flow right away.

And if you have the stock valve springs, the issues tend to go way down anyway.
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Good idea. Thanks much! yeah my friend said the main reason that it could be bad was because it had a higher chance of running lean but i don't think the more dense cold air would effect it that much would it?
 
Block heater and whatever it else it takes to have the engine get up and running right away and not die during the break in cycle.
 
Most importantly you have a zinc additive. You should be fine, I'd check timing right away start with 10-12 deg, inital and go from there. Monitor oil pressure and engine temperature. 65'
 
Plymouth 65 said:
Most importantly you have a zinc additive. You should be fine, I'd check timing right away start with 10-12 deg, inital and go from there. Monitor oil pressure and engine temperature. 65'
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how would I check initial timing sense the motor will be at rpm and be advanced from mechanical/ vacuum advance. what should timing be when im sitting at 2200- 2500
 
David66dart said:
how would I check initial timing sense the motor will be at rpm and be advanced from mechanical/ vacuum advance. what should timing be when im sitting at 2200- 2500
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Get a timing light on it from the get go. You're timing at 2200-2500 will depend on how your distib
 
Distributor is set up. Total mechanical advance at that RPM should be in the low 30's. Hope this helps. 65'
 
I'm going to assume it's in a warm garage to start with? If so I would get absolutely everything ready to fire off in the warm garage push it out and fire it off just like you would any other day. as in any other day breaking a motoor. Youknow get it started as quick as possible get up to over two Grand as quick as possible and hold it there. I always have a timing light hooked up so once I get it running I can dial in the timing since it's almost all in I run it up to about 33-34. And cranking the idle screw till you get it to hold the RPMs you want. Then I usually give it a little tap up to 2500 every minute or so gently up and gently down to two grand. the cooler air should help the initial temperature spike a little bit which it usually does for me but comes back down quickly. I can't tell you how many threads I've seen what people have problems with it overheating at initial startup or that's what they're worried about but this one's a first for me too cold? I thought he was our enemy? Trust me at two grand to 2500 for 20 minutes plus it's going to get plenty warm..
If it's outside yeah I'm like throw a couple electric heaters under there with a blanket for an hour or so just so it's kind of a room temperature kind of thing.
 
get a magnetic oil pan heater at parts store.
Fill radiator with hot water just before start up... Dont run a thermostat for breakin....or drill a few holes in one if you do run one to prevent air pockets.
 
(excess) Heat is your enemy during an engine/camshaft break-in.
Every freshly built engine will run warmer/hot during its break-in time.
Timing isn't optimised yet and all parts need to get 'acquainted'.

You could put a little temp in the oil/carter, but I would certainly not heat up anything else.
Get the timing advance well into the 30° @ 2200rpm or the headers/manifolds will be glowing red.
 
The concern i would have is it will take a little more cranking to get it to fire up in the cold,and if it doesent have choke setup then a squirt of gas to get it going may help. A little 2 cycle oil in the gas wont hurt either.
 
Tooljunkie said:
The concern i would have is it will take a little more cranking to get it to fire up in the cold,and if it doesent have choke setup then a squirt of gas to get it going may help. A little 2 cycle oil in the gas wont hurt either.
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Every first fire I've put a good shot of gas. And manually filled the carb/s....
 
David66dart said:
Good idea. Thanks much! yeah my friend said the main reason that it could be bad was because it had a higher chance of running lean but i don't think the more dense cold air would effect it that much would it?
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Not any concern, especially in Seattle. The carb will not tend to run lean at those temps or altitude, and any humidity will counteract the denser air. It just may need to be enriched to start. (See below.) If it has an electric choke, then you will need to kick it off 15-30 second after starting, but you will have the revs up so it will likely do that anyway. The cam break in process does not know if the engine is running lean or rich.

For timing, assuming you have a Mopar electronic ignition, set the damper on the crank so that the timing on the damper is about 10-15 degress to the left (CCW from) the 0 timing mark on the timing cover. Then, look into the distributor and set it so that one of the 'tangs' on the reluctor is just opposite to the 'groove' in the pickup. That will get your timing very close.

As noted, put 1/4 to 1/2 a cup of gas into the float bowl from a squirter bottle, and then put 1/2-3/4 bottle cap of gas down the carb throat just before you fire it off. If the ignition is hooked up properly, it will fire and run from that. If it initially wants to sputter and die due to being cold, then just keep the revs up and pump the gas pedal in quick, short strokes to use the aceelerator pump to enrich the mixture until things warm up and smooth out.
 
David66dart said:
I have a very mildly built / freshened 360. (FLAT TAPPET cam + intake, 30 over pistons and a few other little things) I want to break in my motor tomorrow or Monday. The day time high is predicted to be 35* F. My friend told me that this may not be a good idea but I wanted to get more experienced peoples opinions. Is there a larger chance of failure?
Thanks
David
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Stop the paranoia and fire it up LOL all of us start worrying about all the things that could go wrong...
It usually has something to do with all the money we spent.
 
David66dart said:
how would I check initial timing sense the motor will be at rpm and be advanced from mechanical/ vacuum advance. what should timing be when im sitting at 2200- 2500
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Prime the engine with a drill. Verify that you have fuel and spark. Fill the carb bowls so you’re not cranking on it all day. Verify you have spark.
Disconnect any vacuum advance. You won’t want it during break in. Turn the engine over by hand with the driver side valve cover off. Once the number 1 intake valve closes, keep turning until the damper timing mark is around 20 btdc. Once that’s set, install the distributor so that the rotor is pointing directly at the #1 wire on the cap. It’ll fire and run on the first revolution. All of this is way more important than what weight oil is in it.

Verify the firing order as well.
 
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don't worry about the cold weather. i just broke my SFT cam in on Friday with -35*C with windchills at -42*C.

i made a test run stand to break cam in and check for leaks. i poured hot hot water into rad and turned on the electric water pump. after a few seconds the heads were warm and ready to fire up. i opened the garage door and rolled it out. fired it up and broke the cam in.
 
79410aspenrt said:
don't worry about the cold weather. i just broke my SFT cam in on Friday with -35*C with windchills at -42*C.

i made a test run stand to break cam in and check for leaks. i poured hot hot water into rad and turned on the electric water pump. after a few seconds the heads were warm and ready to fire up. i opened the garage door and rolled it out. fired it up and broke the cam in.
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That's the spirit!
 
Preoil, ensure it can run the full 20 minutes without stopping, and it fires right up. It will be ambient temp for about 1 minute. Oil will be thin within 3. Temp doesn't mean anything as long as it fires right up, and the lifters rotate, which ironically is just as important if its 100* out...
 
Thanks all for the info I broke in the motor today and all went well other than an oil leak that i will need to fix.
 
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